Gh0st
/
linux
mirror of https://github.com/torvalds/linux.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity
1,107,925 Commits 1 Branch 912 Tags 8.3 GiB
Commit Graph

10951 Commits

Author SHA1 Message Date
Filipe Manana ca93e44bfb btrfs: fallback to blocking mode when doing async dio over multiple extents 
Some users recently reported that MariaDB was getting a read corruption
when using io_uring on top of btrfs. This started to happen in 5.16,
after commit 51bd9563b6 ("btrfs: fix deadlock due to page faults
during direct IO reads and writes"). That changed btrfs to use the new
iomap flag IOMAP_DIO_PARTIAL and to disable page faults before calling
iomap_dio_rw(). This was necessary to fix deadlocks when the iovector
corresponds to a memory mapped file region. That type of scenario is
exercised by test case generic/647 from fstests.

For this MariaDB scenario, we attempt to read 16K from file offset X
using IOCB_NOWAIT and io_uring. In that range we have 4 extents, each
with a size of 4K, and what happens is the following:

1) btrfs_direct_read() disables page faults and calls iomap_dio_rw();

2) iomap creates a struct iomap_dio object, its reference count is
   initialized to 1 and its ->size field is initialized to 0;

3) iomap calls btrfs_dio_iomap_begin() with file offset X, which finds
   the first 4K extent, and setups an iomap for this extent consisting
   of a single page;

4) At iomap_dio_bio_iter(), we are able to access the first page of the
   buffer (struct iov_iter) with bio_iov_iter_get_pages() without
   triggering a page fault;

5) iomap submits a bio for this 4K extent
   (iomap_dio_submit_bio() -> btrfs_submit_direct()) and increments
   the refcount on the struct iomap_dio object to 2; The ->size field
   of the struct iomap_dio object is incremented to 4K;

6) iomap calls btrfs_iomap_begin() again, this time with a file
   offset of X + 4K. There we setup an iomap for the next extent
   that also has a size of 4K;

7) Then at iomap_dio_bio_iter() we call bio_iov_iter_get_pages(),
   which tries to access the next page (2nd page) of the buffer.
   This triggers a page fault and returns -EFAULT;

8) At __iomap_dio_rw() we see the -EFAULT, but we reset the error
   to 0 because we passed the flag IOMAP_DIO_PARTIAL to iomap and
   the struct iomap_dio object has a ->size value of 4K (we submitted
   a bio for an extent already). The 'wait_for_completion' variable
   is not set to true, because our iocb has IOCB_NOWAIT set;

9) At the bottom of __iomap_dio_rw(), we decrement the reference count
   of the struct iomap_dio object from 2 to 1. Because we were not
   the only ones holding a reference on it and 'wait_for_completion' is
   set to false, -EIOCBQUEUED is returned to btrfs_direct_read(), which
   just returns it up the callchain, up to io_uring;

10) The bio submitted for the first extent (step 5) completes and its
    bio endio function, iomap_dio_bio_end_io(), decrements the last
    reference on the struct iomap_dio object, resulting in calling
    iomap_dio_complete_work() -> iomap_dio_complete().

11) At iomap_dio_complete() we adjust the iocb->ki_pos from X to X + 4K
    and return 4K (the amount of io done) to iomap_dio_complete_work();

12) iomap_dio_complete_work() calls the iocb completion callback,
    iocb->ki_complete() with a second argument value of 4K (total io
    done) and the iocb with the adjust ki_pos of X + 4K. This results
    in completing the read request for io_uring, leaving it with a
    result of 4K bytes read, and only the first page of the buffer
    filled in, while the remaining 3 pages, corresponding to the other
    3 extents, were not filled;

13) For the application, the result is unexpected because if we ask
    to read N bytes, it expects to get N bytes read as long as those
    N bytes don't cross the EOF (i_size).

MariaDB reports this as an error, as it's not expecting a short read,
since it knows it's asking for read operations fully within the i_size
boundary. This is typical in many applications, but it may also be
questionable if they should react to such short reads by issuing more
read calls to get the remaining data. Nevertheless, the short read
happened due to a change in btrfs regarding how it deals with page
faults while in the middle of a read operation, and there's no reason
why btrfs can't have the previous behaviour of returning the whole data
that was requested by the application.

The problem can also be triggered with the following simple program:

  /* Get O_DIRECT */
  #ifndef _GNU_SOURCE
  #define _GNU_SOURCE
  #endif

  #include <stdio.h>
  #include <stdlib.h>
  #include <unistd.h>
  #include <fcntl.h>
  #include <errno.h>
  #include <string.h>
  #include <liburing.h>

  int main(int argc, char *argv[])
  {
      char *foo_path;
      struct io_uring ring;
      struct io_uring_sqe *sqe;
      struct io_uring_cqe *cqe;
      struct iovec iovec;
      int fd;
      long pagesize;
      void *write_buf;
      void *read_buf;
      ssize_t ret;
      int i;

      if (argc != 2) {
          fprintf(stderr, "Use: %s <directory>\n", argv[0]);
          return 1;
      }

      foo_path = malloc(strlen(argv[1]) + 5);
      if (!foo_path) {
          fprintf(stderr, "Failed to allocate memory for file path\n");
          return 1;
      }
      strcpy(foo_path, argv[1]);
      strcat(foo_path, "/foo");

      /*
       * Create file foo with 2 extents, each with a size matching
       * the page size. Then allocate a buffer to read both extents
       * with io_uring, using O_DIRECT and IOCB_NOWAIT. Before doing
       * the read with io_uring, access the first page of the buffer
       * to fault it in, so that during the read we only trigger a
       * page fault when accessing the second page of the buffer.
       */
       fd = open(foo_path, O_CREAT | O_TRUNC | O_WRONLY |
                O_DIRECT, 0666);
       if (fd == -1) {
           fprintf(stderr,
                   "Failed to create file 'foo': %s (errno %d)",
                   strerror(errno), errno);
           return 1;
       }

       pagesize = sysconf(_SC_PAGE_SIZE);
       ret = posix_memalign(&write_buf, pagesize, 2 * pagesize);
       if (ret) {
           fprintf(stderr, "Failed to allocate write buffer\n");
           return 1;
       }

       memset(write_buf, 0xab, pagesize);
       memset(write_buf + pagesize, 0xcd, pagesize);

       /* Create 2 extents, each with a size matching page size. */
       for (i = 0; i < 2; i++) {
           ret = pwrite(fd, write_buf + i * pagesize, pagesize,
                        i * pagesize);
           if (ret != pagesize) {
               fprintf(stderr,
                     "Failed to write to file, ret = %ld errno %d (%s)\n",
                      ret, errno, strerror(errno));
               return 1;
           }
           ret = fsync(fd);
           if (ret != 0) {
               fprintf(stderr, "Failed to fsync file\n");
               return 1;
           }
       }

       close(fd);
       fd = open(foo_path, O_RDONLY | O_DIRECT);
       if (fd == -1) {
           fprintf(stderr,
                   "Failed to open file 'foo': %s (errno %d)",
                   strerror(errno), errno);
           return 1;
       }

       ret = posix_memalign(&read_buf, pagesize, 2 * pagesize);
       if (ret) {
           fprintf(stderr, "Failed to allocate read buffer\n");
           return 1;
       }

       /*
        * Fault in only the first page of the read buffer.
        * We want to trigger a page fault for the 2nd page of the
        * read buffer during the read operation with io_uring
        * (O_DIRECT and IOCB_NOWAIT).
        */
       memset(read_buf, 0, 1);

       ret = io_uring_queue_init(1, &ring, 0);
       if (ret != 0) {
           fprintf(stderr, "Failed to create io_uring queue\n");
           return 1;
       }

       sqe = io_uring_get_sqe(&ring);
       if (!sqe) {
           fprintf(stderr, "Failed to get io_uring sqe\n");
           return 1;
       }

       iovec.iov_base = read_buf;
       iovec.iov_len = 2 * pagesize;
       io_uring_prep_readv(sqe, fd, &iovec, 1, 0);

       ret = io_uring_submit_and_wait(&ring, 1);
       if (ret != 1) {
           fprintf(stderr,
                   "Failed at io_uring_submit_and_wait()\n");
           return 1;
       }

       ret = io_uring_wait_cqe(&ring, &cqe);
       if (ret < 0) {
           fprintf(stderr, "Failed at io_uring_wait_cqe()\n");
           return 1;
       }

       printf("io_uring read result for file foo:\n\n");
       printf("  cqe->res == %d (expected %d)\n", cqe->res, 2 * pagesize);
       printf("  memcmp(read_buf, write_buf) == %d (expected 0)\n",
              memcmp(read_buf, write_buf, 2 * pagesize));

       io_uring_cqe_seen(&ring, cqe);
       io_uring_queue_exit(&ring);

       return 0;
  }

When running it on an unpatched kernel:

  $ gcc io_uring_test.c -luring
  $ mkfs.btrfs -f /dev/sda
  $ mount /dev/sda /mnt/sda
  $ ./a.out /mnt/sda
  io_uring read result for file foo:

    cqe->res == 4096 (expected 8192)
    memcmp(read_buf, write_buf) == -205 (expected 0)

After this patch, the read always returns 8192 bytes, with the buffer
filled with the correct data. Although that reproducer always triggers
the bug in my test vms, it's possible that it will not be so reliable
on other environments, as that can happen if the bio for the first
extent completes and decrements the reference on the struct iomap_dio
object before we do the atomic_dec_and_test() on the reference at
__iomap_dio_rw().

Fix this in btrfs by having btrfs_dio_iomap_begin() return -EAGAIN
whenever we try to satisfy a non blocking IO request (IOMAP_NOWAIT flag
set) over a range that spans multiple extents (or a mix of extents and
holes). This avoids returning success to the caller when we only did
partial IO, which is not optimal for writes and for reads it's actually
incorrect, as the caller doesn't expect to get less bytes read than it has
requested (unless EOF is crossed), as previously mentioned. This is also
the type of behaviour that xfs follows (xfs_direct_write_iomap_begin()),
even though it doesn't use IOMAP_DIO_PARTIAL.

A test case for fstests will follow soon.

Link: https://lore.kernel.org/linux-btrfs/CABVffEM0eEWho+206m470rtM0d9J8ue85TtR-A_oVTuGLWFicA@mail.gmail.com/
Link: https://lore.kernel.org/linux-btrfs/CAHF2GV6U32gmqSjLe=XKgfcZAmLCiH26cJ2OnHGp5x=VAH4OHQ@mail.gmail.com/
CC: stable@vger.kernel.org # 5.16+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-03-04 15:09:21 +01:00
Filipe Manana 4751dc9962 btrfs: add missing run of delayed items after unlink during log replay 
During log replay, whenever we need to check if a name (dentry) exists in
a directory we do searches on the subvolume tree for inode references or
or directory entries (BTRFS_DIR_INDEX_KEY keys, and BTRFS_DIR_ITEM_KEY
keys as well, before kernel 5.17). However when during log replay we
unlink a name, through btrfs_unlink_inode(), we may not delete inode
references and dir index keys from a subvolume tree and instead just add
the deletions to the delayed inode's delayed items, which will only be
run when we commit the transaction used for log replay. This means that
after an unlink operation during log replay, if we attempt to search for
the same name during log replay, we will not see that the name was already
deleted, since the deletion is recorded only on the delayed items.

We run delayed items after every unlink operation during log replay,
except at unlink_old_inode_refs() and at add_inode_ref(). This was due
to an overlook, as delayed items should be run after evert unlink, for
the reasons stated above.

So fix those two cases.

Fixes: 0d836392ca ("Btrfs: fix mount failure after fsync due to hard link recreation")
Fixes: 1f250e929a ("Btrfs: fix log replay failure after unlink and link combination")
CC: stable@vger.kernel.org # 4.19+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-03-02 16:53:11 +01:00
Sidong Yang d4aef1e122 btrfs: qgroup: fix deadlock between rescan worker and remove qgroup 
The commit e804861bd4 ("btrfs: fix deadlock between quota disable and
qgroup rescan worker") by Kawasaki resolves deadlock between quota
disable and qgroup rescan worker. But also there is a deadlock case like
it. It's about enabling or disabling quota and creating or removing
qgroup. It can be reproduced in simple script below.

for i in {1..100}
do
    btrfs quota enable /mnt &
    btrfs qgroup create 1/0 /mnt &
    btrfs qgroup destroy 1/0 /mnt &
    btrfs quota disable /mnt &
done

Here's why the deadlock happens:

1) The quota rescan task is running.

2) Task A calls btrfs_quota_disable(), locks the qgroup_ioctl_lock
   mutex, and then calls btrfs_qgroup_wait_for_completion(), to wait for
   the quota rescan task to complete.

3) Task B calls btrfs_remove_qgroup() and it blocks when trying to lock
   the qgroup_ioctl_lock mutex, because it's being held by task A. At that
   point task B is holding a transaction handle for the current transaction.

4) The quota rescan task calls btrfs_commit_transaction(). This results
   in it waiting for all other tasks to release their handles on the
   transaction, but task B is blocked on the qgroup_ioctl_lock mutex
   while holding a handle on the transaction, and that mutex is being held
   by task A, which is waiting for the quota rescan task to complete,
   resulting in a deadlock between these 3 tasks.

To resolve this issue, the thread disabling quota should unlock
qgroup_ioctl_lock before waiting rescan completion. Move
btrfs_qgroup_wait_for_completion() after unlock of qgroup_ioctl_lock.

Fixes: e804861bd4 ("btrfs: fix deadlock between quota disable and qgroup rescan worker")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Sidong Yang <realwakka@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-03-02 16:53:04 +01:00
Omar Sandoval 5fd76bf31c btrfs: fix relocation crash due to premature return from btrfs_commit_transaction() 
We are seeing crashes similar to the following trace:

[38.969182] WARNING: CPU: 20 PID: 2105 at fs/btrfs/relocation.c:4070 btrfs_relocate_block_group+0x2dc/0x340 [btrfs]
[38.973556] CPU: 20 PID: 2105 Comm: btrfs Not tainted 5.17.0-rc4 #54
[38.974580] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
[38.976539] RIP: 0010:btrfs_relocate_block_group+0x2dc/0x340 [btrfs]
[38.980336] RSP: 0000:ffffb0dd42e03c20 EFLAGS: 00010206
[38.981218] RAX: ffff96cfc4ede800 RBX: ffff96cfc3ce0000 RCX: 000000000002ca14
[38.982560] RDX: 0000000000000000 RSI: 4cfd109a0bcb5d7f RDI: ffff96cfc3ce0360
[38.983619] RBP: ffff96cfc309c000 R08: 0000000000000000 R09: 0000000000000000
[38.984678] R10: ffff96cec0000001 R11: ffffe84c80000000 R12: ffff96cfc4ede800
[38.985735] R13: 0000000000000000 R14: 0000000000000000 R15: ffff96cfc3ce0360
[38.987146] FS:  00007f11c15218c0(0000) GS:ffff96d6dfb00000(0000) knlGS:0000000000000000
[38.988662] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[38.989398] CR2: 00007ffc922c8e60 CR3: 00000001147a6001 CR4: 0000000000370ee0
[38.990279] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[38.991219] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[38.992528] Call Trace:
[38.992854]  <TASK>
[38.993148]  btrfs_relocate_chunk+0x27/0xe0 [btrfs]
[38.993941]  btrfs_balance+0x78e/0xea0 [btrfs]
[38.994801]  ? vsnprintf+0x33c/0x520
[38.995368]  ? __kmalloc_track_caller+0x351/0x440
[38.996198]  btrfs_ioctl_balance+0x2b9/0x3a0 [btrfs]
[38.997084]  btrfs_ioctl+0x11b0/0x2da0 [btrfs]
[38.997867]  ? mod_objcg_state+0xee/0x340
[38.998552]  ? seq_release+0x24/0x30
[38.999184]  ? proc_nr_files+0x30/0x30
[38.999654]  ? call_rcu+0xc8/0x2f0
[39.000228]  ? __x64_sys_ioctl+0x84/0xc0
[39.000872]  ? btrfs_ioctl_get_supported_features+0x30/0x30 [btrfs]
[39.001973]  __x64_sys_ioctl+0x84/0xc0
[39.002566]  do_syscall_64+0x3a/0x80
[39.003011]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[39.003735] RIP: 0033:0x7f11c166959b
[39.007324] RSP: 002b:00007fff2543e998 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[39.008521] RAX: ffffffffffffffda RBX: 00007f11c1521698 RCX: 00007f11c166959b
[39.009833] RDX: 00007fff2543ea40 RSI: 00000000c4009420 RDI: 0000000000000003
[39.011270] RBP: 0000000000000003 R08: 0000000000000013 R09: 00007f11c16f94e0
[39.012581] R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff25440df3
[39.014046] R13: 0000000000000000 R14: 00007fff2543ea40 R15: 0000000000000001
[39.015040]  </TASK>
[39.015418] ---[ end trace 0000000000000000 ]---
[43.131559] ------------[ cut here ]------------
[43.132234] kernel BUG at fs/btrfs/extent-tree.c:2717!
[43.133031] invalid opcode: 0000 [#1] PREEMPT SMP PTI
[43.133702] CPU: 1 PID: 1839 Comm: btrfs Tainted: G        W         5.17.0-rc4 #54
[43.134863] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
[43.136426] RIP: 0010:unpin_extent_range+0x37a/0x4f0 [btrfs]
[43.139913] RSP: 0000:ffffb0dd4216bc70 EFLAGS: 00010246
[43.140629] RAX: 0000000000000000 RBX: ffff96cfc34490f8 RCX: 0000000000000001
[43.141604] RDX: 0000000080000001 RSI: 0000000051d00000 RDI: 00000000ffffffff
[43.142645] RBP: 0000000000000000 R08: 0000000000000000 R09: ffff96cfd07dca50
[43.143669] R10: ffff96cfc46e8a00 R11: fffffffffffec000 R12: 0000000041d00000
[43.144657] R13: ffff96cfc3ce0000 R14: ffffb0dd4216bd08 R15: 0000000000000000
[43.145686] FS:  00007f7657dd68c0(0000) GS:ffff96d6df640000(0000) knlGS:0000000000000000
[43.146808] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[43.147584] CR2: 00007f7fe81bf5b0 CR3: 00000001093ee004 CR4: 0000000000370ee0
[43.148589] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[43.149581] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[43.150559] Call Trace:
[43.150904]  <TASK>
[43.151253]  btrfs_finish_extent_commit+0x88/0x290 [btrfs]
[43.152127]  btrfs_commit_transaction+0x74f/0xaa0 [btrfs]
[43.152932]  ? btrfs_attach_transaction_barrier+0x1e/0x50 [btrfs]
[43.153786]  btrfs_ioctl+0x1edc/0x2da0 [btrfs]
[43.154475]  ? __check_object_size+0x150/0x170
[43.155170]  ? preempt_count_add+0x49/0xa0
[43.155753]  ? __x64_sys_ioctl+0x84/0xc0
[43.156437]  ? btrfs_ioctl_get_supported_features+0x30/0x30 [btrfs]
[43.157456]  __x64_sys_ioctl+0x84/0xc0
[43.157980]  do_syscall_64+0x3a/0x80
[43.158543]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[43.159231] RIP: 0033:0x7f7657f1e59b
[43.161819] RSP: 002b:00007ffda5cd1658 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[43.162702] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f7657f1e59b
[43.163526] RDX: 0000000000000000 RSI: 0000000000009408 RDI: 0000000000000003
[43.164358] RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000
[43.165208] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
[43.166029] R13: 00005621b91c3232 R14: 00005621b91ba580 R15: 00007ffda5cd1800
[43.166863]  </TASK>
[43.167125] Modules linked in: btrfs blake2b_generic xor pata_acpi ata_piix libata raid6_pq scsi_mod libcrc32c virtio_net virtio_rng net_failover rng_core failover scsi_common
[43.169552] ---[ end trace 0000000000000000 ]---
[43.171226] RIP: 0010:unpin_extent_range+0x37a/0x4f0 [btrfs]
[43.174767] RSP: 0000:ffffb0dd4216bc70 EFLAGS: 00010246
[43.175600] RAX: 0000000000000000 RBX: ffff96cfc34490f8 RCX: 0000000000000001
[43.176468] RDX: 0000000080000001 RSI: 0000000051d00000 RDI: 00000000ffffffff
[43.177357] RBP: 0000000000000000 R08: 0000000000000000 R09: ffff96cfd07dca50
[43.178271] R10: ffff96cfc46e8a00 R11: fffffffffffec000 R12: 0000000041d00000
[43.179178] R13: ffff96cfc3ce0000 R14: ffffb0dd4216bd08 R15: 0000000000000000
[43.180071] FS:  00007f7657dd68c0(0000) GS:ffff96d6df800000(0000) knlGS:0000000000000000
[43.181073] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[43.181808] CR2: 00007fe09905f010 CR3: 00000001093ee004 CR4: 0000000000370ee0
[43.182706] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[43.183591] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

We first hit the WARN_ON(rc->block_group->pinned > 0) in
btrfs_relocate_block_group() and then the BUG_ON(!cache) in
unpin_extent_range(). This tells us that we are exiting relocation and
removing the block group with bytes still pinned for that block group.
This is supposed to be impossible: the last thing relocate_block_group()
does is commit the transaction to get rid of pinned extents.

Commit d0c2f4fa55 ("btrfs: make concurrent fsyncs wait less when
waiting for a transaction commit") introduced an optimization so that
commits from fsync don't have to wait for the previous commit to unpin
extents. This was only intended to affect fsync, but it inadvertently
made it possible for any commit to skip waiting for the previous commit
to unpin. This is because if a call to btrfs_commit_transaction() finds
that another thread is already committing the transaction, it waits for
the other thread to complete the commit and then returns. If that other
thread was in fsync, then it completes the commit without completing the
previous commit. This makes the following sequence of events possible:

Thread 1____________________|Thread 2 (fsync)_____________________|Thread 3 (balance)___________________
btrfs_commit_transaction(N) |                                     |
  btrfs_run_delayed_refs    |                                     |
    pin extents             |                                     |
  ...                       |                                     |
  state = UNBLOCKED         |btrfs_sync_file                      |
                            |  btrfs_start_transaction(N + 1)     |relocate_block_group
                            |                                     |  btrfs_join_transaction(N + 1)
                            |  btrfs_commit_transaction(N + 1)    |
  ...                       |  trans->state = COMMIT_START        |
                            |                                     |  btrfs_commit_transaction(N + 1)
                            |                                     |    wait_for_commit(N + 1, COMPLETED)
                            |  wait_for_commit(N, SUPER_COMMITTED)|
  state = SUPER_COMMITTED   |  ...                                |
  btrfs_finish_extent_commit|                                     |
    unpin_extent_range()    |  trans->state = COMPLETED           |
                            |                                     |    return
                            |                                     |
    ...                     |                                     |Thread 1 isn't done, so pinned > 0
                            |                                     |and we WARN
                            |                                     |
                            |                                     |btrfs_remove_block_group
    unpin_extent_range()    |                                     |
      Thread 3 removed the  |                                     |
      block group, so we BUG|                                     |

There are other sequences involving SUPER_COMMITTED transactions that
can cause a similar outcome.

We could fix this by making relocation explicitly wait for unpinning,
but there may be other cases that need it. Josef mentioned ENOSPC
flushing and the free space cache inode as other potential victims.
Rather than playing whack-a-mole, this fix is conservative and makes all
commits not in fsync wait for all previous transactions, which is what
the optimization intended.

Fixes: d0c2f4fa55 ("btrfs: make concurrent fsyncs wait less when waiting for a transaction commit")
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-03-02 16:52:46 +01:00
Josef Bacik b4be6aefa7 btrfs: do not start relocation until in progress drops are done 
We hit a bug with a recovering relocation on mount for one of our file
systems in production.  I reproduced this locally by injecting errors
into snapshot delete with balance running at the same time.  This
presented as an error while looking up an extent item

  WARNING: CPU: 5 PID: 1501 at fs/btrfs/extent-tree.c:866 lookup_inline_extent_backref+0x647/0x680
  CPU: 5 PID: 1501 Comm: btrfs-balance Not tainted 5.16.0-rc8+ #8
  RIP: 0010:lookup_inline_extent_backref+0x647/0x680
  RSP: 0018:ffffae0a023ab960 EFLAGS: 00010202
  RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000
  RDX: 0000000000000000 RSI: 000000000000000c RDI: 0000000000000000
  RBP: ffff943fd2a39b60 R08: 0000000000000000 R09: 0000000000000001
  R10: 0001434088152de0 R11: 0000000000000000 R12: 0000000001d05000
  R13: ffff943fd2a39b60 R14: ffff943fdb96f2a0 R15: ffff9442fc923000
  FS:  0000000000000000(0000) GS:ffff944e9eb40000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007f1157b1fca8 CR3: 000000010f092000 CR4: 0000000000350ee0
  Call Trace:
   <TASK>
   insert_inline_extent_backref+0x46/0xd0
   __btrfs_inc_extent_ref.isra.0+0x5f/0x200
   ? btrfs_merge_delayed_refs+0x164/0x190
   __btrfs_run_delayed_refs+0x561/0xfa0
   ? btrfs_search_slot+0x7b4/0xb30
   ? btrfs_update_root+0x1a9/0x2c0
   btrfs_run_delayed_refs+0x73/0x1f0
   ? btrfs_update_root+0x1a9/0x2c0
   btrfs_commit_transaction+0x50/0xa50
   ? btrfs_update_reloc_root+0x122/0x220
   prepare_to_merge+0x29f/0x320
   relocate_block_group+0x2b8/0x550
   btrfs_relocate_block_group+0x1a6/0x350
   btrfs_relocate_chunk+0x27/0xe0
   btrfs_balance+0x777/0xe60
   balance_kthread+0x35/0x50
   ? btrfs_balance+0xe60/0xe60
   kthread+0x16b/0x190
   ? set_kthread_struct+0x40/0x40
   ret_from_fork+0x22/0x30
   </TASK>

Normally snapshot deletion and relocation are excluded from running at
the same time by the fs_info->cleaner_mutex.  However if we had a
pending balance waiting to get the ->cleaner_mutex, and a snapshot
deletion was running, and then the box crashed, we would come up in a
state where we have a half deleted snapshot.

Again, in the normal case the snapshot deletion needs to complete before
relocation can start, but in this case relocation could very well start
before the snapshot deletion completes, as we simply add the root to the
dead roots list and wait for the next time the cleaner runs to clean up
the snapshot.

Fix this by setting a bit on the fs_info if we have any DEAD_ROOT's that
had a pending drop_progress key.  If they do then we know we were in the
middle of the drop operation and set a flag on the fs_info.  Then
balance can wait until this flag is cleared to start up again.

If there are DEAD_ROOT's that don't have a drop_progress set then we're
safe to start balance right away as we'll be properly protected by the
cleaner_mutex.

CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-03-02 16:52:39 +01:00
Su Yue a6ab66eb85 btrfs: tree-checker: use u64 for item data end to avoid overflow 
User reported there is an array-index-out-of-bounds access while
mounting the crafted image:

  [350.411942 ] loop0: detected capacity change from 0 to 262144
  [350.427058 ] BTRFS: device fsid a62e00e8-e94e-4200-8217-12444de93c2e devid 1 transid 8 /dev/loop0 scanned by systemd-udevd (1044)
  [350.428564 ] BTRFS info (device loop0): disk space caching is enabled
  [350.428568 ] BTRFS info (device loop0): has skinny extents
  [350.429589 ]
  [350.429619 ] UBSAN: array-index-out-of-bounds in fs/btrfs/struct-funcs.c:161:1
  [350.429636 ] index 1048096 is out of range for type 'page *[16]'
  [350.429650 ] CPU: 0 PID: 9 Comm: kworker/u8:1 Not tainted 5.16.0-rc4
  [350.429652 ] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1.1 04/01/2014
  [350.429653 ] Workqueue: btrfs-endio-meta btrfs_work_helper [btrfs]
  [350.429772 ] Call Trace:
  [350.429774 ]  <TASK>
  [350.429776 ]  dump_stack_lvl+0x47/0x5c
  [350.429780 ]  ubsan_epilogue+0x5/0x50
  [350.429786 ]  __ubsan_handle_out_of_bounds+0x66/0x70
  [350.429791 ]  btrfs_get_16+0xfd/0x120 [btrfs]
  [350.429832 ]  check_leaf+0x754/0x1a40 [btrfs]
  [350.429874 ]  ? filemap_read+0x34a/0x390
  [350.429878 ]  ? load_balance+0x175/0xfc0
  [350.429881 ]  validate_extent_buffer+0x244/0x310 [btrfs]
  [350.429911 ]  btrfs_validate_metadata_buffer+0xf8/0x100 [btrfs]
  [350.429935 ]  end_bio_extent_readpage+0x3af/0x850 [btrfs]
  [350.429969 ]  ? newidle_balance+0x259/0x480
  [350.429972 ]  end_workqueue_fn+0x29/0x40 [btrfs]
  [350.429995 ]  btrfs_work_helper+0x71/0x330 [btrfs]
  [350.430030 ]  ? __schedule+0x2fb/0xa40
  [350.430033 ]  process_one_work+0x1f6/0x400
  [350.430035 ]  ? process_one_work+0x400/0x400
  [350.430036 ]  worker_thread+0x2d/0x3d0
  [350.430037 ]  ? process_one_work+0x400/0x400
  [350.430038 ]  kthread+0x165/0x190
  [350.430041 ]  ? set_kthread_struct+0x40/0x40
  [350.430043 ]  ret_from_fork+0x1f/0x30
  [350.430047 ]  </TASK>
  [350.430047 ]
  [350.430077 ] BTRFS warning (device loop0): bad eb member start: ptr 0xffe20f4e start 20975616 member offset 4293005178 size 2

btrfs check reports:
  corrupt leaf: root=3 block=20975616 physical=20975616 slot=1, unexpected
  item end, have 4294971193 expect 3897

The first slot item offset is 4293005033 and the size is 1966160.
In check_leaf, we use btrfs_item_end() to check item boundary versus
extent_buffer data size. However, return type of btrfs_item_end() is u32.
(u32)(4293005033 + 1966160) == 3897, overflow happens and the result 3897
equals to leaf data size reasonably.

Fix it by use u64 variable to store item data end in check_leaf() to
avoid u32 overflow.

This commit does solve the invalid memory access showed by the stack
trace.  However, its metadata profile is DUP and another copy of the
leaf is fine.  So the image can be mounted successfully. But when umount
is called, the ASSERT btrfs_mark_buffer_dirty() will be triggered
because the only node in extent tree has 0 item and invalid owner. It's
solved by another commit
"btrfs: check extent buffer owner against the owner rootid".

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=215299
Reported-by: Wenqing Liu <wenqingliu0120@gmail.com>
CC: stable@vger.kernel.org # 4.19+
Signed-off-by: Su Yue <l@damenly.su>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-03-02 16:52:32 +01:00
Josef Bacik a50e1fcbc9 btrfs: do not WARN_ON() if we have PageError set 
Whenever we do any extent buffer operations we call
assert_eb_page_uptodate() to complain loudly if we're operating on an
non-uptodate page.  Our overnight tests caught this warning earlier this
week

  WARNING: CPU: 1 PID: 553508 at fs/btrfs/extent_io.c:6849 assert_eb_page_uptodate+0x3f/0x50
  CPU: 1 PID: 553508 Comm: kworker/u4:13 Tainted: G        W         5.17.0-rc3+ #564
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
  Workqueue: btrfs-cache btrfs_work_helper
  RIP: 0010:assert_eb_page_uptodate+0x3f/0x50
  RSP: 0018:ffffa961440a7c68 EFLAGS: 00010246
  RAX: 0017ffffc0002112 RBX: ffffe6e74453f9c0 RCX: 0000000000001000
  RDX: ffffe6e74467c887 RSI: ffffe6e74453f9c0 RDI: ffff8d4c5efc2fc0
  RBP: 0000000000000d56 R08: ffff8d4d4a224000 R09: 0000000000000000
  R10: 00015817fa9d1ef0 R11: 000000000000000c R12: 00000000000007b1
  R13: ffff8d4c5efc2fc0 R14: 0000000001500000 R15: 0000000001cb1000
  FS:  0000000000000000(0000) GS:ffff8d4dbbd00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007ff31d3448d8 CR3: 0000000118be8004 CR4: 0000000000370ee0
  Call Trace:

   extent_buffer_test_bit+0x3f/0x70
   free_space_test_bit+0xa6/0xc0
   load_free_space_tree+0x1f6/0x470
   caching_thread+0x454/0x630
   ? rcu_read_lock_sched_held+0x12/0x60
   ? rcu_read_lock_sched_held+0x12/0x60
   ? rcu_read_lock_sched_held+0x12/0x60
   ? lock_release+0x1f0/0x2d0
   btrfs_work_helper+0xf2/0x3e0
   ? lock_release+0x1f0/0x2d0
   ? finish_task_switch.isra.0+0xf9/0x3a0
   process_one_work+0x26d/0x580
   ? process_one_work+0x580/0x580
   worker_thread+0x55/0x3b0
   ? process_one_work+0x580/0x580
   kthread+0xf0/0x120
   ? kthread_complete_and_exit+0x20/0x20
   ret_from_fork+0x1f/0x30

This was partially fixed by c2e3930529 ("btrfs: clear extent buffer
uptodate when we fail to write it"), however all that fix did was keep
us from finding extent buffers after a failed writeout.  It didn't keep
us from continuing to use a buffer that we already had found.

In this case we're searching the commit root to cache the block group,
so we can start committing the transaction and switch the commit root
and then start writing.  After the switch we can look up an extent
buffer that hasn't been written yet and start processing that block
group.  Then we fail to write that block out and clear Uptodate on the
page, and then we start spewing these errors.

Normally we're protected by the tree lock to a certain degree here.  If
we read a block we have that block read locked, and we block the writer
from locking the block before we submit it for the write.  However this
isn't necessarily fool proof because the read could happen before we do
the submit_bio and after we locked and unlocked the extent buffer.

Also in this particular case we have path->skip_locking set, so that
won't save us here.  We'll simply get a block that was valid when we
read it, but became invalid while we were using it.

What we really want is to catch the case where we've "read" a block but
it's not marked Uptodate.  On read we ClearPageError(), so if we're
!Uptodate and !Error we know we didn't do the right thing for reading
the page.

Fix this by checking !Uptodate && !Error, this way we will not complain
if our buffer gets invalidated while we're using it, and we'll maintain
the spirit of the check which is to make sure we have a fully in-cache
block while we're messing with it.

CC: stable@vger.kernel.org # 5.4+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-03-02 16:52:24 +01:00
Filipe Manana d994788743 btrfs: fix lost prealloc extents beyond eof after full fsync 
When doing a full fsync, if we have prealloc extents beyond (or at) eof,
and the leaves that contain them were not modified in the current
transaction, we end up not logging them. This results in losing those
extents when we replay the log after a power failure, since the inode is
truncated to the current value of the logged i_size.

Just like for the fast fsync path, we need to always log all prealloc
extents starting at or beyond i_size. The fast fsync case was fixed in
commit 471d557afe ("Btrfs: fix loss of prealloc extents past i_size
after fsync log replay") but it missed the full fsync path. The problem
exists since the very early days, when the log tree was added by
commit e02119d5a7 ("Btrfs: Add a write ahead tree log to optimize
synchronous operations").

Example reproducer:

  $ mkfs.btrfs -f /dev/sdc
  $ mount /dev/sdc /mnt

  # Create our test file with many file extent items, so that they span
  # several leaves of metadata, even if the node/page size is 64K. Use
  # direct IO and not fsync/O_SYNC because it's both faster and it avoids
  # clearing the full sync flag from the inode - we want the fsync below
  # to trigger the slow full sync code path.
  $ xfs_io -f -d -c "pwrite -b 4K 0 16M" /mnt/foo

  # Now add two preallocated extents to our file without extending the
  # file's size. One right at i_size, and another further beyond, leaving
  # a gap between the two prealloc extents.
  $ xfs_io -c "falloc -k 16M 1M" /mnt/foo
  $ xfs_io -c "falloc -k 20M 1M" /mnt/foo

  # Make sure everything is durably persisted and the transaction is
  # committed. This makes all created extents to have a generation lower
  # than the generation of the transaction used by the next write and
  # fsync.
  sync

  # Now overwrite only the first extent, which will result in modifying
  # only the first leaf of metadata for our inode. Then fsync it. This
  # fsync will use the slow code path (inode full sync bit is set) because
  # it's the first fsync since the inode was created/loaded.
  $ xfs_io -c "pwrite 0 4K" -c "fsync" /mnt/foo

  # Extent list before power failure.
  $ xfs_io -c "fiemap -v" /mnt/foo
  /mnt/foo:
   EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
     0: [0..7]:          2178048..2178055     8   0x0
     1: [8..16383]:      26632..43007     16376   0x0
     2: [16384..32767]:  2156544..2172927 16384   0x0
     3: [32768..34815]:  2172928..2174975  2048 0x800
     4: [34816..40959]:  hole              6144
     5: [40960..43007]:  2174976..2177023  2048 0x801

  <power fail>

  # Mount fs again, trigger log replay.
  $ mount /dev/sdc /mnt

  # Extent list after power failure and log replay.
  $ xfs_io -c "fiemap -v" /mnt/foo
  /mnt/foo:
   EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
     0: [0..7]:          2178048..2178055     8   0x0
     1: [8..16383]:      26632..43007     16376   0x0
     2: [16384..32767]:  2156544..2172927 16384   0x1

  # The prealloc extents at file offsets 16M and 20M are missing.

So fix this by calling btrfs_log_prealloc_extents() when we are doing a
full fsync, so that we always log all prealloc extents beyond eof.

A test case for fstests will follow soon.

CC: stable@vger.kernel.org # 4.19+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-03-02 16:51:55 +01:00
Qu Wenruo c992fa1fd5 btrfs: subpage: fix a wrong check on subpage->writers 
[BUG]
When looping btrfs/074 with 64K page size and 4K sectorsize, there is a
low chance (1/50~1/100) to crash with the following ASSERT() triggered
in btrfs_subpage_start_writer():

	ret = atomic_add_return(nbits, &subpage->writers);
	ASSERT(ret == nbits); <<< This one <<<

[CAUSE]
With more debugging output on the parameters of
btrfs_subpage_start_writer(), it shows a very concerning error:

  ret=29 nbits=13 start=393216 len=53248

For @nbits it's correct, but @ret which is the returned value from
atomic_add_return(), it's not only larger than nbits, but also larger
than max sectors per page value (for 64K page size and 4K sector size,
it's 16).

This indicates that some call sites are not properly decreasing the value.

And that's exactly the case, in btrfs_page_unlock_writer(), due to the
fact that we can have page locked either by lock_page() or
process_one_page(), we have to check if the subpage has any writer.

If no writers, it's locked by lock_page() and we only need to unlock it.

But unfortunately the check for the writers are completely opposite:

	if (atomic_read(&subpage->writers))
		/* No writers, locked by plain lock_page() */
		return unlock_page(page);

We directly unlock the page if it has writers, which is the completely
opposite what we want.

Thankfully the affected call site is only limited to
extent_write_locked_range(), so it's mostly affecting compressed write.

[FIX]
Just fix the wrong check condition to fix the bug.

Fixes: e55a0de185 ("btrfs: rework page locking in __extent_writepage()")
CC: stable@vger.kernel.org # 5.16
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-03-02 16:51:39 +01:00
Linus Torvalds c0419188b5 for-5.17-rc5-tag 
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmIY790ACgkQxWXV+ddt
 WDvKxA//ctgUNhKEPOfJlmmaKAVRgrE6FfDgfk6c2v/PrpPFH0U9+frishcsImxu
 XAObMCyPY7PfLDnk6I0Lmxm+8T56+NNGjbxq7/R1Uv0DJm75f51OJbr/H7NSjVfu
 g6IyPmIft7jmt7Vp9lPyYcPNDTFyG+XARdWYS3AFtAfr2MfXgjx9AALxFjaytbLi
 AevXP0qEkbLHv5npEG56pouhn44J/8GZKeUGM1crNNUDQoYpgreifZ2SHpLIfxP5
 lvzrA1noaZSFS3Cth7NBPhHTFS2tiMb96bHFdF56A2EIq5vAXQF7w6IAUlvBEVoR
 5XgWsxGfsv5FbdFmyrRIvOh6gGHwHw8BH5/ZRTRRVuRZAPKPY0oiJ9OJk5kIBCgo
 LiYksqRTOs0Zp/e5wn/8d/UGp2A6mujxwqw7gLcOZBzfhKw7QIha6BM64BfJxBni
 3dakBDCWZ/X+Kje+WaM4Sev7JUIyDVoKWClHrvzoLeEzdIgruNguMnQ+3yOZBFiG
 4YRTPUeafAj0OspJ0LLG01X4NJVmnQVAFoKuFOsGbUsxeCaQ9vF3/IGTlhgkwehf
 KjvE9nzl9DewpvRRd7AAirj5FncuwRw6KNci1gBBixxPaveBClCIuuyfx6lXPusK
 sIF3eb7xcqKYLh0iYPd2XMZInXbWXIGuJoVG/Gu1IYm1OXAFQ5A=
 =q/NS
 -----END PGP SIGNATURE-----

Merge tag 'for-5.17-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "This is a hopefully last batch of fixes for defrag that got broken in
  5.16, all stable material.

  The remaining reported problem is excessive IO with autodefrag due to
  various conditions in the defrag code not met or missing"

* tag 'for-5.17-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: reduce extent threshold for autodefrag
  btrfs: autodefrag: only scan one inode once
  btrfs: defrag: don't use merged extent map for their generation check
  btrfs: defrag: bring back the old file extent search behavior
  btrfs: defrag: remove an ambiguous condition for rejection
  btrfs: defrag: don't defrag extents which are already at max capacity
  btrfs: defrag: don't try to merge regular extents with preallocated extents
  btrfs: defrag: allow defrag_one_cluster() to skip large extent which is not a target
  btrfs: prevent copying too big compressed lzo segment
 2022-02-25 14:08:03 -08:00
Qu Wenruo 558732df21 btrfs: reduce extent threshold for autodefrag 
There is a big gap between inode_should_defrag() and autodefrag extent
size threshold.  For inode_should_defrag() it has a flexible
@small_write value. For compressed extent is 16K, and for non-compressed
extent it's 64K.

However for autodefrag extent size threshold, it's always fixed to the
default value (256K).

This means, the following write sequence will trigger autodefrag to
defrag ranges which didn't trigger autodefrag:

  pwrite 0 8k
  sync
  pwrite 8k 128K
  sync

The latter 128K write will also be considered as a defrag target (if
other conditions are met). While only that 8K write is really
triggering autodefrag.

Such behavior can cause extra IO for autodefrag.

Close the gap, by copying the @small_write value into inode_defrag, so
that later autodefrag can use the same @small_write value which
triggered autodefrag.

With the existing transid value, this allows autodefrag really to scan
the ranges which triggered autodefrag.

Although this behavior change is mostly reducing the extent_thresh value
for autodefrag, I believe in the future we should allow users to specify
the autodefrag extent threshold through mount options, but that's an
other problem to consider in the future.

CC: stable@vger.kernel.org # 5.16+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-02-24 16:11:28 +01:00
Qu Wenruo 26fbac2517 btrfs: autodefrag: only scan one inode once 
Although we have btrfs_requeue_inode_defrag(), for autodefrag we are
still just exhausting all inode_defrag items in the tree.

This means, it doesn't make much difference to requeue an inode_defrag,
other than scan the inode from the beginning till its end.

Change the behaviour to always scan from offset 0 of an inode, and till
the end.

By this we get the following benefit:

- Straight-forward code

- No more re-queue related check

- Fewer members in inode_defrag

We still keep the same btrfs_get_fs_root() and btrfs_iget() check for
each loop, and added extra should_auto_defrag() check per-loop.

Note: the patch needs to be backported and is intentionally written
to minimize the diff size, code will be cleaned up later.

CC: stable@vger.kernel.org # 5.16
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-02-23 17:55:01 +01:00
Qu Wenruo 199257a78b btrfs: defrag: don't use merged extent map for their generation check 
For extent maps, if they are not compressed extents and are adjacent by
logical addresses and file offsets, they can be merged into one larger
extent map.

Such merged extent map will have the higher generation of all the
original ones.

But this brings a problem for autodefrag, as it relies on accurate
extent_map::generation to determine if one extent should be defragged.

For merged extent maps, their higher generation can mark some older
extents to be defragged while the original extent map doesn't meet the
minimal generation threshold.

Thus this will cause extra IO.

So solve the problem, here we introduce a new flag, EXTENT_FLAG_MERGED,
to indicate if the extent map is merged from one or more ems.

And for autodefrag, if we find a merged extent map, and its generation
meets the generation requirement, we just don't use this one, and go
back to defrag_get_extent() to read extent maps from subvolume trees.

This could cause more read IO, but should result less defrag data write,
so in the long run it should be a win for autodefrag.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-02-23 17:43:13 +01:00
Qu Wenruo d5633b0dee btrfs: defrag: bring back the old file extent search behavior 
For defrag, we don't really want to use btrfs_get_extent() to iterate
all extent maps of an inode.

The reasons are:

- btrfs_get_extent() can merge extent maps
  And the result em has the higher generation of the two, causing defrag
  to mark unnecessary part of such merged large extent map.

  This in fact can result extra IO for autodefrag in v5.16+ kernels.

  However this patch is not going to completely solve the problem, as
  one can still using read() to trigger extent map reading, and got
  them merged.

  The completely solution for the extent map merging generation problem
  will come as an standalone fix.

- btrfs_get_extent() caches the extent map result
  Normally it's fine, but for defrag the target range may not get
  another read/write for a long long time.
  Such cache would only increase the memory usage.

- btrfs_get_extent() doesn't skip older extent map
  Unlike the old find_new_extent() which uses btrfs_search_forward() to
  skip the older subtree, thus it will pick up unnecessary extent maps.

This patch will fix the regression by introducing defrag_get_extent() to
replace the btrfs_get_extent() call.

This helper will:

- Not cache the file extent we found
  It will search the file extent and manually convert it to em.

- Use btrfs_search_forward() to skip entire ranges which is modified in
  the past

This should reduce the IO for autodefrag.

Reported-by: Filipe Manana <fdmanana@suse.com>
Fixes: 7b508037d4 ("btrfs: defrag: use defrag_one_cluster() to implement btrfs_defrag_file()")
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-02-23 17:43:07 +01:00
Qu Wenruo 550f133f69 btrfs: defrag: remove an ambiguous condition for rejection 
From the very beginning of btrfs defrag, there is a check to reject
extents which meet both conditions:

- Physically adjacent

  We may want to defrag physically adjacent extents to reduce the number
  of extents or the size of subvolume tree.

- Larger than 128K

  This may be there for compressed extents, but unfortunately 128K is
  exactly the max capacity for compressed extents.
  And the check is > 128K, thus it never rejects compressed extents.

  Furthermore, the compressed extent capacity bug is fixed by previous
  patch, there is no reason for that check anymore.

The original check has a very small ranges to reject (the target extent
size is > 128K, and default extent threshold is 256K), and for
compressed extent it doesn't work at all.

So it's better just to remove the rejection, and allow us to defrag
physically adjacent extents.

CC: stable@vger.kernel.org # 5.16
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-02-23 17:42:55 +01:00
Qu Wenruo 979b25c300 btrfs: defrag: don't defrag extents which are already at max capacity 
[BUG]
For compressed extents, defrag ioctl will always try to defrag any
compressed extents, wasting not only IO but also CPU time to
compress/decompress:

   mkfs.btrfs -f $DEV
   mount -o compress $DEV $MNT
   xfs_io -f -c "pwrite -S 0xab 0 128K" $MNT/foobar
   sync
   xfs_io -f -c "pwrite -S 0xcd 128K 128K" $MNT/foobar
   sync
   echo "=== before ==="
   xfs_io -c "fiemap -v" $MNT/foobar
   btrfs filesystem defrag $MNT/foobar
   sync
   echo "=== after ==="
   xfs_io -c "fiemap -v" $MNT/foobar

Then it shows the 2 128K extents just get COW for no extra benefit, with
extra IO/CPU spent:

    === before ===
    /mnt/btrfs/file1:
     EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
       0: [0..255]:        26624..26879       256   0x8
       1: [256..511]:      26632..26887       256   0x9
    === after ===
    /mnt/btrfs/file1:
     EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
       0: [0..255]:        26640..26895       256   0x8
       1: [256..511]:      26648..26903       256   0x9

This affects not only v5.16 (after the defrag rework), but also v5.15
(before the defrag rework).

[CAUSE]
From the very beginning, btrfs defrag never checks if one extent is
already at its max capacity (128K for compressed extents, 128M
otherwise).

And the default extent size threshold is 256K, which is already beyond
the compressed extent max size.

This means, by default btrfs defrag ioctl will mark all compressed
extent which is not adjacent to a hole/preallocated range for defrag.

[FIX]
Introduce a helper to grab the maximum extent size, and then in
defrag_collect_targets() and defrag_check_next_extent(), reject extents
which are already at their max capacity.

Reported-by: Filipe Manana <fdmanana@suse.com>
CC: stable@vger.kernel.org # 5.16
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-02-23 17:42:53 +01:00
Qu Wenruo 7093f15291 btrfs: defrag: don't try to merge regular extents with preallocated extents 
[BUG]
With older kernels (before v5.16), btrfs will defrag preallocated extents.
While with newer kernels (v5.16 and newer) btrfs will not defrag
preallocated extents, but it will defrag the extent just before the
preallocated extent, even it's just a single sector.

This can be exposed by the following small script:

	mkfs.btrfs -f $dev > /dev/null

	mount $dev $mnt
	xfs_io -f -c "pwrite 0 4k" -c sync -c "falloc 4k 16K" $mnt/file
	xfs_io -c "fiemap -v" $mnt/file
	btrfs fi defrag $mnt/file
	sync
	xfs_io -c "fiemap -v" $mnt/file

The output looks like this on older kernels:

/mnt/btrfs/file:
 EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
   0: [0..7]:          26624..26631         8   0x0
   1: [8..39]:         26632..26663        32 0x801
/mnt/btrfs/file:
 EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
   0: [0..39]:         26664..26703        40   0x1

Which defrags the single sector along with the preallocated extent, and
replace them with an regular extent into a new location (caused by data
COW).
This wastes most of the data IO just for the preallocated range.

On the other hand, v5.16 is slightly better:

/mnt/btrfs/file:
 EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
   0: [0..7]:          26624..26631         8   0x0
   1: [8..39]:         26632..26663        32 0x801
/mnt/btrfs/file:
 EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
   0: [0..7]:          26664..26671         8   0x0
   1: [8..39]:         26632..26663        32 0x801

The preallocated range is not defragged, but the sector before it still
gets defragged, which has no need for it.

[CAUSE]
One of the function reused by the old and new behavior is
defrag_check_next_extent(), it will determine if we should defrag
current extent by checking the next one.

It only checks if the next extent is a hole or inlined, but it doesn't
check if it's preallocated.

On the other hand, out of the function, both old and new kernel will
reject preallocated extents.

Such inconsistent behavior causes above behavior.

[FIX]
- Also check if next extent is preallocated
  If so, don't defrag current extent.

- Add comments for each branch why we reject the extent

This will reduce the IO caused by defrag ioctl and autodefrag.

CC: stable@vger.kernel.org # 5.16
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-02-23 17:42:52 +01:00
Qu Wenruo 966d879baf btrfs: defrag: allow defrag_one_cluster() to skip large extent which is not a target 
In the rework of btrfs_defrag_file(), we always call
defrag_one_cluster() and increase the offset by cluster size, which is
only 256K.

But there are cases where we have a large extent (e.g. 128M) which
doesn't need to be defragged at all.

Before the refactor, we can directly skip the range, but now we have to
scan that extent map again and again until the cluster moves after the
non-target extent.

Fix the problem by allow defrag_one_cluster() to increase
btrfs_defrag_ctrl::last_scanned to the end of an extent, if and only if
the last extent of the cluster is not a target.

The test script looks like this:

	mkfs.btrfs -f $dev > /dev/null

	mount $dev $mnt

	# As btrfs ioctl uses 32M as extent_threshold
	xfs_io -f -c "pwrite 0 64M" $mnt/file1
	sync
	# Some fragemented range to defrag
	xfs_io -s -c "pwrite 65548k 4k" \
		  -c "pwrite 65544k 4k" \
		  -c "pwrite 65540k 4k" \
		  -c "pwrite 65536k 4k" \
		  $mnt/file1
	sync

	echo "=== before ==="
	xfs_io -c "fiemap -v" $mnt/file1
	echo "=== after ==="
	btrfs fi defrag $mnt/file1
	sync
	xfs_io -c "fiemap -v" $mnt/file1
	umount $mnt

With extra ftrace put into defrag_one_cluster(), before the patch it
would result tons of loops:

(As defrag_one_cluster() is inlined, the function name is its caller)

  btrfs-126062  [005] .....  4682.816026: btrfs_defrag_file: r/i=5/257 start=0 len=262144
  btrfs-126062  [005] .....  4682.816027: btrfs_defrag_file: r/i=5/257 start=262144 len=262144
  btrfs-126062  [005] .....  4682.816028: btrfs_defrag_file: r/i=5/257 start=524288 len=262144
  btrfs-126062  [005] .....  4682.816028: btrfs_defrag_file: r/i=5/257 start=786432 len=262144
  btrfs-126062  [005] .....  4682.816028: btrfs_defrag_file: r/i=5/257 start=1048576 len=262144
  ...
  btrfs-126062  [005] .....  4682.816043: btrfs_defrag_file: r/i=5/257 start=67108864 len=262144

But with this patch there will be just one loop, then directly to the
end of the extent:

  btrfs-130471  [014] .....  5434.029558: defrag_one_cluster: r/i=5/257 start=0 len=262144
  btrfs-130471  [014] .....  5434.029559: defrag_one_cluster: r/i=5/257 start=67108864 len=16384

CC: stable@vger.kernel.org # 5.16
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-02-15 19:59:30 +01:00
Dāvis Mosāns 741b23a970 btrfs: prevent copying too big compressed lzo segment 
Compressed length can be corrupted to be a lot larger than memory
we have allocated for buffer.
This will cause memcpy in copy_compressed_segment to write outside
of allocated memory.

This mostly results in stuck read syscall but sometimes when using
btrfs send can get #GP

  kernel: general protection fault, probably for non-canonical address 0x841551d5c1000: 0000 [#1] PREEMPT SMP NOPTI
  kernel: CPU: 17 PID: 264 Comm: kworker/u256:7 Tainted: P           OE     5.17.0-rc2-1 #12
  kernel: Workqueue: btrfs-endio btrfs_work_helper [btrfs]
  kernel: RIP: 0010:lzo_decompress_bio (./include/linux/fortify-string.h:225 fs/btrfs/lzo.c:322 fs/btrfs/lzo.c:394) btrfs
  Code starting with the faulting instruction
  ===========================================
     0:*  48 8b 06                mov    (%rsi),%rax              <-- trapping instruction
     3:   48 8d 79 08             lea    0x8(%rcx),%rdi
     7:   48 83 e7 f8             and    $0xfffffffffffffff8,%rdi
     b:   48 89 01                mov    %rax,(%rcx)
     e:   44 89 f0                mov    %r14d,%eax
    11:   48 8b 54 06 f8          mov    -0x8(%rsi,%rax,1),%rdx
  kernel: RSP: 0018:ffffb110812efd50 EFLAGS: 00010212
  kernel: RAX: 0000000000001000 RBX: 000000009ca264c8 RCX: ffff98996e6d8ff8
  kernel: RDX: 0000000000000064 RSI: 000841551d5c1000 RDI: ffffffff9500435d
  kernel: RBP: ffff989a3be856c0 R08: 0000000000000000 R09: 0000000000000000
  kernel: R10: 0000000000000000 R11: 0000000000001000 R12: ffff98996e6d8000
  kernel: R13: 0000000000000008 R14: 0000000000001000 R15: 000841551d5c1000
  kernel: FS:  0000000000000000(0000) GS:ffff98a09d640000(0000) knlGS:0000000000000000
  kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  kernel: CR2: 00001e9f984d9ea8 CR3: 000000014971a000 CR4: 00000000003506e0
  kernel: Call Trace:
  kernel:  <TASK>
  kernel: end_compressed_bio_read (fs/btrfs/compression.c:104 fs/btrfs/compression.c:1363 fs/btrfs/compression.c:323) btrfs
  kernel: end_workqueue_fn (fs/btrfs/disk-io.c:1923) btrfs
  kernel: btrfs_work_helper (fs/btrfs/async-thread.c:326) btrfs
  kernel: process_one_work (./arch/x86/include/asm/jump_label.h:27 ./include/linux/jump_label.h:212 ./include/trace/events/workqueue.h:108 kernel/workqueue.c:2312)
  kernel: worker_thread (./include/linux/list.h:292 kernel/workqueue.c:2455)
  kernel: ? process_one_work (kernel/workqueue.c:2397)
  kernel: kthread (kernel/kthread.c:377)
  kernel: ? kthread_complete_and_exit (kernel/kthread.c:332)
  kernel: ret_from_fork (arch/x86/entry/entry_64.S:301)
  kernel:  </TASK>

CC: stable@vger.kernel.org # 4.9+
Signed-off-by: Dāvis Mosāns <davispuh@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-02-15 19:59:09 +01:00
Linus Torvalds 705d84a366 for-5.17-rc4-tag 
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmILuxMACgkQxWXV+ddt
 WDvhrA/9Hsyj2DdvvBVR3HudaER51RAJS6dtJCJdFZGWy2tEwtkxhIdbPn1nwJE7
 mvZy2UN79JKwPAdX8inyJ68RCMtcifprkUMC2d7y2mVZcCG/a/iYGdDIVB/z4Pyx
 NneBBgwdG0V505i7/sm07epLUaNI1MwXc9wNAs00zSXw4eYjLq09fp0lfl74RBhv
 HvuYgawk2abY6hPbJnTu2MyyHEZI4oGH/fRurP48cvU/FbIm9en7aX3rEZ+T8yRW
 TkEdFF/60Wce3xkyN87Xqma6L0smypJ888yzpwsJtlFOTr7iI58HYqUfx27Q5VQc
 xy5fyuuplEb0ky4GBnscpsoutj5C241+4+YE4HGqf9ne5EYU1rzJATlEFUBk84hY
 YwjdordS/nTScyFVCBG9yiTL30KsQ2SQc1TzIt/rIJiYIJexJyppOJMFmxbuN9By
 WSrLB5/uN56dRe/A8LMGpuJdwTVrYr2SPXfSseAxCEONt5fppPnDaCGEgVKIdmHq
 sQXbs/LMGHQ1lq2JsPFD12p8kQJ5Redxy0KIzDwmeBAL3HlXwpFiMia0AhvKOzPj
 UFtU/KcOmtqWMMv3P0aHydmDmUid4c3612BtvbKOhIXTVzKodzcQhkyTw1ducAa1
 GMkKIHCaPCzbsJwiogZGSBmIyDyMwitVvAybZIpRTR9i0xSA61A=
 =AqU+
 -----END PGP SIGNATURE-----

Merge tag 'for-5.17-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:

 - yield CPU more often when defragmenting a large file

 - skip defragmenting extents already under writeback

 - improve error message when send fails to write file data

 - get rid of warning when mounted with 'flushoncommit'

* tag 'for-5.17-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: send: in case of IO error log it
  btrfs: get rid of warning on transaction commit when using flushoncommit
  btrfs: defrag: don't try to defrag extents which are under writeback
  btrfs: don't hold CPU for too long when defragging a file
 2022-02-15 09:14:05 -08:00
Dāvis Mosāns 2e7be9db12 btrfs: send: in case of IO error log it 
Currently if we get IO error while doing send then we abort without
logging information about which file caused issue.  So log it to help
with debugging.

CC: stable@vger.kernel.org # 4.9+
Signed-off-by: Dāvis Mosāns <davispuh@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-02-09 18:53:26 +01:00
Filipe Manana a0f0cf8341 btrfs: get rid of warning on transaction commit when using flushoncommit 
When using the flushoncommit mount option, during almost every transaction
commit we trigger a warning from __writeback_inodes_sb_nr():

  $ cat fs/fs-writeback.c:
  (...)
  static void __writeback_inodes_sb_nr(struct super_block *sb, ...
  {
        (...)
        WARN_ON(!rwsem_is_locked(&sb->s_umount));
        (...)
  }
  (...)

The trace produced in dmesg looks like the following:

  [947.473890] WARNING: CPU: 5 PID: 930 at fs/fs-writeback.c:2610 __writeback_inodes_sb_nr+0x7e/0xb3
  [947.481623] Modules linked in: nfsd nls_cp437 cifs asn1_decoder cifs_arc4 fscache cifs_md4 ipmi_ssif
  [947.489571] CPU: 5 PID: 930 Comm: btrfs-transacti Not tainted 95.16.3-srb-asrock-00001-g36437ad63879 #186
  [947.497969] RIP: 0010:__writeback_inodes_sb_nr+0x7e/0xb3
  [947.502097] Code: 24 10 4c 89 44 24 18 c6 (...)
  [947.519760] RSP: 0018:ffffc90000777e10 EFLAGS: 00010246
  [947.523818] RAX: 0000000000000000 RBX: 0000000000963300 RCX: 0000000000000000
  [947.529765] RDX: 0000000000000000 RSI: 000000000000fa51 RDI: ffffc90000777e50
  [947.535740] RBP: ffff888101628a90 R08: ffff888100955800 R09: ffff888100956000
  [947.541701] R10: 0000000000000002 R11: 0000000000000001 R12: ffff888100963488
  [947.547645] R13: ffff888100963000 R14: ffff888112fb7200 R15: ffff888100963460
  [947.553621] FS:  0000000000000000(0000) GS:ffff88841fd40000(0000) knlGS:0000000000000000
  [947.560537] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [947.565122] CR2: 0000000008be50c4 CR3: 000000000220c000 CR4: 00000000001006e0
  [947.571072] Call Trace:
  [947.572354]  <TASK>
  [947.573266]  btrfs_commit_transaction+0x1f1/0x998
  [947.576785]  ? start_transaction+0x3ab/0x44e
  [947.579867]  ? schedule_timeout+0x8a/0xdd
  [947.582716]  transaction_kthread+0xe9/0x156
  [947.585721]  ? btrfs_cleanup_transaction.isra.0+0x407/0x407
  [947.590104]  kthread+0x131/0x139
  [947.592168]  ? set_kthread_struct+0x32/0x32
  [947.595174]  ret_from_fork+0x22/0x30
  [947.597561]  </TASK>
  [947.598553] ---[ end trace 644721052755541c ]---

This is because we started using writeback_inodes_sb() to flush delalloc
when committing a transaction (when using -o flushoncommit), in order to
avoid deadlocks with filesystem freeze operations. This change was made
by commit ce8ea7cc6e ("btrfs: don't call btrfs_start_delalloc_roots
in flushoncommit"). After that change we started producing that warning,
and every now and then a user reports this since the warning happens too
often, it spams dmesg/syslog, and a user is unsure if this reflects any
problem that might compromise the filesystem's reliability.

We can not just lock the sb->s_umount semaphore before calling
writeback_inodes_sb(), because that would at least deadlock with
filesystem freezing, since at fs/super.c:freeze_super() sync_filesystem()
is called while we are holding that semaphore in write mode, and that can
trigger a transaction commit, resulting in a deadlock. It would also
trigger the same type of deadlock in the unmount path. Possibly, it could
also introduce some other locking dependencies that lockdep would report.

To fix this call try_to_writeback_inodes_sb() instead of
writeback_inodes_sb(), because that will try to read lock sb->s_umount
and then will only call writeback_inodes_sb() if it was able to lock it.
This is fine because the cases where it can't read lock sb->s_umount
are during a filesystem unmount or during a filesystem freeze - in those
cases sb->s_umount is write locked and sync_filesystem() is called, which
calls writeback_inodes_sb(). In other words, in all cases where we can't
take a read lock on sb->s_umount, writeback is already being triggered
elsewhere.

An alternative would be to call btrfs_start_delalloc_roots() with a
number of pages different from LONG_MAX, for example matching the number
of delalloc bytes we currently have, in which case we would end up
starting all delalloc with filemap_fdatawrite_wbc() and not with an
async flush via filemap_flush() - that is only possible after the rather
recent commit e076ab2a2c ("btrfs: shrink delalloc pages instead of
full inodes"). However that creates a whole new can of worms due to new
lock dependencies, which lockdep complains, like for example:

[ 8948.247280] ======================================================
[ 8948.247823] WARNING: possible circular locking dependency detected
[ 8948.248353] 5.17.0-rc1-btrfs-next-111 #1 Not tainted
[ 8948.248786] ------------------------------------------------------
[ 8948.249320] kworker/u16:18/933570 is trying to acquire lock:
[ 8948.249812] ffff9b3de1591690 (sb_internal#2){.+.+}-{0:0}, at: find_free_extent+0x141e/0x1590 [btrfs]
[ 8948.250638]
               but task is already holding lock:
[ 8948.251140] ffff9b3e09c717d8 (&root->delalloc_mutex){+.+.}-{3:3}, at: start_delalloc_inodes+0x78/0x400 [btrfs]
[ 8948.252018]
               which lock already depends on the new lock.

[ 8948.252710]
               the existing dependency chain (in reverse order) is:
[ 8948.253343]
               -> #2 (&root->delalloc_mutex){+.+.}-{3:3}:
[ 8948.253950]        __mutex_lock+0x90/0x900
[ 8948.254354]        start_delalloc_inodes+0x78/0x400 [btrfs]
[ 8948.254859]        btrfs_start_delalloc_roots+0x194/0x2a0 [btrfs]
[ 8948.255408]        btrfs_commit_transaction+0x32f/0xc00 [btrfs]
[ 8948.255942]        btrfs_mksubvol+0x380/0x570 [btrfs]
[ 8948.256406]        btrfs_mksnapshot+0x81/0xb0 [btrfs]
[ 8948.256870]        __btrfs_ioctl_snap_create+0x17f/0x190 [btrfs]
[ 8948.257413]        btrfs_ioctl_snap_create_v2+0xbb/0x140 [btrfs]
[ 8948.257961]        btrfs_ioctl+0x1196/0x3630 [btrfs]
[ 8948.258418]        __x64_sys_ioctl+0x83/0xb0
[ 8948.258793]        do_syscall_64+0x3b/0xc0
[ 8948.259146]        entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 8948.259709]
               -> #1 (&fs_info->delalloc_root_mutex){+.+.}-{3:3}:
[ 8948.260330]        __mutex_lock+0x90/0x900
[ 8948.260692]        btrfs_start_delalloc_roots+0x97/0x2a0 [btrfs]
[ 8948.261234]        btrfs_commit_transaction+0x32f/0xc00 [btrfs]
[ 8948.261766]        btrfs_set_free_space_cache_v1_active+0x38/0x60 [btrfs]
[ 8948.262379]        btrfs_start_pre_rw_mount+0x119/0x180 [btrfs]
[ 8948.262909]        open_ctree+0x1511/0x171e [btrfs]
[ 8948.263359]        btrfs_mount_root.cold+0x12/0xde [btrfs]
[ 8948.263863]        legacy_get_tree+0x30/0x50
[ 8948.264242]        vfs_get_tree+0x28/0xc0
[ 8948.264594]        vfs_kern_mount.part.0+0x71/0xb0
[ 8948.265017]        btrfs_mount+0x11d/0x3a0 [btrfs]
[ 8948.265462]        legacy_get_tree+0x30/0x50
[ 8948.265851]        vfs_get_tree+0x28/0xc0
[ 8948.266203]        path_mount+0x2d4/0xbe0
[ 8948.266554]        __x64_sys_mount+0x103/0x140
[ 8948.266940]        do_syscall_64+0x3b/0xc0
[ 8948.267300]        entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 8948.267790]
               -> #0 (sb_internal#2){.+.+}-{0:0}:
[ 8948.268322]        __lock_acquire+0x12e8/0x2260
[ 8948.268733]        lock_acquire+0xd7/0x310
[ 8948.269092]        start_transaction+0x44c/0x6e0 [btrfs]
[ 8948.269591]        find_free_extent+0x141e/0x1590 [btrfs]
[ 8948.270087]        btrfs_reserve_extent+0x14b/0x280 [btrfs]
[ 8948.270588]        cow_file_range+0x17e/0x490 [btrfs]
[ 8948.271051]        btrfs_run_delalloc_range+0x345/0x7a0 [btrfs]
[ 8948.271586]        writepage_delalloc+0xb5/0x170 [btrfs]
[ 8948.272071]        __extent_writepage+0x156/0x3c0 [btrfs]
[ 8948.272579]        extent_write_cache_pages+0x263/0x460 [btrfs]
[ 8948.273113]        extent_writepages+0x76/0x130 [btrfs]
[ 8948.273573]        do_writepages+0xd2/0x1c0
[ 8948.273942]        filemap_fdatawrite_wbc+0x68/0x90
[ 8948.274371]        start_delalloc_inodes+0x17f/0x400 [btrfs]
[ 8948.274876]        btrfs_start_delalloc_roots+0x194/0x2a0 [btrfs]
[ 8948.275417]        flush_space+0x1f2/0x630 [btrfs]
[ 8948.275863]        btrfs_async_reclaim_data_space+0x108/0x1b0 [btrfs]
[ 8948.276438]        process_one_work+0x252/0x5a0
[ 8948.276829]        worker_thread+0x55/0x3b0
[ 8948.277189]        kthread+0xf2/0x120
[ 8948.277506]        ret_from_fork+0x22/0x30
[ 8948.277868]
               other info that might help us debug this:

[ 8948.278548] Chain exists of:
                 sb_internal#2 --> &fs_info->delalloc_root_mutex --> &root->delalloc_mutex

[ 8948.279601]  Possible unsafe locking scenario:

[ 8948.280102]        CPU0                    CPU1
[ 8948.280508]        ----                    ----
[ 8948.280915]   lock(&root->delalloc_mutex);
[ 8948.281271]                                lock(&fs_info->delalloc_root_mutex);
[ 8948.281915]                                lock(&root->delalloc_mutex);
[ 8948.282487]   lock(sb_internal#2);
[ 8948.282800]
                *** DEADLOCK ***

[ 8948.283333] 4 locks held by kworker/u16:18/933570:
[ 8948.283750]  #0: ffff9b3dc00a9d48 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1d2/0x5a0
[ 8948.284609]  #1: ffffa90349dafe70 ((work_completion)(&fs_info->async_data_reclaim_work)){+.+.}-{0:0}, at: process_one_work+0x1d2/0x5a0
[ 8948.285637]  #2: ffff9b3e14db5040 (&fs_info->delalloc_root_mutex){+.+.}-{3:3}, at: btrfs_start_delalloc_roots+0x97/0x2a0 [btrfs]
[ 8948.286674]  #3: ffff9b3e09c717d8 (&root->delalloc_mutex){+.+.}-{3:3}, at: start_delalloc_inodes+0x78/0x400 [btrfs]
[ 8948.287596]
              stack backtrace:
[ 8948.287975] CPU: 3 PID: 933570 Comm: kworker/u16:18 Not tainted 5.17.0-rc1-btrfs-next-111 #1
[ 8948.288677] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[ 8948.289649] Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs]
[ 8948.290298] Call Trace:
[ 8948.290517]  <TASK>
[ 8948.290700]  dump_stack_lvl+0x59/0x73
[ 8948.291026]  check_noncircular+0xf3/0x110
[ 8948.291375]  ? start_transaction+0x228/0x6e0 [btrfs]
[ 8948.291826]  __lock_acquire+0x12e8/0x2260
[ 8948.292241]  lock_acquire+0xd7/0x310
[ 8948.292714]  ? find_free_extent+0x141e/0x1590 [btrfs]
[ 8948.293241]  ? lock_is_held_type+0xea/0x140
[ 8948.293601]  start_transaction+0x44c/0x6e0 [btrfs]
[ 8948.294055]  ? find_free_extent+0x141e/0x1590 [btrfs]
[ 8948.294518]  find_free_extent+0x141e/0x1590 [btrfs]
[ 8948.294957]  ? _raw_spin_unlock+0x29/0x40
[ 8948.295312]  ? btrfs_get_alloc_profile+0x124/0x290 [btrfs]
[ 8948.295813]  btrfs_reserve_extent+0x14b/0x280 [btrfs]
[ 8948.296270]  cow_file_range+0x17e/0x490 [btrfs]
[ 8948.296691]  btrfs_run_delalloc_range+0x345/0x7a0 [btrfs]
[ 8948.297175]  ? find_lock_delalloc_range+0x247/0x270 [btrfs]
[ 8948.297678]  writepage_delalloc+0xb5/0x170 [btrfs]
[ 8948.298123]  __extent_writepage+0x156/0x3c0 [btrfs]
[ 8948.298570]  extent_write_cache_pages+0x263/0x460 [btrfs]
[ 8948.299061]  extent_writepages+0x76/0x130 [btrfs]
[ 8948.299495]  do_writepages+0xd2/0x1c0
[ 8948.299817]  ? sched_clock_cpu+0xd/0x110
[ 8948.300160]  ? lock_release+0x155/0x4a0
[ 8948.300494]  filemap_fdatawrite_wbc+0x68/0x90
[ 8948.300874]  ? do_raw_spin_unlock+0x4b/0xa0
[ 8948.301243]  start_delalloc_inodes+0x17f/0x400 [btrfs]
[ 8948.301706]  ? lock_release+0x155/0x4a0
[ 8948.302055]  btrfs_start_delalloc_roots+0x194/0x2a0 [btrfs]
[ 8948.302564]  flush_space+0x1f2/0x630 [btrfs]
[ 8948.302970]  btrfs_async_reclaim_data_space+0x108/0x1b0 [btrfs]
[ 8948.303510]  process_one_work+0x252/0x5a0
[ 8948.303860]  ? process_one_work+0x5a0/0x5a0
[ 8948.304221]  worker_thread+0x55/0x3b0
[ 8948.304543]  ? process_one_work+0x5a0/0x5a0
[ 8948.304904]  kthread+0xf2/0x120
[ 8948.305184]  ? kthread_complete_and_exit+0x20/0x20
[ 8948.305598]  ret_from_fork+0x22/0x30
[ 8948.305921]  </TASK>

It all comes from the fact that btrfs_start_delalloc_roots() takes the
delalloc_root_mutex, in the transaction commit path we are holding a
read lock on one of the superblock's freeze semaphores (via
sb_start_intwrite()), the async reclaim task can also do a call to
btrfs_start_delalloc_roots(), which ends up triggering writeback with
calls to filemap_fdatawrite_wbc(), resulting in extent allocation which
in turn can call btrfs_start_transaction(), which will result in taking
the freeze semaphore via sb_start_intwrite(), forming a nasty dependency
on all those locks which can be taken in different orders by different
code paths.

So just adopt the simple approach of calling try_to_writeback_inodes_sb()
at btrfs_start_delalloc_flush().

Link: https://lore.kernel.org/linux-btrfs/20220130005258.GA7465@cuci.nl/
Link: https://lore.kernel.org/linux-btrfs/43acc426-d683-d1b6-729d-c6bc4a2fff4d@gmail.com/
Link: https://lore.kernel.org/linux-btrfs/6833930a-08d7-6fbc-0141-eb9cdfd6bb4d@gmail.com/
Link: https://lore.kernel.org/linux-btrfs/20190322041731.GF16651@hungrycats.org/
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
[ add more link reports ]
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-02-09 18:53:26 +01:00
Qu Wenruo 0d1ffa2228 btrfs: defrag: don't try to defrag extents which are under writeback 
Once we start writeback (have called btrfs_run_delalloc_range()), we
allocate an extent, create an extent map point to that extent, with a
generation of (u64)-1, created the ordered extent and then clear the
DELALLOC bit from the range in the inode's io tree.

Such extent map can pass the first call of defrag_collect_targets(), as
its generation is (u64)-1, meets any possible minimal generation check.
And the range will not have DELALLOC bit, also passing the DELALLOC bit
check.

It will only be re-checked in the second call of
defrag_collect_targets(), which will wait for writeback.

But at that stage we have already spent our time waiting for some IO we
may or may not want to defrag.

Let's reject such extents early so we won't waste our time.

CC: stable@vger.kernel.org # 5.16
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-02-09 18:53:24 +01:00
Qu Wenruo ea0eba69a2 btrfs: don't hold CPU for too long when defragging a file 
There is a user report about "btrfs filesystem defrag" causing 120s
timeout problem.

For btrfs_defrag_file() it will iterate all file extents if called from
defrag ioctl, thus it can take a long time.

There is no reason not to release the CPU during such a long operation.

Add cond_resched() after defragged one cluster.

CC: stable@vger.kernel.org # 5.16
Link: https://lore.kernel.org/linux-btrfs/10e51417-2203-f0a4-2021-86c8511cc367@gmx.com
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-02-09 18:50:56 +01:00
Linus Torvalds 86286e486c for-5.17-rc2-tag 
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmH9eUcACgkQxWXV+ddt
 WDvCvQ//bANu7air/Og5r2Mn0ZYyrcQl+yDYE75UC/tzTZNNtP8guwGllwlcsA0v
 RQPiuFFtvjKMgKP6Eo1mVeUPkpX83VQkT+sqFRsFEFxazIXnSvEJ+iHVcuiZvgj1
 VkTjdt7/mLb573zSA0MLhJqK1BBuFhUTCCHFHlCLoiYeekPAui1pbUC4LAE/+ksU
 veCn9YS+NGkDpIv/b9mcALVBe+XkZlmw1LON8ArEbpY4ToafRk0qZfhV7CvyRbSP
 Y1zLUScNLHGoR2WA1WhwlwuMePdhgX/8neGNiXsiw3WnmZhFoUVX7oUa6IWnKkKk
 dD+x5Z3Z2xBQGK8djyqxzUFJ2VAvz15xGIM452ofGa1BJFZgV9hjPA6Y4RFdWx63
 4AZ6OJwhrXhgMtWBhRtM6mGeje56ljwaxku9qhe585z8H5V8ezUNwWVkjY0bLKsd
 iT3bUHEReoYRWuyszI1ZSm1DbyzNY2943ly97p/j8qKp4SHX39/QYAKmnuuHdIup
 TnTBJOh38rj4S8BfF873aKAo7EfLJcDbTcZ1ivbuX5FeByRuQB4F0c1RRi4usMLc
 DL5mhDhT71U1l/LF3IANQ4ieUfZbeFHd+dAVkYsGkYzzaWL8E03L582l/fqaVGsp
 RaVpiuKnh2cyDXUxob8IYT5mZ/saa96xBSK8VEqnwjNEQCzKEeU=
 =5MJl
 -----END PGP SIGNATURE-----

Merge tag 'for-5.17-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "A few fixes and error handling improvements:

   - fix deadlock between quota disable and qgroup rescan worker

   - fix use-after-free after failure to create a snapshot

   - skip warning on unmount after log cleanup failure

   - don't start transaction for scrub if the fs is mounted read-only

   - tree checker verifies item sizes"

* tag 'for-5.17-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: skip reserved bytes warning on unmount after log cleanup failure
  btrfs: fix use of uninitialized variable at rm device ioctl
  btrfs: fix use-after-free after failure to create a snapshot
  btrfs: tree-checker: check item_size for dev_item
  btrfs: tree-checker: check item_size for inode_item
  btrfs: fix deadlock between quota disable and qgroup rescan worker
  btrfs: don't start transaction for scrub if the fs is mounted read-only
 2022-02-04 12:14:58 -08:00
Christoph Hellwig abfc426d1b block: pass a block_device to bio_clone_fast 
Pass a block_device to bio_clone_fast and __bio_clone_fast and give
the functions more suitable names.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-14-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
 2022-02-04 07:43:18 -07:00
Christoph Hellwig a7c50c9404 block: pass a block_device and opf to bio_reset 
Pass the block_device that we plan to use this bio for and the
operation to bio_reset to optimize the assigment.  A NULL block_device
can be passed, both for the passthrough case on a raw request_queue and
to temporarily avoid refactoring some nasty code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-20-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
 2022-02-02 07:50:00 -07:00
Christoph Hellwig 07888c665b block: pass a block_device and opf to bio_alloc 
Pass the block_device and operation that we plan to use this bio for to
bio_alloc to optimize the assignment.  NULL/0 can be passed, both for the
passthrough case on a raw request_queue and to temporarily avoid
refactoring some nasty code.

Also move the gfp_mask argument after the nr_vecs argument for a much
more logical calling convention matching what most of the kernel does.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-18-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
 2022-02-02 07:49:59 -07:00
Christoph Hellwig 609be10667 block: pass a block_device and opf to bio_alloc_bioset 
Pass the block_device and operation that we plan to use this bio for to
bio_alloc_bioset to optimize the assigment.  NULL/0 can be passed, both
for the passthrough case on a raw request_queue and to temporarily avoid
refactoring some nasty code.

Also move the gfp_mask argument after the nr_vecs argument for a much
more logical calling convention matching what most of the kernel does.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-16-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
 2022-02-02 07:49:59 -07:00
Christoph Hellwig 322cbb50de block: remove genhd.h 
There is no good reason to keep genhd.h separate from the main blkdev.h
header that includes it.  So fold the contents of genhd.h into blkdev.h
and remove genhd.h entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20220124093913.742411-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
 2022-02-02 07:49:59 -07:00
Filipe Manana 40cdc50987 btrfs: skip reserved bytes warning on unmount after log cleanup failure 
After the recent changes made by commit c2e3930529 ("btrfs: clear
extent buffer uptodate when we fail to write it") and its followup fix,
commit 651740a502 ("btrfs: check WRITE_ERR when trying to read an
extent buffer"), we can now end up not cleaning up space reservations of
log tree extent buffers after a transaction abort happens, as well as not
cleaning up still dirty extent buffers.

This happens because if writeback for a log tree extent buffer failed,
then we have cleared the bit EXTENT_BUFFER_UPTODATE from the extent buffer
and we have also set the bit EXTENT_BUFFER_WRITE_ERR on it. Later on,
when trying to free the log tree with free_log_tree(), which iterates
over the tree, we can end up getting an -EIO error when trying to read
a node or a leaf, since read_extent_buffer_pages() returns -EIO if an
extent buffer does not have EXTENT_BUFFER_UPTODATE set and has the
EXTENT_BUFFER_WRITE_ERR bit set. Getting that -EIO means that we return
immediately as we can not iterate over the entire tree.

In that case we never update the reserved space for an extent buffer in
the respective block group and space_info object.

When this happens we get the following traces when unmounting the fs:

[174957.284509] BTRFS: error (device dm-0) in cleanup_transaction:1913: errno=-5 IO failure
[174957.286497] BTRFS: error (device dm-0) in free_log_tree:3420: errno=-5 IO failure
[174957.399379] ------------[ cut here ]------------
[174957.402497] WARNING: CPU: 2 PID: 3206883 at fs/btrfs/block-group.c:127 btrfs_put_block_group+0x77/0xb0 [btrfs]
[174957.407523] Modules linked in: btrfs overlay dm_zero (...)
[174957.424917] CPU: 2 PID: 3206883 Comm: umount Tainted: G        W         5.16.0-rc5-btrfs-next-109 #1
[174957.426689] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[174957.428716] RIP: 0010:btrfs_put_block_group+0x77/0xb0 [btrfs]
[174957.429717] Code: 21 48 8b bd (...)
[174957.432867] RSP: 0018:ffffb70d41cffdd0 EFLAGS: 00010206
[174957.433632] RAX: 0000000000000001 RBX: ffff8b09c3848000 RCX: ffff8b0758edd1c8
[174957.434689] RDX: 0000000000000001 RSI: ffffffffc0b467e7 RDI: ffff8b0758edd000
[174957.436068] RBP: ffff8b0758edd000 R08: 0000000000000000 R09: 0000000000000000
[174957.437114] R10: 0000000000000246 R11: 0000000000000000 R12: ffff8b09c3848148
[174957.438140] R13: ffff8b09c3848198 R14: ffff8b0758edd188 R15: dead000000000100
[174957.439317] FS:  00007f328fb82800(0000) GS:ffff8b0a2d200000(0000) knlGS:0000000000000000
[174957.440402] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[174957.441164] CR2: 00007fff13563e98 CR3: 0000000404f4e005 CR4: 0000000000370ee0
[174957.442117] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[174957.443076] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[174957.443948] Call Trace:
[174957.444264]  <TASK>
[174957.444538]  btrfs_free_block_groups+0x255/0x3c0 [btrfs]
[174957.445238]  close_ctree+0x301/0x357 [btrfs]
[174957.445803]  ? call_rcu+0x16c/0x290
[174957.446250]  generic_shutdown_super+0x74/0x120
[174957.446832]  kill_anon_super+0x14/0x30
[174957.447305]  btrfs_kill_super+0x12/0x20 [btrfs]
[174957.447890]  deactivate_locked_super+0x31/0xa0
[174957.448440]  cleanup_mnt+0x147/0x1c0
[174957.448888]  task_work_run+0x5c/0xa0
[174957.449336]  exit_to_user_mode_prepare+0x1e5/0x1f0
[174957.449934]  syscall_exit_to_user_mode+0x16/0x40
[174957.450512]  do_syscall_64+0x48/0xc0
[174957.450980]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[174957.451605] RIP: 0033:0x7f328fdc4a97
[174957.452059] Code: 03 0c 00 f7 (...)
[174957.454320] RSP: 002b:00007fff13564ec8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
[174957.455262] RAX: 0000000000000000 RBX: 00007f328feea264 RCX: 00007f328fdc4a97
[174957.456131] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000560b8ae51dd0
[174957.457118] RBP: 0000560b8ae51ba0 R08: 0000000000000000 R09: 00007fff13563c40
[174957.458005] R10: 00007f328fe49fc0 R11: 0000000000000246 R12: 0000000000000000
[174957.459113] R13: 0000560b8ae51dd0 R14: 0000560b8ae51cb0 R15: 0000000000000000
[174957.460193]  </TASK>
[174957.460534] irq event stamp: 0
[174957.461003] hardirqs last  enabled at (0): [<0000000000000000>] 0x0
[174957.461947] hardirqs last disabled at (0): [<ffffffffb0e94214>] copy_process+0x934/0x2040
[174957.463147] softirqs last  enabled at (0): [<ffffffffb0e94214>] copy_process+0x934/0x2040
[174957.465116] softirqs last disabled at (0): [<0000000000000000>] 0x0
[174957.466323] ---[ end trace bc7ee0c490bce3af ]---
[174957.467282] ------------[ cut here ]------------
[174957.468184] WARNING: CPU: 2 PID: 3206883 at fs/btrfs/block-group.c:3976 btrfs_free_block_groups+0x330/0x3c0 [btrfs]
[174957.470066] Modules linked in: btrfs overlay dm_zero (...)
[174957.483137] CPU: 2 PID: 3206883 Comm: umount Tainted: G        W         5.16.0-rc5-btrfs-next-109 #1
[174957.484691] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[174957.486853] RIP: 0010:btrfs_free_block_groups+0x330/0x3c0 [btrfs]
[174957.488050] Code: 00 00 00 ad de (...)
[174957.491479] RSP: 0018:ffffb70d41cffde0 EFLAGS: 00010206
[174957.492520] RAX: ffff8b08d79310b0 RBX: ffff8b09c3848000 RCX: 0000000000000000
[174957.493868] RDX: 0000000000000001 RSI: fffff443055ee600 RDI: ffffffffb1131846
[174957.495183] RBP: ffff8b08d79310b0 R08: 0000000000000000 R09: 0000000000000000
[174957.496580] R10: 0000000000000001 R11: 0000000000000000 R12: ffff8b08d7931000
[174957.498027] R13: ffff8b09c38492b0 R14: dead000000000122 R15: dead000000000100
[174957.499438] FS:  00007f328fb82800(0000) GS:ffff8b0a2d200000(0000) knlGS:0000000000000000
[174957.500990] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[174957.502117] CR2: 00007fff13563e98 CR3: 0000000404f4e005 CR4: 0000000000370ee0
[174957.503513] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[174957.504864] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[174957.506167] Call Trace:
[174957.506654]  <TASK>
[174957.507047]  close_ctree+0x301/0x357 [btrfs]
[174957.507867]  ? call_rcu+0x16c/0x290
[174957.508567]  generic_shutdown_super+0x74/0x120
[174957.509447]  kill_anon_super+0x14/0x30
[174957.510194]  btrfs_kill_super+0x12/0x20 [btrfs]
[174957.511123]  deactivate_locked_super+0x31/0xa0
[174957.511976]  cleanup_mnt+0x147/0x1c0
[174957.512610]  task_work_run+0x5c/0xa0
[174957.513309]  exit_to_user_mode_prepare+0x1e5/0x1f0
[174957.514231]  syscall_exit_to_user_mode+0x16/0x40
[174957.515069]  do_syscall_64+0x48/0xc0
[174957.515718]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[174957.516688] RIP: 0033:0x7f328fdc4a97
[174957.517413] Code: 03 0c 00 f7 d8 (...)
[174957.521052] RSP: 002b:00007fff13564ec8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
[174957.522514] RAX: 0000000000000000 RBX: 00007f328feea264 RCX: 00007f328fdc4a97
[174957.523950] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000560b8ae51dd0
[174957.525375] RBP: 0000560b8ae51ba0 R08: 0000000000000000 R09: 00007fff13563c40
[174957.526763] R10: 00007f328fe49fc0 R11: 0000000000000246 R12: 0000000000000000
[174957.528058] R13: 0000560b8ae51dd0 R14: 0000560b8ae51cb0 R15: 0000000000000000
[174957.529404]  </TASK>
[174957.529843] irq event stamp: 0
[174957.530256] hardirqs last  enabled at (0): [<0000000000000000>] 0x0
[174957.531061] hardirqs last disabled at (0): [<ffffffffb0e94214>] copy_process+0x934/0x2040
[174957.532075] softirqs last  enabled at (0): [<ffffffffb0e94214>] copy_process+0x934/0x2040
[174957.533083] softirqs last disabled at (0): [<0000000000000000>] 0x0
[174957.533865] ---[ end trace bc7ee0c490bce3b0 ]---
[174957.534452] BTRFS info (device dm-0): space_info 4 has 1070841856 free, is not full
[174957.535404] BTRFS info (device dm-0): space_info total=1073741824, used=2785280, pinned=0, reserved=49152, may_use=0, readonly=65536 zone_unusable=0
[174957.537029] BTRFS info (device dm-0): global_block_rsv: size 0 reserved 0
[174957.537859] BTRFS info (device dm-0): trans_block_rsv: size 0 reserved 0
[174957.538697] BTRFS info (device dm-0): chunk_block_rsv: size 0 reserved 0
[174957.539552] BTRFS info (device dm-0): delayed_block_rsv: size 0 reserved 0
[174957.540403] BTRFS info (device dm-0): delayed_refs_rsv: size 0 reserved 0

This also means that in case we have log tree extent buffers that are
still dirty, we can end up not cleaning them up in case we find an
extent buffer with EXTENT_BUFFER_WRITE_ERR set on it, as in that case
we have no way for iterating over the rest of the tree.

This issue is very often triggered with test cases generic/475 and
generic/648 from fstests.

The issue could almost be fixed by iterating over the io tree attached to
each log root which keeps tracks of the range of allocated extent buffers,
log_root->dirty_log_pages, however that does not work and has some
inconveniences:

1) After we sync the log, we clear the range of the extent buffers from
   the io tree, so we can't find them after writeback. We could keep the
   ranges in the io tree, with a separate bit to signal they represent
   extent buffers already written, but that means we need to hold into
   more memory until the transaction commits.

   How much more memory is used depends a lot on whether we are able to
   allocate contiguous extent buffers on disk (and how often) for a log
   tree - if we are able to, then a single extent state record can
   represent multiple extent buffers, otherwise we need multiple extent
   state record structures to track each extent buffer.
   In fact, my earlier approach did that:

   https://lore.kernel.org/linux-btrfs/3aae7c6728257c7ce2279d6660ee2797e5e34bbd.1641300250.git.fdmanana@suse.com/

   However that can cause a very significant negative impact on
   performance, not only due to the extra memory usage but also because
   we get a larger and deeper dirty_log_pages io tree.
   We got a report that, on beefy machines at least, we can get such
   performance drop with fsmark for example:

   https://lore.kernel.org/linux-btrfs/20220117082426.GE32491@xsang-OptiPlex-9020/

2) We would be doing it only to deal with an unexpected and exceptional
   case, which is basically failure to read an extent buffer from disk
   due to IO failures. On a healthy system we don't expect transaction
   aborts to happen after all;

3) Instead of relying on iterating the log tree or tracking the ranges
   of extent buffers in the dirty_log_pages io tree, using the radix
   tree that tracks extent buffers (fs_info->buffer_radix) to find all
   log tree extent buffers is not reliable either, because after writeback
   of an extent buffer it can be evicted from memory by the release page
   callback of the btree inode (btree_releasepage()).

Since there's no way to be able to properly cleanup a log tree without
being able to read its extent buffers from disk and without using more
memory to track the logical ranges of the allocated extent buffers do
the following:

1) When we fail to cleanup a log tree, setup a flag that indicates that
   failure;

2) Trigger writeback of all log tree extent buffers that are still dirty,
   and wait for the writeback to complete. This is just to cleanup their
   state, page states, page leaks, etc;

3) When unmounting the fs, ignore if the number of bytes reserved in a
   block group and in a space_info is not 0 if, and only if, we failed to
   cleanup a log tree. Also ignore only for metadata block groups and the
   metadata space_info object.

This is far from a perfect solution, but it serves to silence test
failures such as those from generic/475 and generic/648. However having
a non-zero value for the reserved bytes counters on unmount after a
transaction abort, is not such a terrible thing and it's completely
harmless, it does not affect the filesystem integrity in any way.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-31 16:06:50 +01:00
Tom Rix 37b4599547 btrfs: fix use of uninitialized variable at rm device ioctl 
Clang static analysis reports this problem
ioctl.c:3333:8: warning: 3rd function call argument is an
  uninitialized value
    ret = exclop_start_or_cancel_reloc(fs_info,

cancel is only set in one branch of an if-check and is always used.  So
initialize to false.

Fixes: 1a15eb724a ("btrfs: use btrfs_get_dev_args_from_path in dev removal ioctls")
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-31 16:06:21 +01:00
Filipe Manana 28b21c558a btrfs: fix use-after-free after failure to create a snapshot 
At ioctl.c:create_snapshot(), we allocate a pending snapshot structure and
then attach it to the transaction's list of pending snapshots. After that
we call btrfs_commit_transaction(), and if that returns an error we jump
to 'fail' label, where we kfree() the pending snapshot structure. This can
result in a later use-after-free of the pending snapshot:

1) We allocated the pending snapshot and added it to the transaction's
   list of pending snapshots;

2) We call btrfs_commit_transaction(), and it fails either at the first
   call to btrfs_run_delayed_refs() or btrfs_start_dirty_block_groups().
   In both cases, we don't abort the transaction and we release our
   transaction handle. We jump to the 'fail' label and free the pending
   snapshot structure. We return with the pending snapshot still in the
   transaction's list;

3) Another task commits the transaction. This time there's no error at
   all, and then during the transaction commit it accesses a pointer
   to the pending snapshot structure that the snapshot creation task
   has already freed, resulting in a user-after-free.

This issue could actually be detected by smatch, which produced the
following warning:

  fs/btrfs/ioctl.c:843 create_snapshot() warn: '&pending_snapshot->list' not removed from list

So fix this by not having the snapshot creation ioctl directly add the
pending snapshot to the transaction's list. Instead add the pending
snapshot to the transaction handle, and then at btrfs_commit_transaction()
we add the snapshot to the list only when we can guarantee that any error
returned after that point will result in a transaction abort, in which
case the ioctl code can safely free the pending snapshot and no one can
access it anymore.

CC: stable@vger.kernel.org # 5.10+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-31 16:06:09 +01:00
Su Yue ea1d1ca402 btrfs: tree-checker: check item_size for dev_item 
Check item size before accessing the device item to avoid out of bound
access, similar to inode_item check.

Signed-off-by: Su Yue <l@damenly.su>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-31 16:06:04 +01:00
Su Yue 0c982944af btrfs: tree-checker: check item_size for inode_item 
while mounting the crafted image, out-of-bounds access happens:

  [350.429619] UBSAN: array-index-out-of-bounds in fs/btrfs/struct-funcs.c:161:1
  [350.429636] index 1048096 is out of range for type 'page *[16]'
  [350.429650] CPU: 0 PID: 9 Comm: kworker/u8:1 Not tainted 5.16.0-rc4 #1
  [350.429652] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1.1 04/01/2014
  [350.429653] Workqueue: btrfs-endio-meta btrfs_work_helper [btrfs]
  [350.429772] Call Trace:
  [350.429774]  <TASK>
  [350.429776]  dump_stack_lvl+0x47/0x5c
  [350.429780]  ubsan_epilogue+0x5/0x50
  [350.429786]  __ubsan_handle_out_of_bounds+0x66/0x70
  [350.429791]  btrfs_get_16+0xfd/0x120 [btrfs]
  [350.429832]  check_leaf+0x754/0x1a40 [btrfs]
  [350.429874]  ? filemap_read+0x34a/0x390
  [350.429878]  ? load_balance+0x175/0xfc0
  [350.429881]  validate_extent_buffer+0x244/0x310 [btrfs]
  [350.429911]  btrfs_validate_metadata_buffer+0xf8/0x100 [btrfs]
  [350.429935]  end_bio_extent_readpage+0x3af/0x850 [btrfs]
  [350.429969]  ? newidle_balance+0x259/0x480
  [350.429972]  end_workqueue_fn+0x29/0x40 [btrfs]
  [350.429995]  btrfs_work_helper+0x71/0x330 [btrfs]
  [350.430030]  ? __schedule+0x2fb/0xa40
  [350.430033]  process_one_work+0x1f6/0x400
  [350.430035]  ? process_one_work+0x400/0x400
  [350.430036]  worker_thread+0x2d/0x3d0
  [350.430037]  ? process_one_work+0x400/0x400
  [350.430038]  kthread+0x165/0x190
  [350.430041]  ? set_kthread_struct+0x40/0x40
  [350.430043]  ret_from_fork+0x1f/0x30
  [350.430047]  </TASK>
  [350.430077] BTRFS warning (device loop0): bad eb member start: ptr 0xffe20f4e start 20975616 member offset 4293005178 size 2

check_leaf() is checking the leaf:

  corrupt leaf: root=4 block=29396992 slot=1, bad key order, prev (16140901064495857664 1 0) current (1 204 12582912)
  leaf 29396992 items 6 free space 3565 generation 6 owner DEV_TREE
  leaf 29396992 flags 0x1(WRITTEN) backref revision 1
  fs uuid a62e00e8-e94e-4200-8217-12444de93c2e
  chunk uuid cecbd0f7-9ca0-441e-ae9f-f782f9732bd8
	  item 0 key (16140901064495857664 INODE_ITEM 0) itemoff 3955 itemsize 40
		  generation 0 transid 0 size 0 nbytes 17592186044416
		  block group 0 mode 52667 links 33 uid 0 gid 2104132511 rdev 94223634821136
		  sequence 100305 flags 0x2409000(none)
		  atime 0.0 (1970-01-01 08:00:00)
		  ctime 2973280098083405823.4294967295 (-269783007-01-01 21:37:03)
		  mtime 18446744071572723616.4026825121 (1902-04-16 12:40:00)
		  otime 9249929404488876031.4294967295 (622322949-04-16 04:25:58)
	  item 1 key (1 DEV_EXTENT 12582912) itemoff 3907 itemsize 48
		  dev extent chunk_tree 3
		  chunk_objectid 256 chunk_offset 12582912 length 8388608
		  chunk_tree_uuid cecbd0f7-9ca0-441e-ae9f-f782f9732bd8

The corrupted leaf of device tree has an inode item. The leaf passed
checksum and others checks in validate_extent_buffer until check_leaf_item().
Because of the key type BTRFS_INODE_ITEM, check_inode_item() is called even we
are in the device tree. Since the
item offset + sizeof(struct btrfs_inode_item) > eb->len, out-of-bounds access
is triggered.

The item end vs leaf boundary check has been done before
check_leaf_item(), so fix it by checking item size in check_inode_item()
before access of the inode item in extent buffer.

Other check functions except check_dev_item() in check_leaf_item()
have their item size checks.
The commit for check_dev_item() is followed.

No regression observed during running fstests.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=215299
CC: stable@vger.kernel.org # 5.10+
CC: Wenqing Liu <wenqingliu0120@gmail.com>
Signed-off-by: Su Yue <l@damenly.su>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-31 16:05:54 +01:00
Shin'ichiro Kawasaki e804861bd4 btrfs: fix deadlock between quota disable and qgroup rescan worker 
Quota disable ioctl starts a transaction before waiting for the qgroup
rescan worker completes. However, this wait can be infinite and results
in deadlock because of circular dependency among the quota disable
ioctl, the qgroup rescan worker and the other task with transaction such
as block group relocation task.

The deadlock happens with the steps following:

1) Task A calls ioctl to disable quota. It starts a transaction and
   waits for qgroup rescan worker completes.
2) Task B such as block group relocation task starts a transaction and
   joins to the transaction that task A started. Then task B commits to
   the transaction. In this commit, task B waits for a commit by task A.
3) Task C as the qgroup rescan worker starts its job and starts a
   transaction. In this transaction start, task C waits for completion
   of the transaction that task A started and task B committed.

This deadlock was found with fstests test case btrfs/115 and a zoned
null_blk device. The test case enables and disables quota, and the
block group reclaim was triggered during the quota disable by chance.
The deadlock was also observed by running quota enable and disable in
parallel with 'btrfs balance' command on regular null_blk devices.

An example report of the deadlock:

  [372.469894] INFO: task kworker/u16:6:103 blocked for more than 122 seconds.
  [372.479944]       Not tainted 5.16.0-rc8 #7
  [372.485067] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [372.493898] task:kworker/u16:6   state:D stack:    0 pid:  103 ppid:     2 flags:0x00004000
  [372.503285] Workqueue: btrfs-qgroup-rescan btrfs_work_helper [btrfs]
  [372.510782] Call Trace:
  [372.514092]  <TASK>
  [372.521684]  __schedule+0xb56/0x4850
  [372.530104]  ? io_schedule_timeout+0x190/0x190
  [372.538842]  ? lockdep_hardirqs_on+0x7e/0x100
  [372.547092]  ? _raw_spin_unlock_irqrestore+0x3e/0x60
  [372.555591]  schedule+0xe0/0x270
  [372.561894]  btrfs_commit_transaction+0x18bb/0x2610 [btrfs]
  [372.570506]  ? btrfs_apply_pending_changes+0x50/0x50 [btrfs]
  [372.578875]  ? free_unref_page+0x3f2/0x650
  [372.585484]  ? finish_wait+0x270/0x270
  [372.591594]  ? release_extent_buffer+0x224/0x420 [btrfs]
  [372.599264]  btrfs_qgroup_rescan_worker+0xc13/0x10c0 [btrfs]
  [372.607157]  ? lock_release+0x3a9/0x6d0
  [372.613054]  ? btrfs_qgroup_account_extent+0xda0/0xda0 [btrfs]
  [372.620960]  ? do_raw_spin_lock+0x11e/0x250
  [372.627137]  ? rwlock_bug.part.0+0x90/0x90
  [372.633215]  ? lock_is_held_type+0xe4/0x140
  [372.639404]  btrfs_work_helper+0x1ae/0xa90 [btrfs]
  [372.646268]  process_one_work+0x7e9/0x1320
  [372.652321]  ? lock_release+0x6d0/0x6d0
  [372.658081]  ? pwq_dec_nr_in_flight+0x230/0x230
  [372.664513]  ? rwlock_bug.part.0+0x90/0x90
  [372.670529]  worker_thread+0x59e/0xf90
  [372.676172]  ? process_one_work+0x1320/0x1320
  [372.682440]  kthread+0x3b9/0x490
  [372.687550]  ? _raw_spin_unlock_irq+0x24/0x50
  [372.693811]  ? set_kthread_struct+0x100/0x100
  [372.700052]  ret_from_fork+0x22/0x30
  [372.705517]  </TASK>
  [372.709747] INFO: task btrfs-transacti:2347 blocked for more than 123 seconds.
  [372.729827]       Not tainted 5.16.0-rc8 #7
  [372.745907] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [372.767106] task:btrfs-transacti state:D stack:    0 pid: 2347 ppid:     2 flags:0x00004000
  [372.787776] Call Trace:
  [372.801652]  <TASK>
  [372.812961]  __schedule+0xb56/0x4850
  [372.830011]  ? io_schedule_timeout+0x190/0x190
  [372.852547]  ? lockdep_hardirqs_on+0x7e/0x100
  [372.871761]  ? _raw_spin_unlock_irqrestore+0x3e/0x60
  [372.886792]  schedule+0xe0/0x270
  [372.901685]  wait_current_trans+0x22c/0x310 [btrfs]
  [372.919743]  ? btrfs_put_transaction+0x3d0/0x3d0 [btrfs]
  [372.938923]  ? finish_wait+0x270/0x270
  [372.959085]  ? join_transaction+0xc75/0xe30 [btrfs]
  [372.977706]  start_transaction+0x938/0x10a0 [btrfs]
  [372.997168]  transaction_kthread+0x19d/0x3c0 [btrfs]
  [373.013021]  ? btrfs_cleanup_transaction.isra.0+0xfc0/0xfc0 [btrfs]
  [373.031678]  kthread+0x3b9/0x490
  [373.047420]  ? _raw_spin_unlock_irq+0x24/0x50
  [373.064645]  ? set_kthread_struct+0x100/0x100
  [373.078571]  ret_from_fork+0x22/0x30
  [373.091197]  </TASK>
  [373.105611] INFO: task btrfs:3145 blocked for more than 123 seconds.
  [373.114147]       Not tainted 5.16.0-rc8 #7
  [373.120401] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [373.130393] task:btrfs           state:D stack:    0 pid: 3145 ppid:  3141 flags:0x00004000
  [373.140998] Call Trace:
  [373.145501]  <TASK>
  [373.149654]  __schedule+0xb56/0x4850
  [373.155306]  ? io_schedule_timeout+0x190/0x190
  [373.161965]  ? lockdep_hardirqs_on+0x7e/0x100
  [373.168469]  ? _raw_spin_unlock_irqrestore+0x3e/0x60
  [373.175468]  schedule+0xe0/0x270
  [373.180814]  wait_for_commit+0x104/0x150 [btrfs]
  [373.187643]  ? test_and_set_bit+0x20/0x20 [btrfs]
  [373.194772]  ? kmem_cache_free+0x124/0x550
  [373.201191]  ? btrfs_put_transaction+0x69/0x3d0 [btrfs]
  [373.208738]  ? finish_wait+0x270/0x270
  [373.214704]  ? __btrfs_end_transaction+0x347/0x7b0 [btrfs]
  [373.222342]  btrfs_commit_transaction+0x44d/0x2610 [btrfs]
  [373.230233]  ? join_transaction+0x255/0xe30 [btrfs]
  [373.237334]  ? btrfs_record_root_in_trans+0x4d/0x170 [btrfs]
  [373.245251]  ? btrfs_apply_pending_changes+0x50/0x50 [btrfs]
  [373.253296]  relocate_block_group+0x105/0xc20 [btrfs]
  [373.260533]  ? mutex_lock_io_nested+0x1270/0x1270
  [373.267516]  ? btrfs_wait_nocow_writers+0x85/0x180 [btrfs]
  [373.275155]  ? merge_reloc_roots+0x710/0x710 [btrfs]
  [373.283602]  ? btrfs_wait_ordered_extents+0xd30/0xd30 [btrfs]
  [373.291934]  ? kmem_cache_free+0x124/0x550
  [373.298180]  btrfs_relocate_block_group+0x35c/0x930 [btrfs]
  [373.306047]  btrfs_relocate_chunk+0x85/0x210 [btrfs]
  [373.313229]  btrfs_balance+0x12f4/0x2d20 [btrfs]
  [373.320227]  ? lock_release+0x3a9/0x6d0
  [373.326206]  ? btrfs_relocate_chunk+0x210/0x210 [btrfs]
  [373.333591]  ? lock_is_held_type+0xe4/0x140
  [373.340031]  ? rcu_read_lock_sched_held+0x3f/0x70
  [373.346910]  btrfs_ioctl_balance+0x548/0x700 [btrfs]
  [373.354207]  btrfs_ioctl+0x7f2/0x71b0 [btrfs]
  [373.360774]  ? lockdep_hardirqs_on_prepare+0x410/0x410
  [373.367957]  ? lockdep_hardirqs_on_prepare+0x410/0x410
  [373.375327]  ? btrfs_ioctl_get_supported_features+0x20/0x20 [btrfs]
  [373.383841]  ? find_held_lock+0x2c/0x110
  [373.389993]  ? lock_release+0x3a9/0x6d0
  [373.395828]  ? mntput_no_expire+0xf7/0xad0
  [373.402083]  ? lock_is_held_type+0xe4/0x140
  [373.408249]  ? vfs_fileattr_set+0x9f0/0x9f0
  [373.414486]  ? selinux_file_ioctl+0x349/0x4e0
  [373.420938]  ? trace_raw_output_lock+0xb4/0xe0
  [373.427442]  ? selinux_inode_getsecctx+0x80/0x80
  [373.434224]  ? lockdep_hardirqs_on+0x7e/0x100
  [373.440660]  ? force_qs_rnp+0x2a0/0x6b0
  [373.446534]  ? lock_is_held_type+0x9b/0x140
  [373.452763]  ? __blkcg_punt_bio_submit+0x1b0/0x1b0
  [373.459732]  ? security_file_ioctl+0x50/0x90
  [373.466089]  __x64_sys_ioctl+0x127/0x190
  [373.472022]  do_syscall_64+0x3b/0x90
  [373.477513]  entry_SYSCALL_64_after_hwframe+0x44/0xae
  [373.484823] RIP: 0033:0x7f8f4af7e2bb
  [373.490493] RSP: 002b:00007ffcbf936178 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
  [373.500197] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f8f4af7e2bb
  [373.509451] RDX: 00007ffcbf936220 RSI: 00000000c4009420 RDI: 0000000000000003
  [373.518659] RBP: 00007ffcbf93774a R08: 0000000000000013 R09: 00007f8f4b02d4e0
  [373.527872] R10: 00007f8f4ae87740 R11: 0000000000000246 R12: 0000000000000001
  [373.537222] R13: 00007ffcbf936220 R14: 0000000000000000 R15: 0000000000000002
  [373.546506]  </TASK>
  [373.550878] INFO: task btrfs:3146 blocked for more than 123 seconds.
  [373.559383]       Not tainted 5.16.0-rc8 #7
  [373.565748] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [373.575748] task:btrfs           state:D stack:    0 pid: 3146 ppid:  2168 flags:0x00000000
  [373.586314] Call Trace:
  [373.590846]  <TASK>
  [373.595121]  __schedule+0xb56/0x4850
  [373.600901]  ? __lock_acquire+0x23db/0x5030
  [373.607176]  ? io_schedule_timeout+0x190/0x190
  [373.613954]  schedule+0xe0/0x270
  [373.619157]  schedule_timeout+0x168/0x220
  [373.625170]  ? usleep_range_state+0x150/0x150
  [373.631653]  ? mark_held_locks+0x9e/0xe0
  [373.637767]  ? do_raw_spin_lock+0x11e/0x250
  [373.643993]  ? lockdep_hardirqs_on_prepare+0x17b/0x410
  [373.651267]  ? _raw_spin_unlock_irq+0x24/0x50
  [373.657677]  ? lockdep_hardirqs_on+0x7e/0x100
  [373.664103]  wait_for_completion+0x163/0x250
  [373.670437]  ? bit_wait_timeout+0x160/0x160
  [373.676585]  btrfs_quota_disable+0x176/0x9a0 [btrfs]
  [373.683979]  ? btrfs_quota_enable+0x12f0/0x12f0 [btrfs]
  [373.691340]  ? down_write+0xd0/0x130
  [373.696880]  ? down_write_killable+0x150/0x150
  [373.703352]  btrfs_ioctl+0x3945/0x71b0 [btrfs]
  [373.710061]  ? find_held_lock+0x2c/0x110
  [373.716192]  ? lock_release+0x3a9/0x6d0
  [373.722047]  ? __handle_mm_fault+0x23cd/0x3050
  [373.728486]  ? btrfs_ioctl_get_supported_features+0x20/0x20 [btrfs]
  [373.737032]  ? set_pte+0x6a/0x90
  [373.742271]  ? do_raw_spin_unlock+0x55/0x1f0
  [373.748506]  ? lock_is_held_type+0xe4/0x140
  [373.754792]  ? vfs_fileattr_set+0x9f0/0x9f0
  [373.761083]  ? selinux_file_ioctl+0x349/0x4e0
  [373.767521]  ? selinux_inode_getsecctx+0x80/0x80
  [373.774247]  ? __up_read+0x182/0x6e0
  [373.780026]  ? count_memcg_events.constprop.0+0x46/0x60
  [373.787281]  ? up_write+0x460/0x460
  [373.792932]  ? security_file_ioctl+0x50/0x90
  [373.799232]  __x64_sys_ioctl+0x127/0x190
  [373.805237]  do_syscall_64+0x3b/0x90
  [373.810947]  entry_SYSCALL_64_after_hwframe+0x44/0xae
  [373.818102] RIP: 0033:0x7f1383ea02bb
  [373.823847] RSP: 002b:00007fffeb4d71f8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
  [373.833641] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1383ea02bb
  [373.842961] RDX: 00007fffeb4d7210 RSI: 00000000c0109428 RDI: 0000000000000003
  [373.852179] RBP: 0000000000000003 R08: 0000000000000003 R09: 0000000000000078
  [373.861408] R10: 00007f1383daec78 R11: 0000000000000202 R12: 00007fffeb4d874a
  [373.870647] R13: 0000000000493099 R14: 0000000000000001 R15: 0000000000000000
  [373.879838]  </TASK>
  [373.884018]
               Showing all locks held in the system:
  [373.894250] 3 locks held by kworker/4:1/58:
  [373.900356] 1 lock held by khungtaskd/63:
  [373.906333]  #0: ffffffff8945ff60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260
  [373.917307] 3 locks held by kworker/u16:6/103:
  [373.923938]  #0: ffff888127b4f138 ((wq_completion)btrfs-qgroup-rescan){+.+.}-{0:0}, at: process_one_work+0x712/0x1320
  [373.936555]  #1: ffff88810b817dd8 ((work_completion)(&work->normal_work)){+.+.}-{0:0}, at: process_one_work+0x73f/0x1320
  [373.951109]  #2: ffff888102dd4650 (sb_internal#2){.+.+}-{0:0}, at: btrfs_qgroup_rescan_worker+0x1f6/0x10c0 [btrfs]
  [373.964027] 2 locks held by less/1803:
  [373.969982]  #0: ffff88813ed56098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80
  [373.981295]  #1: ffffc90000b3b2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x9e2/0x1060
  [373.992969] 1 lock held by btrfs-transacti/2347:
  [373.999893]  #0: ffff88813d4887a8 (&fs_info->transaction_kthread_mutex){+.+.}-{3:3}, at: transaction_kthread+0xe3/0x3c0 [btrfs]
  [374.015872] 3 locks held by btrfs/3145:
  [374.022298]  #0: ffff888102dd4460 (sb_writers#18){.+.+}-{0:0}, at: btrfs_ioctl_balance+0xc3/0x700 [btrfs]
  [374.034456]  #1: ffff88813d48a0a0 (&fs_info->reclaim_bgs_lock){+.+.}-{3:3}, at: btrfs_balance+0xfe5/0x2d20 [btrfs]
  [374.047646]  #2: ffff88813d488838 (&fs_info->cleaner_mutex){+.+.}-{3:3}, at: btrfs_relocate_block_group+0x354/0x930 [btrfs]
  [374.063295] 4 locks held by btrfs/3146:
  [374.069647]  #0: ffff888102dd4460 (sb_writers#18){.+.+}-{0:0}, at: btrfs_ioctl+0x38b1/0x71b0 [btrfs]
  [374.081601]  #1: ffff88813d488bb8 (&fs_info->subvol_sem){+.+.}-{3:3}, at: btrfs_ioctl+0x38fd/0x71b0 [btrfs]
  [374.094283]  #2: ffff888102dd4650 (sb_internal#2){.+.+}-{0:0}, at: btrfs_quota_disable+0xc8/0x9a0 [btrfs]
  [374.106885]  #3: ffff88813d489800 (&fs_info->qgroup_ioctl_lock){+.+.}-{3:3}, at: btrfs_quota_disable+0xd5/0x9a0 [btrfs]

  [374.126780] =============================================

To avoid the deadlock, wait for the qgroup rescan worker to complete
before starting the transaction for the quota disable ioctl. Clear
BTRFS_FS_QUOTA_ENABLE flag before the wait and the transaction to
request the worker to complete. On transaction start failure, set the
BTRFS_FS_QUOTA_ENABLE flag again. These BTRFS_FS_QUOTA_ENABLE flag
changes can be done safely since the function btrfs_quota_disable is not
called concurrently because of fs_info->subvol_sem.

Also check the BTRFS_FS_QUOTA_ENABLE flag in qgroup_rescan_init to avoid
another qgroup rescan worker to start after the previous qgroup worker
completed.

CC: stable@vger.kernel.org # 5.4+
Suggested-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-31 16:05:44 +01:00
Qu Wenruo 2d192fc4c1 btrfs: don't start transaction for scrub if the fs is mounted read-only 
[BUG]
The following super simple script would crash btrfs at unmount time, if
CONFIG_BTRFS_ASSERT() is set.

 mkfs.btrfs -f $dev
 mount $dev $mnt
 xfs_io -f -c "pwrite 0 4k" $mnt/file
 umount $mnt
 mount -r ro $dev $mnt
 btrfs scrub start -Br $mnt
 umount $mnt

This will trigger the following ASSERT() introduced by commit
0a31daa4b6 ("btrfs: add assertion for empty list of transactions at
late stage of umount").

That patch is definitely not the cause, it just makes enough noise for
developers.

[CAUSE]
We will start transaction for the following call chain during scrub:

  scrub_enumerate_chunks()
  |- btrfs_inc_block_group_ro()
     |- btrfs_join_transaction()

However for RO mount, there is no running transaction at all, thus
btrfs_join_transaction() will start a new transaction.

Furthermore, since it's read-only mount, btrfs_sync_fs() will not call
btrfs_commit_super() to commit the new but empty transaction.

And leads to the ASSERT().

The bug has been there for a long time. Only the new ASSERT() makes it
noisy enough to be noticed.

[FIX]
For read-only scrub on read-only mount, there is no need to start a
transaction nor to allocate new chunks in btrfs_inc_block_group_ro().

Just do extra read-only mount check in btrfs_inc_block_group_ro(), and
if it's read-only, skip all chunk allocation and go inc_block_group_ro()
directly.

CC: stable@vger.kernel.org # 5.4+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-31 16:05:16 +01:00
Linus Torvalds 4897e722b5 \n 
-----BEGIN PGP SIGNATURE-----
 
 iQEzBAABCAAdFiEEq1nRK9aeMoq1VSgcnJ2qBz9kQNkFAmHz0QsACgkQnJ2qBz9k
 QNkN+AgA6XqWHKYyElfgJFt1UqaoNMz/Faz9H/+PKiBNSTf6/+67D+V7DFz6jJrv
 dDwHNzfDg9kR+pbAAPwhl2jfnQoUlsr019Hrqa5HpWlj5geVpbdunYUzS2WOkwqD
 /m+brcLgPdKb2uIysj6wOh9B7wa8V9ksl3EjQvvwaHaU0p1YLUqidVXucYvs8DUo
 bgXNaj9GmeysxnmU+aILotWuuXH2vOP4Q2Uk4qz3rN6xW9eEXtpQ4y7gWBp/GA8y
 Ia8FtFdQdvlSDOJYMdPOTBu5RB7gY9ElrapvVaWNYtCWI/jRv666nZsLaERYNhLN
 uUsG4MWjYbOqW5XqFDbSOwbDqvMh5Q==
 =mEFA
 -----END PGP SIGNATURE-----

Merge tag 'fsnotify_for_v5.17-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

Pull fsnotify fixes from Jan Kara:
 "Fixes for userspace breakage caused by fsnotify changes ~3 years ago
  and one fanotify cleanup"

* tag 'fsnotify_for_v5.17-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  fsnotify: fix fsnotify hooks in pseudo filesystems
  fsnotify: invalidate dcache before IN_DELETE event
  fanotify: remove variable set but not used
 2022-01-28 17:51:31 +02:00
Linus Torvalds 49d766f3a0 for-5.17-rc1-tag 
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmHwDeMACgkQxWXV+ddt
 WDtdMQ//QFqkIB34zW5N3uX1xBFht/G/bCPNdGiK5YerjJZj1f6Rmsytbb6qlWHg
 NlB/XEPeQaQVrSfF37svnvATgySPaqePsufrT2XYu3x2w8muPTl460wmzdMt5h47
 rGB+ct4JdLBH4KJgqe2Bilrqg+FJmL3XT5k0aU3driy4Gb+bcDGeEyVmTWcnNRIg
 DzfUlNwTKhAhZDl8D3B9X2vV8TZDBtrRLquI94eYvooF3LYDL+kExLUW8WDmmAfy
 mjnANs8c+EtcVAzN7tW+O1UqdYYJ8Yo4ngk1nVVRdRvA2BDp9ixgWi/m/3jZ3JmJ
 jySV1zsZJB3ZGp/hIuEvtGY7jheDtbTnfgtI+vwjVdr208acs+XhfDckuOZBZIUY
 7Zk+Qif/narxFAoAvkgkH5QDNSSReKqaHgzohfnzSQqrfO0bh6fw1FnBOm4iXT7C
 cXvReD4m36g46SdTsxnvttpXizXIFe4JPOkpRkBzxIQFaMTA4Is43W0lYC24Ppxj
 A0UVevh3HPhOYzABynuy0EnknZeylb6P+WpGG6Ge+sVrVquQiwR01n4HeoaJO3qe
 re46uUGwO8Q30blYY50HBSJp0bpcciPZRVMJaspcAT9KD0fJ1s/csd2lQyP4ewn6
 A0zg6eabc0PD3LwdlHqp//jTNft/BL4RVZ2c3uM+mgXnGeekcoQ=
 =EysX
 -----END PGP SIGNATURE-----

Merge tag 'for-5.17-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "Several fixes for defragmentation that got broken in 5.16 after
  refactoring and added subpage support. The observed bugs are excessive
  IO or uninterruptible ioctl.

  All stable material"

* tag 'for-5.17-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: update writeback index when starting defrag
  btrfs: add back missing dirty page rate limiting to defrag
  btrfs: fix deadlock when reserving space during defrag
  btrfs: defrag: properly update range->start for autodefrag
  btrfs: defrag: fix wrong number of defragged sectors
  btrfs: allow defrag to be interruptible
  btrfs: fix too long loop when defragging a 1 byte file
 2022-01-25 18:29:10 +02:00
Filipe Manana 27cdfde181 btrfs: update writeback index when starting defrag 
When starting a defrag, we should update the writeback index of the
inode's mapping in case it currently has a value beyond the start of the
range we are defragging. This can help performance and often result in
getting less extents after writeback - for e.g., if the current value
of the writeback index sits somewhere in the middle of a range that
gets dirty by the defrag, then after writeback we can get two smaller
extents instead of a single, larger extent.

We used to have this before the refactoring in 5.16, but it was removed
without any reason to do so. Originally it was added in kernel 3.1, by
commit 2a0f7f5769 ("Btrfs: fix recursive auto-defrag"), in order to
fix a loop with autodefrag resulting in dirtying and writing pages over
and over, but some testing on current code did not show that happening,
at least with the test described in that commit.

So add back the behaviour, as at the very least it is a nice to have
optimization.

Fixes: 7b508037d4 ("btrfs: defrag: use defrag_one_cluster() to implement btrfs_defrag_file()")
CC: stable@vger.kernel.org # 5.16
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-24 18:16:28 +01:00
Filipe Manana 3c9d31c715 btrfs: add back missing dirty page rate limiting to defrag 
A defrag operation can dirty a lot of pages, specially if operating on
the entire file or a large file range. Any task dirtying pages should
periodically call balance_dirty_pages_ratelimited(), as stated in that
function's comments, otherwise they can leave too many dirty pages in
the system. This is what we did before the refactoring in 5.16, and
it should have remained, just like in the buffered write path and
relocation. So restore that behaviour.

Fixes: 7b508037d4 ("btrfs: defrag: use defrag_one_cluster() to implement btrfs_defrag_file()")
CC: stable@vger.kernel.org # 5.16
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-24 18:10:56 +01:00
Filipe Manana 0cb5950f3f btrfs: fix deadlock when reserving space during defrag 
When defragging we can end up collecting a range for defrag that has
already pages under delalloc (dirty), as long as the respective extent
map for their range is not mapped to a hole, a prealloc extent or
the extent map is from an old generation.

Most of the time that is harmless from a functional perspective at
least, however it can result in a deadlock:

1) At defrag_collect_targets() we find an extent map that meets all
   requirements but there's delalloc for the range it covers, and we add
   its range to list of ranges to defrag;

2) The defrag_collect_targets() function is called at defrag_one_range(),
   after it locked a range that overlaps the range of the extent map;

3) At defrag_one_range(), while the range is still locked, we call
   defrag_one_locked_target() for the range associated to the extent
   map we collected at step 1);

4) Then finally at defrag_one_locked_target() we do a call to
   btrfs_delalloc_reserve_space(), which will reserve data and metadata
   space. If the space reservations can not be satisfied right away, the
   flusher might be kicked in and start flushing delalloc and wait for
   the respective ordered extents to complete. If this happens we will
   deadlock, because both flushing delalloc and finishing an ordered
   extent, requires locking the range in the inode's io tree, which was
   already locked at defrag_collect_targets().

So fix this by skipping extent maps for which there's already delalloc.

Fixes: eb793cf857 ("btrfs: defrag: introduce helper to collect target file extents")
CC: stable@vger.kernel.org # 5.16
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-24 18:10:52 +01:00
Amir Goldstein a37d9a17f0 fsnotify: invalidate dcache before IN_DELETE event 
Apparently, there are some applications that use IN_DELETE event as an
invalidation mechanism and expect that if they try to open a file with
the name reported with the delete event, that it should not contain the
content of the deleted file.

Commit 49246466a9 ("fsnotify: move fsnotify_nameremove() hook out of
d_delete()") moved the fsnotify delete hook before d_delete() so fsnotify
will have access to a positive dentry.

This allowed a race where opening the deleted file via cached dentry
is now possible after receiving the IN_DELETE event.

To fix the regression, create a new hook fsnotify_delete() that takes
the unlinked inode as an argument and use a helper d_delete_notify() to
pin the inode, so we can pass it to fsnotify_delete() after d_delete().

Backporting hint: this regression is from v5.3. Although patch will
apply with only trivial conflicts to v5.4 and v5.10, it won't build,
because fsnotify_delete() implementation is different in each of those
versions (see fsnotify_link()).

A follow up patch will fix the fsnotify_unlink/rmdir() calls in pseudo
filesystem that do not need to call d_delete().

Link: https://lore.kernel.org/r/20220120215305.282577-1-amir73il@gmail.com
Reported-by: Ivan Delalande <colona@arista.com>
Link: https://lore.kernel.org/linux-fsdevel/YeNyzoDM5hP5LtGW@visor/
Fixes: 49246466a9 ("fsnotify: move fsnotify_nameremove() hook out of d_delete()")
Cc: stable@vger.kernel.org # v5.3+
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
 2022-01-24 14:16:46 +01:00
Christoph Hellwig 0a4ee51818 mm: remove cleancache 
Patch series "remove Xen tmem leftovers".

Since the removal of the Xen tmem driver in 2019, the cleancache hooks
are entirely unused, as are large parts of frontswap.  This series
against linux-next (with the folio changes included) removes
cleancaches, and cuts down frontswap to the bits actually used by zswap.

This patch (of 13):

The cleancache subsystem is unused since the removal of Xen tmem driver
in commit 814bbf49dc ("xen: remove tmem driver").

[akpm@linux-foundation.org: remove now-unreachable code]

Link: https://lkml.kernel.org/r/20211224062246.1258487-1-hch@lst.de
Link: https://lkml.kernel.org/r/20211224062246.1258487-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2022-01-22 08:33:38 +02:00
Linus Torvalds f4484d138b Merge branch 'akpm' (patches from Andrew) 
Merge more updates from Andrew Morton:
 "55 patches.

  Subsystems affected by this patch series: percpu, procfs, sysctl,
  misc, core-kernel, get_maintainer, lib, checkpatch, binfmt, nilfs2,
  hfs, fat, adfs, panic, delayacct, kconfig, kcov, and ubsan"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (55 commits)
  lib: remove redundant assignment to variable ret
  ubsan: remove CONFIG_UBSAN_OBJECT_SIZE
  kcov: fix generic Kconfig dependencies if ARCH_WANTS_NO_INSTR
  lib/Kconfig.debug: make TEST_KMOD depend on PAGE_SIZE_LESS_THAN_256KB
  btrfs: use generic Kconfig option for 256kB page size limit
  arch/Kconfig: split PAGE_SIZE_LESS_THAN_256KB from PAGE_SIZE_LESS_THAN_64KB
  configs: introduce debug.config for CI-like setup
  delayacct: track delays from memory compact
  Documentation/accounting/delay-accounting.rst: add thrashing page cache and direct compact
  delayacct: cleanup flags in struct task_delay_info and functions use it
  delayacct: fix incomplete disable operation when switch enable to disable
  delayacct: support swapin delay accounting for swapping without blkio
  panic: remove oops_id
  panic: use error_report_end tracepoint on warnings
  fs/adfs: remove unneeded variable make code cleaner
  FAT: use io_schedule_timeout() instead of congestion_wait()
  hfsplus: use struct_group_attr() for memcpy() region
  nilfs2: remove redundant pointer sbufs
  fs/binfmt_elf: use PT_LOAD p_align values for static PIE
  const_structs.checkpatch: add frequently used ops structs
  ...
 2022-01-20 10:41:01 +02:00
Nathan Chancellor e900909599 btrfs: use generic Kconfig option for 256kB page size limit 
Use the newly introduced CONFIG_PAGE_SIZE_LESS_THAN_256KB to describe
the dependency introduced by commit b05fbcc36b ("btrfs: disable build
on platforms having page size 256K").

Link: https://lkml.kernel.org/r/20211129230141.228085-3-nathan@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: David Sterba <dsterba@suse.com>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: kernel test robot <lkp@intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2022-01-20 08:52:55 +02:00
Qu Wenruo c080b4144b btrfs: defrag: properly update range->start for autodefrag 
[BUG]
After commit 7b508037d4 ("btrfs: defrag: use defrag_one_cluster() to
implement btrfs_defrag_file()") autodefrag no longer properly re-defrag
the file from previously finished location.

[CAUSE]
The recent refactoring of defrag only focuses on defrag ioctl subpage
support, doesn't take autodefrag into consideration.

There are two problems involved which prevents autodefrag to restart its
scan:

- No range.start update
  Previously when one defrag target is found, range->start will be
  updated to indicate where next search should start from.

  But now btrfs_defrag_file() doesn't update it anymore, making all
  autodefrag to rescan from file offset 0.

  This would also make autodefrag to mark the same range dirty again and
  again, causing extra IO.

- No proper quick exit for defrag_one_cluster()
  Currently if we reached or exceed @max_sectors limit, we just exit
  defrag_one_cluster(), and let next defrag_one_cluster() call to do a
  quick exit.
  This makes @cur increase, thus no way to properly know which range is
  defragged and which range is skipped.

[FIX]
The fix involves two modifications:

- Update range->start to next cluster start
  This is a little different from the old behavior.
  Previously range->start is updated to the next defrag target.

  But in the end, the behavior should still be pretty much the same,
  as now we skip to next defrag target inside btrfs_defrag_file().

  Thus if auto-defrag determines to re-scan, then we still do the skip,
  just at a different timing.

- Make defrag_one_cluster() to return >0 to indicate a quick exit
  So that btrfs_defrag_file() can also do a quick exit, without
  increasing @cur to the range end, and re-use @cur to update
  @range->start.

- Add comment for btrfs_defrag_file() to mention the range->start update
  Currently only autodefrag utilize this behavior, as defrag ioctl won't
  set @max_to_defrag parameter, thus unless interrupted it will always
  try to defrag the whole range.

Reported-by: Filipe Manana <fdmanana@suse.com>
Fixes: 7b508037d4 ("btrfs: defrag: use defrag_one_cluster() to implement btrfs_defrag_file()")
Link: https://lore.kernel.org/linux-btrfs/0a269612-e43f-da22-c5bc-b34b1b56ebe8@mailbox.org/
CC: stable@vger.kernel.org # 5.16
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-19 18:25:56 +01:00
Qu Wenruo 484167da77 btrfs: defrag: fix wrong number of defragged sectors 
[BUG]
There are users using autodefrag mount option reporting obvious increase
in IO:

> If I compare the write average (in total, I don't have it per process)
> when taking idle periods on the same machine:
>     Linux 5.16:
>         without autodefrag: ~ 10KiB/s
>         with autodefrag: between 1 and 2MiB/s.
>
>     Linux 5.15:
>         with autodefrag:~ 10KiB/s (around the same as without
> autodefrag on 5.16)

[CAUSE]
When autodefrag mount option is enabled, btrfs_defrag_file() will be
called with @max_sectors = BTRFS_DEFRAG_BATCH (1024) to limit how many
sectors we can defrag in one try.

And then use the number of sectors defragged to determine if we need to
re-defrag.

But commit b18c3ab234 ("btrfs: defrag: introduce helper to defrag one
cluster") uses wrong unit to increase @sectors_defragged, which should
be in unit of sector, not byte.

This means, if we have defragged any sector, then @sectors_defragged
will be >= sectorsize (normally 4096), which is larger than
BTRFS_DEFRAG_BATCH.

This makes the @max_sectors check in defrag_one_cluster() to underflow,
rendering the whole @max_sectors check useless.

Thus causing way more IO for autodefrag mount options, as now there is
no limit on how many sectors can really be defragged.

[FIX]
Fix the problems by:

- Use sector as unit when increasing @sectors_defragged

- Include @sectors_defragged > @max_sectors case to break the loop

- Add extra comment on the return value of btrfs_defrag_file()

Reported-by: Anthony Ruhier <aruhier@mailbox.org>
Fixes: b18c3ab234 ("btrfs: defrag: introduce helper to defrag one cluster")
Link: https://lore.kernel.org/linux-btrfs/0a269612-e43f-da22-c5bc-b34b1b56ebe8@mailbox.org/
CC: stable@vger.kernel.org # 5.16
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-19 18:25:54 +01:00
Filipe Manana b767c2fc78 btrfs: allow defrag to be interruptible 
During defrag, at btrfs_defrag_file(), we have this loop that iterates
over a file range in steps no larger than 256K subranges. If the range
is too long, there's no way to interrupt it. So make the loop check in
each iteration if there's signal pending, and if there is, break and
return -AGAIN to userspace.

Before kernel 5.16, we used to allow defrag to be cancelled through a
signal, but that was lost with commit 7b508037d4 ("btrfs: defrag:
use defrag_one_cluster() to implement btrfs_defrag_file()").

This change adds back the possibility to cancel a defrag with a signal
and keeps the same semantics, returning -EAGAIN to user space (and not
the usually more expected -EINTR).

This is also motivated by a recent bug on 5.16 where defragging a 1 byte
file resulted in iterating from file range 0 to (u64)-1, as hitting the
bug triggered a too long loop, basically requiring one to reboot the
machine, as it was not possible to cancel defrag.

Fixes: 7b508037d4 ("btrfs: defrag: use defrag_one_cluster() to implement btrfs_defrag_file()")
CC: stable@vger.kernel.org # 5.16
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-19 18:16:38 +01:00
Filipe Manana 6b34cd8e17 btrfs: fix too long loop when defragging a 1 byte file 
When attempting to defrag a file with a single byte, we can end up in a
too long loop, which is nearly infinite because at btrfs_defrag_file()
we end up with the variable last_byte assigned with a value of
18446744073709551615 (which is (u64)-1). The problem comes from the fact
we end up doing:

    last_byte = round_up(last_byte, fs_info->sectorsize) - 1;

So if last_byte was assigned 0, which is i_size - 1, we underflow and
end up with the value 18446744073709551615.

This is trivial to reproduce and the following script triggers it:

  $ cat test.sh
  #!/bin/bash

  DEV=/dev/sdj
  MNT=/mnt/sdj

  mkfs.btrfs -f $DEV
  mount $DEV $MNT

  echo -n "X" > $MNT/foobar

  btrfs filesystem defragment $MNT/foobar

  umount $MNT

So fix this by not decrementing last_byte by 1 before doing the sector
size round up. Also, to make it easier to follow, make the round up right
after computing last_byte.

Reported-by: Anthony Ruhier <aruhier@mailbox.org>
Fixes: 7b508037d4 ("btrfs: defrag: use defrag_one_cluster() to implement btrfs_defrag_file()")
Link: https://lore.kernel.org/linux-btrfs/0a269612-e43f-da22-c5bc-b34b1b56ebe8@mailbox.org/
CC: stable@vger.kernel.org # 5.16
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-19 18:16:34 +01:00
Qu Wenruo 36c86a9e1b btrfs: output more debug messages for uncommitted transaction 
Print extra information about how many dirty bytes an uncommitted
has at the end of mount.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:27 +01:00
Filipe Manana c2f822635d btrfs: respect the max size in the header when activating swap file 
If we extended the size of a swapfile after its header was created (by the
mkswap utility) and then try to activate it, we will map the entire file
when activating the swap file, instead of limiting to the max size defined
in the swap file's header.

Currently test case generic/643 from fstests fails because we do not
respect that size limit defined in the swap file's header.

So fix this by not mapping file ranges beyond the max size defined in the
swap header.

This is the same type of bug that iomap used to have, and was fixed in
commit 36ca7943ac ("mm/swap: consider max pages in
iomap_swapfile_add_extent").

Fixes: ed46ff3d42 ("Btrfs: support swap files")
CC: stable@vger.kernel.org # 5.4+
Reviewed-and-tested-by: Josef Bacik <josef@toxicpanda.com
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:27 +01:00
Yang Li be8d1a2ab9 btrfs: fix argument list that the kdoc format and script verified 
The warnings were found by running scripts/kernel-doc, which is
caused by using 'make W=1'.

fs/btrfs/extent_io.c:3210: warning: Function parameter or member
'bio_ctrl' not described in 'btrfs_bio_add_page'
fs/btrfs/extent_io.c:3210: warning: Excess function parameter 'bio'
description in 'btrfs_bio_add_page'
fs/btrfs/extent_io.c:3210: warning: Excess function parameter
'prev_bio_flags' description in 'btrfs_bio_add_page'
fs/btrfs/space-info.c:1602: warning: Excess function parameter 'root'
description in 'btrfs_reserve_metadata_bytes'
fs/btrfs/space-info.c:1602: warning: Function parameter or member
'fs_info' not described in 'btrfs_reserve_metadata_bytes'

Note: this is fixing only the warnings regarding parameter list, the
first line is not strictly conforming to the kdoc format as the btrfs
codebase does not stick to that and keeps the first line more free form
(because it's only for internal use).

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add note ]
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:27 +01:00
Su Yue 4a9e803e5b btrfs: remove unnecessary parameter type from compression_decompress_bio 
btrfs_decompress_bio, the only caller of compression_decompress_bio gets
type from @cb and passes it to compression_decompress_bio.
However, compression_decompress_bio can get compression type directly
from @cb.

So remove the parameter and access it through @cb.  No functional
change.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Su Yue <l@damenly.su>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:27 +01:00
Qu Wenruo 856e47946c btrfs: selftests: dump extent io tree if extent-io-tree test failed 
When code modifying extent-io-tree get modified and got that selftest
failed, it can take some time to pin down the cause.

To make it easier to expose the problem, dump the extent io tree if the
selftest failed.

This can save developers debug time, especially since the selftest we
can not use the trace events, thus have to manually add debug trace
points.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:27 +01:00
Qu Wenruo 2ae8ae3d3d btrfs: scrub: cleanup the argument list of scrub_stripe() 
The argument list of btrfs_stripe() has similar problems of
scrub_chunk():

- Duplicated and ambiguous @base argument
  Can be fetched from btrfs_block_group::bg.

- Ambiguous argument @length
  It's again device extent length

- Ambiguous argument @num
  The instinctive guess would be mirror number, but in fact it's stripe
  index.

Fix it by:

- Remove @base parameter

- Rename @length to @dev_extent_len

- Rename @num to @stripe_index

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:27 +01:00
Qu Wenruo d04fbe19ae btrfs: scrub: cleanup the argument list of scrub_chunk() 
The argument list of scrub_chunk() has the following problems:

- Duplicated @chunk_offset
  It is the same as btrfs_block_group::start.

- Confusing @length
  The most instinctive guess is chunk length, and one may want to delete
  it, but the truth is, it's the device extent length.

Fix this by:

- Remove @chunk_offset
  Use btrfs_block_group::start instead.

- Rename @length to @dev_extent_len
  Also rename the caller to remove the ambiguous naming.

- Rename @cache to @bg
  The "_cache" suffix for btrfs_block_group has been removed for a while.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:26 +01:00
Qu Wenruo f26c923860 btrfs: remove reada infrastructure 
Currently there is only one user for btrfs metadata readahead, and
that's scrub.

But even for the single user, it's not providing the correct
functionality it needs, as scrub needs reada for commit root, which
current readahead can't provide. (Although it's pretty easy to add such
feature).

Despite this, there are some extra problems related to metadata
readahead:

- Duplicated feature with btrfs_path::reada

- Partly duplicated feature of btrfs_fs_info::buffer_radix
  Btrfs already caches its metadata in buffer_radix, while readahead
  tries to read the tree block no matter if it's already cached.

- Poor layer separation
  Metadata readahead works kinda at device level.
  This is definitely not the correct layer it should be, since metadata
  is at btrfs logical address space, it should not bother device at all.

  This brings extra chance for bugs to sneak in, while brings
  unnecessary complexity.

- Dead code
  In the very beginning of scrub.c we have #undef DEBUG, rendering all
  the debug related code useless and unable to test.

Thus here I purpose to remove the metadata readahead mechanism
completely.

[BENCHMARK]
There is a full benchmark for the scrub performance difference using the
old btrfs_reada_add() and btrfs_path::reada.

For the worst case (no dirty metadata, slow HDD), there could be a 5%
performance drop for scrub.
For other cases (even SATA SSD), there is no distinguishable performance
difference.

The number is reported scrub speed, in MiB/s.
The resolution is limited by the reported duration, which only has a
resolution of 1 second.

	Old		New		Diff
SSD	455.3		466.332		+2.42%
HDD	103.927 	98.012		-5.69%

Comprehensive test methodology is in the cover letter of the patch.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:26 +01:00
Qu Wenruo dcf62b204c btrfs: scrub: use btrfs_path::reada for extent tree readahead 
For scrub, we trigger two readaheads for two trees, extent tree to get
where to scrub, and csum tree to get the data checksum.

For csum tree we already trigger readahead in
btrfs_lookup_csums_range(), by setting path->reada.
But for extent tree we don't have any path based readahead.

Add the readahead for extent tree as well, so we can later remove the
btrfs_reada_add() based readahead.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:26 +01:00
Qu Wenruo 2522dbe86b btrfs: scrub: remove the unnecessary path parameter for scrub_raid56_parity() 
In function scrub_stripe() we allocated two btrfs_path's, one @path for
extent tree search and another @ppath for full stripe extent tree search
for RAID56.

This is totally umncessary, as the @ppath usage is completely inside
scrub_raid56_parity(), thus we can move the path allocation into
scrub_raid56_parity() completely.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:26 +01:00
Nikolay Borisov c122799643 btrfs: refactor unlock_up 
The purpose of this function is to unlock all nodes in a btrfs path
which are above 'lowest_unlock' and whose slot used is different than 0.
As such it used slightly awkward structure of 'if' as well as somewhat
cryptic "no_skip" control variable which denotes whether we should
check the current level of skipability or no.

This patch does the following (cosmetic) refactorings:

* Renames 'no_skip' to 'check_skip' and makes it a boolean. This
  variable controls whether we are below the lowest_unlock/skip_level
  levels.

* Consolidates the 2 conditions which warrant checking whether the
  current level should be skipped under 1 common if (check_skip) branch,
  this increase indentation level but is not critical.

* Consolidates the 'skip_level < i && i >= lowest_unlock' and
  'i >= lowest_unlock && i > skip_level' condition into a common branch
  since those are identical.

* Eliminates the local extent_buffer variable as in this case it doesn't
  bring anything to function readability.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:26 +01:00
Filipe Manana 1b58ae0e4d btrfs: skip transaction commit after failure to create subvolume 
At ioctl.c:create_subvol(), when we fail to create a subvolume we always
commit the transaction. In most cases this is a no-op, since all the error
paths, except for one, abort the transaction - the only exception is when
we fail to insert the new root item into the root tree, in that case we
don't abort the transaction because we didn't do anything that is
irreversible - however we end up committing the transaction which although
is not a functional problem, it adds unnecessary rotation of the backup
roots in the superblock and unnecessary work.

So change that to commit a transaction only when no error happened,
otherwise just call btrfs_end_transaction() to release our reference on
the transaction.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:26 +01:00
Naohiro Aota 82187d2ecd btrfs: zoned: fix chunk allocation condition for zoned allocator 
The ZNS specification defines a limit on the number of "active"
zones. That limit impose us to limit the number of block groups which
can be used for an allocation at the same time. Not to exceed the
limit, we reuse the existing active block groups as much as possible
when we can't activate any other zones without sacrificing an already
activated block group in commit a85f05e59b ("btrfs: zoned: avoid
chunk allocation if active block group has enough space").

However, the check is wrong in two ways. First, it checks the
condition for every raid index (ffe_ctl->index). Even if it reaches
the condition and "ffe_ctl->max_extent_size >=
ffe_ctl->min_alloc_size" is met, there can be other block groups
having enough space to hold ffe_ctl->num_bytes. (Actually, this won't
happen in the current zoned code as it only supports SINGLE
profile. But, it can happen once it enables other RAID types.)

Second, it checks the active zone availability depending on the
raid index. The raid index is just an index for
space_info->block_groups, so it has nothing to do with chunk allocation.

These mistakes are causing a faulty allocation in a certain
situation. Consider we are running zoned btrfs on a device whose
max_active_zone == 0 (no limit). And, suppose no block group have a
room to fit ffe_ctl->num_bytes but some room to meet
ffe_ctl->min_alloc_size (i.e. max_extent_size > num_bytes >=
min_alloc_size).

In this situation, the following occur:

- With SINGLE raid_index, it reaches the chunk allocation checking
  code
- The check returns true because we can activate a new zone (no limit)
- But, before allocating the chunk, it iterates to the next raid index
  (RAID5)
- Since there are no RAID5 block groups on zoned mode, it again
  reaches the check code
- The check returns false because of btrfs_can_activate_zone()'s "if
  (raid_index != BTRFS_RAID_SINGLE)" part
- That results in returning -ENOSPC without allocating a new chunk

As a result, we end up hitting -ENOSPC too early.

Move the check to the right place in the can_allocate_chunk() hook,
and do the active zone check depending on the allocation flag, not on
the raid index.

CC: stable@vger.kernel.org # 5.16
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:26 +01:00
Naohiro Aota 50475cd577 btrfs: add extent allocator hook to decide to allocate chunk or not 
Introduce a new hook for an extent allocator policy. With the new
hook, a policy can decide to allocate a new block group or not. If
not, it will return -ENOSPC, so btrfs_reserve_extent() will cut the
allocation size in half and retry the allocation if min_alloc_size is
large enough.

The hook has a place holder and will be replaced with the real
implementation in the next patch.

CC: stable@vger.kernel.org # 5.16
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:26 +01:00
Naohiro Aota 1ada69f61c btrfs: zoned: unset dedicated block group on allocation failure 
Allocating an extent from a block group can fail for various reasons.
When an allocation from a dedicated block group (for tree-log or
relocation data) fails, we need to unregister it as a dedicated one so
that we can allocate a new block group for the dedicated one.

However, we are returning early when the block group in case it is
read-only, fully used, or not be able to activate the zone. As a result,
we keep the non-usable block group as a dedicated one, leading to
further allocation failure. With many block groups, the allocator will
iterate hopeless loop to find a free extent, results in a hung task.

Fix the issue by delaying the return and doing the proper cleanups.

CC: stable@vger.kernel.org # 5.16
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:26 +01:00
Johannes Thumshirn 7367271000 btrfs: zoned: drop redundant check for REQ_OP_ZONE_APPEND and btrfs_is_zoned 
REQ_OP_ZONE_APPEND can only work on zoned devices, so it is redundant to
check if the filesystem is zoned when REQ_OP_ZONE_APPEND is set as the
bio's bio_op.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:26 +01:00
Johannes Thumshirn 554aed7da2 btrfs: zoned: sink zone check into btrfs_repair_one_zone 
Sink zone check into btrfs_repair_one_zone() so we don't need to do it
in all callers.

Also as btrfs_repair_one_zone() doesn't return a sensible error, make it
a boolean function and return false in case it got called on a non-zoned
filesystem and true on a zoned filesystem.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:26 +01:00
Johannes Thumshirn 8fdf54fe69 btrfs: zoned: simplify btrfs_check_meta_write_pointer 
btrfs_check_meta_write_pointer() will always be called with a NULL
'cache_ret' argument.

As there's no need to check if we have a valid block_group passed in
remove these checks.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:25 +01:00
Johannes Thumshirn 869f4cdc73 btrfs: zoned: encapsulate inode locking for zoned relocation 
Encapsulate the inode lock needed for serializing the data relocation
writes on a zoned filesystem into a helper.

This streamlines the code reading flow and hides special casing for
zoned filesystems.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:25 +01:00
Anand Jain a26d60dedf btrfs: sysfs: add devinfo/fsid to retrieve actual fsid from the device 
In the case of the seed device, the fsid can be different from the mounted
sprout fsid.  The userland has to read the device superblock to know the
fsid but, that idea fails if the device is missing. So add a sysfs
interface devinfo/<devid>/fsid to show the fsid of the device.

For example:
  $ cd /sys/fs/btrfs/b10b02a5-f9de-4276-b9e8-2bfd09a578a8

  $ cat devinfo/1/fsid
  c44d771f-639d-4df3-99ec-5bc7ad2af93b
  $ cat  devinfo/3/fsid
  b10b02a5-f9de-4276-b9e8-2bfd09a578a8

Though it's related to seeding, the name of the sysfs file is plain fsid as it
matches what blkid says.  A path to the device's fsid will aid scripting.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:25 +01:00
Josef Bacik c18e323564 btrfs: reserve extra space for the free space tree 
Filipe reported a problem where sometimes he'd get an ENOSPC abort when
running delayed refs with generic/619 and the free space tree enabled.
This is partly because we do not reserve space for modifying the free
space tree, nor do we have a block rsv associated with that tree.

The delayed_refs_rsv tracks the amount of space required to run delayed
refs.  This means 1 modification means 1 change to the extent root.
With the free space tree this turns into 2 changes, because modifying 1
extent means updating the extent tree and potentially updating the free
space tree to either remove that entry or add the free space.  Thus if
we have the FST enabled, simply double the reservation size for our
modification.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:25 +01:00
Josef Bacik 9506f95382 btrfs: include the free space tree in the global rsv minimum calculation 
Filipe reported a problem where generic/619 was failing with an ENOSPC
abort while running delayed refs, like the following

  BTRFS: Transaction aborted (error -28)
  WARNING: CPU: 3 PID: 522920 at fs/btrfs/free-space-tree.c:1049 add_to_free_space_tree+0xe5/0x110 [btrfs]
  CPU: 3 PID: 522920 Comm: kworker/u16:19 Tainted: G        W         5.16.0-rc2-btrfs-next-106 #1
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
  Workqueue: events_unbound btrfs_async_reclaim_metadata_space [btrfs]
  RIP: 0010:add_to_free_space_tree+0xe5/0x110 [btrfs]
  RSP: 0000:ffffa65087fb7b20 EFLAGS: 00010282
  RAX: 0000000000000000 RBX: 0000000000001000 RCX: 0000000000000000
  RDX: 0000000000000001 RSI: ffffffff9131eeaa RDI: 00000000ffffffff
  RBP: ffff8d62e26481b8 R08: ffffffff9ad97ce0 R09: 0000000000000001
  R10: 0000000000000000 R11: 0000000000000001 R12: 00000000ffffffe4
  R13: ffff8d61c25fe688 R14: ffff8d61ebd88800 R15: ffff8d61ebd88a90
  FS:  0000000000000000(0000) GS:ffff8d64ed400000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007fa46a8b1000 CR3: 0000000148d18003 CR4: 0000000000370ee0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   <TASK>
   __btrfs_free_extent+0x516/0x950 [btrfs]
   __btrfs_run_delayed_refs+0x2b1/0x1250 [btrfs]
   btrfs_run_delayed_refs+0x86/0x210 [btrfs]
   flush_space+0x403/0x630 [btrfs]
   ? call_rcu_tasks_generic+0x50/0x80
   ? lock_release+0x223/0x4a0
   ? btrfs_get_alloc_profile+0xb5/0x290 [btrfs]
   ? do_raw_spin_unlock+0x4b/0xa0
   btrfs_async_reclaim_metadata_space+0x139/0x320 [btrfs]
   process_one_work+0x24c/0x5b0
   worker_thread+0x55/0x3c0
   ? process_one_work+0x5b0/0x5b0
   kthread+0x17c/0x1a0
   ? set_kthread_struct+0x40/0x40
   ret_from_fork+0x22/0x30

There's a couple of reasons for this, but in generic/619's case the
largest reason is because it is a very small file system, ad we do not
reserve enough space for the global reserve.

With the free space tree we now have the free space tree that we need to
modify when running delayed refs.  This means we need the global reserve
to take this into account when it calculates the minimum size it needs
to be.  This is especially important for very small file systems.

Fix this by adjusting the minimum global block rsv size math to include
the size of the free space tree when calculating the size.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:25 +01:00
Qu Wenruo c9d328c0c4 btrfs: scrub: merge SCRUB_PAGES_PER_RD_BIO and SCRUB_PAGES_PER_WR_BIO 
These two values were introduced in commit ff023aac31 ("Btrfs: add code
to scrub to copy read data to another disk") as an optimization.

But the truth is, block layer scheduler can do whatever it wants to
merge/split bios to improve performance.

Doing such "optimization" is not really going to affect much, especially
considering how good current block layer optimizations are doing.
Remove such old and immature optimization from our code.

Since we're here, also change BUG_ON()s using these two macros to use
ASSERT()s.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:25 +01:00
Qu Wenruo 0bb3acdc48 btrfs: update SCRUB_MAX_PAGES_PER_BLOCK 
Use BTRFS_MAX_METADATA_BLOCKSIZE and SZ_4K (minimal sectorsize) to
calculate this value.

And remove one stale comment on the value, in fact with recent subpage
support, BTRFS_MAX_METADATA_BLOCKSIZE * PAGE_SIZE is already beyond
BTRFS_STRIPE_LEN, just we don't use the full page.

Also since we're here, update the BUG_ON() related to
SCRUB_MAX_PAGES_PER_BLOCK to ASSERT().

As those ASSERT() are really only for developers to catch early obvious
bugs, not to let end users suffer.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:25 +01:00
Josef Bacik 8697b8f88e btrfs: do not check -EAGAIN when truncating inodes in the log root 
We only throttle the btrfs_truncate_inode_items if the root is
SHAREABLE, which isn't set on the log root, which means this loop is
unnecessary.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:25 +01:00
Josef Bacik e48dac7f6f btrfs: make should_throttle loop local in btrfs_truncate_inode_items 
We reset this bool on every loop through the truncate loop, make this
variable local to the loop.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:25 +01:00
Josef Bacik 0adbc6190c btrfs: combine extra if statements in btrfs_truncate_inode_items 
We have

    if (del_item)
	    // do something
    else
	    // something else
    if (del_item)
	    // do yet another thing
    else
	    // something else entirely

back to back in btrfs_truncate_inode_items, collapse these two sets of
if statements into one.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:25 +01:00
Josef Bacik 376b91d570 btrfs: convert BUG() for pending_del_nr into an ASSERT 
This is a logic correctness check, convert it into an ASSERT() instead
of a BUG().

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:25 +01:00
Josef Bacik 56e1edb0e3 btrfs: convert BUG_ON() in btrfs_truncate_inode_items to ASSERT 
We have a correctness BUG_ON() in btrfs_truncate_inode_items to make
sure that we're always using min_type == BTRFS_EXTENT_DATA_KEY if
new_size is > 0.  Convert this to an ASSERT.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:25 +01:00
Josef Bacik 71d18b5354 btrfs: add inode to truncate control 
In the future we're going to want to use btrfs_truncate_inode_items
without looking up the associated inode.  In order to accommodate this
add the inode to btrfs_truncate_control and handle the case where
control->inode is NULL appropriately.  This is fairly straightforward,
we simply need to add a helper for the trace points, as the file extent
map update is controlled by a flag on btrfs_truncate_control.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:24 +01:00
Josef Bacik 487e81d2a4 btrfs: pass the ino via truncate control 
In the future we are going to want to truncate inode items without
needing to have an btrfs_inode to pass in, so add ino to the
btrfs_truncate_control and use that to look up the inode items to
truncate.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:24 +01:00
Josef Bacik 655807b895 btrfs: use a flag to control when to clear the file extent range 
We only care about updating the file extent range when we are doing a
normal truncation.  We skip this for tree logging currently, but we can
also skip this for eviction as well.  Using a flag makes it more
explicit when we want to do this work.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:24 +01:00
Josef Bacik 5caa490ed8 btrfs: control extent reference updates with a control flag for truncate 
We've had weird bugs in the past where we forgot to adjust the truncate
path to deal with the fact that we can be called by the tree log path.
Instead of checking if our root is a LOG_ROOT use a flag on the
btrfs_truncate_control to indicate that we don't want to do extent
reference updates during this truncate.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:24 +01:00
Josef Bacik 462b728ea8 btrfs: only call inode_sub_bytes in truncate paths that care 
We currently have a bunch of awkward checks to make sure we only update
the inode i_bytes if we're truncating the real inode.  Instead keep
track of the number of bytes we need to sub in the
btrfs_truncate_control, and then do the appropriate adjustment in the
truncate paths that care.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:24 +01:00
Josef Bacik c2ddb612a8 btrfs: only update i_size in truncate paths that care 
We currently will update the i_size of the inode as we truncate it down,
however we skip this if we're calling btrfs_truncate_inode_items from
the tree log code.  However we also don't care about this in the case of
evict.  Instead keep track of this value in the btrfs_truncate_control
and then have btrfs_truncate() and the free space cache truncate path
both do the i_size update themselves.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:24 +01:00
Josef Bacik d9ac19c380 btrfs: add truncate control struct 
I'm going to be adding more arguments and counters to
btrfs_truncate_inode_items, so add a control struct to handle all of the
extra arguments to make it easier to follow.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:24 +01:00
Josef Bacik 7097a941bf btrfs: remove found_extent from btrfs_truncate_inode_items 
We only set this if we find a normal file extent, del_item == 1, and the
file extent points to a real extent and isn't a hole extent.  We can use
del_item == 1 && extent_start != 0 to get the same information that
found_extent provides, so remove this variable and use the other
variables instead.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:24 +01:00
Josef Bacik 2adc75d612 btrfs: move btrfs_kill_delayed_inode_items into evict 
We have a special case in btrfs_truncate_inode_items() to call
btrfs_kill_delayed_inode_items() if min_type == 0, which is only called
during evict.

Instead move this out into evict proper, and add some comments because I
erroneously attempted to remove this code altogether without
understanding what we were doing.

Evict is updating the inode only because we only care about making sure
the i_nlink count has hit disk.  If we had pending deletions we don't
want to process those via the delayed inode updates, we simply want to
drop all of them and reclaim the reserved metadata space.  Then from
there the btrfs_truncate_inode_items() will do the work to remove all of
the items as appropriate.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:24 +01:00
Josef Bacik 275312a03c btrfs: remove free space cache inode check in btrfs_truncate_inode_items 
We no longer have inode cache feature, so this check is extraneous as
the only inode cache is in the tree_root, which is not marked as
SHAREABLE.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:24 +01:00
Josef Bacik 9a4a1429ac btrfs: move extent locking outside of btrfs_truncate_inode_items 
Currently we are locking the extent and dropping the extent cache for
any inodes we truncate, unless they're in the tree log.  We call this
helper from:

- truncate
- evict
- tree log
- free space cache truncation

For evict we've already dropped all of the extent cache for this inode
once we've gotten here, and we're the only one accessing this inode, so
this step is unnecessary.

For the tree log code we already skip this part.

Pull this work into the truncate path and the free space cache
truncation path.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:24 +01:00
Josef Bacik 54f03ab1e1 btrfs: move btrfs_truncate_inode_items to inode-item.c 
This is an inode item related manipulation with a few vfs related
adjustments.  I'm going to remove the vfs related code from this helper
and simplify it a lot, but I want those changes to be easily seen via
git blame, so move this function now and then the simplification work
can be done.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:24 +01:00
Josef Bacik 26c2c4540d btrfs: add an inode-item.h 
We have a few helpers in inode-item.c, and I'm going to make a few
changes to how we do truncate in the future, so break out these
definitions into their own header file to trim down ctree.h some and
make it easier to do the work on truncate in the future.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:23 +01:00
Filipe Manana 727e60604f btrfs: remove stale comment about locking at btrfs_search_slot() 
The comment refers to the old extent buffer locking code, where we used to
have custom locks that had blocking and spinning behaviour modes. That is
not the case anymore, since we have transitioned to rw semaphores, so the
comment does not offer any value anymore. Remove it.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:23 +01:00
Filipe Manana bb8e9a6080 btrfs: remove BUG_ON() after splitting leaf 
After calling split_leaf() we BUG_ON() if the returned value is greater
than zero. However split_leaf() only returns 0, in case of success, or a
negative value in case of an error.

The reason for the BUG_ON() is that if we ever get a positive return
value from split_leaf(), we can not simply propagate it to the callers
of btrfs_search_slot(), as that would be interpreted as "key not found"
and not as an error. That means it could result in callers ending up
causing some potential silent corruption.

So change the BUG_ON() to an ASSERT(), and in case assertions are
disabled, produce a warning and set the return value to an error, to make
it not possible to get into a silent corruption and having the error not
noticed.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:23 +01:00
Filipe Manana 109324cfda btrfs: move leaf search logic out of btrfs_search_slot() 
There's quite a significant amount of code for doing the key search for a
leaf at btrfs_search_slot(), with a couple labels and gotos in it, plus
btrfs_search_slot() is already big enough.

So move the logic that does the key search on a leaf into a new helper
function. This makes it better organized, removing the need for the labels
and the gotos, as well as reducing the indentation level and the size of
btrfs_search_slot().

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:23 +01:00
Filipe Manana e5e1c1741b btrfs: remove useless condition check before splitting leaf 
When inserting a key, we check if the write_lock_level is less than 1,
and if so we set it to 1, release the path and retry the tree traversal.

However that is unnecessary, because when ins_len is greater than 0, we
know that write_lock_level can never be less than 1.

The logic to retry is also buggy, because in case ins_len was decremented,
due to an exact key match and the search is not meant for item extension
(path->search_for_extension is 0), we retry without incrementing ins_len,
which would make the next retry decrement it again by the same amount.

So remove the check for write_lock_level being less than 1 and add an
assertion to assert it's always >= 1.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:23 +01:00
Filipe Manana e2e58d0f8d btrfs: try to unlock parent nodes earlier when inserting a key 
When inserting a new key, we release the write lock on the leaf's parent
only after doing the binary search on the leaf. This is because if the
key ends up at slot 0, we will have to update the key at slot 0 of the
parent node. The same reasoning applies to any other upper level nodes
when their slot is 0. We also need to keep the parent locked in case the
leaf does not have enough free space to insert the new key/item, because
in that case we will split the leaf and we will need to add a new key to
the parent due to a new leaf resulting from the split operation.

However if the leaf has enough space for the new key and the key does not
end up at slot 0 of the leaf we could release our write lock on the parent
before doing the binary search on the leaf to figure out the destination
slot. That leads to reducing the amount of time other tasks are blocked
waiting to lock the parent, therefore increasing parallelism when there
are other tasks that are trying to access other leaves accessible through
the same parent. This also applies to other upper nodes besides the
immediate parent, when their slot is 0, since we keep locks on them until
we figure out if the leaf slot is slot 0 or not.

In fact, having the key ending at up slot 0 when is rare. Typically it
only happens when the key is less than or equals to the smallest, the
"left most", key of the entire btree, during a split attempt when we try
to push to the right sibling leaf or when the caller just wants to update
the item of an existing key. It's also very common that a leaf has enough
space to insert a new key, since after a split we move about half of the
keys from one into the new leaf.

So unlock the parent, and any other upper level nodes, when during a key
insertion we notice the key is greater then the first key in the leaf and
the leaf has enough free space. After unlocking the upper level nodes, do
the binary search using a low boundary of slot 1 and not slot 0, to figure
out the slot where the key will be inserted (or where the key already is
in case it exists and the caller wants to modify its item data).
This extra comparison, with the first key, is cheap and the key is very
likely already in a cache line because it immediately follows the header
of the extent buffer and we have recently read the level field of the
header (which in fact is the last field of the header).

The following fs_mark test was run on a non-debug kernel (debian's default
kernel config), with a 12 cores intel CPU, and using a NVMe device:

  $ cat run-fsmark.sh
  #!/bin/bash

  DEV=/dev/nvme0n1
  MNT=/mnt/nvme0n1
  MOUNT_OPTIONS="-o ssd"
  MKFS_OPTIONS="-O no-holes -R free-space-tree"
  FILES=100000
  THREADS=$(nproc --all)
  FILE_SIZE=0

  echo "performance" | \
	tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor

  mkfs.btrfs -f $MKFS_OPTIONS $DEV
  mount $MOUNT_OPTIONS $DEV $MNT

  OPTS="-S 0 -L 10 -n $FILES -s $FILE_SIZE -t $THREADS -k"
  for ((i = 1; i <= $THREADS; i++)); do
      OPTS="$OPTS -d $MNT/d$i"
  done

  fs_mark $OPTS

  umount $MNT

Before this change:

FSUse%        Count         Size    Files/sec     App Overhead
     0      1200000            0     165273.6          5958381
     0      2400000            0     190938.3          6284477
     0      3600000            0     181429.1          6044059
     0      4800000            0     173979.2          6223418
     0      6000000            0     139288.0          6384560
     0      7200000            0     163000.4          6520083
     1      8400000            0      57799.2          5388544
     1      9600000            0      66461.6          5552969
     2     10800000            0      49593.5          5163675
     2     12000000            0      57672.1          4889398

After this change:

FSUse%        Count         Size    Files/sec            App Overhead
     0      1200000            0     167987.3 (+1.6%)         6272730
     0      2400000            0     198563.9 (+4.0%)         6048847
     0      3600000            0     197436.6 (+8.8%)         6163637
     0      4800000            0     202880.7 (+16.6%)        6371771
     1      6000000            0     167275.9 (+20.1%)        6556733
     1      7200000            0     204051.2 (+25.2%)        6817091
     1      8400000            0      69622.8 (+20.5%)        5525675
     1      9600000            0      69384.5 (+4.4%)         5700723
     1     10800000            0      61454.1 (+23.9%)        5363754
     3     12000000            0      61908.7 (+7.3%)         5370196

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:23 +01:00
Filipe Manana fb81212c07 btrfs: allow generic_bin_search() to take low boundary as an argument 
Right now generic_bin_search() always uses a low boundary slot of 0, but
in the next patch we'll want to often skip slot 0 when searching for a
key. So make generic_bin_search() have the low boundary slot specified
as an argument, and move the check for the extent buffer level from
btrfs_bin_search() to generic_bin_search() to avoid adding another
wrapper around generic_bin_search().

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:23 +01:00
Josef Bacik 120de408e4 btrfs: check the root node for uptodate before returning it 
Now that we clear the extent buffer uptodate if we fail to write it out
we need to check to see if our root node is uptodate before we search
down it.  Otherwise we could return stale data (or potentially corrupt
data that was caught by the write verification step) and think that the
path is OK to search down.

CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:23 +01:00
Nikolay Borisov a174c0a2e8 btrfs: allow device add if balance is paused 
Currently paused balance precludes adding a device since they are both
considered exclusive ops and we can have at most one running at a time.
This is problematic in case a filesystem encounters an ENOSPC situation
while balance is running, in this case the only thing the user can do
is mount the fs with "skip_balance" which pauses balance and delete some
data to free up space for balance. However, it should be possible to add
a new device when balance is paused.

Fix this by allowing device add to proceed when balance is paused.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:23 +01:00
Nikolay Borisov 621a1ee1d3 btrfs: make device add compatible with paused balance in btrfs_exclop_start_try_lock 
This is needed to enable device add to work in cases when a file system
has been mounted with 'skip_balance' mount option.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:23 +01:00
Nikolay Borisov efc0e69c2f btrfs: introduce exclusive operation BALANCE_PAUSED state 
Current set of exclusive operation states is not sufficient to handle
all practical use cases. In particular there is a need to be able to add
a device to a filesystem that have paused balance. Currently there is no
way to distinguish between a running and a paused balance. Fix this by
introducing BTRFS_EXCLOP_BALANCE_PAUSED which is going to be set in 2
occasions:

1. When a filesystem is mounted with skip_balance and there is an
   unfinished balance it will now be into BALANCE_PAUSED instead of
   simply BALANCE state.

2. When a running balance is paused.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:23 +01:00
Filipe Manana d96b34248c btrfs: make send work with concurrent block group relocation 
We don't allow send and balance/relocation to run in parallel in order
to prevent send failing or silently producing some bad stream. This is
because while send is using an extent (specially metadata) or about to
read a metadata extent and expecting it belongs to a specific parent
node, relocation can run, the transaction used for the relocation is
committed and the extent gets reallocated while send is still using the
extent, so it ends up with a different content than expected. This can
result in just failing to read a metadata extent due to failure of the
validation checks (parent transid, level, etc), failure to find a
backreference for a data extent, and other unexpected failures. Besides
reallocation, there's also a similar problem of an extent getting
discarded when it's unpinned after the transaction used for block group
relocation is committed.

The restriction between balance and send was added in commit 9e967495e0
("Btrfs: prevent send failures and crashes due to concurrent relocation"),
kernel 5.3, while the more general restriction between send and relocation
was added in commit 1cea5cf0e6 ("btrfs: ensure relocation never runs
while we have send operations running"), kernel 5.14.

Both send and relocation can be very long running operations. Relocation
because it has to do a lot of IO and expensive backreference lookups in
case there are many snapshots, and send due to read IO when operating on
very large trees. This makes it inconvenient for users and tools to deal
with scheduling both operations.

For zoned filesystem we also have automatic block group relocation, so
send can fail with -EAGAIN when users least expect it or send can end up
delaying the block group relocation for too long. In the future we might
also get the automatic block group relocation for non zoned filesystems.

This change makes it possible for send and relocation to run in parallel.
This is achieved the following way:

1) For all tree searches, send acquires a read lock on the commit root
   semaphore;

2) After each tree search, and before releasing the commit root semaphore,
   the leaf is cloned and placed in the search path (struct btrfs_path);

3) After releasing the commit root semaphore, the changed_cb() callback
   is invoked, which operates on the leaf and writes commands to the pipe
   (or file in case send/receive is not used with a pipe). It's important
   here to not hold a lock on the commit root semaphore, because if we did
   we could deadlock when sending and receiving to the same filesystem
   using a pipe - the send task blocks on the pipe because it's full, the
   receive task, which is the only consumer of the pipe, triggers a
   transaction commit when attempting to create a subvolume or reserve
   space for a write operation for example, but the transaction commit
   blocks trying to write lock the commit root semaphore, resulting in a
   deadlock;

4) Before moving to the next key, or advancing to the next change in case
   of an incremental send, check if a transaction used for relocation was
   committed (or is about to finish its commit). If so, release the search
   path(s) and restart the search, to where we were before, so that we
   don't operate on stale extent buffers. The search restarts are always
   possible because both the send and parent roots are RO, and no one can
   add, remove of update keys (change their offset) in RO trees - the
   only exception is deduplication, but that is still not allowed to run
   in parallel with send;

5) Periodically check if there is contention on the commit root semaphore,
   which means there is a transaction commit trying to write lock it, and
   release the semaphore and reschedule if there is contention, so as to
   avoid causing any significant delays to transaction commits.

This leaves some room for optimizations for send to have less path
releases and re searching the trees when there's relocation running, but
for now it's kept simple as it performs quite well (on very large trees
with resulting send streams in the order of a few hundred gigabytes).

Test case btrfs/187, from fstests, stresses relocation, send and
deduplication attempting to run in parallel, but without verifying if send
succeeds and if it produces correct streams. A new test case will be added
that exercises relocation happening in parallel with send and then checks
that send succeeds and the resulting streams are correct.

A final note is that for now this still leaves the mutual exclusion
between send operations and deduplication on files belonging to a root
used by send operations. A solution for that will be slightly more complex
but it will eventually be built on top of this change.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-07 14:18:23 +01:00
Nikolay Borisov 364be84211 btrfs: change name and type of private member of btrfs_free_space_ctl 
btrfs_free_space_ctl::private is either unset or it always points to
struct btrfs_block_group when it is set. So there's no point in keeping
the unhelpful 'private' name and keeping it an untyped pointer. Change
both the type and name to be self-describing. No functional changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:50 +01:00
Nikolay Borisov 290ef19add btrfs: make __btrfs_add_free_space take just block group reference 
There is no point in the function taking an fs_info and a
btrfs_free_space because the ctl passed always belongs to the block
group. Furthermore fs_info can be referenced from the block group. No
functional changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:50 +01:00
Nikolay Borisov 32e1649b53 btrfs: consolidate unlink_free_space/__unlink_free_space functions 
The only difference between the two is whether btrfs_free_space::bytes
is adjusted. Instead of having 2 separate functions control this
behavior via an additional parameter and make them one function instead.
No functional changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:50 +01:00
Nikolay Borisov f594f13c19 btrfs: consolidate bitmap_clear_bits/__bitmap_clear_bits 
The only difference is the former adjusts btrfs_free_space::bytes
member. Consolidate the two function into 1 and add a bool parameter
which controls whether the adjustment is made or not. No functional
changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:50 +01:00
Josef Bacik abed4aaae4 btrfs: track the csum, extent, and free space trees in a rb tree 
In the future we are going to have multiple copies of these trees.  To
facilitate this we need a way to lookup the different roots we are
looking for.  Handle this by adding a global root rb tree that is
indexed on the root->root_key.  Then instead of loading the roots at
mount time with individually targeted keys, simply search the tree_root
for anything with the specific objectid we want.  This will make it
straightforward to support both old style and new style file systems.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:50 +01:00
Josef Bacik 7fcf8a0050 btrfs: remove useless WARN_ON in record_root_in_trans 
We don't set SHAREABLE on the extent root, we don't need to have this
safety check here.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:49 +01:00
Josef Bacik 7939dd9f35 btrfs: stop accessing ->free_space_root directly 
We're going to have multiple free space roots in the future, so adjust
all the users of the free space root to use a helper to access the root.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:49 +01:00
Josef Bacik fc28b25e1f btrfs: stop accessing ->csum_root directly 
We are going to have multiple csum roots in the future, so convert all
users of ->csum_root to btrfs_csum_root() and rename ->csum_root to
->_csum_root so we can easily find remaining users in the future.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:49 +01:00
Josef Bacik 056c831116 btrfs: set BTRFS_FS_STATE_NO_CSUMS if we fail to load the csum root 
We have a few places where we skip doing csums if we mounted with one of
the rescue options that ignores bad csum roots.  In the future when
there are multiple csum roots it'll be costly to check and see if there
are any missing csum roots, so simply add a flag to indicate the fs
should skip loading csums in case of errors.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:49 +01:00
Josef Bacik 84d2d6c701 btrfs: fix csum assert to check objectid of the root 
In the future we may have multiple csum roots, so simply check the
objectid is for a csum root instead of checking against ->csum_root.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:49 +01:00
Josef Bacik 29cbcf4017 btrfs: stop accessing ->extent_root directly 
When we start having multiple extent roots we'll need to use a helper to
get to the correct extent_root.  Rename fs_info->extent_root to
_extent_root and convert all of the users of the extent root to using
the btrfs_extent_root() helper.  This will allow us to easily clean up
the remaining direct accesses in the future.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:49 +01:00
Josef Bacik 2e608bd1dd btrfs: init root block_rsv at init root time 
In the future we're going to have multiple csum and extent root trees,
so init the roots block_rsv at setup_root time based on their root key
objectid.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:48 +01:00
Josef Bacik ce5603d015 btrfs: don't use the extent_root in flush_space 
We only need the root to start a transaction, and since it's a global
root we can pick anything, change to the tree_root as we'll have a lot
of extent roots in the future.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:48 +01:00
Josef Bacik 30a9da5d8d btrfs: don't use extent_root in iterate_extent_inodes 
We are going to have many extent_roots soon, and we don't need a root
here necessarily as we're not modifying anything, we're just getting the
trans handle so we can have an accurate view of references, so use the
tree_root here.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:48 +01:00
Josef Bacik fd51eb2f07 btrfs: don't use the extent root in btrfs_chunk_alloc_add_chunk_item 
We're just using the extent_root to set the chunk owner to
root_key->objectid, which is BTRFS_EXTENT_TREE_OBJECTID, so use that
directly instead of using the root.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:48 +01:00
Josef Bacik 3478c73252 btrfs: remove unnecessary extent root check in btrfs_defrag_leaves 
We only defrag leaves on roots that have SHAREABLE set, so we don't need
to check if we're the extent root as it doesn't have SHAREABLE set.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:48 +01:00
Josef Bacik 826582cabc btrfs: do not special case the extent root for switch commit roots 
This is a leftover from when we used to independently swap the extent
root's commit root and the fs tree commit roots.  At the time I simply
changed the helper to a list_add.  There's actually no reason to not add
the extent root to the switch commit root at this point, we don't care
about the order we do the switching since it's all done under the
commit_root_sem.

If we re-mark the extent root dirty after adding it to the
switch_commits list we'll see that BTRFS_ROOT_DIRTY isn't set and then
list_move it back onto the dirty list, and then we'll redo the tree
update and everything will be ok.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:48 +01:00
Josef Bacik 8e1d029091 btrfs: use chunk_root in find_free_extent_update_loop 
We're only using this to start the transaction with to possibly allocate
a chunk.  It doesn't really matter which root to use, but with extent
tree v2 we'll need a bytenr to look up a extent root which makes the
usage of the extent_root awkward here.  Simply change it to the
chunk_root.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:48 +01:00
Josef Bacik 76d76e789d btrfs: make remove_extent_backref pass the root 
With extent tree v2 we'll have a different extent root based on where
the bytenr is located, so adjust the remove_extent_backref() helper and
it's helpers to pass the extent_root around.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:48 +01:00
Josef Bacik dfe8aec452 btrfs: add a btrfs_block_group_root() helper 
With extent tree v2 we will have a separate root to hold the block group
items.  Add a btrfs_block_group_root() that will return the appropriate
root given the flags of the fs, and convert all functions that need to
modify block group items to use the helper.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:47 +01:00
Josef Bacik 9f05c09d6b btrfs: remove BUG_ON(!eie) in find_parent_nodes 
If we're looking for leafs that point to a data extent we want to record
the extent items that point at our bytenr.  At this point we have the
reference and we know for a fact that this leaf should have a reference
to our bytenr.  However if there's some sort of corruption we may not
find any references to our leaf, and thus could end up with eie == NULL.
Replace this BUG_ON() with an ASSERT() and then return -EUCLEAN for the
mortals.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:47 +01:00
Josef Bacik fcba0120ed btrfs: remove BUG_ON() in find_parent_nodes() 
We search for an extent entry with .offset = -1, which shouldn't be a
thing, but corruption happens.  Add an ASSERT() for the developers,
return -EUCLEAN for mortals.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:47 +01:00
Josef Bacik e0b7661d44 btrfs: remove SANITY_TESTS check form find_parent_nodes 
We define __TRANS_DUMMY always, so this extra ifdef stuff is not needed.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:47 +01:00
Josef Bacik 9665ebd5db btrfs: move comment in find_parent_nodes() 
This comment was much closer to the related code when it was originally
added, but has slowly migrated north far from its ancestral lands.  Move
it back down with its people.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:47 +01:00
Josef Bacik 98cc42227a btrfs: pass the root to add_keyed_refs 
We pass in the path, but use btrfs_next_item() using the root we
searched with.  Pass the root down to add_keyed_refs() instead of the
fs_info so we can continue to use the same root we searched with.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:47 +01:00
Josef Bacik 7a60751a33 btrfs: remove trans_handle->root 
Nobody is using this anymore, remove it.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:47 +01:00
Josef Bacik 2e4e97abac btrfs: pass fs_info to trace_btrfs_transaction_commit 
The root on the trans->root can be anything, and generally we're
committing from the transaction kthread so it's usually the tree_root.
Change this to just take an fs_info, and to maintain compatibility
simply put the ROOT_TREE_OBJECTID as the root objectid for the
tracepoint.  This will allow use to remove trans->root.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:47 +01:00
Josef Bacik fdfbf02066 btrfs: rework async transaction committing 
Currently we do this awful thing where we get another ref on a trans
handle, async off that handle and commit the transaction from that work.
Because we do this we have to mess with current->journal_info and the
freeze counting stuff.

We already have an async thing to kick for the transaction commit, the
transaction kthread.  Replace this work struct with a flag on the
fs_info to tell the kthread to go ahead and commit even if it's before
our timeout.  Then we can drastically simplify the async transaction
commit path.

Note: this can be simplified and functionality based on the pending
operation COMMIT.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
[ add note ]
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:46 +01:00
Josef Bacik 0af4769da6 btrfs: remove unused BTRFS_FS_BARRIER flag 
This is no longer used, the -o nobarrier is handled by
BTRFS_MOUNT_NOBARRIER.  Remove the flag.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:46 +01:00
Nikolay Borisov f1a8fc6265 btrfs: eliminate if in main loop in tree_search_offset 
Reshuffle the code inside the first loop of tree_search_offset so that
one if() is eliminated and the becomes more linear.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:46 +01:00
Qu Wenruo bf08387fb4 btrfs: don't check stripe length if the profile is not stripe based 
[BUG]
When debugging calc_bio_boundaries(), I found that even for RAID1
metadata, we're following stripe length to calculate stripe boundary.

  # mkfs.btrfs -m raid1 -d raid1 /dev/test/scratch[12]
  # mount /dev/test/scratch /mnt/btrfs
  # xfs_io -f -c "pwrite 0 64K" /mnt/btrfs/file
  # umount

Above very basic operations will make calc_bio_boundaries() to report
the following result:

  submit_extent_page: r/i=1/1 file_offset=22036480 len_to_stripe_boundary=49152
  submit_extent_page: r/i=1/1 file_offset=30474240 len_to_stripe_boundary=65536
  ...
  submit_extent_page: r/i=1/1 file_offset=30523392 len_to_stripe_boundary=16384
  submit_extent_page: r/i=1/1 file_offset=30457856 len_to_stripe_boundary=16384
  submit_extent_page: r/i=5/257 file_offset=0 len_to_stripe_boundary=65536
  submit_extent_page: r/i=5/257 file_offset=65536 len_to_stripe_boundary=65536
  submit_extent_page: r/i=1/1 file_offset=30490624 len_to_stripe_boundary=49152
  submit_extent_page: r/i=1/1 file_offset=30507008 len_to_stripe_boundary=32768

Where "r/i" is the rootid and inode, 1/1 means they metadata.
The remaining names match the member used in kernel.

Even all data/metadata are using RAID1, we're still following stripe
length.

[CAUSE]
This behavior is caused by a wrong condition in btrfs_get_io_geometry():

	if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
		/* Fill using stripe_len */
		len = min_t(u64, em->len - offset, max_len);
	} else {
		len = em->len - offset;
	}

This means, only for SINGLE we will not follow stripe_len.

However for profiles like RAID1*, DUP, they don't need to bother
stripe_len.

This can lead to unnecessary bio split for RAID1*/DUP profiles, and can
even be a blockage for future zoned RAID support.

[FIX]
Introduce one single-use macro, BTRFS_BLOCK_GROUP_STRIPE_MASK, and
change the condition to only calculate the length using stripe length
for stripe based profiles.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:46 +01:00
Nikolay Borisov 167c0bd377 btrfs: get next entry in tree_search_offset before doing checks 
This is a small optimisation since the currently 'entry' is already
checked in the if () {} else if {} construct above the loop. In essence
the first iteration of the final while loop is redundant. To eliminate
this extra check simply get the next entry at the beginning of the loop.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:46 +01:00
Josef Bacik bbf27275f2 btrfs: add self test for bytes_index free space cache 
I noticed a few corner cases when looking at my bytes_index patch for
obvious bugs, so add a bunch of tests to validate proper behavior of the
bytes_index tree.  A couple of basic tests to make sure it puts things
in the correct order, and then more complicated tests to make sure it
re-arranges bitmap entries properly and does the right thing when we try
to make allocations.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:46 +01:00
Josef Bacik 59c7b566a3 btrfs: index free space entries on size 
Currently we index free space on offset only, because usually we have a
hint from the allocator that we want to honor for locality reasons.
However if we fail to use this hint we have to go back to a brute force
search through the free space entries to find a large enough extent.

With sufficiently fragmented free space this becomes quite expensive, as
we have to linearly search all of the free space entries to find if we
have a part that's long enough.

To fix this add a cached rb tree to index based on free space entry
bytes.  This will allow us to quickly look up the largest chunk in the
free space tree for this block group, and stop searching once we've
found an entry that is too small to satisfy our allocation.  We simply
choose to use this tree if we're searching from the beginning of the
block group, as we know we do not care about locality at that point.

I wrote an allocator test that creates a 10TiB ram backed null block
device and then fallocates random files until the file system is full.
I think go through and delete all of the odd files.  Then I spawn 8
threads that fallocate 64MiB files (1/2 our extent size cap) until the
file system is full again.  I use bcc's funclatency to measure the
latency of find_free_extent.  The baseline results are

     nsecs               : count     distribution
         0 -> 1          : 0        |                                        |
         2 -> 3          : 0        |                                        |
         4 -> 7          : 0        |                                        |
         8 -> 15         : 0        |                                        |
        16 -> 31         : 0        |                                        |
        32 -> 63         : 0        |                                        |
        64 -> 127        : 0        |                                        |
       128 -> 255        : 0        |                                        |
       256 -> 511        : 10356    |****                                    |
       512 -> 1023       : 58242    |*************************               |
      1024 -> 2047       : 74418    |********************************        |
      2048 -> 4095       : 90393    |****************************************|
      4096 -> 8191       : 79119    |***********************************     |
      8192 -> 16383      : 35614    |***************                         |
     16384 -> 32767      : 13418    |*****                                   |
     32768 -> 65535      : 12811    |*****                                   |
     65536 -> 131071     : 17090    |*******                                 |
    131072 -> 262143     : 26465    |***********                             |
    262144 -> 524287     : 40179    |*****************                       |
    524288 -> 1048575    : 55469    |************************                |
   1048576 -> 2097151    : 48807    |*********************                   |
   2097152 -> 4194303    : 26744    |***********                             |
   4194304 -> 8388607    : 35351    |***************                         |
   8388608 -> 16777215   : 13918    |******                                  |
  16777216 -> 33554431   : 21       |                                        |

avg = 908079 nsecs, total: 580889071441 nsecs, count: 639690

And the patch results are

     nsecs               : count     distribution
         0 -> 1          : 0        |                                        |
         2 -> 3          : 0        |                                        |
         4 -> 7          : 0        |                                        |
         8 -> 15         : 0        |                                        |
        16 -> 31         : 0        |                                        |
        32 -> 63         : 0        |                                        |
        64 -> 127        : 0        |                                        |
       128 -> 255        : 0        |                                        |
       256 -> 511        : 6883     |**                                      |
       512 -> 1023       : 54346    |*********************                   |
      1024 -> 2047       : 79170    |********************************        |
      2048 -> 4095       : 98890    |****************************************|
      4096 -> 8191       : 81911    |*********************************       |
      8192 -> 16383      : 27075    |**********                              |
     16384 -> 32767      : 14668    |*****                                   |
     32768 -> 65535      : 13251    |*****                                   |
     65536 -> 131071     : 15340    |******                                  |
    131072 -> 262143     : 26715    |**********                              |
    262144 -> 524287     : 43274    |*****************                       |
    524288 -> 1048575    : 53870    |*********************                   |
   1048576 -> 2097151    : 55368    |**********************                  |
   2097152 -> 4194303    : 41036    |****************                        |
   4194304 -> 8388607    : 24927    |**********                              |
   8388608 -> 16777215   : 33       |                                        |
  16777216 -> 33554431   : 9        |                                        |

avg = 623599 nsecs, total: 397259314759 nsecs, count: 637042

There's a little variation in the amount of calls done because of timing
of the threads with metadata requirements, but the avg, total, and
count's are relatively consistent between runs (usually within 2-5% of
each other).  As you can see here we have around a 30% decrease in
average latency with a 30% decrease in overall time spent in
find_free_extent.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:46 +01:00
Josef Bacik 950575c023 btrfs: only use ->max_extent_size if it is set in the bitmap 
While adding self tests for my space index change I was hitting a
problem where the space indexed tree wasn't returning the expected
->max_extent_size.  This is because we will skip searching any entry
that doesn't have ->bytes >= the amount of bytes we want.  However we'll
still set the max_extent_size based on that entry.  The problem is if we
don't search the bitmap we won't have ->max_extent_size set properly, so
we can't really trust it.

This doesn't really result in a problem per-se, it can just result in us
not finding contiguous area that may exist.  Fix the max_extent_size
helper to return ->bytes if ->max_extent_size isn't set, and add a big
comment explaining why we're doing this.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:46 +01:00
Qu Wenruo 83f1b68002 btrfs: remove unnecessary @nr_written parameters 
We use @nr_written to record how many pages have been started by
btrfs_run_delalloc_range().

Currently there are only two cases that would populate @nr_written:

- Inline extent creation
- Compressed write

But both cases will also set @page_started to one.

In fact, in writepage_delalloc() we have the following code, showing
that @nr_written is really only utilized for above two cases:

	/* did the fill delalloc function already unlock and start
	 * the IO?
	 */
	if (page_started) {
		/*
		 * we've unlocked the page, so we can't update
		 * the mapping's writeback index, just update
		 * nr_to_write.
		 */
		wbc->nr_to_write -= nr_written;
		return 1;
	}

But for such cases, writepage_delalloc() will return 1, and exit
__extent_writepage() without going through __extent_writepage_io().

Thus this means, inside __extent_writepage_io(), we always get
@nr_written as 0.

So this patch is going to remove the unnecessary parameter from the
following functions:

- writepage_delalloc()

  As @nr_written passed in is always the initial value 0.

  Although inside that function, we still need a local @nr_written
  to update wbc->nr_to_write.

- __extent_writepage_io()

  As explained above, @nr_written passed in can only be 0.

  This also means we can remove one update_nr_written() call.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:45 +01:00
Josef Bacik 9270501c16 btrfs: change root to fs_info for btrfs_reserve_metadata_bytes 
We used to need the root for btrfs_reserve_metadata_bytes to check the
orphan cleanup state, but we no longer need that, we simply need the
fs_info.  Change btrfs_reserve_metadata_bytes() to use the fs_info, and
change both btrfs_block_rsv_refill() and btrfs_block_rsv_add() to do the
same as they simply call btrfs_reserve_metadata_bytes() and then
manipulate the block_rsv that is being used.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:45 +01:00
Josef Bacik 54230013d4 btrfs: get rid of root->orphan_cleanup_state 
Now that we don't care about the stage of the orphan_cleanup_state,
simply replace it with a bit on ->state to make sure we don't call the
orphan cleanup every time we wander into this root.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:45 +01:00
Josef Bacik 6dbdd578cd btrfs: remove global rsv stealing logic for orphan cleanup 
This is very old code before we were stealing from the global reserve
during evict.  We have proper ways to steal from the global reserve
while we're evicting, so rip out this code as it's no longer necessary.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:45 +01:00
Josef Bacik ee6adbfd6a btrfs: make BTRFS_RESERVE_FLUSH_EVICT use the global rsv stealing code 
I forgot to convert this over when I introduced the global reserve
stealing code to the space flushing code.  Evict was simply trying to
make its reservation and then if it failed it would steal from the
global rsv, which is racey because it's outside of the normal ticketing
code.

Fix this by setting ticket->steal if we are BTRFS_RESERVE_FLUSH_EVICT,
and then make the priority flushing path do the steal for us.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:45 +01:00
Josef Bacik 1b0309eaa4 btrfs: check ticket->steal in steal_from_global_block_rsv 
We're going to use this helper in the priority flushing loop, move this
check into the helper to simplify the logic.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:45 +01:00
Josef Bacik 9cd8dcdc5e btrfs: check for priority ticket granting before flushing 
Since we're dropping locks before we enter the priority flushing loops
we could have had our ticket granted before we got the space_info->lock.
So add this check to avoid doing some extra flushing in the priority
flushing cases.

The case in priority_reclaim_metadata_space is an optimization.  Think
we came in to reserve, we didn't have the space, we added our ticket to
the list.  But at the same time somebody was waiting on the space_info
lock to add space and do btrfs_try_granting_ticket(), so we drop the
lock, get satisfied, come in to do our loop, and we have been
satisfied.

This is the priority reclaim path, so to_reclaim could be !0 still
because we may have only satisfied the priority tickets and still left
non priority tickets on the list.  We would then have to_reclaim but
->bytes == 0.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
[ add note about the optimization ]
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:45 +01:00
Josef Bacik 9f35f76d7d btrfs: handle priority ticket failures in their respective helpers 
Currently the error case for the priority tickets is handled where we
deal with all of the tickets, priority and non-priority.  This is OK in
general, but it makes for some awkward locking.  We take and drop the
space_info->lock back to back because of these different types of
tickets.

Rework the code to handle priority ticket failures in their respective
helpers.  This allows us to be less wonky with our space_info->lock
usage, and means that the main handler simply has to check
ticket->error, as the ticket is guaranteed to be off any list and
completely handled by the time it exits one of the handlers.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:45 +01:00
Naohiro Aota 16beac87e9 btrfs: zoned: cache reported zone during mount 
When mounting a device, we are reporting the zones twice: once for
checking the zone attributes in btrfs_get_dev_zone_info and once for
loading block groups' zone info in
btrfs_load_block_group_zone_info(). With a lot of block groups, that
leads to a lot of REPORT ZONE commands and slows down the mount
process.

This patch introduces a zone info cache in struct
btrfs_zoned_device_info. The cache is populated while in
btrfs_get_dev_zone_info() and used for
btrfs_load_block_group_zone_info() to reduce the number of REPORT ZONE
commands. The zone cache is then released after loading the block
groups, as it will not be much effective during the run time.

Benchmark: Mount an HDD with 57,007 block groups
Before patch: 171.368 seconds
After patch: 64.064 seconds

While it still takes a minute due to the slowness of loading all the
block groups, the patch reduces the mount time by 1/3.

Link: https://lore.kernel.org/linux-btrfs/CAHQ7scUiLtcTqZOMMY5kbWUBOhGRwKo6J6wYPT5WY+C=cD49nQ@mail.gmail.com/
Fixes: 5b31646898 ("btrfs: get zone information of zoned block devices")
CC: stable@vger.kernel.org
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:44 +01:00
Su Yue d21deec5e7 btrfs: remove unused parameter fs_devices from btrfs_init_workqueues 
Since commit ba8a9d0795 ("Btrfs: delete the entire async bio submission
framework") removed submit workqueues, the parameter fs_devices is not used
anymore.

Remove it, no functional changes.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Su Yue <l@damenly.su>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:44 +01:00
Filipe Manana dfba78dc1c btrfs: reduce the scope of the tree log mutex during transaction commit 
In the transaction commit path we are acquiring the tree log mutex too
early and we have a stale comment because:

1) It mentions a function named btrfs_commit_tree_roots(), which does not
   exists anymore, it was the old name of commit_cowonly_roots(), renamed
   a very long time ago by commit 5d4f98a28c ("Btrfs: Mixed back
   reference  (FORWARD ROLLING FORMAT CHANGE)"));

2) It mentions that we need to acquire the tree log mutex at that point
   to ensure we have no running log writers. That is not correct anymore,
   for many years at least, since we are guaranteed that we do not have
   any log writers at that point simply because we have set the state of
   the transaction to TRANS_STATE_COMMIT_DOING and have waited for all
   writers to complete - meaning no one can log until we change the state
   of the transaction to TRANS_STATE_UNBLOCKED. Any attempts to join the
   transaction or start a new one will block until we do that state
   transition;

3) The comment mentions a "trans mutex" which doesn't exists since 2011,
   commit a4abeea41a ("Btrfs: kill trans_mutex") removed it;

4) The current use of the tree log mutex is to ensure proper serialization
   of super block writes - if someone started a new transaction and uses it
   for logging, it will wait for the previous transaction to write its
   super block before writing the super block when attempting to sync the
   log.

So acquire the tree log mutex only when it's absolutely needed, before
setting the transaction state to TRANS_STATE_UNBLOCKED, fix and move the
stale comment, add some assertions and new comments where appropriate.

Also, this has no effect on concurrency or performance, since the new
start of the critical section is still when the transaction is in the
state TRANS_STATE_COMMIT_DOING.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:44 +01:00
Anand Jain 849eae5e57 btrfs: consolidate device_list_mutex in prepare_sprout to its parent 
btrfs_prepare_sprout() splices seed devices into its own struct fs_devices,
so that its parent function btrfs_init_new_device() can add the new sprout
device to fs_info->fs_devices.

Both btrfs_prepare_sprout() and btrfs_init_new_device() need
device_list_mutex. But they are holding it separately, thus create a
small race window. Close it and hold device_list_mutex across both
functions btrfs_init_new_device() and btrfs_prepare_sprout().

Split btrfs_prepare_sprout() into btrfs_init_sprout() and
btrfs_setup_sprout(). This split is essential because device_list_mutex
must not be held for allocations in btrfs_init_sprout() but must be held
for btrfs_setup_sprout(). So now a common device_list_mutex can be used
between btrfs_init_new_device() and btrfs_setup_sprout().

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:44 +01:00
Anand Jain fd8808097a btrfs: switch seeding_dev in init_new_device to bool 
Declare int seeding_dev as a bool. Also, move its declaration a line
below to adjust packing.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:44 +01:00
Omar Sandoval b1dea4e732 btrfs: send: remove unused type parameter to iterate_inode_ref_t 
Again, I don't think this was ever used since iterate_dir_item() is only
used for xattrs. No functional change.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:44 +01:00
Omar Sandoval eab67c0645 btrfs: send: remove unused found_type parameter to lookup_dir_item_inode() 
As far as I can tell, this was never used. No functional change.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:43 +01:00
Josef Bacik dc2e724e0f btrfs: rename btrfs_item_end_nr to btrfs_item_data_end 
The name btrfs_item_end_nr() is a bit of a misnomer, as it's actually
the offset of the end of the data the item points to.  In fact all of
the helpers that we use btrfs_item_end_nr() use data in their name, like
BTRFS_LEAF_DATA_SIZE() and leaf_data().  Rename to btrfs_item_data_end()
to make it clear what this helper is giving us.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:43 +01:00
Josef Bacik 5a08663d01 btrfs: remove the btrfs_item_end() helper 
We're only using btrfs_item_end() from btrfs_item_end_nr(), so this can
be collapsed.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:43 +01:00
Josef Bacik 3212fa14e7 btrfs: drop the _nr from the item helpers 
Now that all call sites are using the slot number to modify item values,
rename the SETGET helpers to raw_item_*(), and then rework the _nr()
helpers to be the btrfs_item_*() btrfs_set_item_*() helpers, and then
rename all of the callers to the new helpers.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:43 +01:00
Josef Bacik 7479420736 btrfs: introduce item_nr token variant helpers 
The last remaining place where we have the pattern of

	item = btrfs_item_nr(slot)
	<do something with the item>

are the token helpers.  Handle this by introducing token helpers that
will do the btrfs_item_nr() work inside of the helper itself, and then
convert all users of the btrfs_item token helpers to the new _nr()
variants.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:43 +01:00
Josef Bacik 437bd07e6c btrfs: make btrfs_file_extent_inline_item_len take a slot 
Instead of getting the btrfs_item for this, simply pass in the slot of
the item and then use the btrfs_item_size_nr() helper inside of
btrfs_file_extent_inline_item_len().

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:43 +01:00
Josef Bacik c91666b1f6 btrfs: add btrfs_set_item_*_nr() helpers 
We have the pattern of

	item = btrfs_item_nr(slot);
	btrfs_set_item_*(leaf, item);

in a bunch of places in our code.  Fix this by adding
btrfs_set_item_*_nr() helpers which will do the appropriate work, and
replace those calls with

	btrfs_set_item_*_nr(leaf, slot);

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:42 +01:00
Josef Bacik 227f3cd0d5 btrfs: use btrfs_item_size_nr/btrfs_item_offset_nr everywhere 
We have this pattern in a lot of places

	item = btrfs_item_nr(slot);
	btrfs_item_size(leaf, item);

when we could simply use

	btrfs_item_size(leaf, slot);

Fix all callers of btrfs_item_size() and btrfs_item_offset() to use the
_nr variation of the helpers.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:42 +01:00
Filipe Manana ccae4a19c9 btrfs: remove no longer needed logic for replaying directory deletes 
Now that we log only dir index keys when logging a directory, we no longer
need to deal with dir item keys in the log replay code for replaying
directory deletes. This is also true for the case when we replay a log
tree created by a kernel that still logs dir items.

So remove the remaining code of the replay of directory deletes algorithm
that deals with dir item keys.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:42 +01:00
Filipe Manana 339d035424 btrfs: only copy dir index keys when logging a directory 
Currently, when logging a directory, we copy both dir items and dir index
items from the fs/subvolume tree to the log tree. Both items have exactly
the same data (same struct btrfs_dir_item), the difference lies in the key
values, where a dir index key contains the index number of a directory
entry while the dir item key does not, as it's used for doing fast lookups
of an entry by name, while the former is used for sorting entries when
listing a directory.

We can exploit that and log only the dir index items, since they contain
all the information needed to correctly add, replace and delete directory
entries when replaying a log tree. Logging only the dir index items is
also backward and forward compatible: an unpatched kernel (without this
change) can correctly replay a log tree generated by a patched kernel
(with this patch), and a patched kernel can correctly replay a log tree
generated by an unpatched kernel.

The backward compatibility is ensured because:

1) For inserting a new dentry: a dentry is only inserted when we find a
   new dir index key - we can only insert if we know the dir index offset,
   which is encoded in the dir index key's offset;

2) For deleting dentries: during log replay, before adding or replacing
   dentries, we first replay dentry deletions. Whenever we find a dir item
   key or a dir index key in the subvolume/fs tree that is not logged in
   a range for which the log tree is authoritative, we do the unlink of
   the dentry, which removes both the existing dir item key and the dir
   index key. Therefore logging just dir index keys is enough to ensure
   dentry deletions are correctly replayed;

3) For dentry replacements: they work when we log only dir index keys
   and this is mostly due to a combination of 1) and 2). If we replace a
   dentry with name "foobar" to point from inode A to inode B, then we
   know the dir index key for the new dentry is different from the old
   one, as it has an index number (key offset) larger than the old one.
   This results in replaying a deletion, through replay_dir_deletes(),
   that causes the old dentry to be removed, both the dir item key and
   the dir index key, as mentioned at 2). Then when processing the new
   dir index key, we add the new dentry, adding both a new dir item key
   and a new index key pointing to inode B, as stated in 1).

The forward compatibility, the ability for a patched kernel to replay a
log created by an older, unpatched kernel, comes from the changes required
for making sure we are able to replay a log that only contains dir index
keys - we simply ignore every dir item key we find.

So modify directory logging to log only dir index items, and modify the
log replay process to ignore dir item keys, from log trees created by an
unpatched kernel, and process only with dir index keys. This reduces the
amount of logged metadata by about half, and therefore the time spent
logging or fsyncing large directories (less CPU time and less IO).

The following test script was used to measure this change:

   #!/bin/bash

   DEV=/dev/nvme0n1
   MNT=/mnt/nvme0n1

   NUM_NEW_FILES=1000000
   NUM_FILE_DELETES=10000

   mkfs.btrfs -f $DEV
   mount -o ssd $DEV $MNT

   mkdir $MNT/testdir

   for ((i = 1; i <= $NUM_NEW_FILES; i++)); do
           echo -n > $MNT/testdir/file_$i
   done

   start=$(date +%s%N)
   xfs_io -c "fsync" $MNT/testdir
   end=$(date +%s%N)

   dur=$(( (end - start) / 1000000 ))
   echo "dir fsync took $dur ms after adding $NUM_NEW_FILES files"

   # sync to force transaction commit and wipeout the log.
   sync

   del_inc=$(( $NUM_NEW_FILES / $NUM_FILE_DELETES ))
   for ((i = 1; i <= $NUM_NEW_FILES; i += $del_inc)); do
           rm -f $MNT/testdir/file_$i
   done

   start=$(date +%s%N)
   xfs_io -c "fsync" $MNT/testdir
   end=$(date +%s%N)

   dur=$(( (end - start) / 1000000 ))
   echo "dir fsync took $dur ms after deleting $NUM_FILE_DELETES files"
   echo

   umount $MNT

The tests were run on a physical machine, with a non-debug kernel (Debian's
default kernel config), for different values of $NUM_NEW_FILES and
$NUM_FILE_DELETES, and the results were the following:

** Before patch, NUM_NEW_FILES = 1 000 000, NUM_DELETE_FILES = 10 000 **

dir fsync took 8412 ms after adding 1000000 files
dir fsync took 500 ms after deleting 10000 files

** After patch, NUM_NEW_FILES = 1 000 000, NUM_DELETE_FILES = 10 000 **

dir fsync took 4252 ms after adding 1000000 files   (-49.5%)
dir fsync took 269 ms after deleting 10000 files    (-46.2%)

** Before patch, NUM_NEW_FILES = 100 000, NUM_DELETE_FILES = 1 000 **

dir fsync took 745 ms after adding 100000 files
dir fsync took 59 ms after deleting 1000 files

** After patch, NUM_NEW_FILES = 100 000, NUM_DELETE_FILES = 1 000 **

dir fsync took 404 ms after adding 100000 files   (-45.8%)
dir fsync took 31 ms after deleting 1000 files    (-47.5%)

** Before patch, NUM_NEW_FILES = 10 000, NUM_DELETE_FILES = 1 000 **

dir fsync took 67 ms after adding 10000 files
dir fsync took 9 ms after deleting 1000 files

** After patch, NUM_NEW_FILES = 10 000, NUM_DELETE_FILES = 1 000 **

dir fsync took 36 ms after adding 10000 files   (-46.3%)
dir fsync took 5 ms after deleting 1000 files   (-44.4%)

** Before patch, NUM_NEW_FILES = 1 000, NUM_DELETE_FILES = 100 **

dir fsync took 9 ms after adding 1000 files
dir fsync took 4 ms after deleting 100 files

** After patch, NUM_NEW_FILES = 1 000, NUM_DELETE_FILES = 100 **

dir fsync took 7 ms after adding 1000 files     (-22.2%)
dir fsync took 3 ms after deleting 100 files    (-25.0%)

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:42 +01:00
Nikolay Borisov 17130a65f0 btrfs: remove spurious unlock/lock of unused_bgs_lock 
Since both unused block groups and reclaim bgs lists are protected by
unused_bgs_lock then free them in the same critical section without
doing an extra unlock/lock pair.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:42 +01:00
Filipe Manana 232796df8c btrfs: fix deadlock between quota enable and other quota operations 
When enabling quotas, we attempt to commit a transaction while holding the
mutex fs_info->qgroup_ioctl_lock. This can result on a deadlock with other
quota operations such as:

- qgroup creation and deletion, ioctl BTRFS_IOC_QGROUP_CREATE;

- adding and removing qgroup relations, ioctl BTRFS_IOC_QGROUP_ASSIGN.

This is because these operations join a transaction and after that they
attempt to lock the mutex fs_info->qgroup_ioctl_lock. Acquiring that mutex
after joining or starting a transaction is a pattern followed everywhere
in qgroups, so the quota enablement operation is the one at fault here,
and should not commit a transaction while holding that mutex.

Fix this by making the transaction commit while not holding the mutex.
We are safe from two concurrent tasks trying to enable quotas because
we are serialized by the rw semaphore fs_info->subvol_sem at
btrfs_ioctl_quota_ctl(), which is the only call site for enabling
quotas.

When this deadlock happens, it produces a trace like the following:

  INFO: task syz-executor:25604 blocked for more than 143 seconds.
  Not tainted 5.15.0-rc6 #4
  "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  task:syz-executor state:D stack:24800 pid:25604 ppid: 24873 flags:0x00004004
  Call Trace:
  context_switch kernel/sched/core.c:4940 [inline]
  __schedule+0xcd9/0x2530 kernel/sched/core.c:6287
  schedule+0xd3/0x270 kernel/sched/core.c:6366
  btrfs_commit_transaction+0x994/0x2e90 fs/btrfs/transaction.c:2201
  btrfs_quota_enable+0x95c/0x1790 fs/btrfs/qgroup.c:1120
  btrfs_ioctl_quota_ctl fs/btrfs/ioctl.c:4229 [inline]
  btrfs_ioctl+0x637e/0x7b70 fs/btrfs/ioctl.c:5010
  vfs_ioctl fs/ioctl.c:51 [inline]
  __do_sys_ioctl fs/ioctl.c:874 [inline]
  __se_sys_ioctl fs/ioctl.c:860 [inline]
  __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
  do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
  entry_SYSCALL_64_after_hwframe+0x44/0xae
  RIP: 0033:0x7f86920b2c4d
  RSP: 002b:00007f868f61ac58 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
  RAX: ffffffffffffffda RBX: 00007f86921d90a0 RCX: 00007f86920b2c4d
  RDX: 0000000020005e40 RSI: 00000000c0109428 RDI: 0000000000000008
  RBP: 00007f869212bd80 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 00007f86921d90a0
  R13: 00007fff6d233e4f R14: 00007fff6d233ff0 R15: 00007f868f61adc0
  INFO: task syz-executor:25628 blocked for more than 143 seconds.
  Not tainted 5.15.0-rc6 #4
  "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  task:syz-executor state:D stack:29080 pid:25628 ppid: 24873 flags:0x00004004
  Call Trace:
  context_switch kernel/sched/core.c:4940 [inline]
  __schedule+0xcd9/0x2530 kernel/sched/core.c:6287
  schedule+0xd3/0x270 kernel/sched/core.c:6366
  schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6425
  __mutex_lock_common kernel/locking/mutex.c:669 [inline]
  __mutex_lock+0xc96/0x1680 kernel/locking/mutex.c:729
  btrfs_remove_qgroup+0xb7/0x7d0 fs/btrfs/qgroup.c:1548
  btrfs_ioctl_qgroup_create fs/btrfs/ioctl.c:4333 [inline]
  btrfs_ioctl+0x683c/0x7b70 fs/btrfs/ioctl.c:5014
  vfs_ioctl fs/ioctl.c:51 [inline]
  __do_sys_ioctl fs/ioctl.c:874 [inline]
  __se_sys_ioctl fs/ioctl.c:860 [inline]
  __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
  do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
  entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported-by: Hao Sun <sunhao.th@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/CACkBjsZQF19bQ1C6=yetF3BvL10OSORpFUcWXTP6HErshDB4dQ@mail.gmail.com/
Fixes: 340f1aa27f ("btrfs: qgroups: Move transaction management inside btrfs_quota_enable/disable")
CC: stable@vger.kernel.org # 4.19
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:41 +01:00
Filipe Manana f0bfa76a11 btrfs: fix ENOSPC failure when attempting direct IO write into NOCOW range 
When doing a direct IO write against a file range that either has
preallocated extents in that range or has regular extents and the file
has the NOCOW attribute set, the write fails with -ENOSPC when all of
the following conditions are met:

1) There are no data blocks groups with enough free space matching
   the size of the write;

2) There's not enough unallocated space for allocating a new data block
   group;

3) The extents in the target file range are not shared, neither through
   snapshots nor through reflinks.

This is wrong because a NOCOW write can be done in such case, and in fact
it's possible to do it using a buffered IO write, since when failing to
allocate data space, the buffered IO path checks if a NOCOW write is
possible.

The failure in direct IO write path comes from the fact that early on,
at btrfs_dio_iomap_begin(), we try to allocate data space for the write
and if it that fails we return the error and stop - we never check if we
can do NOCOW. But later, at btrfs_get_blocks_direct_write(), we check
if we can do a NOCOW write into the range, or a subset of the range, and
then release the previously reserved data space.

Fix this by doing the data reservation only if needed, when we must COW,
at btrfs_get_blocks_direct_write() instead of doing it at
btrfs_dio_iomap_begin(). This also simplifies a bit the logic and removes
the inneficiency of doing unnecessary data reservations.

The following example test script reproduces the problem:

  $ cat dio-nocow-enospc.sh
  #!/bin/bash

  DEV=/dev/sdj
  MNT=/mnt/sdj

  # Use a small fixed size (1G) filesystem so that it's quick to fill
  # it up.
  # Make sure the mixed block groups feature is not enabled because we
  # later want to not have more space available for allocating data
  # extents but still have enough metadata space free for the file writes.
  mkfs.btrfs -f -b $((1024 * 1024 * 1024)) -O ^mixed-bg $DEV
  mount $DEV $MNT

  # Create our test file with the NOCOW attribute set.
  touch $MNT/foobar
  chattr +C $MNT/foobar

  # Now fill in all unallocated space with data for our test file.
  # This will allocate a data block group that will be full and leave
  # no (or a very small amount of) unallocated space in the device, so
  # that it will not be possible to allocate a new block group later.
  echo
  echo "Creating test file with initial data..."
  xfs_io -c "pwrite -S 0xab -b 1M 0 900M" $MNT/foobar

  # Now try a direct IO write against file range [0, 10M[.
  # This should succeed since this is a NOCOW file and an extent for the
  # range was previously allocated.
  echo
  echo "Trying direct IO write over allocated space..."
  xfs_io -d -c "pwrite -S 0xcd -b 10M 0 10M" $MNT/foobar

  umount $MNT

When running the test:

  $ ./dio-nocow-enospc.sh
  (...)

  Creating test file with initial data...
  wrote 943718400/943718400 bytes at offset 0
  900 MiB, 900 ops; 0:00:01.43 (625.526 MiB/sec and 625.5265 ops/sec)

  Trying direct IO write over allocated space...
  pwrite: No space left on device

A test case for fstests will follow, testing both this direct IO write
scenario as well as the buffered IO write scenario to make it less likely
to get future regressions on the buffered IO case.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2022-01-03 15:09:41 +01:00
Linus Torvalds 9609134186 for-5.16-rc5-tag 
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmG8+tEACgkQxWXV+ddt
 WDuuGA/9E75ZMqsMLW5az7z8Rt5voBjPeweyRHmGCLZKpgfaj0QjrJRvu0CTKU/W
 zCSQf+ShTTY2D3cmh1eEwKyX/waKQ71qBrMX/SgIeA0OjmlhK1UGB18MF5sAVGCB
 mymVYJh7IntYJE7S7OiMUL/yILmIWZYrYT+iaPZlIc9M6h0b1gjMIsE0VEmxJMCN
 X8RAQ4CfL9bpTTKItNehSyXx+J7TB5yamh5AspaiB/ivyN1DcUcsFf3AoaWXeh2D
 YIBzq4WbGnDMfUdWXKE2rqDfQgaTXtN9ffGUvphJnegg8Tqfp29LyLZ1GU0qGSXc
 /K8g5QNmM3nhubXq2MG5zfbHPJ1H2CgnvkDqiCcyeop+09yj/ugxTt+ULaIbJL76
 pKSpcuIFXTmoW2Z7ZwijIEX4H5Dgk2l2DbE8SkJT4LjJybgpHfBT1KDQrj5iQdx+
 XgmG/CbRELuGGltJNuldp0SqIyMNRgDuv6Rheg9N9H73m9epwfH5oiM0Fj/FYyQ6
 lfgle6DQCP4xaDmk1zA9zrJHTUqi8Caeyg+tQYT6AbkoeCoXnvEAPgv9OOGe1M+C
 Ks7zeAseWs3A/j/+wCdiCKombOfR+AY3RGkPzlodUJj4YYOTyXrigtb5yhTz6Zdv
 ozVBZ71LUMMOf0NV45mGtqsiLqyfe3cnlqj1XtHQKaajyjgHvW8=
 =G7CE
 -----END PGP SIGNATURE-----

Merge tag 'for-5.16-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "A few more fixes, almost all error handling one-liners and for stable.

   - regression fix in directory logging items

   - regression fix of extent buffer status bits handling after an error

   - fix memory leak in error handling path in tree-log

   - fix freeing invalid anon device number when handling errors during
     subvolume creation

   - fix warning when freeing leaf after subvolume creation failure

   - fix missing blkdev put in device scan error handling

   - fix invalid delayed ref after subvolume creation failure"

* tag 'for-5.16-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: fix missing blkdev_put() call in btrfs_scan_one_device()
  btrfs: fix warning when freeing leaf after subvolume creation failure
  btrfs: fix invalid delayed ref after subvolume creation failure
  btrfs: check WRITE_ERR when trying to read an extent buffer
  btrfs: fix missing last dir item offset update when logging directory
  btrfs: fix double free of anon_dev after failure to create subvolume
  btrfs: fix memory leak in __add_inode_ref()
 2021-12-17 13:50:58 -08:00
Shin'ichiro Kawasaki 4989d4a0ae btrfs: fix missing blkdev_put() call in btrfs_scan_one_device() 
The function btrfs_scan_one_device() calls blkdev_get_by_path() and
blkdev_put() to get and release its target block device. However, when
btrfs_sb_log_location_bdev() fails, blkdev_put() is not called and the
block device is left without clean up. This triggered failure of fstests
generic/085. Fix the failure path of btrfs_sb_log_location_bdev() to
call blkdev_put().

Fixes: 12659251ca ("btrfs: implement log-structured superblock for ZONED mode")
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-12-15 17:07:34 +01:00
Filipe Manana 212a58fda9 btrfs: fix warning when freeing leaf after subvolume creation failure 
When creating a subvolume, at ioctl.c:create_subvol(), if we fail to
insert the root item for the new subvolume into the root tree, we can
trigger the following warning:

[78961.741046] WARNING: CPU: 0 PID: 4079814 at fs/btrfs/extent-tree.c:3357 btrfs_free_tree_block+0x2af/0x310 [btrfs]
[78961.743344] Modules linked in:
[78961.749440]  dm_snapshot dm_thin_pool (...)
[78961.773648] CPU: 0 PID: 4079814 Comm: fsstress Not tainted 5.16.0-rc4-btrfs-next-108 #1
[78961.775198] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[78961.777266] RIP: 0010:btrfs_free_tree_block+0x2af/0x310 [btrfs]
[78961.778398] Code: 17 00 48 85 (...)
[78961.781067] RSP: 0018:ffffaa4001657b28 EFLAGS: 00010202
[78961.781877] RAX: 0000000000000213 RBX: ffff897f8a796910 RCX: 0000000000000000
[78961.782780] RDX: 0000000000000000 RSI: 0000000011004000 RDI: 00000000ffffffff
[78961.783764] RBP: ffff8981f490e800 R08: 0000000000000001 R09: 0000000000000000
[78961.784740] R10: 0000000000000000 R11: 0000000000000001 R12: ffff897fc963fcc8
[78961.785665] R13: 0000000000000001 R14: ffff898063548000 R15: ffff898063548000
[78961.786620] FS:  00007f31283c6b80(0000) GS:ffff8982ace00000(0000) knlGS:0000000000000000
[78961.787717] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[78961.788598] CR2: 00007f31285c3000 CR3: 000000023fcc8003 CR4: 0000000000370ef0
[78961.789568] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[78961.790585] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[78961.791684] Call Trace:
[78961.792082]  <TASK>
[78961.792359]  create_subvol+0x5d1/0x9a0 [btrfs]
[78961.793054]  btrfs_mksubvol+0x447/0x4c0 [btrfs]
[78961.794009]  ? preempt_count_add+0x49/0xa0
[78961.794705]  __btrfs_ioctl_snap_create+0x123/0x190 [btrfs]
[78961.795712]  ? _copy_from_user+0x66/0xa0
[78961.796382]  btrfs_ioctl_snap_create_v2+0xbb/0x140 [btrfs]
[78961.797392]  btrfs_ioctl+0xd1e/0x35c0 [btrfs]
[78961.798172]  ? __slab_free+0x10a/0x360
[78961.798820]  ? rcu_read_lock_sched_held+0x12/0x60
[78961.799664]  ? lock_release+0x223/0x4a0
[78961.800321]  ? lock_acquired+0x19f/0x420
[78961.800992]  ? rcu_read_lock_sched_held+0x12/0x60
[78961.801796]  ? trace_hardirqs_on+0x1b/0xe0
[78961.802495]  ? _raw_spin_unlock_irqrestore+0x3e/0x60
[78961.803358]  ? kmem_cache_free+0x321/0x3c0
[78961.804071]  ? __x64_sys_ioctl+0x83/0xb0
[78961.804711]  __x64_sys_ioctl+0x83/0xb0
[78961.805348]  do_syscall_64+0x3b/0xc0
[78961.805969]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[78961.806830] RIP: 0033:0x7f31284bc957
[78961.807517] Code: 3c 1c 48 f7 d8 (...)

This is because we are calling btrfs_free_tree_block() on an extent
buffer that is dirty. Fix that by cleaning the extent buffer, with
btrfs_clean_tree_block(), before freeing it.

This was triggered by test case generic/475 from fstests.

Fixes: 67addf2900 ("btrfs: fix metadata extent leak after failure to create subvolume")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-12-15 17:07:33 +01:00
Filipe Manana 7a1636089a btrfs: fix invalid delayed ref after subvolume creation failure 
When creating a subvolume, at ioctl.c:create_subvol(), if we fail to
insert the new root's root item into the root tree, we are freeing the
metadata extent we reserved for the new root to prevent a metadata
extent leak, as we don't abort the transaction at that point (since
there is nothing at that point that is irreversible).

However we allocated the metadata extent for the new root which we are
creating for the new subvolume, so its delayed reference refers to the
ID of this new root. But when we free the metadata extent we pass the
root of the subvolume where the new subvolume is located to
btrfs_free_tree_block() - this is incorrect because this will generate
a delayed reference that refers to the ID of the parent subvolume's root,
and not to ID of the new root.

This results in a failure when running delayed references that leads to
a transaction abort and a trace like the following:

[3868.738042] RIP: 0010:__btrfs_free_extent+0x709/0x950 [btrfs]
[3868.739857] Code: 68 0f 85 e6 fb ff (...)
[3868.742963] RSP: 0018:ffffb0e9045cf910 EFLAGS: 00010246
[3868.743908] RAX: 00000000fffffffe RBX: 00000000fffffffe RCX: 0000000000000002
[3868.745312] RDX: 00000000fffffffe RSI: 0000000000000002 RDI: ffff90b0cd793b88
[3868.746643] RBP: 000000000e5d8000 R08: 0000000000000000 R09: ffff90b0cd793b88
[3868.747979] R10: 0000000000000002 R11: 00014ded97944d68 R12: 0000000000000000
[3868.749373] R13: ffff90b09afe4a28 R14: 0000000000000000 R15: ffff90b0cd793b88
[3868.750725] FS:  00007f281c4a8b80(0000) GS:ffff90b3ada00000(0000) knlGS:0000000000000000
[3868.752275] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[3868.753515] CR2: 00007f281c6a5000 CR3: 0000000108a42006 CR4: 0000000000370ee0
[3868.754869] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[3868.756228] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[3868.757803] Call Trace:
[3868.758281]  <TASK>
[3868.758655]  ? btrfs_merge_delayed_refs+0x178/0x1c0 [btrfs]
[3868.759827]  __btrfs_run_delayed_refs+0x2b1/0x1250 [btrfs]
[3868.761047]  btrfs_run_delayed_refs+0x86/0x210 [btrfs]
[3868.762069]  ? lock_acquired+0x19f/0x420
[3868.762829]  btrfs_commit_transaction+0x69/0xb20 [btrfs]
[3868.763860]  ? _raw_spin_unlock+0x29/0x40
[3868.764614]  ? btrfs_block_rsv_release+0x1c2/0x1e0 [btrfs]
[3868.765870]  create_subvol+0x1d8/0x9a0 [btrfs]
[3868.766766]  btrfs_mksubvol+0x447/0x4c0 [btrfs]
[3868.767669]  ? preempt_count_add+0x49/0xa0
[3868.768444]  __btrfs_ioctl_snap_create+0x123/0x190 [btrfs]
[3868.769639]  ? _copy_from_user+0x66/0xa0
[3868.770391]  btrfs_ioctl_snap_create_v2+0xbb/0x140 [btrfs]
[3868.771495]  btrfs_ioctl+0xd1e/0x35c0 [btrfs]
[3868.772364]  ? __slab_free+0x10a/0x360
[3868.773198]  ? rcu_read_lock_sched_held+0x12/0x60
[3868.774121]  ? lock_release+0x223/0x4a0
[3868.774863]  ? lock_acquired+0x19f/0x420
[3868.775634]  ? rcu_read_lock_sched_held+0x12/0x60
[3868.776530]  ? trace_hardirqs_on+0x1b/0xe0
[3868.777373]  ? _raw_spin_unlock_irqrestore+0x3e/0x60
[3868.778280]  ? kmem_cache_free+0x321/0x3c0
[3868.779011]  ? __x64_sys_ioctl+0x83/0xb0
[3868.779718]  __x64_sys_ioctl+0x83/0xb0
[3868.780387]  do_syscall_64+0x3b/0xc0
[3868.781059]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[3868.781953] RIP: 0033:0x7f281c59e957
[3868.782585] Code: 3c 1c 48 f7 d8 4c (...)
[3868.785867] RSP: 002b:00007ffe1f83e2b8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
[3868.787198] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f281c59e957
[3868.788450] RDX: 00007ffe1f83e2c0 RSI: 0000000050009418 RDI: 0000000000000003
[3868.789748] RBP: 00007ffe1f83f300 R08: 0000000000000000 R09: 00007ffe1f83fe36
[3868.791214] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003
[3868.792468] R13: 0000000000000003 R14: 00007ffe1f83e2c0 R15: 00000000000003cc
[3868.793765]  </TASK>
[3868.794037] irq event stamp: 0
[3868.794548] hardirqs last  enabled at (0): [<0000000000000000>] 0x0
[3868.795670] hardirqs last disabled at (0): [<ffffffff98294214>] copy_process+0x934/0x2040
[3868.797086] softirqs last  enabled at (0): [<ffffffff98294214>] copy_process+0x934/0x2040
[3868.798309] softirqs last disabled at (0): [<0000000000000000>] 0x0
[3868.799284] ---[ end trace be24c7002fe27747 ]---
[3868.799928] BTRFS info (device dm-0): leaf 241188864 gen 1268 total ptrs 214 free space 469 owner 2
[3868.801133] BTRFS info (device dm-0): refs 2 lock_owner 225627 current 225627
[3868.802056]  item 0 key (237436928 169 0) itemoff 16250 itemsize 33
[3868.802863]          extent refs 1 gen 1265 flags 2
[3868.803447]          ref#0: tree block backref root 1610
(...)
[3869.064354]  item 114 key (241008640 169 0) itemoff 12488 itemsize 33
[3869.065421]          extent refs 1 gen 1268 flags 2
[3869.066115]          ref#0: tree block backref root 1689
(...)
[3869.403834] BTRFS error (device dm-0): unable to find ref byte nr 241008640 parent 0 root 1622  owner 0 offset 0
[3869.405641] BTRFS: error (device dm-0) in __btrfs_free_extent:3076: errno=-2 No such entry
[3869.407138] BTRFS: error (device dm-0) in btrfs_run_delayed_refs:2159: errno=-2 No such entry

Fix this by passing the new subvolume's root ID to btrfs_free_tree_block().
This requires changing the root argument of btrfs_free_tree_block() from
struct btrfs_root * to a u64, since at this point during the subvolume
creation we have not yet created the struct btrfs_root for the new
subvolume, and btrfs_free_tree_block() only needs a root ID and nothing
else from a struct btrfs_root.

This was triggered by test case generic/475 from fstests.

Fixes: 67addf2900 ("btrfs: fix metadata extent leak after failure to create subvolume")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-12-15 17:07:33 +01:00
Josef Bacik 651740a502 btrfs: check WRITE_ERR when trying to read an extent buffer 
Filipe reported a hang when we have errors on btrfs.  This turned out to
be a side-effect of my fix c2e3930529 ("btrfs: clear extent buffer
uptodate when we fail to write it") which made it so we clear
EXTENT_BUFFER_UPTODATE on an eb when we fail to write it out.

Below is a paste of Filipe's analysis he got from using drgn to debug
the hang

"""
btree readahead code calls read_extent_buffer_pages(), sets ->io_pages to
a value while writeback of all pages has not yet completed:
   --> writeback for the first 3 pages finishes, we clear
       EXTENT_BUFFER_UPTODATE from eb on the first page when we get an
       error.
   --> at this point eb->io_pages is 1 and we cleared Uptodate bit from the
       first 3 pages
   --> read_extent_buffer_pages() does not see EXTENT_BUFFER_UPTODATE() so
       it continues, it's able to lock the pages since we obviously don't
       hold the pages locked during writeback
   --> read_extent_buffer_pages() then computes 'num_reads' as 3, and sets
       eb->io_pages to 3, since only the first page does not have Uptodate
       bit set at this point
   --> writeback for the remaining page completes, we ended decrementing
       eb->io_pages by 1, resulting in eb->io_pages == 2, and therefore
       never calling end_extent_buffer_writeback(), so
       EXTENT_BUFFER_WRITEBACK remains in the eb's flags
   --> of course, when the read bio completes, it doesn't and shouldn't
       call end_extent_buffer_writeback()
   --> we should clear EXTENT_BUFFER_UPTODATE only after all pages of
       the eb finished writeback?  or maybe make the read pages code
       wait for writeback of all pages of the eb to complete before
       checking which pages need to be read, touch ->io_pages, submit
       read bio, etc

writeback bit never cleared means we can hang when aborting a
transaction, at:

    btrfs_cleanup_one_transaction()
       btrfs_destroy_marked_extents()
         wait_on_extent_buffer_writeback()
"""

This is a problem because our writes are not synchronized with reads in
any way.  We clear the UPTODATE flag and then we can easily come in and
try to read the EB while we're still waiting on other bio's to
complete.

We have two options here, we could lock all the pages, and then check to
see if eb->io_pages != 0 to know if we've already got an outstanding
write on the eb.

Or we can simply check to see if we have WRITE_ERR set on this extent
buffer.  We set this bit _before_ we clear UPTODATE, so if the read gets
triggered because we aren't UPTODATE because of a write error we're
guaranteed to have WRITE_ERR set, and in this case we can simply return
-EIO.  This will fix the reported hang.

Reported-by: Filipe Manana <fdmanana@suse.com>
Fixes: c2e3930529 ("btrfs: clear extent buffer uptodate when we fail to write it")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-12-15 17:07:31 +01:00
Filipe Manana 1b2e5e5c7f btrfs: fix missing last dir item offset update when logging directory 
When logging a directory, once we finish processing a leaf that is full
of dir items, if we find the next leaf was not modified in the current
transaction, we grab the first key of that next leaf and log it as to
mark the end of a key range boundary.

However we did not update the value of ctx->last_dir_item_offset, which
tracks the offset of the last logged key. This can result in subsequent
logging of the same directory in the current transaction to not realize
that key was already logged, and then add it to the middle of a batch
that starts with a lower key, resulting later in a leaf with one key
that is duplicated and at non-consecutive slots. When that happens we get
an error later when writing out the leaf, reporting that there is a pair
of keys in wrong order. The report is something like the following:

Dec 13 21:44:50 kernel: BTRFS critical (device dm-0): corrupt leaf:
root=18446744073709551610 block=118444032 slot=21, bad key order, prev
(704687 84 4146773349) current (704687 84 1063561078)
Dec 13 21:44:50 kernel: BTRFS info (device dm-0): leaf 118444032 gen
91449 total ptrs 39 free space 546 owner 18446744073709551610
Dec 13 21:44:50 kernel:         item 0 key (704687 1 0) itemoff 3835
itemsize 160
Dec 13 21:44:50 kernel:                 inode generation 35532 size
1026 mode 40755
Dec 13 21:44:50 kernel:         item 1 key (704687 12 704685) itemoff
3822 itemsize 13
Dec 13 21:44:50 kernel:         item 2 key (704687 24 3817753667)
itemoff 3736 itemsize 86
Dec 13 21:44:50 kernel:         item 3 key (704687 60 0) itemoff 3728 itemsize 8
Dec 13 21:44:50 kernel:         item 4 key (704687 72 0) itemoff 3720 itemsize 8
Dec 13 21:44:50 kernel:         item 5 key (704687 84 140445108)
itemoff 3666 itemsize 54
Dec 13 21:44:50 kernel:                 dir oid 704793 type 1
Dec 13 21:44:50 kernel:         item 6 key (704687 84 298800632)
itemoff 3599 itemsize 67
Dec 13 21:44:50 kernel:                 dir oid 707849 type 2
Dec 13 21:44:50 kernel:         item 7 key (704687 84 476147658)
itemoff 3532 itemsize 67
Dec 13 21:44:50 kernel:                 dir oid 707901 type 2
Dec 13 21:44:50 kernel:         item 8 key (704687 84 633818382)
itemoff 3471 itemsize 61
Dec 13 21:44:50 kernel:                 dir oid 704694 type 2
Dec 13 21:44:50 kernel:         item 9 key (704687 84 654256665)
itemoff 3403 itemsize 68
Dec 13 21:44:50 kernel:                 dir oid 707841 type 1
Dec 13 21:44:50 kernel:         item 10 key (704687 84 995843418)
itemoff 3331 itemsize 72
Dec 13 21:44:50 kernel:                 dir oid 2167736 type 1
Dec 13 21:44:50 kernel:         item 11 key (704687 84 1063561078)
itemoff 3278 itemsize 53
Dec 13 21:44:50 kernel:                 dir oid 704799 type 2
Dec 13 21:44:50 kernel:         item 12 key (704687 84 1101156010)
itemoff 3225 itemsize 53
Dec 13 21:44:50 kernel:                 dir oid 704696 type 1
Dec 13 21:44:50 kernel:         item 13 key (704687 84 2521936574)
itemoff 3173 itemsize 52
Dec 13 21:44:50 kernel:                 dir oid 704704 type 2
Dec 13 21:44:50 kernel:         item 14 key (704687 84 2618368432)
itemoff 3112 itemsize 61
Dec 13 21:44:50 kernel:                 dir oid 704738 type 1
Dec 13 21:44:50 kernel:         item 15 key (704687 84 2676316190)
itemoff 3046 itemsize 66
Dec 13 21:44:50 kernel:                 dir oid 2167729 type 1
Dec 13 21:44:50 kernel:         item 16 key (704687 84 3319104192)
itemoff 2986 itemsize 60
Dec 13 21:44:50 kernel:                 dir oid 704745 type 2
Dec 13 21:44:50 kernel:         item 17 key (704687 84 3908046265)
itemoff 2929 itemsize 57
Dec 13 21:44:50 kernel:                 dir oid 2167734 type 1
Dec 13 21:44:50 kernel:         item 18 key (704687 84 3945713089)
itemoff 2857 itemsize 72
Dec 13 21:44:50 kernel:                 dir oid 2167730 type 1
Dec 13 21:44:50 kernel:         item 19 key (704687 84 4077169308)
itemoff 2795 itemsize 62
Dec 13 21:44:50 kernel:                 dir oid 704688 type 1
Dec 13 21:44:50 kernel:         item 20 key (704687 84 4146773349)
itemoff 2727 itemsize 68
Dec 13 21:44:50 kernel:                 dir oid 707892 type 1
Dec 13 21:44:50 kernel:         item 21 key (704687 84 1063561078)
itemoff 2674 itemsize 53
Dec 13 21:44:50 kernel:                 dir oid 704799 type 2
Dec 13 21:44:50 kernel:         item 22 key (704687 96 2) itemoff 2612
itemsize 62
Dec 13 21:44:50 kernel:         item 23 key (704687 96 6) itemoff 2551
itemsize 61
Dec 13 21:44:50 kernel:         item 24 key (704687 96 7) itemoff 2498
itemsize 53
Dec 13 21:44:50 kernel:         item 25 key (704687 96 12) itemoff
2446 itemsize 52
Dec 13 21:44:50 kernel:         item 26 key (704687 96 14) itemoff
2385 itemsize 61
Dec 13 21:44:50 kernel:         item 27 key (704687 96 18) itemoff
2325 itemsize 60
Dec 13 21:44:50 kernel:         item 28 key (704687 96 24) itemoff
2271 itemsize 54
Dec 13 21:44:50 kernel:         item 29 key (704687 96 28) itemoff
2218 itemsize 53
Dec 13 21:44:50 kernel:         item 30 key (704687 96 62) itemoff
2150 itemsize 68
Dec 13 21:44:50 kernel:         item 31 key (704687 96 66) itemoff
2083 itemsize 67
Dec 13 21:44:50 kernel:         item 32 key (704687 96 75) itemoff
2015 itemsize 68
Dec 13 21:44:50 kernel:         item 33 key (704687 96 79) itemoff
1948 itemsize 67
Dec 13 21:44:50 kernel:         item 34 key (704687 96 82) itemoff
1882 itemsize 66
Dec 13 21:44:50 kernel:         item 35 key (704687 96 83) itemoff
1810 itemsize 72
Dec 13 21:44:50 kernel:         item 36 key (704687 96 85) itemoff
1753 itemsize 57
Dec 13 21:44:50 kernel:         item 37 key (704687 96 87) itemoff
1681 itemsize 72
Dec 13 21:44:50 kernel:         item 38 key (704694 1 0) itemoff 1521
itemsize 160
Dec 13 21:44:50 kernel:                 inode generation 35534 size 30
mode 40755
Dec 13 21:44:50 kernel: BTRFS error (device dm-0): block=118444032
write time tree block corruption detected

So fix that by adding the missing update of ctx->last_dir_item_offset with
the offset of the boundary key.

Reported-by: Chris Murphy <lists@colorremedies.com>
Link: https://lore.kernel.org/linux-btrfs/CAJCQCtT+RSzpUjbMq+UfzNUMe1X5+1G+DnAGbHC=OZ=iRS24jg@mail.gmail.com/
Fixes: dc2872247e ("btrfs: keep track of the last logged keys when logging a directory")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-12-14 15:52:10 +01:00
Filipe Manana 33fab97249 btrfs: fix double free of anon_dev after failure to create subvolume 
When creating a subvolume, at create_subvol(), we allocate an anonymous
device and later call btrfs_get_new_fs_root(), which in turn just calls
btrfs_get_root_ref(). There we call btrfs_init_fs_root() which assigns
the anonymous device to the root, but if after that call there's an error,
when we jump to 'fail' label, we call btrfs_put_root(), which frees the
anonymous device and then returns an error that is propagated back to
create_subvol(). Than create_subvol() frees the anonymous device again.

When this happens, if the anonymous device was not reallocated after
the first time it was freed with btrfs_put_root(), we get a kernel
message like the following:

  (...)
  [13950.282466] BTRFS: error (device dm-0) in create_subvol:663: errno=-5 IO failure
  [13950.283027] ida_free called for id=65 which is not allocated.
  [13950.285974] BTRFS info (device dm-0): forced readonly
  (...)

If the anonymous device gets reallocated by another btrfs filesystem
or any other kernel subsystem, then bad things can happen.

So fix this by setting the root's anonymous device to 0 at
btrfs_get_root_ref(), before we call btrfs_put_root(), if an error
happened.

Fixes: 2dfb1e43f5 ("btrfs: preallocate anon block device at first phase of snapshot creation")
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-12-14 15:52:04 +01:00
Jianglei Nie f35838a693 btrfs: fix memory leak in __add_inode_ref() 
Line 1169 (#3) allocates a memory chunk for victim_name by kmalloc(),
but  when the function returns in line 1184 (#4) victim_name allocated
by line 1169 (#3) is not freed, which will lead to a memory leak.
There is a similar snippet of code in this function as allocating a memory
chunk for victim_name in line 1104 (#1) as well as releasing the memory
in line 1116 (#2).

We should kfree() victim_name when the return value of backref_in_log()
is less than zero and before the function returns in line 1184 (#4).

1057 static inline int __add_inode_ref(struct btrfs_trans_handle *trans,
1058 				  struct btrfs_root *root,
1059 				  struct btrfs_path *path,
1060 				  struct btrfs_root *log_root,
1061 				  struct btrfs_inode *dir,
1062 				  struct btrfs_inode *inode,
1063 				  u64 inode_objectid, u64 parent_objectid,
1064 				  u64 ref_index, char *name, int namelen,
1065 				  int *search_done)
1066 {

1104 	victim_name = kmalloc(victim_name_len, GFP_NOFS);
	// #1: kmalloc (victim_name-1)
1105 	if (!victim_name)
1106 		return -ENOMEM;

1112	ret = backref_in_log(log_root, &search_key,
1113			parent_objectid, victim_name,
1114			victim_name_len);
1115	if (ret < 0) {
1116		kfree(victim_name); // #2: kfree (victim_name-1)
1117		return ret;
1118	} else if (!ret) {

1169 	victim_name = kmalloc(victim_name_len, GFP_NOFS);
	// #3: kmalloc (victim_name-2)
1170 	if (!victim_name)
1171 		return -ENOMEM;

1180 	ret = backref_in_log(log_root, &search_key,
1181 			parent_objectid, victim_name,
1182 			victim_name_len);
1183 	if (ret < 0) {
1184 		return ret; // #4: missing kfree (victim_name-2)
1185 	} else if (!ret) {

1241 	return 0;
1242 }

Fixes: d3316c8233 ("btrfs: Properly handle backref_in_log retval")
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Jianglei Nie <niejianglei2021@163.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-12-14 15:52:00 +01:00
Linus Torvalds 6f51352929 for-5.16-rc4-tag 
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmGwxl8ACgkQxWXV+ddt
 WDvSeQ//T+mv4o7ucldQZCVdN0TTVCkQUhia+ZdMwBcPty2/ZEdap+KEIVmfCV/v
 OLRmSNkIPDhHcIc/O3zJ1/AY0DFbb9brYGkMD/qidgPbRArhDZSrDIr+xnrKJ0iq
 HFxM01B54l8hJe6GWIGFuuOz+nXUP1o9SfiDOwMDTkqgzz1JSvPec70RKMxG8pTC
 4plVrGaUXkKTC8WyBXnSvkP2gvjfJxqnEKv2Ru1eP1t7Bq65aed0+Z32Mogzl2ip
 ZSHVlRergeB03xF9YErWSfgofVWLEIXgLCh/Wfq73sMnHUHUGM/dpEKxP911MI00
 A5TuTl3I25cVnDv3qMayBPECMCCGZc2vUyXTLCWUNYLb/vEUTI36QBu/KglRURmO
 Zx20B+3/7Yu9pFeZ23S+nlNdGDADmjkOfvZIZDoYDzqBAKWM6kZ/9oWiib21Uwi6
 ql5oZNl7G6UXLPvgJoq8dqZIj/HYeLEHeqwf/tepSVQLXYzQyWYDMp686z958XI1
 K/A/TKaKk19nn1Dhsz4KJeb3xhMFlFN30K7BNjdH3XRH1RrwJP6pLF/WUduJq2qn
 rAvJoODLHkby1D9+HqSKW/RToeR5NbBYYdfB0Q8zpy9zF/gZX7wgFc21/4B7qtib
 hkKfNSfAVjedOJJWTFCUDnZwwrqtcrKxYzUpdcls/O1AjifK7+U=
 =Mh19
 -----END PGP SIGNATURE-----

Merge tag 'for-5.16-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "A few more regression fixes and stable patches, mostly one-liners.

  Regression fixes:

   - fix pointer/ERR_PTR mismatch returned from memdup_user

   - reset dedicated zoned mode relocation block group to avoid using it
     and filling it without any recourse

  Fixes:

   - handle a case to FITRIM range (also to make fstests/generic/260
     work)

   - fix warning when extent buffer state and pages get out of sync
     after an IO error

   - fix transaction abort when syncing due to missing mapping error set
     on metadata inode after inlining a compressed file

   - fix transaction abort due to tree-log and zoned mode interacting in
     an unexpected way

   - fix memory leak of additional extent data when qgroup reservation
     fails

   - do proper handling of slot search call when deleting root refs"

* tag 'for-5.16-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: replace the BUG_ON in btrfs_del_root_ref with proper error handling
  btrfs: zoned: clear data relocation bg on zone finish
  btrfs: free exchange changeset on failures
  btrfs: fix re-dirty process of tree-log nodes
  btrfs: call mapping_set_error() on btree inode with a write error
  btrfs: clear extent buffer uptodate when we fail to write it
  btrfs: fail if fstrim_range->start == U64_MAX
  btrfs: fix error pointer dereference in btrfs_ioctl_rm_dev_v2()
 2021-12-10 17:28:02 -08:00
Qu Wenruo 8289ed9f93 btrfs: replace the BUG_ON in btrfs_del_root_ref with proper error handling 
I hit the BUG_ON() with generic/475 test case, and to my surprise, all
callers of btrfs_del_root_ref() are already aborting transaction, thus
there is not need for such BUG_ON(), just go to @out label and caller
will properly handle the error.

CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-12-08 15:45:27 +01:00
Johannes Thumshirn 5911f53820 btrfs: zoned: clear data relocation bg on zone finish 
When finishing a zone that is used by a dedicated data relocation
block group, also remove its reference from fs_info, so we're not trying
to use a full block group for allocations during data relocation, which
will always fail.

The result is we're not making any forward progress and end up in a
deadlock situation.

Fixes: c2707a2556 ("btrfs: zoned: add a dedicated data relocation block group")
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-12-08 15:42:32 +01:00
Johannes Thumshirn da5e817d9d btrfs: free exchange changeset on failures 
Fstests runs on my VMs have show several kmemleak reports like the following.

  unreferenced object 0xffff88811ae59080 (size 64):
    comm "xfs_io", pid 12124, jiffies 4294987392 (age 6.368s)
    hex dump (first 32 bytes):
      00 c0 1c 00 00 00 00 00 ff cf 1c 00 00 00 00 00  ................
      90 97 e5 1a 81 88 ff ff 90 97 e5 1a 81 88 ff ff  ................
    backtrace:
      [<00000000ac0176d2>] ulist_add_merge+0x60/0x150 [btrfs]
      [<0000000076e9f312>] set_state_bits+0x86/0xc0 [btrfs]
      [<0000000014fe73d6>] set_extent_bit+0x270/0x690 [btrfs]
      [<000000004f675208>] set_record_extent_bits+0x19/0x20 [btrfs]
      [<00000000b96137b1>] qgroup_reserve_data+0x274/0x310 [btrfs]
      [<0000000057e9dcbb>] btrfs_check_data_free_space+0x5c/0xa0 [btrfs]
      [<0000000019c4511d>] btrfs_delalloc_reserve_space+0x1b/0xa0 [btrfs]
      [<000000006d37e007>] btrfs_dio_iomap_begin+0x415/0x970 [btrfs]
      [<00000000fb8a74b8>] iomap_iter+0x161/0x1e0
      [<0000000071dff6ff>] __iomap_dio_rw+0x1df/0x700
      [<000000002567ba53>] iomap_dio_rw+0x5/0x20
      [<0000000072e555f8>] btrfs_file_write_iter+0x290/0x530 [btrfs]
      [<000000005eb3d845>] new_sync_write+0x106/0x180
      [<000000003fb505bf>] vfs_write+0x24d/0x2f0
      [<000000009bb57d37>] __x64_sys_pwrite64+0x69/0xa0
      [<000000003eba3fdf>] do_syscall_64+0x43/0x90

In case brtfs_qgroup_reserve_data() or btrfs_delalloc_reserve_metadata()
fail the allocated extent_changeset will not be freed.

So in btrfs_check_data_free_space() and btrfs_delalloc_reserve_space()
free the allocated extent_changeset to get rid of the allocated memory.

The issue currently only happens in the direct IO write path, but only
after 65b3c08606e5 ("btrfs: fix ENOSPC failure when attempting direct IO
write into NOCOW range"), and also at defrag_one_locked_target(). Every
other place is always calling extent_changeset_free() even if its call
to btrfs_delalloc_reserve_space() or btrfs_check_data_free_space() has
failed.

CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-12-08 15:42:32 +01:00
Naohiro Aota 84c2544892 btrfs: fix re-dirty process of tree-log nodes 
There is a report of a transaction abort of -EAGAIN with the following
script.

  #!/bin/sh

  for d in sda sdb; do
          mkfs.btrfs -d single -m single -f /dev/\${d}
  done

  mount /dev/sda /mnt/test
  mount /dev/sdb /mnt/scratch

  for dir in test scratch; do
          echo 3 >/proc/sys/vm/drop_caches
          fio --directory=/mnt/\${dir} --name=fio.\${dir} --rw=read --size=50G --bs=64m \
                  --numjobs=$(nproc) --time_based --ramp_time=5 --runtime=480 \
                  --group_reporting |& tee /dev/shm/fio.\${dir}
          echo 3 >/proc/sys/vm/drop_caches
  done

  for d in sda sdb; do
          umount /dev/\${d}
  done

The stack trace is shown in below.

  [3310.967991] BTRFS: error (device sda) in btrfs_commit_transaction:2341: errno=-11 unknown (Error while writing out transaction)
  [3310.968060] BTRFS info (device sda): forced readonly
  [3310.968064] BTRFS warning (device sda): Skipping commit of aborted transaction.
  [3310.968065] ------------[ cut here ]------------
  [3310.968066] BTRFS: Transaction aborted (error -11)
  [3310.968074] WARNING: CPU: 14 PID: 1684 at fs/btrfs/transaction.c:1946 btrfs_commit_transaction.cold+0x209/0x2c8
  [3310.968131] CPU: 14 PID: 1684 Comm: fio Not tainted 5.14.10-300.fc35.x86_64 #1
  [3310.968135] Hardware name: DIAWAY Tartu/Tartu, BIOS V2.01.B10 04/08/2021
  [3310.968137] RIP: 0010:btrfs_commit_transaction.cold+0x209/0x2c8
  [3310.968144] RSP: 0018:ffffb284ce393e10 EFLAGS: 00010282
  [3310.968147] RAX: 0000000000000026 RBX: ffff973f147b0f60 RCX: 0000000000000027
  [3310.968149] RDX: ffff974ecf098a08 RSI: 0000000000000001 RDI: ffff974ecf098a00
  [3310.968150] RBP: ffff973f147b0f08 R08: 0000000000000000 R09: ffffb284ce393c48
  [3310.968151] R10: ffffb284ce393c40 R11: ffffffff84f47468 R12: ffff973f101bfc00
  [3310.968153] R13: ffff971f20cf2000 R14: 00000000fffffff5 R15: ffff973f147b0e58
  [3310.968154] FS:  00007efe65468740(0000) GS:ffff974ecf080000(0000) knlGS:0000000000000000
  [3310.968157] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [3310.968158] CR2: 000055691bcbe260 CR3: 000000105cfa4001 CR4: 0000000000770ee0
  [3310.968160] PKRU: 55555554
  [3310.968161] Call Trace:
  [3310.968167]  ? dput+0xd4/0x300
  [3310.968174]  btrfs_sync_file+0x3f1/0x490
  [3310.968180]  __x64_sys_fsync+0x33/0x60
  [3310.968185]  do_syscall_64+0x3b/0x90
  [3310.968190]  entry_SYSCALL_64_after_hwframe+0x44/0xae
  [3310.968194] RIP: 0033:0x7efe6557329b
  [3310.968200] RSP: 002b:00007ffe0236ebc0 EFLAGS: 00000293 ORIG_RAX: 000000000000004a
  [3310.968203] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007efe6557329b
  [3310.968204] RDX: 0000000000000000 RSI: 00007efe58d77010 RDI: 0000000000000006
  [3310.968205] RBP: 0000000004000000 R08: 0000000000000000 R09: 00007efe58d77010
  [3310.968207] R10: 0000000016cacc0c R11: 0000000000000293 R12: 00007efe5ce95980
  [3310.968208] R13: 0000000000000000 R14: 00007efe6447c790 R15: 0000000c80000000
  [3310.968212] ---[ end trace 1a346f4d3c0d96ba ]---
  [3310.968214] BTRFS: error (device sda) in cleanup_transaction:1946: errno=-11 unknown

The abort occurs because of a write hole while writing out freeing tree
nodes of a tree-log tree. For zoned btrfs, we re-dirty a freed tree
node to ensure btrfs can write the region and does not leave a hole on
write on a zoned device. The current code fails to re-dirty a node
when the tree-log tree's depth is greater or equal to 2. That leads to
a transaction abort with -EAGAIN.

Fix the issue by properly re-dirtying a node on walking up the tree.

Fixes: d3575156f6 ("btrfs: zoned: redirty released extent buffers")
CC: stable@vger.kernel.org # 5.12+
Link: https://github.com/kdave/btrfs-progs/issues/415
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-12-08 15:42:32 +01:00
Josef Bacik 68b85589ba btrfs: call mapping_set_error() on btree inode with a write error 
generic/484 fails sometimes with compression on because the write ends
up small enough that it goes into the btree.  This means that we never
call mapping_set_error() on the inode itself, because the page gets
marked as fine when we inline it into the metadata.  When the metadata
writeback happens we see it and abort the transaction properly and mark
the fs as readonly, however we don't do the mapping_set_error() on
anything.  In syncfs() we will simply return 0 if the sb is marked
read-only, so we can't check for this in our syncfs callback.  The only
way the error gets returned if we called mapping_set_error() on
something.  Fix this by calling mapping_set_error() on the btree inode
mapping.  This allows us to properly return an error on syncfs and pass
generic/484 with compression on.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-12-08 15:42:32 +01:00
Josef Bacik c2e3930529 btrfs: clear extent buffer uptodate when we fail to write it 
I got dmesg errors on generic/281 on our overnight fstests.  Looking at
the history this happens occasionally, with errors like this

  WARNING: CPU: 0 PID: 673217 at fs/btrfs/extent_io.c:6848 assert_eb_page_uptodate+0x3f/0x50
  CPU: 0 PID: 673217 Comm: kworker/u4:13 Tainted: G        W         5.16.0-rc2+ #469
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
  Workqueue: btrfs-cache btrfs_work_helper
  RIP: 0010:assert_eb_page_uptodate+0x3f/0x50
  RSP: 0018:ffffae598230bc60 EFLAGS: 00010246
  RAX: 0017ffffc0002112 RBX: ffffebaec4100900 RCX: 0000000000001000
  RDX: ffffebaec45733c7 RSI: ffffebaec4100900 RDI: ffff9fd98919f340
  RBP: 0000000000000d56 R08: ffff9fd98e300000 R09: 0000000000000000
  R10: 0001207370a91c50 R11: 0000000000000000 R12: 00000000000007b0
  R13: ffff9fd98919f340 R14: 0000000001500000 R15: 0000000001cb0000
  FS:  0000000000000000(0000) GS:ffff9fd9fbc00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007f549fcf8940 CR3: 0000000114908004 CR4: 0000000000370ef0
  Call Trace:

   extent_buffer_test_bit+0x3f/0x70
   free_space_test_bit+0xa6/0xc0
   load_free_space_tree+0x1d6/0x430
   caching_thread+0x454/0x630
   ? rcu_read_lock_sched_held+0x12/0x60
   ? rcu_read_lock_sched_held+0x12/0x60
   ? rcu_read_lock_sched_held+0x12/0x60
   ? lock_release+0x1f0/0x2d0
   btrfs_work_helper+0xf2/0x3e0
   ? lock_release+0x1f0/0x2d0
   ? finish_task_switch.isra.0+0xf9/0x3a0
   process_one_work+0x270/0x5a0
   worker_thread+0x55/0x3c0
   ? process_one_work+0x5a0/0x5a0
   kthread+0x174/0x1a0
   ? set_kthread_struct+0x40/0x40
   ret_from_fork+0x1f/0x30

This happens because we're trying to read from a extent buffer page that
is !PageUptodate.  This happens because we will clear the page uptodate
when we have an IO error, but we don't clear the extent buffer uptodate.
If we do a read later and find this extent buffer we'll think its valid
and not return an error, and then trip over this warning.

Fix this by also clearing uptodate on the extent buffer when this
happens, so that we get an error when we do a btrfs_search_slot() and
find this block later.

CC: stable@vger.kernel.org # 5.4+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-12-08 15:42:32 +01:00
Josef Bacik f981fec12c btrfs: fail if fstrim_range->start == U64_MAX 
We've always been failing generic/260 because it's testing things we
actually don't care about and thus won't fail for.  However we probably
should fail for fstrim_range->start == U64_MAX since we clearly can't
trim anything past that.  This in combination with an update to
generic/260 will allow us to pass this test properly.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-12-08 15:42:24 +01:00
Dan Carpenter d815b3f2f2 btrfs: fix error pointer dereference in btrfs_ioctl_rm_dev_v2() 
If memdup_user() fails the error handing will crash when it tries
to kfree() an error pointer.  Just return directly because there is
no cleanup required.

Fixes: 1a15eb724a ("btrfs: use btrfs_get_dev_args_from_path in dev removal ioctls")
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-12-08 15:40:19 +01:00
Linus Torvalds 7e63545264 for-5.16-rc2-tag 
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmGg+PIACgkQxWXV+ddt
 WDsWDBAAk//y15bs3SGQLPshFuFidcRmudQkXGE8431ftjWZtuz1UY046rVvC8I5
 FkotiiDVrnuyg1kBU1k0vYGS0Fo687JHw2E+8abD2KCicF4MSNIAlc5D9M5B7jzp
 GpSIPoZjs05H85kxcoy3BmdQR1DyjR/xOqvTe2IVswPQSj2B1qZKMCbU4927U+e8
 Tu18kr7FTxpnzLhtt9Ahr8xVol6bcV/3zB0nC+O5hRbfg5gH87tpb7giLICwfipq
 eYY8I361iYDKtDQlR/qvpmkUAfPO4ahYz1yumTxm0twuIv34PugcCP0oLtGCbWwU
 71YflcuZa6L2vmXNK8cjXf/9Frg/7k0FlyepEAhjhbooqT92m9Sv4iCX5z9mrsqf
 40aoLBXrrPCewa9j31Aw+JuUEjWC4G7U2v+TqJ3waHgUyfeDQUGhOGLmvQJqGyMd
 SL4QhGz9aQGlLmUVkDlUemkmMtGBwn87sD1HCJkkNrHS0OWOHb12tpijOu7UAIp3
 ih/nXtAayVZV5LS1hfxfYuXzpP8E6dXUnR2vWpvvDqihvfq6ubkt497yVN+vUFBw
 6GEhvePwa/w0U1Kn4cZUZxFnalBAmeYcahBBL9ngrHLBD57IJL/yLcOue5nCgqqN
 DvLKl8tJUDQTmayx1MjdpdPNckAbY3cp0OP8uEowL0rJjxJPyAE=
 =/pKc
 -----END PGP SIGNATURE-----

Merge tag 'for-5.16-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fix from David Sterba:
 "One more fix to the lzo code, a missing put_page causing memory leaks
  when some error branches are taken"

* tag 'for-5.16-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: fix the memory leak caused in lzo_compress_pages()
 2021-11-26 11:24:32 -08:00
Qu Wenruo daf87e9535 btrfs: fix the memory leak caused in lzo_compress_pages() 
[BUG]
Fstests generic/027 is pretty easy to trigger a slow but steady memory
leak if run with "-o compress=lzo" mount option.

Normally one single run of generic/027 is enough to eat up at least 4G ram.

[CAUSE]
In commit d4088803f5 ("btrfs: subpage: make lzo_compress_pages()
compatible") we changed how @page_in is released.

But that refactoring makes @page_in only released after all pages being
compressed.

This leaves error path not releasing @page_in. And by "error path"
things like incompressible data will also be treated as an error
(-E2BIG).

Thus it can cause a memory leak if even nothing wrong happened.

[FIX]
Add check under @out label to release @page_in when needed, so when we
hit any error, the input page is properly released.

Reported-by: Josef Bacik <josef@toxicpanda.com>
Fixes: d4088803f5 ("btrfs: subpage: make lzo_compress_pages() compatible")
Reviewed-and-tested-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-11-26 16:10:05 +01:00
Linus Torvalds 6fdf886424 for-5.16-rc1-tag 
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmGWiSAACgkQxWXV+ddt
 WDtKiA//VFrxg5I1yrTyyVvc2RqcPg0aCopO6wIAgcHV1yzseJ7AyP7two1p5dg8
 3DPDKaXFvONZYXl8j9ZuzFiryKPGJxp1KSagKyt6EKDRYm50HOreTC1Qt2ZvLJHn
 wHohwHX96yv+4gyKvpCBZVpp3dSIDbsbCxlpz3mm7kZv//wHxA5l0chZpHbTqUF6
 JloRSrOIGlSeQYPog1Lnu1c92qoGzLL5n47aXS3s5afpkqqkOlKZLsyb90N4uJx4
 M1htsl4ga7b3OB8jbR95wlbd/qXsB+dvaBUQHgDm4hafW6ma5ft9NhuePQnQlaVH
 ub/rlfNTsKl6jly9eNJ6wGpqi/OBlhA4qCmQVbVDE+HhWUJbdUiQ5UgxoOrQlkOP
 Pd3NvW+95qg+Lj/egUA/Mrtz1v/6oSKcf3gQVKMNIrnk6lOUVZWtQhBe5YS3qHih
 PzxrCp4ThlvmVeemHS7783akiwkI49wUn7a6dUD87x81ghemUHJzC83/mgs1rl/0
 7Q1QLetgfrZpko3W4GzS2J3WwKTB0tvBXxsZ8gU5gI0FNkx90bR8+xI0fVF8IGJo
 QglHn9gepb6si7BCxyKDTlQNMt23s7GFH5/4hHtkomtlR6vpRbPJAq5mpOrqsLgJ
 VGc/SwCJPSmynqRAxuCn+DqlfaMZZaqtvgVVWnhJl9ylKyUAQKU=
 =ze0L
 -----END PGP SIGNATURE-----

Merge tag 'for-5.16-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "Several xes and one old ioctl deprecation. Namely there's fix for
  crashes/warnings with lzo compression that was suspected to be caused
  by first pull merge resolution, but it was a different bug.

  Summary:

   - regression fix for a crash in lzo due to missing boundary checks of
     the page array

   - fix crashes on ARM64 due to missing barriers when synchronizing
     status bits between work queues

   - silence lockdep when reading chunk tree during mount

   - fix false positive warning in integrity checker on devices with
     disabled write caching

   - fix signedness of bitfields in scrub

   - start deprecation of balance v1 ioctl"

* tag 'for-5.16-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: deprecate BTRFS_IOC_BALANCE ioctl
  btrfs: make 1-bit bit-fields of scrub_page unsigned int
  btrfs: check-integrity: fix a warning on write caching disabled disk
  btrfs: silence lockdep when reading chunk tree during mount
  btrfs: fix memory ordering between normal and ordered work functions
  btrfs: fix a out-of-bound access in copy_compressed_data_to_page()
 2021-11-18 12:41:14 -08:00
Nikolay Borisov 6c405b2409 btrfs: deprecate BTRFS_IOC_BALANCE ioctl 
The v2 balance ioctl has been introduced more than 9 years ago. Users of
the old v1 ioctl should have long been migrated to it. It's time we
deprecate it and eventually remove it.

The only known user is in btrfs-progs that tries v1 as a fallback in
case v2 is not supported. This is not necessary anymore.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-11-16 16:51:19 +01:00
Colin Ian King d08e38b623 btrfs: make 1-bit bit-fields of scrub_page unsigned int 
The bitfields have_csum and io_error are currently signed which is not
recommended as the representation is an implementation defined
behaviour. Fix this by making the bit-fields unsigned ints.

Fixes: 2c36395430 ("btrfs: scrub: remove the anonymous structure from scrub_page")
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-11-16 16:51:11 +01:00
Wang Yugui a91cf0ffbc btrfs: check-integrity: fix a warning on write caching disabled disk 
When a disk has write caching disabled, we skip submission of a bio with
flush and sync requests before writing the superblock, since it's not
needed. However when the integrity checker is enabled, this results in
reports that there are metadata blocks referred by a superblock that
were not properly flushed. So don't skip the bio submission only when
the integrity checker is enabled for the sake of simplicity, since this
is a debug tool and not meant for use in non-debug builds.

fstests/btrfs/220 trigger a check-integrity warning like the following
when CONFIG_BTRFS_FS_CHECK_INTEGRITY=y and the disk with WCE=0.

  btrfs: attempt to write superblock which references block M @5242880 (sdb2/5242880/0) which is not flushed out of disk's write cache (block flush_gen=1, dev->flush_gen=0)!
  ------------[ cut here ]------------
  WARNING: CPU: 28 PID: 843680 at fs/btrfs/check-integrity.c:2196 btrfsic_process_written_superblock+0x22a/0x2a0 [btrfs]
  CPU: 28 PID: 843680 Comm: umount Not tainted 5.15.0-0.rc5.39.el8.x86_64 #1
  Hardware name: Dell Inc. Precision T7610/0NK70N, BIOS A18 09/11/2019
  RIP: 0010:btrfsic_process_written_superblock+0x22a/0x2a0 [btrfs]
  RSP: 0018:ffffb642afb47940 EFLAGS: 00010246
  RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000000000
  RDX: 00000000ffffffff RSI: ffff8b722fc97d00 RDI: ffff8b722fc97d00
  RBP: ffff8b5601c00000 R08: 0000000000000000 R09: c0000000ffff7fff
  R10: 0000000000000001 R11: ffffb642afb476f8 R12: ffffffffffffffff
  R13: ffffb642afb47974 R14: ffff8b5499254c00 R15: 0000000000000003
  FS:  00007f00a06d4080(0000) GS:ffff8b722fc80000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007fff5cff5ff0 CR3: 00000001c0c2a006 CR4: 00000000001706e0
  Call Trace:
   btrfsic_process_written_block+0x2f7/0x850 [btrfs]
   __btrfsic_submit_bio.part.19+0x310/0x330 [btrfs]
   ? bio_associate_blkg_from_css+0xa4/0x2c0
   btrfsic_submit_bio+0x18/0x30 [btrfs]
   write_dev_supers+0x81/0x2a0 [btrfs]
   ? find_get_pages_range_tag+0x219/0x280
   ? pagevec_lookup_range_tag+0x24/0x30
   ? __filemap_fdatawait_range+0x6d/0xf0
   ? __raw_callee_save___native_queued_spin_unlock+0x11/0x1e
   ? find_first_extent_bit+0x9b/0x160 [btrfs]
   ? __raw_callee_save___native_queued_spin_unlock+0x11/0x1e
   write_all_supers+0x1b3/0xa70 [btrfs]
   ? __raw_callee_save___native_queued_spin_unlock+0x11/0x1e
   btrfs_commit_transaction+0x59d/0xac0 [btrfs]
   close_ctree+0x11d/0x339 [btrfs]
   generic_shutdown_super+0x71/0x110
   kill_anon_super+0x14/0x30
   btrfs_kill_super+0x12/0x20 [btrfs]
   deactivate_locked_super+0x31/0x70
   cleanup_mnt+0xb8/0x140
   task_work_run+0x6d/0xb0
   exit_to_user_mode_prepare+0x1f0/0x200
   syscall_exit_to_user_mode+0x12/0x30
   do_syscall_64+0x46/0x80
   entry_SYSCALL_64_after_hwframe+0x44/0xae
  RIP: 0033:0x7f009f711dfb
  RSP: 002b:00007fff5cff7928 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
  RAX: 0000000000000000 RBX: 000055b68c6c9970 RCX: 00007f009f711dfb
  RDX: 0000000000000001 RSI: 0000000000000000 RDI: 000055b68c6c9b50
  RBP: 0000000000000000 R08: 000055b68c6ca900 R09: 00007f009f795580
  R10: 0000000000000000 R11: 0000000000000246 R12: 000055b68c6c9b50
  R13: 00007f00a04bf184 R14: 0000000000000000 R15: 00000000ffffffff
  ---[ end trace 2c4b82abcef9eec4 ]---
  S-65536(sdb2/65536/1)
   -->
  M-1064960(sdb2/1064960/1)

Reviewed-by: Filipe Manana <fdmanana@gmail.com>
Signed-off-by: Wang Yugui <wangyugui@e16-tech.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-11-16 16:50:51 +01:00
Filipe Manana 4d9380e0da btrfs: silence lockdep when reading chunk tree during mount 
Often some test cases like btrfs/161 trigger lockdep splats that complain
about possible unsafe lock scenario due to the fact that during mount,
when reading the chunk tree we end up calling blkdev_get_by_path() while
holding a read lock on a leaf of the chunk tree. That produces a lockdep
splat like the following:

[ 3653.683975] ======================================================
[ 3653.685148] WARNING: possible circular locking dependency detected
[ 3653.686301] 5.15.0-rc7-btrfs-next-103 #1 Not tainted
[ 3653.687239] ------------------------------------------------------
[ 3653.688400] mount/447465 is trying to acquire lock:
[ 3653.689320] ffff8c6b0c76e528 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0xe7/0x320
[ 3653.691054]
               but task is already holding lock:
[ 3653.692155] ffff8c6b0a9f39e0 (btrfs-chunk-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x24/0x110 [btrfs]
[ 3653.693978]
               which lock already depends on the new lock.

[ 3653.695510]
               the existing dependency chain (in reverse order) is:
[ 3653.696915]
               -> #3 (btrfs-chunk-00){++++}-{3:3}:
[ 3653.698053]        down_read_nested+0x4b/0x140
[ 3653.698893]        __btrfs_tree_read_lock+0x24/0x110 [btrfs]
[ 3653.699988]        btrfs_read_lock_root_node+0x31/0x40 [btrfs]
[ 3653.701205]        btrfs_search_slot+0x537/0xc00 [btrfs]
[ 3653.702234]        btrfs_insert_empty_items+0x32/0x70 [btrfs]
[ 3653.703332]        btrfs_init_new_device+0x563/0x15b0 [btrfs]
[ 3653.704439]        btrfs_ioctl+0x2110/0x3530 [btrfs]
[ 3653.705405]        __x64_sys_ioctl+0x83/0xb0
[ 3653.706215]        do_syscall_64+0x3b/0xc0
[ 3653.706990]        entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 3653.708040]
               -> #2 (sb_internal#2){.+.+}-{0:0}:
[ 3653.708994]        lock_release+0x13d/0x4a0
[ 3653.709533]        up_write+0x18/0x160
[ 3653.710017]        btrfs_sync_file+0x3f3/0x5b0 [btrfs]
[ 3653.710699]        __loop_update_dio+0xbd/0x170 [loop]
[ 3653.711360]        lo_ioctl+0x3b1/0x8a0 [loop]
[ 3653.711929]        block_ioctl+0x48/0x50
[ 3653.712442]        __x64_sys_ioctl+0x83/0xb0
[ 3653.712991]        do_syscall_64+0x3b/0xc0
[ 3653.713519]        entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 3653.714233]
               -> #1 (&lo->lo_mutex){+.+.}-{3:3}:
[ 3653.715026]        __mutex_lock+0x92/0x900
[ 3653.715648]        lo_open+0x28/0x60 [loop]
[ 3653.716275]        blkdev_get_whole+0x28/0x90
[ 3653.716867]        blkdev_get_by_dev.part.0+0x142/0x320
[ 3653.717537]        blkdev_open+0x5e/0xa0
[ 3653.718043]        do_dentry_open+0x163/0x390
[ 3653.718604]        path_openat+0x3f0/0xa80
[ 3653.719128]        do_filp_open+0xa9/0x150
[ 3653.719652]        do_sys_openat2+0x97/0x160
[ 3653.720197]        __x64_sys_openat+0x54/0x90
[ 3653.720766]        do_syscall_64+0x3b/0xc0
[ 3653.721285]        entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 3653.721986]
               -> #0 (&disk->open_mutex){+.+.}-{3:3}:
[ 3653.722775]        __lock_acquire+0x130e/0x2210
[ 3653.723348]        lock_acquire+0xd7/0x310
[ 3653.723867]        __mutex_lock+0x92/0x900
[ 3653.724394]        blkdev_get_by_dev.part.0+0xe7/0x320
[ 3653.725041]        blkdev_get_by_path+0xb8/0xd0
[ 3653.725614]        btrfs_get_bdev_and_sb+0x1b/0xb0 [btrfs]
[ 3653.726332]        open_fs_devices+0xd7/0x2c0 [btrfs]
[ 3653.726999]        btrfs_read_chunk_tree+0x3ad/0x870 [btrfs]
[ 3653.727739]        open_ctree+0xb8e/0x17bf [btrfs]
[ 3653.728384]        btrfs_mount_root.cold+0x12/0xde [btrfs]
[ 3653.729130]        legacy_get_tree+0x30/0x50
[ 3653.729676]        vfs_get_tree+0x28/0xc0
[ 3653.730192]        vfs_kern_mount.part.0+0x71/0xb0
[ 3653.730800]        btrfs_mount+0x11d/0x3a0 [btrfs]
[ 3653.731427]        legacy_get_tree+0x30/0x50
[ 3653.731970]        vfs_get_tree+0x28/0xc0
[ 3653.732486]        path_mount+0x2d4/0xbe0
[ 3653.732997]        __x64_sys_mount+0x103/0x140
[ 3653.733560]        do_syscall_64+0x3b/0xc0
[ 3653.734080]        entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 3653.734782]
               other info that might help us debug this:

[ 3653.735784] Chain exists of:
                 &disk->open_mutex --> sb_internal#2 --> btrfs-chunk-00

[ 3653.737123]  Possible unsafe locking scenario:

[ 3653.737865]        CPU0                    CPU1
[ 3653.738435]        ----                    ----
[ 3653.739007]   lock(btrfs-chunk-00);
[ 3653.739449]                                lock(sb_internal#2);
[ 3653.740193]                                lock(btrfs-chunk-00);
[ 3653.740955]   lock(&disk->open_mutex);
[ 3653.741431]
                *** DEADLOCK ***

[ 3653.742176] 3 locks held by mount/447465:
[ 3653.742739]  #0: ffff8c6acf85c0e8 (&type->s_umount_key#44/1){+.+.}-{3:3}, at: alloc_super+0xd5/0x3b0
[ 3653.744114]  #1: ffffffffc0b28f70 (uuid_mutex){+.+.}-{3:3}, at: btrfs_read_chunk_tree+0x59/0x870 [btrfs]
[ 3653.745563]  #2: ffff8c6b0a9f39e0 (btrfs-chunk-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x24/0x110 [btrfs]
[ 3653.747066]
               stack backtrace:
[ 3653.747723] CPU: 4 PID: 447465 Comm: mount Not tainted 5.15.0-rc7-btrfs-next-103 #1
[ 3653.748873] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[ 3653.750592] Call Trace:
[ 3653.750967]  dump_stack_lvl+0x57/0x72
[ 3653.751526]  check_noncircular+0xf3/0x110
[ 3653.752136]  ? stack_trace_save+0x4b/0x70
[ 3653.752748]  __lock_acquire+0x130e/0x2210
[ 3653.753356]  lock_acquire+0xd7/0x310
[ 3653.753898]  ? blkdev_get_by_dev.part.0+0xe7/0x320
[ 3653.754596]  ? lock_is_held_type+0xe8/0x140
[ 3653.755125]  ? blkdev_get_by_dev.part.0+0xe7/0x320
[ 3653.755729]  ? blkdev_get_by_dev.part.0+0xe7/0x320
[ 3653.756338]  __mutex_lock+0x92/0x900
[ 3653.756794]  ? blkdev_get_by_dev.part.0+0xe7/0x320
[ 3653.757400]  ? do_raw_spin_unlock+0x4b/0xa0
[ 3653.757930]  ? _raw_spin_unlock+0x29/0x40
[ 3653.758437]  ? bd_prepare_to_claim+0x129/0x150
[ 3653.758999]  ? trace_module_get+0x2b/0xd0
[ 3653.759508]  ? try_module_get.part.0+0x50/0x80
[ 3653.760072]  blkdev_get_by_dev.part.0+0xe7/0x320
[ 3653.760661]  ? devcgroup_check_permission+0xc1/0x1f0
[ 3653.761288]  blkdev_get_by_path+0xb8/0xd0
[ 3653.761797]  btrfs_get_bdev_and_sb+0x1b/0xb0 [btrfs]
[ 3653.762454]  open_fs_devices+0xd7/0x2c0 [btrfs]
[ 3653.763055]  ? clone_fs_devices+0x8f/0x170 [btrfs]
[ 3653.763689]  btrfs_read_chunk_tree+0x3ad/0x870 [btrfs]
[ 3653.764370]  ? kvm_sched_clock_read+0x14/0x40
[ 3653.764922]  open_ctree+0xb8e/0x17bf [btrfs]
[ 3653.765493]  ? super_setup_bdi_name+0x79/0xd0
[ 3653.766043]  btrfs_mount_root.cold+0x12/0xde [btrfs]
[ 3653.766780]  ? rcu_read_lock_sched_held+0x3f/0x80
[ 3653.767488]  ? kfree+0x1f2/0x3c0
[ 3653.767979]  legacy_get_tree+0x30/0x50
[ 3653.768548]  vfs_get_tree+0x28/0xc0
[ 3653.769076]  vfs_kern_mount.part.0+0x71/0xb0
[ 3653.769718]  btrfs_mount+0x11d/0x3a0 [btrfs]
[ 3653.770381]  ? rcu_read_lock_sched_held+0x3f/0x80
[ 3653.771086]  ? kfree+0x1f2/0x3c0
[ 3653.771574]  legacy_get_tree+0x30/0x50
[ 3653.772136]  vfs_get_tree+0x28/0xc0
[ 3653.772673]  path_mount+0x2d4/0xbe0
[ 3653.773201]  __x64_sys_mount+0x103/0x140
[ 3653.773793]  do_syscall_64+0x3b/0xc0
[ 3653.774333]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 3653.775094] RIP: 0033:0x7f648bc45aaa

This happens because through btrfs_read_chunk_tree(), which is called only
during mount, ends up acquiring the mutex open_mutex of a block device
while holding a read lock on a leaf of the chunk tree while other paths
need to acquire other locks before locking extent buffers of the chunk
tree.

Since at mount time when we call btrfs_read_chunk_tree() we know that
we don't have other tasks running in parallel and modifying the chunk
tree, we can simply skip locking of chunk tree extent buffers. So do
that and move the assertion that checks the fs is not yet mounted to the
top block of btrfs_read_chunk_tree(), with a comment before doing it.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-11-16 16:50:47 +01:00
Nikolay Borisov 45da9c1767 btrfs: fix memory ordering between normal and ordered work functions 
Ordered work functions aren't guaranteed to be handled by the same thread
which executed the normal work functions. The only way execution between
normal/ordered functions is synchronized is via the WORK_DONE_BIT,
unfortunately the used bitops don't guarantee any ordering whatsoever.

This manifested as seemingly inexplicable crashes on ARM64, where
async_chunk::inode is seen as non-null in async_cow_submit which causes
submit_compressed_extents to be called and crash occurs because
async_chunk::inode suddenly became NULL. The call trace was similar to:

    pc : submit_compressed_extents+0x38/0x3d0
    lr : async_cow_submit+0x50/0xd0
    sp : ffff800015d4bc20

    <registers omitted for brevity>

    Call trace:
     submit_compressed_extents+0x38/0x3d0
     async_cow_submit+0x50/0xd0
     run_ordered_work+0xc8/0x280
     btrfs_work_helper+0x98/0x250
     process_one_work+0x1f0/0x4ac
     worker_thread+0x188/0x504
     kthread+0x110/0x114
     ret_from_fork+0x10/0x18

Fix this by adding respective barrier calls which ensure that all
accesses preceding setting of WORK_DONE_BIT are strictly ordered before
setting the flag. At the same time add a read barrier after reading of
WORK_DONE_BIT in run_ordered_work which ensures all subsequent loads
would be strictly ordered after reading the bit. This in turn ensures
are all accesses before WORK_DONE_BIT are going to be strictly ordered
before any access that can occur in ordered_func.

Reported-by: Chris Murphy <lists@colorremedies.com>
Fixes: 08a9ff3264 ("btrfs: Added btrfs_workqueue_struct implemented ordered execution based on kernel workqueue")
CC: stable@vger.kernel.org # 4.4+
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2011928
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Tested-by: Chris Murphy <chris@colorremedies.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-11-16 16:50:23 +01:00
Qu Wenruo 6f019c0e01 btrfs: fix a out-of-bound access in copy_compressed_data_to_page() 
[BUG]
The following script can cause btrfs to crash:

  $ mount -o compress-force=lzo $DEV /mnt
  $ dd if=/dev/urandom of=/mnt/foo bs=4k count=1
  $ sync

The call trace looks like this:

  general protection fault, probably for non-canonical address 0xe04b37fccce3b000: 0000 [#1] PREEMPT SMP NOPTI
  CPU: 5 PID: 164 Comm: kworker/u20:3 Not tainted 5.15.0-rc7-custom+ #4
  Workqueue: btrfs-delalloc btrfs_work_helper [btrfs]
  RIP: 0010:__memcpy+0x12/0x20
  Call Trace:
   lzo_compress_pages+0x236/0x540 [btrfs]
   btrfs_compress_pages+0xaa/0xf0 [btrfs]
   compress_file_range+0x431/0x8e0 [btrfs]
   async_cow_start+0x12/0x30 [btrfs]
   btrfs_work_helper+0xf6/0x3e0 [btrfs]
   process_one_work+0x294/0x5d0
   worker_thread+0x55/0x3c0
   kthread+0x140/0x170
   ret_from_fork+0x22/0x30
  ---[ end trace 63c3c0f131e61982 ]---

[CAUSE]
In lzo_compress_pages(), parameter @out_pages is not only an output
parameter (for the number of compressed pages), but also an input
parameter, as the upper limit of compressed pages we can utilize.

In commit d4088803f5 ("btrfs: subpage: make lzo_compress_pages()
compatible"), the refactoring doesn't take @out_pages as an input, thus
completely ignoring the limit.

And for compress-force case, we could hit incompressible data that
compressed size would go beyond the page limit, and cause the above
crash.

[FIX]
Save @out_pages as @max_nr_page, and pass it to lzo_compress_pages(),
and check if we're beyond the limit before accessing the pages.

Note: this also fixes crash on 32bit architectures that was suspected to
be caused by merge of btrfs patches to 5.16-rc1. Reported in
https://lore.kernel.org/all/20211104115001.GU20319@twin.jikos.cz/ .

Reported-by: Omar Sandoval <osandov@fb.com>
Fixes: d4088803f5 ("btrfs: subpage: make lzo_compress_pages() compatible")
Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add note ]
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-11-16 16:46:40 +01:00
Linus Torvalds c8c109546a Update to zstd-1.4.10 
This PR includes 5 commits that update the zstd library version:
 
 1. Adds a new kernel-style wrapper around zstd. This wrapper API
    is functionally equivalent to the subset of the current zstd API that is
    currently used. The wrapper API changes to be kernel style so that the symbols
    don't collide with zstd's symbols. The update to zstd-1.4.10 maintains the same
    API and preserves the semantics, so that none of the callers need to be
    updated. All callers are updated in the commit, because there are zero
    functional changes.
 2. Adds an indirection for `lib/decompress_unzstd.c` so it
    doesn't depend on the layout of `lib/zstd/` to include every source file.
    This allows the next patch to be automatically generated.
 3. Imports the zstd-1.4.10 source code. This commit is automatically generated
    from upstream zstd (https://github.com/facebook/zstd).
 4. Adds me (terrelln@fb.com) as the maintainer of `lib/zstd`.
 5. Fixes a newly added build warning for clang.
 
 The discussion around this patchset has been pretty long, so I've included a
 FAQ-style summary of the history of the patchset, and why we are taking this
 approach.
 
 Why do we need to update?
 -------------------------
 
 The zstd version in the kernel is based off of zstd-1.3.1, which is was released
 August 20, 2017. Since then zstd has seen many bug fixes and performance
 improvements. And, importantly, upstream zstd is continuously fuzzed by OSS-Fuzz,
 and bug fixes aren't backported to older versions. So the only way to sanely get
 these fixes is to keep up to date with upstream zstd. There are no known security
 issues that affect the kernel, but we need to be able to update in case there
 are. And while there are no known security issues, there are relevant bug fixes.
 For example the problem with large kernel decompression has been fixed upstream
 for over 2 years https://lkml.org/lkml/2020/9/29/27.
 
 Additionally the performance improvements for kernel use cases are significant.
 Measured for x86_64 on my Intel i9-9900k @ 3.6 GHz:
 
 - BtrFS zstd compression at levels 1 and 3 is 5% faster
 - BtrFS zstd decompression+read is 15% faster
 - SquashFS zstd decompression+read is 15% faster
 - F2FS zstd compression+write at level 3 is 8% faster
 - F2FS zstd decompression+read is 20% faster
 - ZRAM decompression+read is 30% faster
 - Kernel zstd decompression is 35% faster
 - Initramfs zstd decompression+build is 5% faster
 
 On top of this, there are significant performance improvements coming down the
 line in the next zstd release, and the new automated update patch generation
 will allow us to pull them easily.
 
 How is the update patch generated?
 ----------------------------------
 
 The first two patches are preparation for updating the zstd version. Then the
 3rd patch in the series imports upstream zstd into the kernel. This patch is
 automatically generated from upstream. A script makes the necessary changes and
 imports it into the kernel. The changes are:
 
 - Replace all libc dependencies with kernel replacements and rewrite includes.
 - Remove unncessary portability macros like: #if defined(_MSC_VER).
 - Use the kernel xxhash instead of bundling it.
 
 This automation gets tested every commit by upstream's continuous integration.
 When we cut a new zstd release, we will submit a patch to the kernel to update
 the zstd version in the kernel.
 
 The automated process makes it easy to keep the kernel version of zstd up to
 date. The current zstd in the kernel shares the guts of the code, but has a lot
 of API and minor changes to work in the kernel. This is because at the time
 upstream zstd was not ready to be used in the kernel envrionment as-is. But,
 since then upstream zstd has evolved to support being used in the kernel as-is.
 
 Why are we updating in one big patch?
 -------------------------------------
 
 The 3rd patch in the series is very large. This is because it is restructuring
 the code, so it both deletes the existing zstd, and re-adds the new structure.
 Future updates will be directly proportional to the changes in upstream zstd
 since the last import. They will admittidly be large, as zstd is an actively
 developed project, and has hundreds of commits between every release. However,
 there is no other great alternative.
 
 One option ruled out is to replay every upstream zstd commit. This is not feasible
 for several reasons:
 - There are over 3500 upstream commits since the zstd version in the kernel.
 - The automation to automatically generate the kernel update was only added recently,
   so older commits cannot easily be imported.
 - Not every upstream zstd commit builds.
 - Only zstd releases are "supported", and individual commits may have bugs that were
   fixed before a release.
 
 Another option to reduce the patch size would be to first reorganize to the new
 file structure, and then apply the patch. However, the current kernel zstd is formatted
 with clang-format to be more "kernel-like". But, the new method imports zstd as-is,
 without additional formatting, to allow for closer correlation with upstream, and
 easier debugging. So the patch wouldn't be any smaller.
 
 It also doesn't make sense to import upstream zstd commit by commit going
 forward. Upstream zstd doesn't support production use cases running of the
 development branch. We have a lot of post-commit fuzzing that catches many bugs,
 so indiviudal commits may be buggy, but fixed before a release. So going forward,
 I intend to import every (important) zstd release into the Kernel.
 
 So, while it isn't ideal, updating in one big patch is the only patch I see forward.
 
 Who is responsible for this code?
 ---------------------------------
 
 I am. This patchset adds me as the maintainer for zstd. Previously, there was no tree
 for zstd patches. Because of that, there were several patches that either got ignored,
 or took a long time to merge, since it wasn't clear which tree should pick them up.
 I'm officially stepping up as maintainer, and setting up my tree as the path through
 which zstd patches get merged. I'll make sure that patches to the kernel zstd get
 ported upstream, so they aren't erased when the next version update happens.
 
 How is this code tested?
 ------------------------
 
 I tested every caller of zstd on x86_64 (BtrFS, ZRAM, SquashFS, F2FS, Kernel,
 InitRAMFS). I also tested Kernel & InitRAMFS on i386 and aarch64. I checked both
 performance and correctness.
 
 Also, thanks to many people in the community who have tested these patches locally.
 If you have tested the patches, please reply with a Tested-By so I can collect them
 for the PR I will send to Linus.
 
 Lastly, this code will bake in linux-next before being merged into v5.16.
 
 Why update to zstd-1.4.10 when zstd-1.5.0 has been released?
 ------------------------------------------------------------
 
 This patchset has been outstanding since 2020, and zstd-1.4.10 was the latest
 release when it was created. Since the update patch is automatically generated
 from upstream, I could generate it from zstd-1.5.0. However, there were some
 large stack usage regressions in zstd-1.5.0, and are only fixed in the latest
 development branch. And the latest development branch contains some new code that
 needs to bake in the fuzzer before I would feel comfortable releasing to the
 kernel.
 
 Once this patchset has been merged, and we've released zstd-1.5.1, we can update
 the kernel to zstd-1.5.1, and exercise the update process.
 
 You may notice that zstd-1.4.10 doesn't exist upstream. This release is an
 artifical release based off of zstd-1.4.9, with some fixes for the kernel
 backported from the development branch. I will tag the zstd-1.4.10 release after
 this patchset is merged, so the Linux Kernel is running a known version of zstd
 that can be debugged upstream.
 
 Why was a wrapper API added?
 ----------------------------
 
 The first versions of this patchset migrated the kernel to the upstream zstd
 API. It first added a shim API that supported the new upstream API with the old
 code, then updated callers to use the new shim API, then transitioned to the
 new code and deleted the shim API. However, Cristoph Hellwig suggested that we
 transition to a kernel style API, and hide zstd's upstream API behind that.
 This is because zstd's upstream API is supports many other use cases, and does
 not follow the kernel style guide, while the kernel API is focused on the
 kernel's use cases, and follows the kernel style guide.
 
 Where is the previous discussion?
 ---------------------------------
 
 Links for the discussions of the previous versions of the patch set.
 The largest changes in the design of the patchset are driven by the discussions
 in V11, V5, and V1. Sorry for the mix of links, I couldn't find most of the the
 threads on lkml.org.
 
 V12: https://www.spinics.net/lists/linux-crypto/msg58189.html
 V11: https://lore.kernel.org/linux-btrfs/20210430013157.747152-1-nickrterrell@gmail.com/
 V10: https://lore.kernel.org/lkml/20210426234621.870684-2-nickrterrell@gmail.com/
 V9: https://lore.kernel.org/linux-btrfs/20210330225112.496213-1-nickrterrell@gmail.com/
 V8: https://lore.kernel.org/linux-f2fs-devel/20210326191859.1542272-1-nickrterrell@gmail.com/
 V7: https://lkml.org/lkml/2020/12/3/1195
 V6: https://lkml.org/lkml/2020/12/2/1245
 V5: https://lore.kernel.org/linux-btrfs/20200916034307.2092020-1-nickrterrell@gmail.com/
 V4: https://www.spinics.net/lists/linux-btrfs/msg105783.html
 V3: https://lkml.org/lkml/2020/9/23/1074
 V2: https://www.spinics.net/lists/linux-btrfs/msg105505.html
 V1: https://lore.kernel.org/linux-btrfs/20200916034307.2092020-1-nickrterrell@gmail.com/
 
 Signed-off-by: Nick Terrell <terrelln@fb.com>
 Tested By: Paul Jones <paul@pauljones.id.au>
 Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
 Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM/Clang v13.0.0 on x86-64
 Tested-by: Jean-Denis Girard <jd.girard@sysnux.pf>
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEEmIwAqlFIzbQodPwyuzRpqaNEqPUFAmGJyKIACgkQuzRpqaNE
 qPXnmw/+PKyCn6LvRQqNfdpF5f59j/B1Fab15tkpVyz3UWnCw+EKaPZOoTfIsjRf
 7TMUVm4iGsm+6xBO/YrGdRl4IxocNgXzsgnJ1lTGDbvfRC1tG+YNwuv+EEXwKYq5
 Yz3DRwDotgsrV0Kg05b+VIgkmAuY3ukmu2n09LnAdKkxoIgmHw3MIDCdVZW2Br4c
 sjJmYI+fiJd7nAlbDa42VOrdTiLzkl/2BsjWBqTv6zbiQ5uuJGsKb7P3kpcybWzD
 5C118pyE3qlVyvFz+UFu8WbN0NSf47DP22KV/3IrhNX7CVQxYBe+9/oVuPWTgRx0
 4Vl0G6u7rzh4wDZuGqTC3LYWwH9GfycI0fnVC0URP2XMOcGfPlGd3L0PEmmAeTmR
 fEbaGAN4dr0jNO3lmbyAGe/G8tvtXQx/4ZjS9Pa3TlQP24GARU/f78/blbKR87Vz
 BGMndmSi92AscgXb9buO3bCwAY1YtH5WiFaZT1XVk42cj4MiOLvPTvP4UMzDDxcZ
 56ahmAP/84kd6H+cv9LmgEMqcIBmxdUcO1nuAItJ4wdrMUgw3+lrbxwFkH9xPV7I
 okC1K0TIVEobADbxbdMylxClAylbuW+37Pko97NmAlnzNCPNE38f3s3gtXRrUTaR
 IP8jv5UQ7q3dFiWnNLLodx5KM6s32GVBKRLRnn/6SJB7QzlyHXU=
 =Xb18
 -----END PGP SIGNATURE-----

Merge tag 'zstd-for-linus-v5.16' of git://github.com/terrelln/linux

Pull zstd update from Nick Terrell:
 "Update to zstd-1.4.10.

  Add myself as the maintainer of zstd and update the zstd version in
  the kernel, which is now 4 years out of date, to a much more recent
  zstd release. This includes bug fixes, much more extensive fuzzing,
  and performance improvements. And generates the kernel zstd
  automatically from upstream zstd, so it is easier to keep the zstd
  verison up to date, and we don't fall so far out of date again.

  This includes 5 commits that update the zstd library version:

   - Adds a new kernel-style wrapper around zstd.

     This wrapper API is functionally equivalent to the subset of the
     current zstd API that is currently used. The wrapper API changes to
     be kernel style so that the symbols don't collide with zstd's
     symbols. The update to zstd-1.4.10 maintains the same API and
     preserves the semantics, so that none of the callers need to be
     updated. All callers are updated in the commit, because there are
     zero functional changes.

   - Adds an indirection for `lib/decompress_unzstd.c` so it doesn't
     depend on the layout of `lib/zstd/` to include every source file.
     This allows the next patch to be automatically generated.

   - Imports the zstd-1.4.10 source code. This commit is automatically
     generated from upstream zstd (https://github.com/facebook/zstd).

   - Adds me (terrelln@fb.com) as the maintainer of `lib/zstd`.

   - Fixes a newly added build warning for clang.

  The discussion around this patchset has been pretty long, so I've
  included a FAQ-style summary of the history of the patchset, and why
  we are taking this approach.

  Why do we need to update?
  -------------------------

  The zstd version in the kernel is based off of zstd-1.3.1, which is
  was released August 20, 2017. Since then zstd has seen many bug fixes
  and performance improvements. And, importantly, upstream zstd is
  continuously fuzzed by OSS-Fuzz, and bug fixes aren't backported to
  older versions. So the only way to sanely get these fixes is to keep
  up to date with upstream zstd.

  There are no known security issues that affect the kernel, but we need
  to be able to update in case there are. And while there are no known
  security issues, there are relevant bug fixes. For example the problem
  with large kernel decompression has been fixed upstream for over 2
  years [1]

  Additionally the performance improvements for kernel use cases are
  significant. Measured for x86_64 on my Intel i9-9900k @ 3.6 GHz:

   - BtrFS zstd compression at levels 1 and 3 is 5% faster

   - BtrFS zstd decompression+read is 15% faster

   - SquashFS zstd decompression+read is 15% faster

   - F2FS zstd compression+write at level 3 is 8% faster

   - F2FS zstd decompression+read is 20% faster

   - ZRAM decompression+read is 30% faster

   - Kernel zstd decompression is 35% faster

   - Initramfs zstd decompression+build is 5% faster

  On top of this, there are significant performance improvements coming
  down the line in the next zstd release, and the new automated update
  patch generation will allow us to pull them easily.

  How is the update patch generated?
  ----------------------------------

  The first two patches are preparation for updating the zstd version.
  Then the 3rd patch in the series imports upstream zstd into the
  kernel. This patch is automatically generated from upstream. A script
  makes the necessary changes and imports it into the kernel. The
  changes are:

   - Replace all libc dependencies with kernel replacements and rewrite
     includes.

   - Remove unncessary portability macros like: #if defined(_MSC_VER).

   - Use the kernel xxhash instead of bundling it.

  This automation gets tested every commit by upstream's continuous
  integration. When we cut a new zstd release, we will submit a patch to
  the kernel to update the zstd version in the kernel.

  The automated process makes it easy to keep the kernel version of zstd
  up to date. The current zstd in the kernel shares the guts of the
  code, but has a lot of API and minor changes to work in the kernel.
  This is because at the time upstream zstd was not ready to be used in
  the kernel envrionment as-is. But, since then upstream zstd has
  evolved to support being used in the kernel as-is.

  Why are we updating in one big patch?
  -------------------------------------

  The 3rd patch in the series is very large. This is because it is
  restructuring the code, so it both deletes the existing zstd, and
  re-adds the new structure. Future updates will be directly
  proportional to the changes in upstream zstd since the last import.
  They will admittidly be large, as zstd is an actively developed
  project, and has hundreds of commits between every release. However,
  there is no other great alternative.

  One option ruled out is to replay every upstream zstd commit. This is
  not feasible for several reasons:

   - There are over 3500 upstream commits since the zstd version in the
     kernel.

   - The automation to automatically generate the kernel update was only
     added recently, so older commits cannot easily be imported.

   - Not every upstream zstd commit builds.

   - Only zstd releases are "supported", and individual commits may have
     bugs that were fixed before a release.

  Another option to reduce the patch size would be to first reorganize
  to the new file structure, and then apply the patch. However, the
  current kernel zstd is formatted with clang-format to be more
  "kernel-like". But, the new method imports zstd as-is, without
  additional formatting, to allow for closer correlation with upstream,
  and easier debugging. So the patch wouldn't be any smaller.

  It also doesn't make sense to import upstream zstd commit by commit
  going forward. Upstream zstd doesn't support production use cases
  running of the development branch. We have a lot of post-commit
  fuzzing that catches many bugs, so indiviudal commits may be buggy,
  but fixed before a release. So going forward, I intend to import every
  (important) zstd release into the Kernel.

  So, while it isn't ideal, updating in one big patch is the only patch
  I see forward.

  Who is responsible for this code?
  ---------------------------------

  I am. This patchset adds me as the maintainer for zstd. Previously,
  there was no tree for zstd patches. Because of that, there were
  several patches that either got ignored, or took a long time to merge,
  since it wasn't clear which tree should pick them up. I'm officially
  stepping up as maintainer, and setting up my tree as the path through
  which zstd patches get merged. I'll make sure that patches to the
  kernel zstd get ported upstream, so they aren't erased when the next
  version update happens.

  How is this code tested?
  ------------------------

  I tested every caller of zstd on x86_64 (BtrFS, ZRAM, SquashFS, F2FS,
  Kernel, InitRAMFS). I also tested Kernel & InitRAMFS on i386 and
  aarch64. I checked both performance and correctness.

  Also, thanks to many people in the community who have tested these
  patches locally.

  Lastly, this code will bake in linux-next before being merged into
  v5.16.

  Why update to zstd-1.4.10 when zstd-1.5.0 has been released?
  ------------------------------------------------------------

  This patchset has been outstanding since 2020, and zstd-1.4.10 was the
  latest release when it was created. Since the update patch is
  automatically generated from upstream, I could generate it from
  zstd-1.5.0.

  However, there were some large stack usage regressions in zstd-1.5.0,
  and are only fixed in the latest development branch. And the latest
  development branch contains some new code that needs to bake in the
  fuzzer before I would feel comfortable releasing to the kernel.

  Once this patchset has been merged, and we've released zstd-1.5.1, we
  can update the kernel to zstd-1.5.1, and exercise the update process.

  You may notice that zstd-1.4.10 doesn't exist upstream. This release
  is an artifical release based off of zstd-1.4.9, with some fixes for
  the kernel backported from the development branch. I will tag the
  zstd-1.4.10 release after this patchset is merged, so the Linux Kernel
  is running a known version of zstd that can be debugged upstream.

  Why was a wrapper API added?
  ----------------------------

  The first versions of this patchset migrated the kernel to the
  upstream zstd API. It first added a shim API that supported the new
  upstream API with the old code, then updated callers to use the new
  shim API, then transitioned to the new code and deleted the shim API.
  However, Cristoph Hellwig suggested that we transition to a kernel
  style API, and hide zstd's upstream API behind that. This is because
  zstd's upstream API is supports many other use cases, and does not
  follow the kernel style guide, while the kernel API is focused on the
  kernel's use cases, and follows the kernel style guide.

  Where is the previous discussion?
  ---------------------------------

  Links for the discussions of the previous versions of the patch set
  below. The largest changes in the design of the patchset are driven by
  the discussions in v11, v5, and v1. Sorry for the mix of links, I
  couldn't find most of the the threads on lkml.org"

Link: https://lkml.org/lkml/2020/9/29/27 [1]
Link: https://www.spinics.net/lists/linux-crypto/msg58189.html [v12]
Link: https://lore.kernel.org/linux-btrfs/20210430013157.747152-1-nickrterrell@gmail.com/ [v11]
Link: https://lore.kernel.org/lkml/20210426234621.870684-2-nickrterrell@gmail.com/ [v10]
Link: https://lore.kernel.org/linux-btrfs/20210330225112.496213-1-nickrterrell@gmail.com/ [v9]
Link: https://lore.kernel.org/linux-f2fs-devel/20210326191859.1542272-1-nickrterrell@gmail.com/ [v8]
Link: https://lkml.org/lkml/2020/12/3/1195 [v7]
Link: https://lkml.org/lkml/2020/12/2/1245 [v6]
Link: https://lore.kernel.org/linux-btrfs/20200916034307.2092020-1-nickrterrell@gmail.com/ [v5]
Link: https://www.spinics.net/lists/linux-btrfs/msg105783.html [v4]
Link: https://lkml.org/lkml/2020/9/23/1074 [v3]
Link: https://www.spinics.net/lists/linux-btrfs/msg105505.html [v2]
Link: https://lore.kernel.org/linux-btrfs/20200916034307.2092020-1-nickrterrell@gmail.com/ [v1]
Signed-off-by: Nick Terrell <terrelln@fb.com>
Tested By: Paul Jones <paul@pauljones.id.au>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM/Clang v13.0.0 on x86-64
Tested-by: Jean-Denis Girard <jd.girard@sysnux.pf>

* tag 'zstd-for-linus-v5.16' of git://github.com/terrelln/linux:
  lib: zstd: Add cast to silence clang's -Wbitwise-instead-of-logical
  MAINTAINERS: Add maintainer entry for zstd
  lib: zstd: Upgrade to latest upstream zstd version 1.4.10
  lib: zstd: Add decompress_sources.h for decompress_unzstd
  lib: zstd: Add kernel-specific API
 2021-11-13 15:32:30 -08:00
Filipe Manana 51bd9563b6 btrfs: fix deadlock due to page faults during direct IO reads and writes 
If we do a direct IO read or write when the buffer given by the user is
memory mapped to the file range we are going to do IO, we end up ending
in a deadlock. This is triggered by the new test case generic/647 from
fstests.

For a direct IO read we get a trace like this:

  [967.872718] INFO: task mmap-rw-fault:12176 blocked for more than 120 seconds.
  [967.874161]       Not tainted 5.14.0-rc7-btrfs-next-95 #1
  [967.874909] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [967.875983] task:mmap-rw-fault   state:D stack:    0 pid:12176 ppid: 11884 flags:0x00000000
  [967.875992] Call Trace:
  [967.875999]  __schedule+0x3ca/0xe10
  [967.876015]  schedule+0x43/0xe0
  [967.876020]  wait_extent_bit.constprop.0+0x1eb/0x260 [btrfs]
  [967.876109]  ? do_wait_intr_irq+0xb0/0xb0
  [967.876118]  lock_extent_bits+0x37/0x90 [btrfs]
  [967.876150]  btrfs_lock_and_flush_ordered_range+0xa9/0x120 [btrfs]
  [967.876184]  ? extent_readahead+0xa7/0x530 [btrfs]
  [967.876214]  extent_readahead+0x32d/0x530 [btrfs]
  [967.876253]  ? lru_cache_add+0x104/0x220
  [967.876255]  ? kvm_sched_clock_read+0x14/0x40
  [967.876258]  ? sched_clock_cpu+0xd/0x110
  [967.876263]  ? lock_release+0x155/0x4a0
  [967.876271]  read_pages+0x86/0x270
  [967.876274]  ? lru_cache_add+0x125/0x220
  [967.876281]  page_cache_ra_unbounded+0x1a3/0x220
  [967.876291]  filemap_fault+0x626/0xa20
  [967.876303]  __do_fault+0x36/0xf0
  [967.876308]  __handle_mm_fault+0x83f/0x15f0
  [967.876322]  handle_mm_fault+0x9e/0x260
  [967.876327]  __get_user_pages+0x204/0x620
  [967.876332]  ? get_user_pages_unlocked+0x69/0x340
  [967.876340]  get_user_pages_unlocked+0xd3/0x340
  [967.876349]  internal_get_user_pages_fast+0xbca/0xdc0
  [967.876366]  iov_iter_get_pages+0x8d/0x3a0
  [967.876374]  bio_iov_iter_get_pages+0x82/0x4a0
  [967.876379]  ? lock_release+0x155/0x4a0
  [967.876387]  iomap_dio_bio_actor+0x232/0x410
  [967.876396]  iomap_apply+0x12a/0x4a0
  [967.876398]  ? iomap_dio_rw+0x30/0x30
  [967.876414]  __iomap_dio_rw+0x29f/0x5e0
  [967.876415]  ? iomap_dio_rw+0x30/0x30
  [967.876420]  ? lock_acquired+0xf3/0x420
  [967.876429]  iomap_dio_rw+0xa/0x30
  [967.876431]  btrfs_file_read_iter+0x10b/0x140 [btrfs]
  [967.876460]  new_sync_read+0x118/0x1a0
  [967.876472]  vfs_read+0x128/0x1b0
  [967.876477]  __x64_sys_pread64+0x90/0xc0
  [967.876483]  do_syscall_64+0x3b/0xc0
  [967.876487]  entry_SYSCALL_64_after_hwframe+0x44/0xae
  [967.876490] RIP: 0033:0x7fb6f2c038d6
  [967.876493] RSP: 002b:00007fffddf586b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000011
  [967.876496] RAX: ffffffffffffffda RBX: 0000000000001000 RCX: 00007fb6f2c038d6
  [967.876498] RDX: 0000000000001000 RSI: 00007fb6f2c17000 RDI: 0000000000000003
  [967.876499] RBP: 0000000000001000 R08: 0000000000000003 R09: 0000000000000000
  [967.876501] R10: 0000000000001000 R11: 0000000000000246 R12: 0000000000000003
  [967.876502] R13: 0000000000000000 R14: 00007fb6f2c17000 R15: 0000000000000000

This happens because at btrfs_dio_iomap_begin() we lock the extent range
and return with it locked - we only unlock in the endio callback, at
end_bio_extent_readpage() -> endio_readpage_release_extent(). Then after
iomap called the btrfs_dio_iomap_begin() callback, it triggers the page
faults that resulting in reading the pages, through the readahead callback
btrfs_readahead(), and through there we end to attempt to lock again the
same extent range (or a subrange of what we locked before), resulting in
the deadlock.

For a direct IO write, the scenario is a bit different, and it results in
trace like this:

  [1132.442520] run fstests generic/647 at 2021-08-31 18:53:35
  [1330.349355] INFO: task mmap-rw-fault:184017 blocked for more than 120 seconds.
  [1330.350540]       Not tainted 5.14.0-rc7-btrfs-next-95 #1
  [1330.351158] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [1330.351900] task:mmap-rw-fault   state:D stack:    0 pid:184017 ppid:183725 flags:0x00000000
  [1330.351906] Call Trace:
  [1330.351913]  __schedule+0x3ca/0xe10
  [1330.351930]  schedule+0x43/0xe0
  [1330.351935]  btrfs_start_ordered_extent+0x108/0x1c0 [btrfs]
  [1330.352020]  ? do_wait_intr_irq+0xb0/0xb0
  [1330.352028]  btrfs_lock_and_flush_ordered_range+0x8c/0x120 [btrfs]
  [1330.352064]  ? extent_readahead+0xa7/0x530 [btrfs]
  [1330.352094]  extent_readahead+0x32d/0x530 [btrfs]
  [1330.352133]  ? lru_cache_add+0x104/0x220
  [1330.352135]  ? kvm_sched_clock_read+0x14/0x40
  [1330.352138]  ? sched_clock_cpu+0xd/0x110
  [1330.352143]  ? lock_release+0x155/0x4a0
  [1330.352151]  read_pages+0x86/0x270
  [1330.352155]  ? lru_cache_add+0x125/0x220
  [1330.352162]  page_cache_ra_unbounded+0x1a3/0x220
  [1330.352172]  filemap_fault+0x626/0xa20
  [1330.352176]  ? filemap_map_pages+0x18b/0x660
  [1330.352184]  __do_fault+0x36/0xf0
  [1330.352189]  __handle_mm_fault+0x1253/0x15f0
  [1330.352203]  handle_mm_fault+0x9e/0x260
  [1330.352208]  __get_user_pages+0x204/0x620
  [1330.352212]  ? get_user_pages_unlocked+0x69/0x340
  [1330.352220]  get_user_pages_unlocked+0xd3/0x340
  [1330.352229]  internal_get_user_pages_fast+0xbca/0xdc0
  [1330.352246]  iov_iter_get_pages+0x8d/0x3a0
  [1330.352254]  bio_iov_iter_get_pages+0x82/0x4a0
  [1330.352259]  ? lock_release+0x155/0x4a0
  [1330.352266]  iomap_dio_bio_actor+0x232/0x410
  [1330.352275]  iomap_apply+0x12a/0x4a0
  [1330.352278]  ? iomap_dio_rw+0x30/0x30
  [1330.352292]  __iomap_dio_rw+0x29f/0x5e0
  [1330.352294]  ? iomap_dio_rw+0x30/0x30
  [1330.352306]  btrfs_file_write_iter+0x238/0x480 [btrfs]
  [1330.352339]  new_sync_write+0x11f/0x1b0
  [1330.352344]  ? NF_HOOK_LIST.constprop.0.cold+0x31/0x3e
  [1330.352354]  vfs_write+0x292/0x3c0
  [1330.352359]  __x64_sys_pwrite64+0x90/0xc0
  [1330.352365]  do_syscall_64+0x3b/0xc0
  [1330.352369]  entry_SYSCALL_64_after_hwframe+0x44/0xae
  [1330.352372] RIP: 0033:0x7f4b0a580986
  [1330.352379] RSP: 002b:00007ffd34d75418 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
  [1330.352382] RAX: ffffffffffffffda RBX: 0000000000001000 RCX: 00007f4b0a580986
  [1330.352383] RDX: 0000000000001000 RSI: 00007f4b0a3a4000 RDI: 0000000000000003
  [1330.352385] RBP: 00007f4b0a3a4000 R08: 0000000000000003 R09: 0000000000000000
  [1330.352386] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
  [1330.352387] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Unlike for reads, at btrfs_dio_iomap_begin() we return with the extent
range unlocked, but later when the page faults are triggered and we try
to read the extents, we end up btrfs_lock_and_flush_ordered_range() where
we find the ordered extent for our write, created by the iomap callback
btrfs_dio_iomap_begin(), and we wait for it to complete, which makes us
deadlock since we can't complete the ordered extent without reading the
pages (the iomap code only submits the bio after the pages are faulted
in).

Fix this by setting the nofault attribute of the given iov_iter and retry
the direct IO read/write if we get an -EFAULT error returned from iomap.
For reads, also disable page faults completely, this is because when we
read from a hole or a prealloc extent, we can still trigger page faults
due to the call to iov_iter_zero() done by iomap - at the moment, it is
oblivious to the value of the ->nofault attribute of an iov_iter.
We also need to keep track of the number of bytes written or read, and
pass it to iomap_dio_rw(), as well as use the new flag IOMAP_DIO_PARTIAL.

This depends on the iov_iter and iomap changes introduced in commit
c03098d4b9 ("Merge tag 'gfs2-v5.15-rc5-mmap-fault' of
git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2").

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-11-09 13:46:07 +01:00
Nick Terrell cf30f6a5f0 lib: zstd: Add kernel-specific API 
This patch:
- Moves `include/linux/zstd.h` -> `include/linux/zstd_lib.h`
- Updates modified zstd headers to yearless copyright
- Adds a new API in `include/linux/zstd.h` that is functionally
  equivalent to the in-use subset of the current API. Functions are
  renamed to avoid symbol collisions with zstd, to make it clear it is
  not the upstream zstd API, and to follow the kernel style guide.
- Updates all callers to use the new API.

There are no functional changes in this patch. Since there are no
functional change, I felt it was okay to update all the callers in a
single patch. Once the API is approved, the callers are mechanically
changed.

This patch is preparing for the 3rd patch in this series, which updates
zstd to version 1.4.10. Since the upstream zstd API is no longer exposed
to callers, the update can happen transparently.

Signed-off-by: Nick Terrell <terrelln@fb.com>
Tested By: Paul Jones <paul@pauljones.id.au>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM/Clang v13.0.0 on x86-64
Tested-by: Jean-Denis Girard <jd.girard@sysnux.pf>
 2021-11-08 16:55:21 -08:00
Linus Torvalds c03098d4b9 gfs2: Fix mmap + page fault deadlocks 
Functions gfs2_file_read_iter and gfs2_file_write_iter are both
 accessing the user buffer to write to or read from while holding the
 inode glock.  In the most basic scenario, that buffer will not be
 resident and it will be mapped to the same file.  Accessing the buffer
 will trigger a page fault, and gfs2 will deadlock trying to take the
 same inode glock again while trying to handle that fault.
 
 Fix that and similar, more complex scenarios by disabling page faults
 while accessing user buffers.  To make this work, introduce a small
 amount of new infrastructure and fix some bugs that didn't trigger so
 far, with page faults enabled.
 -----BEGIN PGP SIGNATURE-----
 
 iQJIBAABCAAyFiEEJZs3krPW0xkhLMTc1b+f6wMTZToFAmGBPisUHGFncnVlbmJh
 QHJlZGhhdC5jb20ACgkQ1b+f6wMTZTpE6A/7BezUnGuNJxJrR8pC+vcLYA7xAgUU
 6STQ6IN7w5UHRlSkNzZxZ2XPxW4uVQ4SxSEeaLqBsHZihepjcLNFZ/8MhQ6UPSD0
 8noHOi7CoIcp6IuWQtCpxRM/xjjm2SlMt2XbVJZaiJcdzCV9gB6TU9EkBRq7Zm/X
 9WFBbv1xZF0skn9ISCJvNtiiI+VyWKgMDUKxJUiTQjmJcklyyqHcVGmQi9BjqPz4
 4s3F+WH6CoGbDKlmNk/6Y9wZ/2+sbvGswVscUxPwJVPoZWsR1xBBUdAeAmEMD1P4
 BgE/Y1J8JXyVPYtyvZKq70XUhKdQkxB7RfX87YasOk9mY4Kjd5rIIGEykh+o2vC9
 kDhCHvf2Mnw5I6Rum3B7UXyB1vemY+fECIHsXhgBnS+ztabRtcAdpCuWoqb43ymw
 yEX1KwXyU4FpRYbrRvdZT42Fmh6ty8TW+N4swg8S2TrffirvgAi5yrcHZ4mPupYv
 lyzvsCW7Wv8hPXn/twNObX+okRgJnsxcCdBXARdCnRXfA8tH23xmu88u8RA1Vdxh
 nzTvv6Dx2EowwojuDWMx29Mw3fA2IqIfbOV+4FaRU7NZ2ZKtknL8yGl27qQUsMoJ
 vYsHTmagasjQr+NDJ3vQRLCw+JQ6B1hENpdkmixFD9moo7X1ZFW3HBi/UL973Bv6
 5CmgeXto8FRUFjI=
 =WeNd
 -----END PGP SIGNATURE-----

Merge tag 'gfs2-v5.15-rc5-mmap-fault' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2

Pull gfs2 mmap + page fault deadlocks fixes from Andreas Gruenbacher:
 "Functions gfs2_file_read_iter and gfs2_file_write_iter are both
  accessing the user buffer to write to or read from while holding the
  inode glock.

  In the most basic deadlock scenario, that buffer will not be resident
  and it will be mapped to the same file. Accessing the buffer will
  trigger a page fault, and gfs2 will deadlock trying to take the same
  inode glock again while trying to handle that fault.

  Fix that and similar, more complex scenarios by disabling page faults
  while accessing user buffers. To make this work, introduce a small
  amount of new infrastructure and fix some bugs that didn't trigger so
  far, with page faults enabled"

* tag 'gfs2-v5.15-rc5-mmap-fault' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
  gfs2: Fix mmap + page fault deadlocks for direct I/O
  iov_iter: Introduce nofault flag to disable page faults
  gup: Introduce FOLL_NOFAULT flag to disable page faults
  iomap: Add done_before argument to iomap_dio_rw
  iomap: Support partial direct I/O on user copy failures
  iomap: Fix iomap_dio_rw return value for user copies
  gfs2: Fix mmap + page fault deadlocks for buffered I/O
  gfs2: Eliminate ip->i_gh
  gfs2: Move the inode glock locking to gfs2_file_buffered_write
  gfs2: Introduce flag for glock holder auto-demotion
  gfs2: Clean up function may_grant
  gfs2: Add wrapper for iomap_file_buffered_write
  iov_iter: Introduce fault_in_iov_iter_writeable
  iov_iter: Turn iov_iter_fault_in_readable into fault_in_iov_iter_readable
  gup: Turn fault_in_pages_{readable,writeable} into fault_in_{readable,writeable}
  powerpc/kvm: Fix kvm_use_magic_page
  iov_iter: Fix iov_iter_get_pages{,_alloc} page fault return value
 2021-11-02 12:25:03 -07:00
Linus Torvalds 2dc26d98cf overflow updates for v5.16-rc1 
The end goal of the current buffer overflow detection work[0] is to gain
 full compile-time and run-time coverage of all detectable buffer overflows
 seen via array indexing or memcpy(), memmove(), and memset(). The str*()
 family of functions already have full coverage.
 
 While much of the work for these changes have been on-going for many
 releases (i.e. 0-element and 1-element array replacements, as well as
 avoiding false positives and fixing discovered overflows[1]), this series
 contains the foundational elements of several related buffer overflow
 detection improvements by providing new common helpers and FORTIFY_SOURCE
 changes needed to gain the introspection required for compiler visibility
 into array sizes. Also included are a handful of already Acked instances
 using the helpers (or related clean-ups), with many more waiting at the
 ready to be taken via subsystem-specific trees[2]. The new helpers are:
 
 - struct_group() for gaining struct member range introspection.
 - memset_after() and memset_startat() for clearing to the end of structures.
 - DECLARE_FLEX_ARRAY() for using flex arrays in unions or alone in structs.
 
 Also included is the beginning of the refactoring of FORTIFY_SOURCE to
 support memcpy() introspection, fix missing and regressed coverage under
 GCC, and to prepare to fix the currently broken Clang support. Finishing
 this work is part of the larger series[0], but depends on all the false
 positives and buffer overflow bug fixes to have landed already and those
 that depend on this series to land.
 
 As part of the FORTIFY_SOURCE refactoring, a set of both a compile-time
 and run-time tests are added for FORTIFY_SOURCE and the mem*()-family
 functions respectively. The compile time tests have found a legitimate
 (though corner-case) bug[6] already.
 
 Please note that the appearance of "panic" and "BUG" in the
 FORTIFY_SOURCE refactoring are the result of relocating existing code,
 and no new use of those code-paths are expected nor desired.
 
 Finally, there are two tree-wide conversions for 0-element arrays and
 flexible array unions to gain sane compiler introspection coverage that
 result in no known object code differences.
 
 After this series (and the changes that have now landed via netdev
 and usb), we are very close to finally being able to build with
 -Warray-bounds and -Wzero-length-bounds. However, due corner cases in
 GCC[3] and Clang[4], I have not included the last two patches that turn
 on these options, as I don't want to introduce any known warnings to
 the build. Hopefully these can be solved soon.
 
 [0] https://lore.kernel.org/lkml/20210818060533.3569517-1-keescook@chromium.org/
 [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/log/?qt=grep&q=FORTIFY_SOURCE
 [2] https://lore.kernel.org/lkml/202108220107.3E26FE6C9C@keescook/
 [3] https://lore.kernel.org/lkml/3ab153ec-2798-da4c-f7b1-81b0ac8b0c5b@roeck-us.net/
 [4] https://bugs.llvm.org/show_bug.cgi?id=51682
 [5] https://lore.kernel.org/lkml/202109051257.29B29745C0@keescook/
 [6] https://lore.kernel.org/lkml/20211020200039.170424-1-keescook@chromium.org/
 -----BEGIN PGP SIGNATURE-----
 
 iQJKBAABCgA0FiEEpcP2jyKd1g9yPm4TiXL039xtwCYFAmGAFWcWHGtlZXNjb29r
 QGNocm9taXVtLm9yZwAKCRCJcvTf3G3AJmKFD/45MJdnvW5MhIEeW5tc5UjfcIPS
 ae+YvlEX/2ZwgSlTxocFVocE6hz7b6eCiX3dSAChPkPxsSfgeiuhjxsU+4ROnELR
 04RqTA/rwT6JXfJcXbDPXfxDL4huUkgktAW3m1sT771AZspeap2GrSwFyttlTqKA
 +kTiZ3lXJVFcw10uyhfp3Lk6eFJxdf5iOjuEou5kBOQfpNKEOduRL2K15hSowOwB
 lARiAC+HbmN+E+npvDE7YqK4V7ZQ0/dtB0BlfqgTkn1spQz8N21kBAMpegV5vvIk
 A+qGHc7q2oyk4M14TRTidQHGQ4juW1Kkvq3NV6KzwQIVD+mIfz0ESn3d4tnp28Hk
 Y+OXTI1BRFlApQU9qGWv33gkNEozeyqMLDRLKhDYRSFPA9UKkpgXQRzeTzoLKyrQ
 4B6n5NnUGcu7I6WWhpyZQcZLDsHGyy0vHzjQGs/NXtb1PzXJ5XIGuPdmx9pVMykk
 IVKnqRcWyGWahfh3asOnoXvdhi1No4NSHQ/ZHfUM+SrIGYjBMaUisw66qm3Fe8ZU
 lbO2CFkCsfGSoKNPHf0lUEGlkyxAiDolazOfflDNxdzzlZo2X1l/a7O/yoO4Pqul
 cdL0eDjiNoQ2YR2TSYPnXq5KSL1RI0tlfS8pH8k1hVhZsQx0wpAQ+qki0S+fLePV
 PdA9XB82G2tmqKc9cQ==
 =9xbT
 -----END PGP SIGNATURE-----

Merge tag 'overflow-v5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull overflow updates from Kees Cook:
 "The end goal of the current buffer overflow detection work[0] is to
  gain full compile-time and run-time coverage of all detectable buffer
  overflows seen via array indexing or memcpy(), memmove(), and
  memset(). The str*() family of functions already have full coverage.

  While much of the work for these changes have been on-going for many
  releases (i.e. 0-element and 1-element array replacements, as well as
  avoiding false positives and fixing discovered overflows[1]), this
  series contains the foundational elements of several related buffer
  overflow detection improvements by providing new common helpers and
  FORTIFY_SOURCE changes needed to gain the introspection required for
  compiler visibility into array sizes. Also included are a handful of
  already Acked instances using the helpers (or related clean-ups), with
  many more waiting at the ready to be taken via subsystem-specific
  trees[2].

  The new helpers are:

   - struct_group() for gaining struct member range introspection

   - memset_after() and memset_startat() for clearing to the end of
     structures

   - DECLARE_FLEX_ARRAY() for using flex arrays in unions or alone in
     structs

  Also included is the beginning of the refactoring of FORTIFY_SOURCE to
  support memcpy() introspection, fix missing and regressed coverage
  under GCC, and to prepare to fix the currently broken Clang support.
  Finishing this work is part of the larger series[0], but depends on
  all the false positives and buffer overflow bug fixes to have landed
  already and those that depend on this series to land.

  As part of the FORTIFY_SOURCE refactoring, a set of both a
  compile-time and run-time tests are added for FORTIFY_SOURCE and the
  mem*()-family functions respectively. The compile time tests have
  found a legitimate (though corner-case) bug[6] already.

  Please note that the appearance of "panic" and "BUG" in the
  FORTIFY_SOURCE refactoring are the result of relocating existing code,
  and no new use of those code-paths are expected nor desired.

  Finally, there are two tree-wide conversions for 0-element arrays and
  flexible array unions to gain sane compiler introspection coverage
  that result in no known object code differences.

  After this series (and the changes that have now landed via netdev and
  usb), we are very close to finally being able to build with
  -Warray-bounds and -Wzero-length-bounds.

  However, due corner cases in GCC[3] and Clang[4], I have not included
  the last two patches that turn on these options, as I don't want to
  introduce any known warnings to the build. Hopefully these can be
  solved soon"

Link: https://lore.kernel.org/lkml/20210818060533.3569517-1-keescook@chromium.org/ [0]
Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/log/?qt=grep&q=FORTIFY_SOURCE [1]
Link: https://lore.kernel.org/lkml/202108220107.3E26FE6C9C@keescook/ [2]
Link: https://lore.kernel.org/lkml/3ab153ec-2798-da4c-f7b1-81b0ac8b0c5b@roeck-us.net/ [3]
Link: https://bugs.llvm.org/show_bug.cgi?id=51682 [4]
Link: https://lore.kernel.org/lkml/202109051257.29B29745C0@keescook/ [5]
Link: https://lore.kernel.org/lkml/20211020200039.170424-1-keescook@chromium.org/ [6]

* tag 'overflow-v5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (30 commits)
  fortify: strlen: Avoid shadowing previous locals
  compiler-gcc.h: Define __SANITIZE_ADDRESS__ under hwaddress sanitizer
  treewide: Replace 0-element memcpy() destinations with flexible arrays
  treewide: Replace open-coded flex arrays in unions
  stddef: Introduce DECLARE_FLEX_ARRAY() helper
  btrfs: Use memset_startat() to clear end of struct
  string.h: Introduce memset_startat() for wiping trailing members and padding
  xfrm: Use memset_after() to clear padding
  string.h: Introduce memset_after() for wiping trailing members/padding
  lib: Introduce CONFIG_MEMCPY_KUNIT_TEST
  fortify: Add compile-time FORTIFY_SOURCE tests
  fortify: Allow strlen() and strnlen() to pass compile-time known lengths
  fortify: Prepare to improve strnlen() and strlen() warnings
  fortify: Fix dropped strcpy() compile-time write overflow check
  fortify: Explicitly disable Clang support
  fortify: Move remaining fortify helpers into fortify-string.h
  lib/string: Move helper functions out of string.c
  compiler_types.h: Remove __compiletime_object_size()
  cm4000_cs: Use struct_group() to zero struct cm4000_dev region
  can: flexcan: Use struct_group() to zero struct flexcan_regs regions
  ...
 2021-11-01 17:12:56 -07:00
Linus Torvalds 037c50bfbe for-5.16-tag 
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmF/7PAACgkQxWXV+ddt
 WDtp6A//SbVYeuHWpsXkhBiOpJt2PpS1K8VY5LIJc3brua5EZm8IarlR57X9IqYu
 89ZlWnuANrw4d5RRiIO+NYhc+DR6+ydxHesJG+I2B+o5OnR0Ynb06gLhsP1tSK6y
 lYZORQFJZP051ODU/uEc8A0KZN7DySIUmqezAibfyxepF6oPEap0nFp17/B80tWp
 sKdMp2TBN5ymZwsdSK1nZ7ws1ZL57HgkFDPqp8m8CuPTkneG4CtNol6yUpuPExpL
 QzvQsqTygmiFoy0uNTG7Rg7IlKqEuhbR7lwfkmcBZCV66JmhFco5QhxN13QIn42s
 +YSug52SMWc8YVHIEj16xtBgHEqZXWYey8d2ewhc0tDSGDm0HmXCNjcn1vYr0NJr
 5bW/7/3bpkHYejasy1wDEK5P8Uo2xsgpRyAvuEReGoRi8ze66EohahvP3o7YJi/Q
 o0pROXdCT89JbM/T4MTvN/5MUlCSM7rnexXZ39ldGNacPgn9FAUCPw6KtzKKyVRe
 DF19nPOUXSg6SLECbVkRQUwcOjxOTFP+T0Jx61Um8bomFskYJJnmr4SD3pqlzgp7
 NxV5ad0+r7zU0x9MADkyqboObo0ROAfD4hthcZiRN+0UIK+Gq5nATTD5ur6/nwsT
 0PJGOXDPz7cmfqUdmvpA0ctRxbFEqpaz6sDh7nq/iUSmaGITcUM=
 =HvYu
 -----END PGP SIGNATURE-----

Merge tag 'for-5.16-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs updates from David Sterba:
 "The updates this time are more under the hood and enhancing existing
  features (subpage with compression and zoned namespaces).

  Performance related:

   - misc small inode logging improvements (+3% throughput, -11% latency
     on sample dbench workload)

   - more efficient directory logging: bulk item insertion, less tree
     searches and locking

   - speed up bulk insertion of items into a b-tree, which is used when
     logging directories, when running delayed items for directories
     (fsync and transaction commits) and when running the slow path
     (full sync) of an fsync (bulk creation run time -4%, deletion -12%)

  Core:

   - continued subpage support
      - make defragmentation work
      - make compression write work

   - zoned mode
      - support ZNS (zoned namespaces), zone capacity is number of
        usable blocks in each zone
      - add dedicated block group (zoned) for relocation, to prevent
        out of order writes in some cases
      - greedy block group reclaim, pick the ones with least usable
        space first

   - preparatory work for send protocol updates

   - error handling improvements

   - cleanups and refactoring

  Fixes:

   - lockdep warnings
      - in show_devname callback, on seeding device
      - device delete on loop device due to conversions to workqueues

   - fix deadlock between chunk allocation and chunk btree modifications

   - fix tracking of missing device count and status"

* tag 'for-5.16-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (140 commits)
  btrfs: remove root argument from check_item_in_log()
  btrfs: remove root argument from add_link()
  btrfs: remove root argument from btrfs_unlink_inode()
  btrfs: remove root argument from drop_one_dir_item()
  btrfs: clear MISSING device status bit in btrfs_close_one_device
  btrfs: call btrfs_check_rw_degradable only if there is a missing device
  btrfs: send: prepare for v2 protocol
  btrfs: fix comment about sector sizes supported in 64K systems
  btrfs: update device path inode time instead of bd_inode
  fs: export an inode_update_time helper
  btrfs: fix deadlock when defragging transparent huge pages
  btrfs: sysfs: convert scnprintf and snprintf to sysfs_emit
  btrfs: make btrfs_super_block size match BTRFS_SUPER_INFO_SIZE
  btrfs: update comments for chunk allocation -ENOSPC cases
  btrfs: fix deadlock between chunk allocation and chunk btree modifications
  btrfs: zoned: use greedy gc for auto reclaim
  btrfs: check-integrity: stop storing the block device name in btrfsic_dev_state
  btrfs: use btrfs_get_dev_args_from_path in dev removal ioctls
  btrfs: add a btrfs_get_dev_args_from_path helper
  btrfs: handle device lookup with btrfs_dev_lookup_args
  ...
 2021-11-01 12:48:25 -07:00
Linus Torvalds 2cf3f8133b btrfs: fix lzo_decompress_bio() kmap leakage 
Commit ccaa66c8dd reinstated the kmap/kunmap that had been dropped in
commit 8c945d32e6 ("btrfs: compression: drop kmap/kunmap from lzo").

However, it seems to have done so incorrectly due to the change not
reverting cleanly, and lzo_decompress_bio() ended up not having a
matching "kunmap()" to the "kmap()" that was put back.

Also, any assert that the page pointer is not NULL should be before the
kmap() of said pointer, since otherwise you'd just oops in the kmap()
before the assert would even trigger.

I noticed this when trying to verify my btrfs merge, and things not
adding up.  I'm doing this fixup before re-doing my merge, because this
commit needs to also be backported to 5.15 (after verification from the
btrfs people).

Fixes: ccaa66c8dd ("Revert 'btrfs: compression: drop kmap/kunmap from lzo'")
Cc: David Sterba <dsterba@suse.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2021-11-01 12:46:47 -07:00
Linus Torvalds 19901165d9 for-5.16/inode-sync-2021-10-29 
-----BEGIN PGP SIGNATURE-----
 
 iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAmF8MEkQHGF4Ym9lQGtl
 cm5lbC5kawAKCRD301j7KXHgpkWyEACBp3TltQu/jvyFlCzuOQJqpIqVw6ZeRn9h
 0cYZaYsRzNBTzIOKogpmhT3lWYOMxIbFMq6RyzLCPaQz6juEP+tmQIdLdPMxC5ON
 XdzItF0bMaLzoW0IRK21/aF1s/7UFcr1OLT0BT8F0umeQQXcEOOSim4kZuK9u6mS
 4pOvh61yXeB7UZxDOpMqH3aVlwrLjIr51j0ECGx/Qz1OZtXREQSeptlRUKEKVTXB
 uYPCB9FLL6ZWFyiDAuaiO4Gi//dhpoOe7Yich9m0tbtfei8gl74TqgzeaCBu+gFj
 aRyfwhyvFcm69MJqPGmRBDVxtXVC6ofjd4G6PSG8R/cAuAgPFywL/s0ETmjUJBvY
 HqnExUnMcr8FUHGIfYHmX7EWCAtD+FbpUSnCgWH2ulUhziKFR/LLE/ZYayPbhrgL
 aA89BYpeDS/POc94KXJJON/Ux612vGwhJxVsngYBEboYNeiP7YwsaQapU9RsKp0o
 YTlhz8zFuToUPEh6BQLYuOZek5AsEue5o7525Aj0vdjpxH/qH6JhjE790c7yWhL+
 hbxlTAAdqdVO2Xxrr3qdMXBUI3wnFKKu8Z6+oqi7ujQRKJZmLnXYn4ZkNRs6C858
 3NEW0mySPHxNRCZrt2M7zWmoq/eZtcJIzPy4JMW3xkQgqgdImuT1z7PrgRDw6/h8
 GB382CO2AQ==
 =AKpp
 -----END PGP SIGNATURE-----

Merge tag 'for-5.16/inode-sync-2021-10-29' of git://git.kernel.dk/linux-block

Pull block inode sync updates from Jens Axboe:
 "This contains improvements to how bdev inode syncing is handled,
  unifying the API"

* tag 'for-5.16/inode-sync-2021-10-29' of git://git.kernel.dk/linux-block:
  block: simplify the block device syncing code
  ntfs3: use sync_blockdev_nowait
  fat: use sync_blockdev_nowait
  btrfs: use sync_blockdev
  xen-blkback: use sync_blockdev
  block: remove __sync_blockdev
  fs: remove __sync_filesystem
 2021-11-01 10:25:27 -07:00
Linus Torvalds 3f01727f75 for-5.16/bdev-size-2021-10-29 
-----BEGIN PGP SIGNATURE-----
 
 iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAmF8L70QHGF4Ym9lQGtl
 cm5lbC5kawAKCRD301j7KXHgpo9YEAC17yEJ0xwwtUUwZW8avzss4vdcIreFdiZu
 gaS+9Oi1bLxj0d2SjaZXJxjT9K+W2LftEsLuQ4oM6VHiLQkcEDbjJdVm3goftTt5
 aOvVormDdKbWNcGSbgxA/OcyUT39DH7y17NRVdqYzQSpnrhCod/1tb2ssck0OoYb
 VEyBKogMwYeYR55Z3I8yL5pNcEhR8TihZv3rL1iQ7DNpvh5I0I9naSEtGNC84aLP
 s4nwRIG+TYll+mg0sfSB29KF7xkoFQO7X7s1rnC/on+gsFEzbJcgkJPDIWeVLnLm
 ma8F1i+vJliCGaztyXoleAdg5QDiFmwTQwXRPAk2u8njJhcKi/RwIk2QYMZBZmEJ
 bB5EJnlnEaWxjgpCD7JDrtKgIgpbbQHc5QVHRZccsu43UqvDqOZIlvZNYY+h3ivz
 jT1zKuKDaTf8YWbfdOJwqm9e+qyR0AFm3rLMdHO58QEh1DBvSLIIdRCNE8wX7nFM
 Wx/GmQEkPqNTIZwJOQJMygK+sIuFUDybt3oAH2pjX1zyMx7kTJkrXvj0dhSS/B5u
 +gfMs3otWqxQ4P1qfnaUd9mYl8JabV7le2NHzhjdARm4NKFJEtcJe5BJBwiMbo0n
 vodqt7aUIAXwMrZXnWZL+w8CobhJBp8I5XHUgng147gDBuCjYQjBQT334auAXxgz
 MUCgbjBDqw==
 =Vadi
 -----END PGP SIGNATURE-----

Merge tag 'for-5.16/bdev-size-2021-10-29' of git://git.kernel.dk/linux-block

Pull bdev size cleanups from Jens Axboe:
 "Clean up the bdev size handling with new bdev_nr_bytes() helper"

* tag 'for-5.16/bdev-size-2021-10-29' of git://git.kernel.dk/linux-block: (34 commits)
  partitions/ibm: use bdev_nr_sectors instead of open coding it
  partitions/efi: use bdev_nr_bytes instead of open coding it
  block/ioctl: use bdev_nr_sectors and bdev_nr_bytes
  block: cache inode size in bdev
  udf: use sb_bdev_nr_blocks
  reiserfs: use sb_bdev_nr_blocks
  ntfs: use sb_bdev_nr_blocks
  jfs: use sb_bdev_nr_blocks
  ext4: use sb_bdev_nr_blocks
  block: add a sb_bdev_nr_blocks helper
  block: use bdev_nr_bytes instead of open coding it in blkdev_fallocate
  squashfs: use bdev_nr_bytes instead of open coding it
  reiserfs: use bdev_nr_bytes instead of open coding it
  pstore/blk: use bdev_nr_bytes instead of open coding it
  ntfs3: use bdev_nr_bytes instead of open coding it
  nilfs2: use bdev_nr_bytes instead of open coding it
  nfs/blocklayout: use bdev_nr_bytes instead of open coding it
  jfs: use bdev_nr_bytes instead of open coding it
  hfsplus: use bdev_nr_sectors instead of open coding it
  hfs: use bdev_nr_sectors instead of open coding it
  ...
 2021-11-01 09:50:37 -07:00
Linus Torvalds 33c8846c81 for-5.16/block-2021-10-29 
-----BEGIN PGP SIGNATURE-----
 
 iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAmF8KDgQHGF4Ym9lQGtl
 cm5lbC5kawAKCRD301j7KXHgpmQ2D/wO0nH3U+3+OZChi3XUwYck9Dev3o6BANCF
 ClATiK/kivZY0xY1r8J4ixirZo2gcjIMpWSC3JGYZ5LdspfmYGLUbMjfZsaeU23i
 lAKaX1IqfArmHN76k3IU1bKCg7B0/LFwC0q9QTFWTSwNSs8RK/EZLJ61U1hEXUb3
 OfIpaMmvPiMaU7yuPqhcZK14m1cg1srrLM4rFB/PqsWWStF07pHq32WeArGDAU0e
 Fe0YSnYD7qqA5Qc37KwqjCTmmxKX5YZf7etIcA6p3DNmwcuQrVNzKoCH/ZEDijaD
 E2bS/BWbN1x96+rtoEZfBYEaNIrkmJzmW6+fJ53OITbJF3KqP6V66erhqNcFYCzC
 mhFlRe7voXb/8AP7zQqSIhK529BUBM36sQ6nF7EiQcDrfLc1z39mq6eblUxbknIA
 DDPISD5Tseik9N9x0bc7vINseKyHI1E90VAU/XKADcuGbzLvehPx+2p+Iq5ch5Ah
 oa1G3RdlWWQOZxphJHWJhu1qMfo5+FP9dFZj1aoo7b8Kbc/CedyoQe71cpIE5wNh
 Jj/EpWJnuyKXwuTic2VYGC+6ezM9O5DSdqCfP3YuZky95VESyvRCKJYMMgBYRVdC
 /LuxhnBXIY2G8An7ZTnX0kLCCvLbapIwa0NyA98/xeOngO843coJ6wn8ZmE9LJNH
 kMmpCygUrA==
 =QWC+
 -----END PGP SIGNATURE-----

Merge tag 'for-5.16/block-2021-10-29' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:

 - mq-deadline accounting improvements (Bart)

 - blk-wbt timer fix (Andrea)

 - Untangle the block layer includes (Christoph)

 - Rework the poll support to be bio based, which will enable adding
   support for polling for bio based drivers (Christoph)

 - Block layer core support for multi-actuator drives (Damien)

 - blk-crypto improvements (Eric)

 - Batched tag allocation support (me)

 - Request completion batching support (me)

 - Plugging improvements (me)

 - Shared tag set improvements (John)

 - Concurrent queue quiesce support (Ming)

 - Cache bdev in ->private_data for block devices (Pavel)

 - bdev dio improvements (Pavel)

 - Block device invalidation and block size improvements (Xie)

 - Various cleanups, fixes, and improvements (Christoph, Jackie,
   Masahira, Tejun, Yu, Pavel, Zheng, me)

* tag 'for-5.16/block-2021-10-29' of git://git.kernel.dk/linux-block: (174 commits)
  blk-mq-debugfs: Show active requests per queue for shared tags
  block: improve readability of blk_mq_end_request_batch()
  virtio-blk: Use blk_validate_block_size() to validate block size
  loop: Use blk_validate_block_size() to validate block size
  nbd: Use blk_validate_block_size() to validate block size
  block: Add a helper to validate the block size
  block: re-flow blk_mq_rq_ctx_init()
  block: prefetch request to be initialized
  block: pass in blk_mq_tags to blk_mq_rq_ctx_init()
  block: add rq_flags to struct blk_mq_alloc_data
  block: add async version of bio_set_polled
  block: kill DIO_MULTI_BIO
  block: kill unused polling bits in __blkdev_direct_IO()
  block: avoid extra iter advance with async iocb
  block: Add independent access ranges support
  blk-mq: don't issue request directly in case that current is to be blocked
  sbitmap: silence data race warning
  blk-cgroup: synchronize blkg creation against policy deactivation
  block: refactor bio_iov_bvec_set()
  block: add single bio async direct IO helper
  ...
 2021-11-01 09:19:50 -07:00
Linus Torvalds fd919bbd33 for-5.15-rc7-tag 
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmF72q0ACgkQxWXV+ddt
 WDvFOxAAkcryx2FP5aqaoMzBKfoCtMFHO3uAvm+rsMcglWe5kaXhBnHa2HPzoyEh
 YqEx2TeXMTuA2I15bU8KV1RMhQzzRjC4NhdRqY6uaKAcKgON6sJlK5qsq2BnB+V3
 nrue1jppM2Vv8wNzjMNeVETQNC7pmg29yQP/fvWaB36Yar2tyfyWDF11e42HR7cU
 yLQUedg30WEayz3Mp6MTBF36h09WXQrZSs7Iwk1JMQbpxWcpn2CjXrO+vIZOMdvH
 XZZsxBTNB8GJIaJlXssgsq3OP2wspK1lrVHNfi5PYtcZEaFrhkPaVB6enDfd41YV
 zXwj1dnemCni9fh88gZprel9bLyB37dSVfIqq2Ly3hQbSAN4dmHIpxGwPSRIr+Hl
 Bn3UfClHpAftbpd/Y77U7GgcYnkuRo3Bd4mGTF3ZuPDLVrf/QX5BlfGa2dmJYoml
 NfBit7Ha4UrxLW6C8RC6fyEbLQxpNYFY55Ra0Tj0BBO/uhWiqtQGZwC/qbyPKfzN
 YZFcPR6iTILoCHXNan3iZIuLeASMT0djgAtunXXf/BuFnxGfnOuqL3bKt2vojh3+
 rsqpeIxSP/VklKv4JcP3axeLmUK6cA8/9dV2ES0M0Fc0o341jfh+AoVw0GleFeus
 gXlDFPRJeE8yyXmjKyW4shctOczqoeMIq3umebXPP9R4jd/LU/g=
 =YWGa
 -----END PGP SIGNATURE-----

Merge tag 'for-5.15-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "Last minute fixes for crash on 32bit architectures when compression is
  in use. It's a regression introduced in 5.15-rc and I'd really like
  not let this into the final release, fixes via stable trees would add
  unnecessary delay.

  The problem is on 32bit architectures with highmem enabled, the pages
  for compression may need to be kmapped, while the patches removed that
  as we don't use GFP_HIGHMEM allocations anymore. The pages that don't
  come from local allocation still may be from highmem. Despite being on
  32bit there's enough such ARM machines in use so it's not a marginal
  issue.

  I did full reverts of the patches one by one instead of a huge one.
  There's one exception for the "lzo" revert as there was an
  intermediate patch touching the same code to make it compatible with
  subpage. I can't revert that one too, so the revert in lzo.c is
  manual. Qu Wenruo has worked on that with me and verified the changes"

* tag 'for-5.15-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Revert "btrfs: compression: drop kmap/kunmap from lzo"
  Revert "btrfs: compression: drop kmap/kunmap from zlib"
  Revert "btrfs: compression: drop kmap/kunmap from zstd"
  Revert "btrfs: compression: drop kmap/kunmap from generic helpers"
 2021-10-29 10:46:59 -07:00
David Sterba ccaa66c8dd Revert "btrfs: compression: drop kmap/kunmap from lzo" 
This reverts commit 8c945d32e6.

The kmaps in compression code are still needed and cause crashes on
32bit machines (ARM, x86). Reproducible eg. by running fstest btrfs/004
with enabled LZO or ZSTD compression.

The revert does not apply cleanly due to changes in a6e66e6f8c
("btrfs: rework lzo_decompress_bio() to make it subpage compatible")
that reworked the page iteration so the revert is done to be equivalent
to the original code.

Link: https://lore.kernel.org/all/CAJCQCtT+OuemovPO7GZk8Y8=qtOObr0XTDp8jh4OHD6y84AFxw@mail.gmail.com/
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=214839
Tested-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-29 13:25:43 +02:00
David Sterba 55276e14df Revert "btrfs: compression: drop kmap/kunmap from zlib" 
This reverts commit 696ab562e6.

The kmaps in compression code are still needed and cause crashes on
32bit machines (ARM, x86). Reproducible eg. by running fstest btrfs/004
with enabled LZO or ZSTD compression.

Link: https://lore.kernel.org/all/CAJCQCtT+OuemovPO7GZk8Y8=qtOObr0XTDp8jh4OHD6y84AFxw@mail.gmail.com/
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=214839
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-29 13:03:05 +02:00
David Sterba 56ee254d23 Revert "btrfs: compression: drop kmap/kunmap from zstd" 
This reverts commit bbaf9715f3.

The kmaps in compression code are still needed and cause crashes on
32bit machines (ARM, x86). Reproducible eg. by running fstest btrfs/004
with enabled LZO or ZSTD compression.

Example stacktrace with ZSTD on a 32bit ARM machine:

  Unable to handle kernel NULL pointer dereference at virtual address 00000000
  pgd = c4159ed3
  [00000000] *pgd=00000000
  Internal error: Oops: 5 [#1] PREEMPT SMP ARM
  Modules linked in:
  CPU: 0 PID: 210 Comm: kworker/u2:3 Not tainted 5.14.0-rc79+ #12
  Hardware name: Allwinner sun4i/sun5i Families
  Workqueue: btrfs-delalloc btrfs_work_helper
  PC is at mmiocpy+0x48/0x330
  LR is at ZSTD_compressStream_generic+0x15c/0x28c

  (mmiocpy) from [<c0629648>] (ZSTD_compressStream_generic+0x15c/0x28c)
  (ZSTD_compressStream_generic) from [<c06297dc>] (ZSTD_compressStream+0x64/0xa0)
  (ZSTD_compressStream) from [<c049444c>] (zstd_compress_pages+0x170/0x488)
  (zstd_compress_pages) from [<c0496798>] (btrfs_compress_pages+0x124/0x12c)
  (btrfs_compress_pages) from [<c043c068>] (compress_file_range+0x3c0/0x834)
  (compress_file_range) from [<c043c4ec>] (async_cow_start+0x10/0x28)
  (async_cow_start) from [<c0475c3c>] (btrfs_work_helper+0x100/0x230)
  (btrfs_work_helper) from [<c014ef68>] (process_one_work+0x1b4/0x418)
  (process_one_work) from [<c014f210>] (worker_thread+0x44/0x524)
  (worker_thread) from [<c0156aa4>] (kthread+0x180/0x1b0)
  (kthread) from [<c0100150>]

Link: https://lore.kernel.org/all/CAJCQCtT+OuemovPO7GZk8Y8=qtOObr0XTDp8jh4OHD6y84AFxw@mail.gmail.com/
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=214839
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-29 13:02:50 +02:00
Filipe Manana d1ed82f355 btrfs: remove root argument from check_item_in_log() 
The root argument passed to check_item_in_log() always matches the root
of the given directory, so it can be eliminated.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-29 12:39:13 +02:00
Filipe Manana 6d9cc07215 btrfs: remove root argument from add_link() 
The root argument for tree-log.c:add_link() always matches the root of the
given directory and the given inode, so it can eliminated.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-29 12:39:13 +02:00
Filipe Manana 4467af8809 btrfs: remove root argument from btrfs_unlink_inode() 
The root argument passed to btrfs_unlink_inode() and its callee,
__btrfs_unlink_inode(), always matches the root of the given directory and
the given inode. So remove the argument and make __btrfs_unlink_inode()
use the root of the directory.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-29 12:39:13 +02:00
Filipe Manana 9798ba24cb btrfs: remove root argument from drop_one_dir_item() 
The root argument for drop_one_dir_item() always matches the root of the
given directory inode, since each log tree is associated to one and only
one subvolume/root, so remove the argument.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-29 12:39:13 +02:00
Li Zhang 5d03dbebba btrfs: clear MISSING device status bit in btrfs_close_one_device 
Reported bug: https://github.com/kdave/btrfs-progs/issues/389

There's a problem with scrub reporting aborted status but returning
error code 0, on a filesystem with missing and readded device.

Roughly these steps:

- mkfs -d raid1 dev1 dev2
- fill with data
- unmount
- make dev1 disappear
- mount -o degraded
- copy more data
- make dev1 appear again

Running scrub afterwards reports that the command was aborted, but the
system log message says the exit code was 0.

It seems that the cause of the error is decrementing
fs_devices->missing_devices but not clearing device->dev_state.  Every
time we umount filesystem, it would call close_ctree, And it would
eventually involve btrfs_close_one_device to close the device, but it
only decrements fs_devices->missing_devices but does not clear the
device BTRFS_DEV_STATE_MISSING bit. Worse, this bug will cause Integer
Overflow, because every time umount, fs_devices->missing_devices will
decrease. If fs_devices->missing_devices value hit 0, it would overflow.

With added debugging:

   loop1: detected capacity change from 0 to 20971520
   BTRFS: device fsid 56ad51f1-5523-463b-8547-c19486c51ebb devid 1 transid 21 /dev/loop1 scanned by systemd-udevd (2311)
   loop2: detected capacity change from 0 to 20971520
   BTRFS: device fsid 56ad51f1-5523-463b-8547-c19486c51ebb devid 2 transid 17 /dev/loop2 scanned by systemd-udevd (2313)
   BTRFS info (device loop1): flagging fs with big metadata feature
   BTRFS info (device loop1): allowing degraded mounts
   BTRFS info (device loop1): using free space tree
   BTRFS info (device loop1): has skinny extents
   BTRFS info (device loop1):  before clear_missing.00000000f706684d /dev/loop1 0
   BTRFS warning (device loop1): devid 2 uuid 6635ac31-56dd-4852-873b-c60f5e2d53d2 is missing
   BTRFS info (device loop1):  before clear_missing.0000000000000000 /dev/loop2 1
   BTRFS info (device loop1): flagging fs with big metadata feature
   BTRFS info (device loop1): allowing degraded mounts
   BTRFS info (device loop1): using free space tree
   BTRFS info (device loop1): has skinny extents
   BTRFS info (device loop1):  before clear_missing.00000000f706684d /dev/loop1 0
   BTRFS warning (device loop1): devid 2 uuid 6635ac31-56dd-4852-873b-c60f5e2d53d2 is missing
   BTRFS info (device loop1):  before clear_missing.0000000000000000 /dev/loop2 0
   BTRFS info (device loop1): flagging fs with big metadata feature
   BTRFS info (device loop1): allowing degraded mounts
   BTRFS info (device loop1): using free space tree
   BTRFS info (device loop1): has skinny extents
   BTRFS info (device loop1):  before clear_missing.00000000f706684d /dev/loop1 18446744073709551615
   BTRFS warning (device loop1): devid 2 uuid 6635ac31-56dd-4852-873b-c60f5e2d53d2 is missing
   BTRFS info (device loop1):  before clear_missing.0000000000000000 /dev/loop2 18446744073709551615

If fs_devices->missing_devices is 0, next time it would be 18446744073709551615

After apply this patch, the fs_devices->missing_devices seems to be
right:

  $ truncate -s 10g test1
  $ truncate -s 10g test2
  $ losetup /dev/loop1 test1
  $ losetup /dev/loop2 test2
  $ mkfs.btrfs -draid1 -mraid1 /dev/loop1 /dev/loop2 -f
  $ losetup -d /dev/loop2
  $ mount -o degraded /dev/loop1 /mnt/1
  $ umount /mnt/1
  $ mount -o degraded /dev/loop1 /mnt/1
  $ umount /mnt/1
  $ mount -o degraded /dev/loop1 /mnt/1
  $ umount /mnt/1
  $ dmesg

   loop1: detected capacity change from 0 to 20971520
   loop2: detected capacity change from 0 to 20971520
   BTRFS: device fsid 15aa1203-98d3-4a66-bcae-ca82f629c2cd devid 1 transid 5 /dev/loop1 scanned by mkfs.btrfs (1863)
   BTRFS: device fsid 15aa1203-98d3-4a66-bcae-ca82f629c2cd devid 2 transid 5 /dev/loop2 scanned by mkfs.btrfs (1863)
   BTRFS info (device loop1): flagging fs with big metadata feature
   BTRFS info (device loop1): allowing degraded mounts
   BTRFS info (device loop1): disk space caching is enabled
   BTRFS info (device loop1): has skinny extents
   BTRFS info (device loop1):  before clear_missing.00000000975bd577 /dev/loop1 0
   BTRFS warning (device loop1): devid 2 uuid 8b333791-0b3f-4f57-b449-1c1ab6b51f38 is missing
   BTRFS info (device loop1):  before clear_missing.0000000000000000 /dev/loop2 1
   BTRFS info (device loop1): checking UUID tree
   BTRFS info (device loop1): flagging fs with big metadata feature
   BTRFS info (device loop1): allowing degraded mounts
   BTRFS info (device loop1): disk space caching is enabled
   BTRFS info (device loop1): has skinny extents
   BTRFS info (device loop1):  before clear_missing.00000000975bd577 /dev/loop1 0
   BTRFS warning (device loop1): devid 2 uuid 8b333791-0b3f-4f57-b449-1c1ab6b51f38 is missing
   BTRFS info (device loop1):  before clear_missing.0000000000000000 /dev/loop2 1
   BTRFS info (device loop1): flagging fs with big metadata feature
   BTRFS info (device loop1): allowing degraded mounts
   BTRFS info (device loop1): disk space caching is enabled
   BTRFS info (device loop1): has skinny extents
   BTRFS info (device loop1):  before clear_missing.00000000975bd577 /dev/loop1 0
   BTRFS warning (device loop1): devid 2 uuid 8b333791-0b3f-4f57-b449-1c1ab6b51f38 is missing
   BTRFS info (device loop1):  before clear_missing.0000000000000000 /dev/loop2 1

CC: stable@vger.kernel.org # 4.19+
Signed-off-by: Li Zhang <zhanglikernel@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-29 12:39:13 +02:00
Anand Jain 5c78a5e7aa btrfs: call btrfs_check_rw_degradable only if there is a missing device 
In open_ctree() in btrfs_check_rw_degradable() [1], we check each block
group individually if at least the minimum number of devices is available
for that profile. If all the devices are available, then we don't have to
check degradable.

[1]
open_ctree()
::
3559 if (!sb_rdonly(sb) && !btrfs_check_rw_degradable(fs_info, NULL)) {

Also before calling btrfs_check_rw_degradable() in open_ctee() at the
line number shown below [2] we call btrfs_read_chunk_tree() and down to
add_missing_dev() to record number of missing devices.

[2]
open_ctree()
::
3454         ret = btrfs_read_chunk_tree(fs_info);

btrfs_read_chunk_tree()
  read_one_chunk() / read_one_dev()
    add_missing_dev()

So, check if there is any missing device before btrfs_check_rw_degradable()
in open_ctree().

Also, with this the mount command could save ~16ms.[3] in the most
common case, that is no device is missing.

[3]
 1) * 16934.96 us | btrfs_check_rw_degradable [btrfs]();

CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-29 12:39:13 +02:00
David Sterba e77fbf9903 btrfs: send: prepare for v2 protocol 
This is preparatory work for send protocol update to version 2 and
higher.

We have many pending protocol update requests but still don't have the
basic protocol rev in place, the first thing that must happen is to do
the actual versioning support.

The protocol version is u32 and is a new member in the send ioctl
struct. Validity of the version field is backed by a new flag bit. Old
kernels would fail when a higher version is requested. Version protocol
0 will pick the highest supported version, BTRFS_SEND_STREAM_VERSION,
  that's also exported in sysfs.

The version is still unchanged and will be increased once we have new
incompatible commands or stream updates.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-29 12:38:43 +02:00
David Sterba 3a60f6537c Revert "btrfs: compression: drop kmap/kunmap from generic helpers" 
This reverts commit 4c2bf276b5.

The kmaps in compression code are still needed and cause crashes on
32bit machines (ARM, x86). Reproducible eg. by running fstest btrfs/004
with enabled LZO or ZSTD compression.

Link: https://lore.kernel.org/all/CAJCQCtT+OuemovPO7GZk8Y8=qtOObr0XTDp8jh4OHD6y84AFxw@mail.gmail.com/
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=214839
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-27 10:39:03 +02:00
Anand Jain 50780d9baa btrfs: fix comment about sector sizes supported in 64K systems 
Commit 95ea0486b2 ("btrfs: allow read-write for 4K sectorsize on 64K
page size systems") added write support for 4K sectorsize on a 64K
systems. Fix the now stale comments.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:08 +02:00
Josef Bacik 54fde91f52 btrfs: update device path inode time instead of bd_inode 
Christoph pointed out that I'm updating bdev->bd_inode for the device
time when we remove block devices from a btrfs file system, however this
isn't actually exposed to anything.  The inode we want to update is the
one that's associated with the path to the device, usually on devtmpfs,
so that blkid notices the difference.

We still don't want to do the blkdev_open, so use kern_path() to get the
path to the given device and do the update time on that inode.

Fixes: 8f96a5bfa1 ("btrfs: update the bdev time directly when closing")
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:08 +02:00
Omar Sandoval 24bcb45429 btrfs: fix deadlock when defragging transparent huge pages 
Attempting to defragment a Btrfs file containing a transparent huge page
immediately deadlocks with the following stack trace:

  #0  context_switch (kernel/sched/core.c:4940:2)
  #1  __schedule (kernel/sched/core.c:6287:8)
  #2  schedule (kernel/sched/core.c:6366:3)
  #3  io_schedule (kernel/sched/core.c:8389:2)
  #4  wait_on_page_bit_common (mm/filemap.c:1356:4)
  #5  __lock_page (mm/filemap.c:1648:2)
  #6  lock_page (./include/linux/pagemap.h:625:3)
  #7  pagecache_get_page (mm/filemap.c:1910:4)
  #8  find_or_create_page (./include/linux/pagemap.h:420:9)
  #9  defrag_prepare_one_page (fs/btrfs/ioctl.c:1068:9)
  #10 defrag_one_range (fs/btrfs/ioctl.c:1326:14)
  #11 defrag_one_cluster (fs/btrfs/ioctl.c:1421:9)
  #12 btrfs_defrag_file (fs/btrfs/ioctl.c:1523:9)
  #13 btrfs_ioctl_defrag (fs/btrfs/ioctl.c:3117:9)
  #14 btrfs_ioctl (fs/btrfs/ioctl.c:4872:10)
  #15 vfs_ioctl (fs/ioctl.c:51:10)
  #16 __do_sys_ioctl (fs/ioctl.c:874:11)
  #17 __se_sys_ioctl (fs/ioctl.c:860:1)
  #18 __x64_sys_ioctl (fs/ioctl.c:860:1)
  #19 do_syscall_x64 (arch/x86/entry/common.c:50:14)
  #20 do_syscall_64 (arch/x86/entry/common.c:80:7)
  #21 entry_SYSCALL_64+0x7c/0x15b (arch/x86/entry/entry_64.S:113)

A huge page is represented by a compound page, which consists of a
struct page for each PAGE_SIZE page within the huge page. The first
struct page is the "head page", and the remaining are "tail pages".

Defragmentation attempts to lock each page in the range. However,
lock_page() on a tail page actually locks the corresponding head page.
So, if defragmentation tries to lock more than one struct page in a
compound page, it tries to lock the same head page twice and deadlocks
with itself.

Ideally, we should be able to defragment transparent huge pages.
However, THP for filesystems is currently read-only, so a lot of code is
not ready to use huge pages for I/O. For now, let's just return
ETXTBUSY.

This can be reproduced with the following on a kernel with
CONFIG_READ_ONLY_THP_FOR_FS=y:

  $ cat create_thp_file.c
  #include <fcntl.h>
  #include <stdbool.h>
  #include <stdio.h>
  #include <stdint.h>
  #include <stdlib.h>
  #include <unistd.h>
  #include <sys/mman.h>

  static const char zeroes[1024 * 1024];
  static const size_t FILE_SIZE = 2 * 1024 * 1024;

  int main(int argc, char **argv)
  {
          if (argc != 2) {
                  fprintf(stderr, "usage: %s PATH\n", argv[0]);
                  return EXIT_FAILURE;
          }
          int fd = creat(argv[1], 0777);
          if (fd == -1) {
                  perror("creat");
                  return EXIT_FAILURE;
          }
          size_t written = 0;
          while (written < FILE_SIZE) {
                  ssize_t ret = write(fd, zeroes,
                                      sizeof(zeroes) < FILE_SIZE - written ?
                                      sizeof(zeroes) : FILE_SIZE - written);
                  if (ret < 0) {
                          perror("write");
                          return EXIT_FAILURE;
                  }
                  written += ret;
          }
          close(fd);
          fd = open(argv[1], O_RDONLY);
          if (fd == -1) {
                  perror("open");
                  return EXIT_FAILURE;
          }

          /*
           * Reserve some address space so that we can align the file mapping to
           * the huge page size.
           */
          void *placeholder_map = mmap(NULL, FILE_SIZE * 2, PROT_NONE,
                                       MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
          if (placeholder_map == MAP_FAILED) {
                  perror("mmap (placeholder)");
                  return EXIT_FAILURE;
          }

          void *aligned_address =
                  (void *)(((uintptr_t)placeholder_map + FILE_SIZE - 1) & ~(FILE_SIZE - 1));

          void *map = mmap(aligned_address, FILE_SIZE, PROT_READ | PROT_EXEC,
                           MAP_SHARED | MAP_FIXED, fd, 0);
          if (map == MAP_FAILED) {
                  perror("mmap");
                  return EXIT_FAILURE;
          }
          if (madvise(map, FILE_SIZE, MADV_HUGEPAGE) < 0) {
                  perror("madvise");
                  return EXIT_FAILURE;
          }

          char *line = NULL;
          size_t line_capacity = 0;
          FILE *smaps_file = fopen("/proc/self/smaps", "r");
          if (!smaps_file) {
                  perror("fopen");
                  return EXIT_FAILURE;
          }
          for (;;) {
                  for (size_t off = 0; off < FILE_SIZE; off += 4096)
                          ((volatile char *)map)[off];

                  ssize_t ret;
                  bool this_mapping = false;
                  while ((ret = getline(&line, &line_capacity, smaps_file)) > 0) {
                          unsigned long start, end, huge;
                          if (sscanf(line, "%lx-%lx", &start, &end) == 2) {
                                  this_mapping = (start <= (uintptr_t)map &&
                                                  (uintptr_t)map < end);
                          } else if (this_mapping &&
                                     sscanf(line, "FilePmdMapped: %ld", &huge) == 1 &&
                                     huge > 0) {
                                  return EXIT_SUCCESS;
                          }
                  }

                  sleep(6);
                  rewind(smaps_file);
                  fflush(smaps_file);
          }
  }
  $ ./create_thp_file huge
  $ btrfs fi defrag -czstd ./huge

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:07 +02:00
Anand Jain 020e527758 btrfs: sysfs: convert scnprintf and snprintf to sysfs_emit 
Commit 2efc459d06 ("sysfs: Add sysfs_emit and sysfs_emit_at to format
sysfs out") merged in 5.10 introduced two new functions sysfs_emit() and
sysfs_emit_at() which are aware of the PAGE_SIZE limit of the output
buffer.

Use the above two new functions instead of scnprintf() and snprintf()
in various sysfs show().

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:07 +02:00
Qu Wenruo 3873247451 btrfs: make btrfs_super_block size match BTRFS_SUPER_INFO_SIZE 
It's a common practice to avoid use sizeof(struct btrfs_super_block)
(3531), but to use BTRFS_SUPER_INFO_SIZE (4096).

The problem is that, sizeof(struct btrfs_super_block) doesn't match
BTRFS_SUPER_INFO_SIZE from the very beginning.

Furthermore, for all call sites except selftests, we always allocate
BTRFS_SUPER_INFO_SIZE space for super block, there isn't any real reason
to use the smaller value, and it doesn't really save any space.

So let's get rid of such confusing behavior, and unify those two values.

This modification also adds a new static_assert() to verify the size,
and moves the BTRFS_SUPER_INFO_* macros to the definition of
btrfs_super_block for the static_assert().

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:07 +02:00
Filipe Manana ecd84d5467 btrfs: update comments for chunk allocation -ENOSPC cases 
Update the comments at btrfs_chunk_alloc() and do_chunk_alloc() that
describe which cases can lead to a failure to allocate metadata and system
space despite having previously reserved space. This adds one more reason
that I previously forgot to mention.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:07 +02:00
Filipe Manana 2bb2e00ed9 btrfs: fix deadlock between chunk allocation and chunk btree modifications 
When a task is doing some modification to the chunk btree and it is not in
the context of a chunk allocation or a chunk removal, it can deadlock with
another task that is currently allocating a new data or metadata chunk.

These contexts are the following:

* When relocating a system chunk, when we need to COW the extent buffers
  that belong to the chunk btree;

* When adding a new device (ioctl), where we need to add a new device item
  to the chunk btree;

* When removing a device (ioctl), where we need to remove a device item
  from the chunk btree;

* When resizing a device (ioctl), where we need to update a device item in
  the chunk btree and may need to relocate a system chunk that lies beyond
  the new device size when shrinking a device.

The problem happens due to a sequence of steps like the following:

1) Task A starts a data or metadata chunk allocation and it locks the
   chunk mutex;

2) Task B is relocating a system chunk, and when it needs to COW an extent
   buffer of the chunk btree, it has locked both that extent buffer as
   well as its parent extent buffer;

3) Since there is not enough available system space, either because none
   of the existing system block groups have enough free space or because
   the only one with enough free space is in RO mode due to the relocation,
   task B triggers a new system chunk allocation. It blocks when trying to
   acquire the chunk mutex, currently held by task A;

4) Task A enters btrfs_chunk_alloc_add_chunk_item(), in order to insert
   the new chunk item into the chunk btree and update the existing device
   items there. But in order to do that, it has to lock the extent buffer
   that task B locked at step 2, or its parent extent buffer, but task B
   is waiting on the chunk mutex, which is currently locked by task A,
   therefore resulting in a deadlock.

One example report when the deadlock happens with system chunk relocation:

  INFO: task kworker/u9:5:546 blocked for more than 143 seconds.
        Not tainted 5.15.0-rc3+ #1
  "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  task:kworker/u9:5    state:D stack:25936 pid:  546 ppid:     2 flags:0x00004000
  Workqueue: events_unbound btrfs_async_reclaim_metadata_space
  Call Trace:
   context_switch kernel/sched/core.c:4940 [inline]
   __schedule+0xcd9/0x2530 kernel/sched/core.c:6287
   schedule+0xd3/0x270 kernel/sched/core.c:6366
   rwsem_down_read_slowpath+0x4ee/0x9d0 kernel/locking/rwsem.c:993
   __down_read_common kernel/locking/rwsem.c:1214 [inline]
   __down_read kernel/locking/rwsem.c:1223 [inline]
   down_read_nested+0xe6/0x440 kernel/locking/rwsem.c:1590
   __btrfs_tree_read_lock+0x31/0x350 fs/btrfs/locking.c:47
   btrfs_tree_read_lock fs/btrfs/locking.c:54 [inline]
   btrfs_read_lock_root_node+0x8a/0x320 fs/btrfs/locking.c:191
   btrfs_search_slot_get_root fs/btrfs/ctree.c:1623 [inline]
   btrfs_search_slot+0x13b4/0x2140 fs/btrfs/ctree.c:1728
   btrfs_update_device+0x11f/0x500 fs/btrfs/volumes.c:2794
   btrfs_chunk_alloc_add_chunk_item+0x34d/0xea0 fs/btrfs/volumes.c:5504
   do_chunk_alloc fs/btrfs/block-group.c:3408 [inline]
   btrfs_chunk_alloc+0x84d/0xf50 fs/btrfs/block-group.c:3653
   flush_space+0x54e/0xd80 fs/btrfs/space-info.c:670
   btrfs_async_reclaim_metadata_space+0x396/0xa90 fs/btrfs/space-info.c:953
   process_one_work+0x9df/0x16d0 kernel/workqueue.c:2297
   worker_thread+0x90/0xed0 kernel/workqueue.c:2444
   kthread+0x3e5/0x4d0 kernel/kthread.c:319
   ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
  INFO: task syz-executor:9107 blocked for more than 143 seconds.
        Not tainted 5.15.0-rc3+ #1
  "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  task:syz-executor    state:D stack:23200 pid: 9107 ppid:  7792 flags:0x00004004
  Call Trace:
   context_switch kernel/sched/core.c:4940 [inline]
   __schedule+0xcd9/0x2530 kernel/sched/core.c:6287
   schedule+0xd3/0x270 kernel/sched/core.c:6366
   schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6425
   __mutex_lock_common kernel/locking/mutex.c:669 [inline]
   __mutex_lock+0xc96/0x1680 kernel/locking/mutex.c:729
   btrfs_chunk_alloc+0x31a/0xf50 fs/btrfs/block-group.c:3631
   find_free_extent_update_loop fs/btrfs/extent-tree.c:3986 [inline]
   find_free_extent+0x25cb/0x3a30 fs/btrfs/extent-tree.c:4335
   btrfs_reserve_extent+0x1f1/0x500 fs/btrfs/extent-tree.c:4415
   btrfs_alloc_tree_block+0x203/0x1120 fs/btrfs/extent-tree.c:4813
   __btrfs_cow_block+0x412/0x1620 fs/btrfs/ctree.c:415
   btrfs_cow_block+0x2f6/0x8c0 fs/btrfs/ctree.c:570
   btrfs_search_slot+0x1094/0x2140 fs/btrfs/ctree.c:1768
   relocate_tree_block fs/btrfs/relocation.c:2694 [inline]
   relocate_tree_blocks+0xf73/0x1770 fs/btrfs/relocation.c:2757
   relocate_block_group+0x47e/0xc70 fs/btrfs/relocation.c:3673
   btrfs_relocate_block_group+0x48a/0xc60 fs/btrfs/relocation.c:4070
   btrfs_relocate_chunk+0x96/0x280 fs/btrfs/volumes.c:3181
   __btrfs_balance fs/btrfs/volumes.c:3911 [inline]
   btrfs_balance+0x1f03/0x3cd0 fs/btrfs/volumes.c:4301
   btrfs_ioctl_balance+0x61e/0x800 fs/btrfs/ioctl.c:4137
   btrfs_ioctl+0x39ea/0x7b70 fs/btrfs/ioctl.c:4949
   vfs_ioctl fs/ioctl.c:51 [inline]
   __do_sys_ioctl fs/ioctl.c:874 [inline]
   __se_sys_ioctl fs/ioctl.c:860 [inline]
   __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
   do_syscall_x64 arch/x86/entry/common.c:50 [inline]
   do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
   entry_SYSCALL_64_after_hwframe+0x44/0xae

So fix this by making sure that whenever we try to modify the chunk btree
and we are neither in a chunk allocation context nor in a chunk remove
context, we reserve system space before modifying the chunk btree.

Reported-by: Hao Sun <sunhao.th@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/CACkBjsax51i4mu6C0C3vJqQN3NR_iVuucoeG3U1HXjrgzn5FFQ@mail.gmail.com/
Fixes: 79bd37120b ("btrfs: rework chunk allocation to avoid exhaustion of the system chunk array")
CC: stable@vger.kernel.org # 5.14+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:07 +02:00
Johannes Thumshirn 2ca0ec770c btrfs: zoned: use greedy gc for auto reclaim 
Currently auto reclaim of unusable zones reclaims the block-groups in
the order they have been added to the reclaim list.

Change this to a greedy algorithm by sorting the list so we have the
block-groups with the least amount of valid bytes reclaimed first.

Note: we can't splice the block groups from reclaim_bgs to let the sort
happen outside of the lock. The block groups can be still in use by
other parts eg. via bg_list and we must hold unused_bgs_lock while
processing them.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ write note and comment why we can't splice the list ]
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:07 +02:00
Christoph Hellwig 813ebc164e btrfs: check-integrity: stop storing the block device name in btrfsic_dev_state 
Just use the %pg format specifier in all the debug printks previously
using it.  Note that both bdevname and the %pg specifier never print
a pathname, so the kbasename call wasn't needed to start with.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
[ adjust messages and indentation ]
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:07 +02:00
Josef Bacik 1a15eb724a btrfs: use btrfs_get_dev_args_from_path in dev removal ioctls 
For device removal and replace we call btrfs_find_device_by_devspec,
which if we give it a device path and nothing else will call
btrfs_get_dev_args_from_path, which opens the block device and reads the
super block and then looks up our device based on that.

However at this point we're holding the sb write "lock", so reading the
block device pulls in the dependency of ->open_mutex, which produces the
following lockdep splat

======================================================
WARNING: possible circular locking dependency detected
5.14.0-rc2+ #405 Not tainted
------------------------------------------------------
losetup/11576 is trying to acquire lock:
ffff9bbe8cded938 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x67/0x5e0

but task is already holding lock:
ffff9bbe88e4fc68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #4 (&lo->lo_mutex){+.+.}-{3:3}:
       __mutex_lock+0x7d/0x750
       lo_open+0x28/0x60 [loop]
       blkdev_get_whole+0x25/0xf0
       blkdev_get_by_dev.part.0+0x168/0x3c0
       blkdev_open+0xd2/0xe0
       do_dentry_open+0x161/0x390
       path_openat+0x3cc/0xa20
       do_filp_open+0x96/0x120
       do_sys_openat2+0x7b/0x130
       __x64_sys_openat+0x46/0x70
       do_syscall_64+0x38/0x90
       entry_SYSCALL_64_after_hwframe+0x44/0xae

-> #3 (&disk->open_mutex){+.+.}-{3:3}:
       __mutex_lock+0x7d/0x750
       blkdev_get_by_dev.part.0+0x56/0x3c0
       blkdev_get_by_path+0x98/0xa0
       btrfs_get_bdev_and_sb+0x1b/0xb0
       btrfs_find_device_by_devspec+0x12b/0x1c0
       btrfs_rm_device+0x127/0x610
       btrfs_ioctl+0x2a31/0x2e70
       __x64_sys_ioctl+0x80/0xb0
       do_syscall_64+0x38/0x90
       entry_SYSCALL_64_after_hwframe+0x44/0xae

-> #2 (sb_writers#12){.+.+}-{0:0}:
       lo_write_bvec+0xc2/0x240 [loop]
       loop_process_work+0x238/0xd00 [loop]
       process_one_work+0x26b/0x560
       worker_thread+0x55/0x3c0
       kthread+0x140/0x160
       ret_from_fork+0x1f/0x30

-> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}:
       process_one_work+0x245/0x560
       worker_thread+0x55/0x3c0
       kthread+0x140/0x160
       ret_from_fork+0x1f/0x30

-> #0 ((wq_completion)loop0){+.+.}-{0:0}:
       __lock_acquire+0x10ea/0x1d90
       lock_acquire+0xb5/0x2b0
       flush_workqueue+0x91/0x5e0
       drain_workqueue+0xa0/0x110
       destroy_workqueue+0x36/0x250
       __loop_clr_fd+0x9a/0x660 [loop]
       block_ioctl+0x3f/0x50
       __x64_sys_ioctl+0x80/0xb0
       do_syscall_64+0x38/0x90
       entry_SYSCALL_64_after_hwframe+0x44/0xae

other info that might help us debug this:

Chain exists of:
  (wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&lo->lo_mutex);
                               lock(&disk->open_mutex);
                               lock(&lo->lo_mutex);
  lock((wq_completion)loop0);

 *** DEADLOCK ***

1 lock held by losetup/11576:
 #0: ffff9bbe88e4fc68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]

stack backtrace:
CPU: 0 PID: 11576 Comm: losetup Not tainted 5.14.0-rc2+ #405
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
 dump_stack_lvl+0x57/0x72
 check_noncircular+0xcf/0xf0
 ? stack_trace_save+0x3b/0x50
 __lock_acquire+0x10ea/0x1d90
 lock_acquire+0xb5/0x2b0
 ? flush_workqueue+0x67/0x5e0
 ? lockdep_init_map_type+0x47/0x220
 flush_workqueue+0x91/0x5e0
 ? flush_workqueue+0x67/0x5e0
 ? verify_cpu+0xf0/0x100
 drain_workqueue+0xa0/0x110
 destroy_workqueue+0x36/0x250
 __loop_clr_fd+0x9a/0x660 [loop]
 ? blkdev_ioctl+0x8d/0x2a0
 block_ioctl+0x3f/0x50
 __x64_sys_ioctl+0x80/0xb0
 do_syscall_64+0x38/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f31b02404cb

Instead what we want to do is populate our device lookup args before we
grab any locks, and then pass these args into btrfs_rm_device().  From
there we can find the device and do the appropriate removal.

Suggested-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:07 +02:00
Josef Bacik faa775c41d btrfs: add a btrfs_get_dev_args_from_path helper 
We are going to want to populate our device lookup args outside of any
locks and then do the actual device lookup later, so add a helper to do
this work and make btrfs_find_device_by_devspec() use this helper for
now.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:07 +02:00
Josef Bacik 562d7b1512 btrfs: handle device lookup with btrfs_dev_lookup_args 
We have a lot of device lookup functions that all do something slightly
different.  Clean this up by adding a struct to hold the different
lookup criteria, and then pass this around to btrfs_find_device() so it
can do the proper matching based on the lookup criteria.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:07 +02:00
Josef Bacik 8b41393fe7 btrfs: do not call close_fs_devices in btrfs_rm_device 
There's a subtle case where if we're removing the seed device from a
file system we need to free its private copy of the fs_devices.  However
we do not need to call close_fs_devices(), because at this point there
are no devices left to close as we've closed the last one.  The only
thing that close_fs_devices() does is decrement ->opened, which should
be 1.  We want to avoid calling close_fs_devices() here because it has a
lockdep_assert_held(&uuid_mutex), and we are going to stop holding the
uuid_mutex in this path.

So simply decrement the  ->opened counter like we should, and then clean
up like normal.  Also add a comment explaining what we're doing here as
I initially removed this code erroneously.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:07 +02:00
Anand Jain add9745adc btrfs: add comments for device counts in struct btrfs_fs_devices 
A bug was was checking a wrong device count before we delete the struct
btrfs_fs_devices in btrfs_rm_device(). To avoid future confusion and
easy reference add a comment about the various device counts that we have
in the struct btrfs_fs_devices.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:06 +02:00
Anand Jain 8e906945c0 btrfs: use num_device to check for the last surviving seed device 
For both sprout and seed fsids,
 btrfs_fs_devices::num_devices provides device count including missing
 btrfs_fs_devices::open_devices provides device count excluding missing

We create a dummy struct btrfs_device for the missing device, so
num_devices != open_devices when there is a missing device.

In btrfs_rm_devices() we wrongly check for %cur_devices->open_devices
before freeing the seed fs_devices. Instead we should check for
%cur_devices->num_devices.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:06 +02:00
Filipe Manana 10adb1152d btrfs: fix lost error handling when replaying directory deletes 
At replay_dir_deletes(), if find_dir_range() returns an error we break out
of the main while loop and then assign a value of 0 (success) to the 'ret'
variable, resulting in completely ignoring that an error happened. Fix
that by jumping to the 'out' label when find_dir_range() returns an error
(negative value).

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:06 +02:00
Qu Wenruo f4f39fc5dc btrfs: remove btrfs_bio::logical member 
The member btrfs_bio::logical is only initialized by two call sites:

- btrfs_repair_one_sector()
  No corresponding site to utilize it.

- btrfs_submit_direct()
  The corresponding site to utilize it is btrfs_check_read_dio_bio().

However for btrfs_check_read_dio_bio(), we can grab the file_offset from
btrfs_dio_private::file_offset directly.

Thus it turns out we don't really need that btrfs_bio::logical member at
all.

For btrfs_bio, the logical bytenr can be fetched from its
bio->bi_iter.bi_sector directly.

So let's just remove the member to save 8 bytes for structure btrfs_bio.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:06 +02:00
Qu Wenruo 47926ab535 btrfs: rename btrfs_dio_private::logical_offset to file_offset 
The naming of "logical_offset" can be confused with logical bytenr of
the dio range.

In fact it's file offset, and the naming "file_offset" is already widely
used in all other sites.

Just do the rename to avoid confusion.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:06 +02:00
Christoph Hellwig 3dcfbcce1b btrfs: use bvec_kmap_local in btrfs_csum_one_bio 
Using local kmaps slightly reduces the chances to stray writes, and
the bvec interface cleans up the code a little bit.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:06 +02:00
Anand Jain 11b66fa6ee btrfs: reduce btrfs_update_block_group alloc argument to bool 
btrfs_update_block_group() accounts for the number of bytes allocated or
freed. Argument @alloc specifies whether the call is for alloc or free.
Convert the argument @alloc type from int to bool.

Reviewed-by: Su Yue <l@damenly.su>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:06 +02:00
Nikolay Borisov eed2037fc5 btrfs: make btrfs_ref::real_root optional 
Now that real_root is only used in ref-verify core gate it behind
CONFIG_BTRFS_FS_REF_VERIFY ifdef. This shrinks the size of pending
delayed refs by 8 bytes per ref, of which we can have many at any one
time depending on intensity of the workload. Also change the comment
about the member as it no longer deals with qgroups.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:06 +02:00
Nikolay Borisov 681145d4ac btrfs: pull up qgroup checks from delayed-ref core to init time 
Instead of checking whether qgroup processing for a dealyed ref has to
happen in the core of delayed ref, simply pull the check at init time of
respective delayed ref structures. This eliminates the final use of
real_root in delayed-ref core paving the way to making this member
optional.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:06 +02:00
Nikolay Borisov f42c5da6c1 btrfs: add additional parameters to btrfs_init_tree_ref/btrfs_init_data_ref 
In order to make 'real_root' used only in ref-verify it's required to
have the necessary context to perform the same checks that this member
is used for. So add 'mod_root' which will contain the root on behalf of
which a delayed ref was created and a 'skip_group' parameter which
will contain callsite-specific override of skip_qgroup.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:06 +02:00
Nikolay Borisov d55b9e687e btrfs: rely on owning_root field in btrfs_add_delayed_tree_ref to detect CHUNK_ROOT 
The real_root field is going to be used only by ref-verify tool so limit
its use outside of it. Blocks belonging to the chunk root will always
have it as an owner so the check is equivalent.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:06 +02:00
Nikolay Borisov 113479d5b8 btrfs: rename root fields in delayed refs structs 
Both data and metadata delayed ref structures have fields named
root/ref_root respectively. Those are somewhat cryptic and don't really
convey the real meaning. In fact those roots are really the original
owners of the respective block (i.e in case of a snapshot a data delayed
ref will contain the original root that owns the given block). Rename
those fields accordingly and adjust comments.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:06 +02:00
Josef Bacik 0e24f6d84b btrfs: do not infinite loop in data reclaim if we aborted 
Error injection stressing uncovered a busy loop in our data reclaim
loop.  There are two cases here, one where we loop creating block groups
until space_info->full is set, or in the main loop we will skip erroring
out any tickets if space_info->full == 0.  Unfortunately if we aborted
the transaction then we will never allocate chunks or reclaim any space
and thus never get ->full, and you'll see stack traces like this:

  watchdog: BUG: soft lockup - CPU#0 stuck for 26s! [kworker/u4:4:139]
  CPU: 0 PID: 139 Comm: kworker/u4:4 Tainted: G        W         5.13.0-rc1+ #328
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
  Workqueue: events_unbound btrfs_async_reclaim_data_space
  RIP: 0010:btrfs_join_transaction+0x12/0x20
  RSP: 0018:ffffb2b780b77de0 EFLAGS: 00000246
  RAX: ffffb2b781863d58 RBX: 0000000000000000 RCX: 0000000000000000
  RDX: 0000000000000801 RSI: ffff987952b57400 RDI: ffff987940aa3000
  RBP: ffff987954d55000 R08: 0000000000000001 R09: ffff98795539e8f0
  R10: 000000000000000f R11: 000000000000000f R12: ffffffffffffffff
  R13: ffff987952b574c8 R14: ffff987952b57400 R15: 0000000000000008
  FS:  0000000000000000(0000) GS:ffff9879bbc00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007f0703da4000 CR3: 0000000113398004 CR4: 0000000000370ef0
  Call Trace:
   flush_space+0x4a8/0x660
   btrfs_async_reclaim_data_space+0x55/0x130
   process_one_work+0x1e9/0x380
   worker_thread+0x53/0x3e0
   ? process_one_work+0x380/0x380
   kthread+0x118/0x140
   ? __kthread_bind_mask+0x60/0x60
   ret_from_fork+0x1f/0x30

Fix this by checking to see if we have a btrfs fs error in either of the
reclaim loops, and if so fail the tickets and bail.  In addition to
this, fix maybe_fail_all_tickets() to not try to grant tickets if we've
aborted, simply fail everything.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:05 +02:00
Josef Bacik 8496153945 btrfs: add a BTRFS_FS_ERROR helper 
We have a few flags that are inconsistently used to describe the fs in
different states of failure.  As of 5963ffcaf3 ("btrfs: always abort
the transaction if we abort a trans handle") we will always set
BTRFS_FS_STATE_ERROR if we abort, so we don't have to check both ABORTED
and ERROR to see if things have gone wrong.  Add a helper to check
BTRFS_FS_STATE_ERROR and then convert all checkers of FS_STATE_ERROR to
use the helper.

The TRANS_ABORTED bit check was added in af72273381 ("Btrfs: clean up
resources during umount after trans is aborted") but is not actually
specific.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:05 +02:00
Josef Bacik 9a35fc9542 btrfs: change error handling for btrfs_delete_*_in_log 
Currently we will abort the transaction if we get a random error (like
-EIO) while trying to remove the directory entries from the root log
during rename.

However since these are simply log tree related errors, we can mark the
trans as needing a full commit.  Then if the error was truly
catastrophic we'll hit it during the normal commit and abort as
appropriate.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:05 +02:00
Josef Bacik ba51e2a11e btrfs: change handle_fs_error in recover_log_trees to aborts 
During inspection of the return path for replay I noticed that we don't
actually abort the transaction if we get a failure during replay.  This
isn't a problem necessarily, as we properly return the error and will
fail to mount.  However we still leave this dangling transaction that
could conceivably be committed without thinking there was an error.

We were using btrfs_handle_fs_error() here, but that pre-dates the
transaction abort code.  Simply replace the btrfs_handle_fs_error()
calls with transaction aborts, so we still know where exactly things
went wrong, and add a few in some other un-handled error cases.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:05 +02:00
Kai Song 64259baa39 btrfs: zoned: use kmemdup() to replace kmalloc + memcpy 
Fix memdup.cocci warning:
fs/btrfs/zoned.c:1198:23-30: WARNING opportunity for kmemdup

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Kai Song <songkai01@inspur.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:05 +02:00
Qu Wenruo 0cf9b244e7 btrfs: subpage: only allow compression if the range is fully page aligned 
For compressed write, we use a mechanism called async COW, which unlike
regular run_delalloc_cow() or cow_file_range() will also unlock the
first page.

This mechanism allows us to continue handling next ranges, without
waiting for the time consuming compression.

But this has a problem for subpage case, as we could have the following
delalloc range for a page:

0		32K		64K
|	|///////|	|///////|
		\- A		\- B

In the above case, if we pass both ranges to cow_file_range_async(),
both range A and range B will try to unlock the full page [0, 64K).

And which one finishes later than the other one will try to do other
page operations like end_page_writeback() on a unlocked page, triggering
VM layer BUG_ON().

To make subpage compression work at least partially, here we add another
restriction for it, only allow compression if the delalloc range is
fully page aligned.

By that, async extent is always ensured to unlock the first page
exclusively, just like it used to be for regular sectorsize.

In theory, we only need to make sure the delalloc range fully covers its
first page, but the tail page will be locked anyway, blocking later
writeback until the compression finishes.

Thus here we choose to make sure the range is fully page aligned before
doing the compression.

In the future, we could optimize the situation by properly increasing
subpage::writers number for the locked page, but that also means we need
to change how we run delalloc range of page.
(Instead of running each delalloc range we hit, we need to find and lock
all delalloc ranges covering the page, then run each of them).

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:05 +02:00
Qu Wenruo 2749f7ef36 btrfs: subpage: avoid potential deadlock with compression and delalloc 
[BUG]
With experimental subpage compression enabled, a simple fsstress can
lead to self deadlock on page 720896:

        mkfs.btrfs -f -s 4k $dev > /dev/null
        mount $dev -o compress $mnt
        $fsstress -p 1 -n 100 -w -d $mnt -v -s 1625511156

[CAUSE]
If we have a file layout looks like below:

	0	32K	64K	96K	128K
	|//|		|///////////////|
	   4K

Then we run delalloc range for the inode, it will:

- Call find_lock_delalloc_range() with @delalloc_start = 0
  Then we got a delalloc range [0, 4K).

  This range will be COWed.

- Call find_lock_delalloc_range() again with @delalloc_start = 4K
  Since find_lock_delalloc_range() never cares whether the range
  is still inside page range [0, 64K), it will return range [64K, 128K).

  This range meets the condition for subpage compression, will go
  through async COW path.

  And async COW path will return @page_started.

  But that @page_started is now for range [64K, 128K), not for range
  [0, 64K).

- writepage_dellloc() returned 1 for page [0, 64K)
  Thus page [0, 64K) will not be unlocked, nor its page dirty status
  will be cleared.

Next time when we try to lock page [0, 64K) we will deadlock, as there
is no one to release page [0, 64K).

This problem will never happen for regular page size as one page only
contains one sector.  After the first find_lock_delalloc_range() call,
the @delalloc_end will go beyond @page_end no matter if we found a
delalloc range or not

Thus this bug only happens for subpage, as now we need multiple runs to
exhaust the delalloc range of a page.

[FIX]
Fix the problem by ensuring the delalloc range we ran at least started
inside @locked_page.

So that we will never get incorrect @page_started.

And to prevent such problem from happening again:

- Make find_lock_delalloc_range() return false if the found range is
  beyond @end value passed in.

  Since @end will be utilized now, add an ASSERT() to ensure we pass
  correct @end into find_lock_delalloc_range().

  This also means, for selftests we needs to populate @end before calling
  find_lock_delalloc_range().

- New ASSERT() in find_lock_delalloc_range()
  Now we will make sure the @start/@end passed in at least covers part
  of the page.

- New ASSERT() in run_delalloc_range()
  To make sure the range at least starts inside @locked page.

- Use @delalloc_start as proper cursor, while @delalloc_end is always
  reset to @page_end.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:05 +02:00
Qu Wenruo 164674a76b btrfs: handle page locking in btrfs_page_end_writer_lock with no writers 
There are several call sites of extent_clear_unlock_delalloc() which get
@locked_page = NULL.
So that extent_clear_unlock_delalloc() will try to call
process_one_page() to unlock every page even the first page is not
locked by btrfs_page_start_writer_lock().

This will trigger an ASSERT() in btrfs_subpage_end_and_test_writer() as
previously we require every page passed to
btrfs_subpage_end_and_test_writer() to be locked by
btrfs_page_start_writer_lock().

But compression path doesn't go that way.

Thankfully it's not hard to distinguish page locked by lock_page() and
btrfs_page_start_writer_lock().

So do the check in btrfs_subpage_end_and_test_writer() so now it can
handle both cases well.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:05 +02:00
Qu Wenruo e55a0de185 btrfs: rework page locking in __extent_writepage() 
Pages passed to __extent_writepage() are always locked, but they may be
locked by different functions.

There are two types of locked page for __extent_writepage():

- Page locked by plain lock_page()
  It should not have any subpage::writers count.
  Can be unlocked by unlock_page().
  This is the most common locked page for __extent_writepage() called
  inside extent_write_cache_pages() or extent_write_full_page().
  Rarer cases include the @locked_page from extent_write_locked_range().

- Page locked by lock_delalloc_pages()
  There is only one caller, all pages except @locked_page for
  extent_write_locked_range().
  In this case, we have to call subpage helper to handle the case.

So here we introduce a helper, btrfs_page_unlock_writer(), to allow
__extent_writepage() to unlock different locked pages.

And since for all other callers of __extent_writepage() their pages are
ensured to be locked by lock_page(), also add an extra check for
epd::extent_locked to unlock such pages directly.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:05 +02:00
Qu Wenruo d4088803f5 btrfs: subpage: make lzo_compress_pages() compatible 
There are several problems in lzo_compress_pages() preventing it from
being subpage compatible:

- No page offset is calculated when reading from inode pages
  For subpage case, we could have @start which is not aligned to
  PAGE_SIZE.

  Thus the destination where we read data from must take offset in page
  into consideration.

- The padding for segment header is bound to PAGE_SIZE
  This means, for subpage case we can skip several corners where on x86
  machines we need to add padding zeros.

The rework will:

- Update the comment to replace "page" with "sector"

- Introduce a new helper, copy_compressed_data_to_page(), to do the copy
  So that we don't need to bother page switching for both input and
  output.

  Now in lzo_compress_pages() we only care about page switching for
  input, while in copy_compressed_data_to_page() we only care about the
  page switching for output.

- Only one main cursor
  For lzo_compress_pages() we use @cur_in as main cursor.
  It will be the file offset we are currently at.

  All other helper variables will be only declared inside the loop.

  For copy_compressed_data_to_page() it's similar, we will have
  @cur_out at the main cursor, which records how many bytes are in the
  output.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:05 +02:00
Qu Wenruo 2b83a0eea5 btrfs: factor uncompressed async extent submission code into a new helper 
Introduce a new helper, submit_uncompressed_range(), for async cow cases
where we fallback to COW.

There are some new updates introduced to the helper:

- Proper locked_page detection
  It's possible that the async_extent range doesn't cover the locked
  page.  In that case we shouldn't unlock the locked page.

  In the new helper, we will ensure that we only unlock the locked page
  when:

  * The locked page covers part of the async_extent range
  * The locked page is not unlocked by cow_file_range() nor
    extent_write_locked_range()

  This also means extra comments are added focusing on the page locking.

- Add extra comment on some rare parameter used.
  We use @unlock_page = 0 for cow_file_range(), where only two call
  sites doing the same thing, including the new helper.

  It's definitely worth some comments.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:05 +02:00
Qu Wenruo 66448b9d5b btrfs: subpage: make extent_write_locked_range() compatible 
There are two sites are not subpage compatible yet for
extent_write_locked_range():

- How @nr_pages are calculated
  For subpage we can have the following range with 64K page size:

  0   32K  64K   96K 128K
  |   |////|/////|   |

  In that case, although 96K - 32K == 64K, thus it looks like one page
  is enough, but the range spans two pages, not one.

  Fix it by doing proper round_up() and round_down() to calculate
  @nr_pages.

  Also add some extra ASSERT()s to ensure the range passed in is already
  aligned.

- How the page end is calculated
  Currently we just use cur + PAGE_SIZE - 1 to calculate the page end.

  Which can't handle the above range layout, and will trigger ASSERT()
  in btrfs_writepage_endio_finish_ordered(), as the range is no longer
  covered by the page range.

  Fix it by taking page end into consideration.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:05 +02:00
Qu Wenruo 741ec653ab btrfs: subpage: make end_compressed_bio_writeback() compatible 
In end_compressed_writeback() we just clear the full page writeback.
For subpage case, if there are two delalloc ranges in the same page, the
2nd range will trigger a BUG_ON() as the page writeback is already
cleared by previous range.

Fix it by using btrfs_page_clamp_clear_writeback() helper.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:04 +02:00
Qu Wenruo bbbff01a47 btrfs: subpage: make btrfs_submit_compressed_write() compatible 
There is a WARN_ON() checking if @start is aligned to PAGE_SIZE, not
sectorsize, which will cause false alert for subpage.  Fix it to check
against sectorsize.

Furthermore:

- Use ASSERT() to do the check
  So that in the future we may skip the check for production build

- Also check alignment for @len

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:04 +02:00
Qu Wenruo 4c162778d6 btrfs: subpage: make compress_file_range() compatible 
In function compress_file_range(), when the compression is finished, the
function just rounds up @total_in to PAGE_SIZE.  This is fine for
regular sectorsize == PAGE_SIZE case, but not for subpage.

Just change the ALIGN(, PAGE_SIZE) to round_up(, sectorsize) so that
both regular sectorsize and subpage sectorsize will be happy.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:04 +02:00
Qu Wenruo 2bd0fc9349 btrfs: cleanup for extent_write_locked_range() 
There are several cleanups for extent_write_locked_range(), most of them
are pure cleanups, but with some preparation for future subpage support.

- Add a proper comment for which call sites are suitable
  Unlike regular synchronized extent write back, if async COW or zoned
  COW happens, we have all pages in the range still locked.

  Thus for those (only) two call sites, we need this function to submit
  page content into bios and submit them.

- Remove @mode parameter
  All the existing two call sites pass WB_SYNC_ALL. No need for @mode
  parameter.

- Better error handling
  Currently if we hit an error during the page iteration loop, we
  overwrite @ret, causing only the last error can be recorded.

  Here we add @found_error and @first_error variable to record if we hit
  any error, and the first error we hit.
  So the first error won't get lost.

- Don't reuse @start as the cursor
  We reuse the parameter @start as the cursor to iterate the range, not
  a big problem, but since we're here, introduce a proper @cur as the
  cursor.

- Remove impossible branch
  Since all pages are still locked after the ordered extent is inserted,
  there is no way that pages can get its dirty bit cleared.
  Remove the branch where page is not dirty and replace it with an
  ASSERT().

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:04 +02:00
Qu Wenruo b4ccace878 btrfs: refactor submit_compressed_extents() 
We have a big chunk of code inside a while() loop, with tons of strange
jumps for error handling.  It's definitely not to the code standard of
today.  Move the code into a new function, submit_one_async_extent().

Since we're here, also do the following changes:

- Comment style change
  To follow the current scheme

- Don't fallback to non-compressed write then hitting ENOSPC
  If we hit ENOSPC for compressed write, how could we reserve more space
  for non-compressed write?
  Thus we go error path directly.
  This removes the retry: label.

- Add more comment for super long parameter list
  Explain which parameter is for, so we don't need to check the
  prototype.

- Move the error handling to submit_one_async_extent()
  Thus no strange code like:

  out_free:
	...
	goto again;

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:04 +02:00
Qu Wenruo 6aabd85835 btrfs: remove unused function btrfs_bio_fits_in_stripe() 
As the last caller in compression.c has been removed, we don't need that
function anymore.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:04 +02:00
Qu Wenruo 9150724048 btrfs: determine stripe boundary at bio allocation time in btrfs_submit_compressed_write 
Currently btrfs_submit_compressed_write() will check
btrfs_bio_fits_in_stripe() each time a new page is going to be added.
Even if compressed extent is small, we don't really need to do that for
every page.

Align the behavior to extent_io.c, by determining the stripe boundary
when allocating a bio.

Unlike extent_io.c, in compressed.c we don't need to bother things like
different bio flags, thus no need to re-use bio_ctrl.

Here we just manually introduce new local variable, next_stripe_start,
and use that value returned from alloc_compressed_bio() to calculate
the stripe boundary.

Then each time we add some page range into the bio, we check if we
reached the boundary.  And if reached, submit it.

Also, since we have @cur_disk_bytenr to determine whether we're the last
bio, we don't need a explicit last_bio: tag for error handling any more.

And since we use @cur_disk_bytenr to wait, there is no need for
pending_bios, also remove it to save some memory of compressed_bio.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:04 +02:00
Qu Wenruo f472c28f2e btrfs: determine stripe boundary at bio allocation time in btrfs_submit_compressed_read 
Currently btrfs_submit_compressed_read() will check
btrfs_bio_fits_in_stripe() each time a new page is going to be added.
Even if compressed extent is small, we don't really need to do that for
every page.

This patch will align the behavior to extent_io.c, by determining the
stripe boundary when allocating a bio.

Unlike extent_io.c, in compressed.c we don't need to bother things like
different bio flags, thus no need to re-use bio_ctrl.

Here we just manually introduce new local variable, next_stripe_start,
and teach alloc_compressed_bio() to calculate the stripe boundary.

Then each time we add some page range into the bio, we check if we
reached the boundary.  And if reached, submit it.

Also, since we have @cur_disk_byte to determine whether we're the last
bio, we don't need a explicit last_bio: tag for error handling any more.

And we can use @cur_disk_byte to track which range has been added to
bio, we can also use @cur_disk_byte to calculate the wait condition, no
need for @pending_bios.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:04 +02:00
Qu Wenruo 22c306fe0d btrfs: introduce alloc_compressed_bio() for compression 
Just aggregate the bio allocation code into one helper, so that we can
replace 4 call sites.

There is one special note for zoned write.

Currently btrfs_submit_compressed_write() will only allocate the first
bio using ZONE_APPEND.  If we have to submit current bio due to stripe
boundary, the new bio allocated will not use ZONE_APPEND.

In theory this should be a bug, but considering zoned mode currently
only support SINGLE profile, which doesn't have any stripe boundary
limit, it should never be a problem and we have assertions in place.

This function will provide a good entrance for any work which needs to
be done at bio allocation time. Like determining the stripe boundary.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:04 +02:00
Qu Wenruo 2d4e0b84b4 btrfs: introduce submit_compressed_bio() for compression 
The new helper, submit_compressed_bio(), will aggregate the following
work:

- Increase compressed_bio::pending_bios
- Remap the endio function
- Map and submit the bio

This slightly reorders calls to btrfs_csum_one_bio or
btrfs_lookup_bio_sums but but none of them does anything regarding IO
submission so this is effectively no change. We mainly care about order
of

- atomic_inc
- btrfs_bio_wq_end_io
- btrfs_map_bio

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:04 +02:00
Qu Wenruo 6853c64a6e btrfs: handle errors properly inside btrfs_submit_compressed_write() 
Just like btrfs_submit_compressed_read(), there are quite some BUG_ON()s
inside btrfs_submit_compressed_write() for the bio submission path.

Fix them using the same method:

- For last bio, just endio the bio
  As in that case, one of the endio function of all these submitted bio
  will be able to free the compressed_bio

- For half-submitted bio, wait and finish the compressed_bio manually
  In this case, as long as all other bio finish, we're the only one
  referring the compressed bio, and can manually finish it.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:04 +02:00
Qu Wenruo 86ccbb4d2a btrfs: handle errors properly inside btrfs_submit_compressed_read() 
There are quite some BUG_ON()s inside btrfs_submit_compressed_read(),
namely all errors inside the for() loop relies on BUG_ON() to handle
-ENOMEM.

Handle these errors properly by:

- Wait for submitted bios to finish first
  Using wake_var_event() APIs to wait without introducing extra memory
  overhead inside compressed_bio.
  This allows us to wait for any submitted bio to finish, while still
  keeps the compressed_bio from being freed.

- Introduce finish_compressed_bio_read() to finish the compressed_bio

- Properly end the bio and finish compressed_bio when error happens

Now in btrfs_submit_compressed_read() even when the bio submission
failed, we can properly handle the error without triggering BUG_ON().

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:04 +02:00
Qu Wenruo e4f9434749 btrfs: subpage: add bitmap for PageChecked flag 
Although in btrfs we have very limited usage of PageChecked flag, it's
still some page flag not yet subpage compatible.

Fix it by introducing btrfs_subpage::checked_offset to do the convert.

For most call sites, especially for free-space cache, COW fixup and
btrfs_invalidatepage(), they all work in full page mode anyway.

For other call sites, they work as subpage compatible mode.

Some call sites need extra modification:

- btrfs_drop_pages()
  Needs extra parameter to get the real range we need to clear checked
  flag.

  Also since btrfs_drop_pages() will accept pages beyond the dirtied
  range, update btrfs_subpage_clamp_range() to handle such case
  by setting @len to 0 if the page is beyond target range.

- btrfs_invalidatepage()
  We need to call subpage helper before calling __btrfs_releasepage(),
  or it will trigger ASSERT() as page->private will be cleared.

- btrfs_verify_data_csum()
  In theory we don't need the io_bio->csum check anymore, but it's
  won't hurt.  Just change the comment.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:03 +02:00
Qu Wenruo 6ec9765d74 btrfs: introduce compressed_bio::pending_sectors to trace compressed bio 
For btrfs_submit_compressed_read() and btrfs_submit_compressed_write(),
we have a pretty weird dance around compressed_bio::pending_bios:

  btrfs_submit_compressed_read/write()
  {
	cb = kmalloc()
	refcount_set(&cb->pending_bios, 0);
	bio = btrfs_alloc_bio();

	/* NOTE here, we haven't yet submitted any bio */
	refcount_set(&cb->pending_bios, 1);

	for (pg_index = 0; pg_index < cb->nr_pages; pg_index++) {
		if (submit) {
			/* Here we submit bio, but we always have one
			 * extra pending_bios */
			refcount_inc(&cb->pending_bios);
			ret = btrfs_map_bio();
		}
	}

	/* Submit the last bio */
	ret = btrfs_map_bio();
  }

There are two reasons why we do this:

- compressed_bio::pending_bios is a refcount
  Thus if it's reduced to 0, it can not be increased again.

- To ensure the compressed_bio is not freed by some submitted bios
  If the submitted bio is finished before the next bio submitted,
  we can free the compressed_bio completely.

But the above code is sometimes confusing, and we can do it better by
introducing a new member, compressed_bio::pending_sectors.

Now we use compressed_bio::pending_sectors to indicate whether we have
any pending sectors under IO or not yet submitted.

If pending_sectors == 0, we're definitely the last bio of compressed_bio,
and is OK to release the compressed bio.

Now the workflow looks like this:

  btrfs_submit_compressed_read/write()
  {
	cb = kmalloc()
	atomic_set(&cb->pending_bios, 0);
	refcount_set(&cb->pending_sectors,
		     compressed_len >> sectorsize_bits);
	bio = btrfs_alloc_bio();

	for (pg_index = 0; pg_index < cb->nr_pages; pg_index++) {
		if (submit) {
			refcount_inc(&cb->pending_bios);
			ret = btrfs_map_bio();
		}
	}

	/* Submit the last bio */
	refcount_inc(&cb->pending_bios);
	ret = btrfs_map_bio();
  }

For now we still need pending_bios for later error handling, but will
remove pending_bios eventually after properly handling the errors.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:03 +02:00
Qu Wenruo 6a40491020 btrfs: subpage: make add_ra_bio_pages() compatible 
[BUG]
If we remove the subpage limitation in add_ra_bio_pages(), then read a
compressed extent which has part of its range in next page, like the
following inode layout:

	0	32K	64K	96K	128K
	|<--------------|-------------->|

Btrfs will trigger ASSERT() in endio function:

  assertion failed: atomic_read(&subpage->readers) >= nbits
  ------------[ cut here ]------------
  kernel BUG at fs/btrfs/ctree.h:3431!
  Internal error: Oops - BUG: 0 [#1] SMP
  Workqueue: btrfs-endio btrfs_work_helper [btrfs]
  Call trace:
   assertfail.constprop.0+0x28/0x2c [btrfs]
   btrfs_subpage_end_reader+0x148/0x14c [btrfs]
   end_page_read+0x8c/0x100 [btrfs]
   end_bio_extent_readpage+0x320/0x6b0 [btrfs]
   bio_endio+0x15c/0x1dc
   end_workqueue_fn+0x44/0x64 [btrfs]
   btrfs_work_helper+0x74/0x250 [btrfs]
   process_one_work+0x1d4/0x47c
   worker_thread+0x180/0x400
   kthread+0x11c/0x120
   ret_from_fork+0x10/0x30
  ---[ end trace c8b7b552d3bb408c ]---

[CAUSE]
When we read the page range [0, 64K), we find it's a compressed extent,
and we will try to add extra pages in add_ra_bio_pages() to avoid
reading the same compressed extent.

But when we add such page into the read bio, it doesn't follow the
behavior of btrfs_do_readpage() to properly set subpage::readers.

This means, for page [64K, 128K), its subpage::readers is still 0.

And when endio is executed on both pages, since page [64K, 128K) has 0
subpage::readers, it triggers above ASSERT()

[FIX]
Function add_ra_bio_pages() is far from subpage compatible, it always
assume PAGE_SIZE == sectorsize, thus when it skip to next range it
always just skip PAGE_SIZE.

Make it subpage compatible by:

- Skip to next page properly when needed
  If we find there is already a page cache, we need to skip to next page.
  For that case, we shouldn't just skip PAGE_SIZE bytes, but use
  @pg_index to calculate the next bytenr and continue.

- Only add the page range covered by current extent map
  We need to calculate which range is covered by current extent map and
  only add that part into the read bio.

- Update subpage::readers before submitting the bio

- Use proper cursor other than confusing @last_offset

- Calculate the missed threshold based on sector size
  It's no longer using missed pages, as for 64K page size, we have at
  most 3 pages to skip. (If aligned only 2 pages)

- Add ASSERT() to make sure our bytenr is always aligned

- Add comment for the function
  Add a special note for subpage case, as the function won't really
  work well for subpage cases.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:03 +02:00
Qu Wenruo 584691748c btrfs: don't pass compressed pages to btrfs_writepage_endio_finish_ordered() 
Since async_extent holds the compressed page, it would trigger the new
ASSERT() in btrfs_mark_ordered_io_finished() which checks that the range
is inside the page.

Now btrfs_writepage_endio_finish_ordered() can accept @page == NULL,
just pass NULL to btrfs_writepage_endio_finish_ordered().

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:03 +02:00
Qu Wenruo 9e895a8f7e btrfs: use async_chunk::async_cow to replace the confusing pending pointer 
For structure async_chunk, we use a very strange member layout to grab
structure async_cow who owns this async_chunk.

At initialization, it goes like this:

		async_chunk[i].pending = &ctx->num_chunks;

Then at async_cow_free() we do a super weird freeing:

	/*
	 * Since the pointer to 'pending' is at the beginning of the array of
	 * async_chunk's, freeing it ensures the whole array has been freed.
	 */
	if (atomic_dec_and_test(async_chunk->pending))
		kvfree(async_chunk->pending);

This is absolutely an abuse of kvfree().

Replace async_chunk::pending with async_chunk::async_cow, so that we can
grab the async_cow structure directly, without this strange dancing.

And with this change, there is no requirement for any specific member
location.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:03 +02:00
Qu Wenruo cf3075fb36 btrfs: remove unnecessary parameter delalloc_start for writepage_delalloc() 
In function __extent_writepage() we always pass page start to
@delalloc_start for writepage_delalloc().

Thus we don't really need @delalloc_start parameter as we can extract it
from @page.

Remove @delalloc_start parameter and make __extent_writepage() to
declare @page_start and @page_end as const.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:03 +02:00
Qu Wenruo cd9255be69 btrfs: remove unused parameter nr_pages in add_ra_bio_pages() 
Variable @nr_pages only gets increased but never used.  Remove it.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:03 +02:00
Filipe Manana da1b811fcd btrfs: use single bulk copy operations when logging directories 
When logging a directory and inserting a batch of directory items, we are
copying the data of each item from a leaf in the fs/subvolume tree to a
leaf in a log tree, separately. This is not really needed, since we are
copying from a contiguous memory area into another one, so we can use a
single copy operation to copy all items at once.

This patch is part of a small patchset that is comprised of the following
patches:

  btrfs: loop only once over data sizes array when inserting an item batch
  btrfs: unexport setup_items_for_insert()
  btrfs: use single bulk copy operations when logging directories

This is patch 3/3.

The following test was used to compare performance of a branch without the
patchset versus one branch that has the whole patchset applied:

  $ cat dir-fsync-test.sh
  #!/bin/bash

  DEV=/dev/nvme0n1
  MNT=/mnt/nvme0n1

  NUM_NEW_FILES=1000000
  NUM_FILE_DELETES=1000
  LEAF_SIZE=16K

  mkfs.btrfs -f -n $LEAF_SIZE $DEV
  mount -o ssd $DEV $MNT

  mkdir $MNT/testdir

  for ((i = 1; i <= $NUM_NEW_FILES; i++)); do
      echo -n > $MNT/testdir/file_$i
  done

  # Fsync the directory, this will log the new dir items and the inodes
  # they point to, because these are new inodes.
  start=$(date +%s%N)
  xfs_io -c "fsync" $MNT/testdir
  end=$(date +%s%N)

  dur=$(( (end - start) / 1000000 ))
  echo "dir fsync took $dur ms after adding $NUM_NEW_FILES files"

  # sync to force transaction commit and wipeout the log.
  sync

  del_inc=$(( $NUM_NEW_FILES / $NUM_FILE_DELETES ))
  for ((i = 1; i <= $NUM_NEW_FILES; i += $del_inc)); do
      rm -f $MNT/testdir/file_$i
  done

  # Fsync the directory, this will only log dir items, there are no
  # dentries pointing to new inodes.
  start=$(date +%s%N)
  xfs_io -c "fsync" $MNT/testdir
  end=$(date +%s%N)

  dur=$(( (end - start) / 1000000 ))
  echo "dir fsync took $dur ms after deleting $NUM_FILE_DELETES files"

  umount $MNT

The tests were run on a non-debug kernel (Debian's default kernel config)
and were the following:

*** with a leaf size of 16K, before patchset ***

dir fsync took 8482 ms after adding 1000000 files
dir fsync took 166 ms after deleting 1000 files

*** with a leaf size of 16K, after patchset ***

dir fsync took 8196 ms after adding 1000000 files  (-3.4%)
dir fsync took 143 ms after deleting 1000 files    (-14.9%)

*** with a leaf size of 64K, before patchset ***

dir fsync took 12851 ms after adding 1000000 files
dir fsync took 466 ms after deleting 1000 files

*** with a leaf size of 64K, after  patchset ***

dir fsync took 12287 ms after adding 1000000 files (-4.5%)
dir fsync took 414 ms after deleting 1000 files    (-11.8%)

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:03 +02:00
Filipe Manana f064165661 btrfs: unexport setup_items_for_insert() 
Since setup_items_for_insert() is not used anymore outside of ctree.c,
make it static and remove its prototype from ctree.h. This also requires
to move the definition of setup_item_for_insert() from ctree.h to ctree.c
and move down btrfs_duplicate_item() so that it's defined after
setup_items_for_insert().

Further, since setup_item_for_insert() is used outside ctree.c, rename it
to btrfs_setup_item_for_insert().

This patch is part of a small patchset that is comprised of the following
patches:

  btrfs: loop only once over data sizes array when inserting an item batch
  btrfs: unexport setup_items_for_insert()
  btrfs: use single bulk copy operations when logging directories

This is patch 2/3 and performance results, and the specific tests, are
included in the changelog of patch 3/3.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:03 +02:00
Filipe Manana b7ef5f3a6f btrfs: loop only once over data sizes array when inserting an item batch 
When inserting a batch of items into a btree, we end up looping over the
data sizes array 3 times:

1) Once in the caller of btrfs_insert_empty_items(), when it populates the
   array with the data sizes for each item;

2) Once at btrfs_insert_empty_items() to sum the elements of the data
   sizes array and compute the total data size;

3) And then once again at setup_items_for_insert(), where we do exactly
   the same as what we do at btrfs_insert_empty_items(), to compute the
   total data size.

That is not bad for small arrays, but when the arrays have hundreds of
elements, the time spent on looping is not negligible. For example when
doing batch inserts of delayed items for dir index items or when logging
a directory, it's common to have 200 to 260 dir index items in a single
batch when using a leaf size of 16K and using file names between 8 and 12
characters. For a 64K leaf size, multiply that by 4. Taking into account
that during directory logging or when flushing delayed dir index items we
can have many of those large batches, the time spent on the looping adds
up quickly.

It's also more important to avoid it at setup_items_for_insert(), since
we are holding a write lock on a leaf and, in some cases, on upper nodes
of the btree, which causes us to block other tasks that want to access
the leaf and nodes for longer than necessary.

So change the code so that setup_items_for_insert() and
btrfs_insert_empty_items() no longer compute the total data size, and
instead rely on the caller to supply it. This makes us loop over the
array only once, where we can both populate the data size array and
compute the total data size, taking advantage of spatial and temporal
locality. To make this more manageable, use a structure to contain
all the relevant details for a batch of items (keys array, data sizes
array, total data size, number of items), and use it as an argument
for btrfs_insert_empty_items() and setup_items_for_insert().

This patch is part of a small patchset that is comprised of the following
patches:

  btrfs: loop only once over data sizes array when inserting an item batch
  btrfs: unexport setup_items_for_insert()
  btrfs: use single bulk copy operations when logging directories

This is patch 1/3 and performance results, and the specific tests, are
included in the changelog of patch 3/3.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:03 +02:00
Qu Wenruo 6a258d725d btrfs: remove btrfs_raid_bio::fs_info member 
We can grab fs_info reliably from btrfs_raid_bio::bioc, as the bioc is
always passed into alloc_rbio(), and only get released when the raid bio
is released.

Remove btrfs_raid_bio::fs_info member, and cleanup all the @fs_info
parameters for alloc_rbio() callers.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:03 +02:00
Qu Wenruo 731ccf15c9 btrfs: make sure btrfs_io_context::fs_info is always initialized 
Currently btrfs_io_context::fs_info is only initialized in
btrfs_map_bio, but there are call sites like btrfs_map_sblock() which
calls __btrfs_map_block() directly, leaving bioc::fs_info uninitialized
(NULL).

Currently this is fine, but later cleanup will rely on bioc::fs_info to
grab fs_info, and this can be a hidden problem for such usage.

This patch will remove such hidden uninitialized member by always
assigning bioc::fs_info at alloc_btrfs_io_context().

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:02 +02:00
Filipe Manana 49d0c6424c btrfs: assert that extent buffers are write locked instead of only locked 
We currently use lockdep_assert_held() at btrfs_assert_tree_locked(), and
that checks that we hold a lock either in read mode or write mode.

However in all contexts we use btrfs_assert_tree_locked(), we actually
want to check if we are holding a write lock on the extent buffer's rw
semaphore - it would be a bug if in any of those contexts we were holding
a read lock instead.

So change btrfs_assert_tree_locked() to use lockdep_assert_held_write()
instead and, to make it more explicit, rename btrfs_assert_tree_locked()
to btrfs_assert_tree_write_locked(), so that it's clear we want to check
we are holding a write lock.

For now there are no contexts where we want to assert that we must have
a read lock, but in case that is needed in the future, we can add a new
helper function that just calls out lockdep_assert_held_read().

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:02 +02:00
Josef Bacik 8ef9dc0f14 btrfs: do not take the uuid_mutex in btrfs_rm_device 
We got the following lockdep splat while running fstests (specifically
btrfs/003 and btrfs/020 in a row) with the new rc.  This was uncovered
by 87579e9b7d ("loop: use worker per cgroup instead of kworker") which
converted loop to using workqueues, which comes with lockdep
annotations that don't exist with kworkers.  The lockdep splat is as
follows:

  WARNING: possible circular locking dependency detected
  5.14.0-rc2-custom+ #34 Not tainted
  ------------------------------------------------------
  losetup/156417 is trying to acquire lock:
  ffff9c7645b02d38 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x84/0x600

  but task is already holding lock:
  ffff9c7647395468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x650 [loop]

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #5 (&lo->lo_mutex){+.+.}-{3:3}:
	 __mutex_lock+0xba/0x7c0
	 lo_open+0x28/0x60 [loop]
	 blkdev_get_whole+0x28/0xf0
	 blkdev_get_by_dev.part.0+0x168/0x3c0
	 blkdev_open+0xd2/0xe0
	 do_dentry_open+0x163/0x3a0
	 path_openat+0x74d/0xa40
	 do_filp_open+0x9c/0x140
	 do_sys_openat2+0xb1/0x170
	 __x64_sys_openat+0x54/0x90
	 do_syscall_64+0x3b/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xae

  -> #4 (&disk->open_mutex){+.+.}-{3:3}:
	 __mutex_lock+0xba/0x7c0
	 blkdev_get_by_dev.part.0+0xd1/0x3c0
	 blkdev_get_by_path+0xc0/0xd0
	 btrfs_scan_one_device+0x52/0x1f0 [btrfs]
	 btrfs_control_ioctl+0xac/0x170 [btrfs]
	 __x64_sys_ioctl+0x83/0xb0
	 do_syscall_64+0x3b/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xae

  -> #3 (uuid_mutex){+.+.}-{3:3}:
	 __mutex_lock+0xba/0x7c0
	 btrfs_rm_device+0x48/0x6a0 [btrfs]
	 btrfs_ioctl+0x2d1c/0x3110 [btrfs]
	 __x64_sys_ioctl+0x83/0xb0
	 do_syscall_64+0x3b/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xae

  -> #2 (sb_writers#11){.+.+}-{0:0}:
	 lo_write_bvec+0x112/0x290 [loop]
	 loop_process_work+0x25f/0xcb0 [loop]
	 process_one_work+0x28f/0x5d0
	 worker_thread+0x55/0x3c0
	 kthread+0x140/0x170
	 ret_from_fork+0x22/0x30

  -> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}:
	 process_one_work+0x266/0x5d0
	 worker_thread+0x55/0x3c0
	 kthread+0x140/0x170
	 ret_from_fork+0x22/0x30

  -> #0 ((wq_completion)loop0){+.+.}-{0:0}:
	 __lock_acquire+0x1130/0x1dc0
	 lock_acquire+0xf5/0x320
	 flush_workqueue+0xae/0x600
	 drain_workqueue+0xa0/0x110
	 destroy_workqueue+0x36/0x250
	 __loop_clr_fd+0x9a/0x650 [loop]
	 lo_ioctl+0x29d/0x780 [loop]
	 block_ioctl+0x3f/0x50
	 __x64_sys_ioctl+0x83/0xb0
	 do_syscall_64+0x3b/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xae

  other info that might help us debug this:
  Chain exists of:
    (wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex
   Possible unsafe locking scenario:
	 CPU0                    CPU1
	 ----                    ----
    lock(&lo->lo_mutex);
				 lock(&disk->open_mutex);
				 lock(&lo->lo_mutex);
    lock((wq_completion)loop0);

   *** DEADLOCK ***
  1 lock held by losetup/156417:
   #0: ffff9c7647395468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x650 [loop]

  stack backtrace:
  CPU: 8 PID: 156417 Comm: losetup Not tainted 5.14.0-rc2-custom+ #34
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
  Call Trace:
   dump_stack_lvl+0x57/0x72
   check_noncircular+0x10a/0x120
   __lock_acquire+0x1130/0x1dc0
   lock_acquire+0xf5/0x320
   ? flush_workqueue+0x84/0x600
   flush_workqueue+0xae/0x600
   ? flush_workqueue+0x84/0x600
   drain_workqueue+0xa0/0x110
   destroy_workqueue+0x36/0x250
   __loop_clr_fd+0x9a/0x650 [loop]
   lo_ioctl+0x29d/0x780 [loop]
   ? __lock_acquire+0x3a0/0x1dc0
   ? update_dl_rq_load_avg+0x152/0x360
   ? lock_is_held_type+0xa5/0x120
   ? find_held_lock.constprop.0+0x2b/0x80
   block_ioctl+0x3f/0x50
   __x64_sys_ioctl+0x83/0xb0
   do_syscall_64+0x3b/0x90
   entry_SYSCALL_64_after_hwframe+0x44/0xae
  RIP: 0033:0x7f645884de6b

Usually the uuid_mutex exists to protect the fs_devices that map
together all of the devices that match a specific uuid.  In rm_device
we're messing with the uuid of a device, so it makes sense to protect
that here.

However in doing that it pulls in a whole host of lockdep dependencies,
as we call mnt_may_write() on the sb before we grab the uuid_mutex, thus
we end up with the dependency chain under the uuid_mutex being added
under the normal sb write dependency chain, which causes problems with
loop devices.

We don't need the uuid mutex here however.  If we call
btrfs_scan_one_device() before we scratch the super block we will find
the fs_devices and not find the device itself and return EBUSY because
the fs_devices is open.  If we call it after the scratch happens it will
not appear to be a valid btrfs file system.

We do not need to worry about other fs_devices modifying operations here
because we're protected by the exclusive operations locking.

So drop the uuid_mutex here in order to fix the lockdep splat.

A more detailed explanation from the discussion:

We are worried about rm and scan racing with each other, before this
change we'll zero the device out under the UUID mutex so when scan does
run it'll make sure that it can go through the whole device scan thing
without rm messing with us.

We aren't worried if the scratch happens first, because the result is we
don't think this is a btrfs device and we bail out.

The only case we are concerned with is we scratch _after_ scan is able
to read the superblock and gets a seemingly valid super block, so lets
consider this case.

Scan will call device_list_add() with the device we're removing.  We'll
call find_fsid_with_metadata_uuid() and get our fs_devices for this
UUID.  At this point we lock the fs_devices->device_list_mutex.  This is
what protects us in this case, but we have two cases here.

1. We aren't to the device removal part of the RM.  We found our device,
   and device name matches our path, we go down and we set total_devices
   to our super number of devices, which doesn't affect anything because
   we haven't done the remove yet.

2. We are past the device removal part, which is protected by the
   device_list_mutex.  Scan doesn't find the device, it goes down and
   does the

   if (fs_devices->opened)
	   return -EBUSY;

   check and we bail out.

Nothing about this situation is ideal, but the lockdep splat is real,
and the fix is safe, tho admittedly a bit scary looking.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ copy more from the discussion ]
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:02 +02:00
Qu Wenruo c3a3b19bac btrfs: rename struct btrfs_io_bio to btrfs_bio 
Previously we had "struct btrfs_bio", which records IO context for
mirrored IO and RAID56, and "strcut btrfs_io_bio", which records extra
btrfs specific info for logical bytenr bio.

With "btrfs_bio" renamed to "btrfs_io_context", we are safe to rename
"btrfs_io_bio" to "btrfs_bio" which is a more suitable name now.

The struct btrfs_bio changes meaning by this commit. There was a
suggested name like btrfs_logical_bio but it's a bit long and we'd
prefer to use a shorter name.

This could be a concern for backports to older kernels where the
different meaning could possibly cause confusion or bugs. Comparing the
new and old structures, there's no overlap among the struct members so a
build would break in case of incorrect backport.

We haven't had many backports to bio code anyway so this is more of a
theoretical cause of bugs and a matter of precaution but we'll need to
keep the semantic change in mind.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:02 +02:00
Qu Wenruo cd8e0cca95 btrfs: remove btrfs_bio_alloc() helper 
The helper btrfs_bio_alloc() is almost the same as btrfs_io_bio_alloc(),
except it's allocating using BIO_MAX_VECS as @nr_iovecs, and initializes
bio->bi_iter.bi_sector.

However the naming itself is not using "btrfs_io_bio" to indicate its
parameter is "strcut btrfs_io_bio" and can be easily confused with
"struct btrfs_bio".

Considering assigned bio->bi_iter.bi_sector is such a simple work and
there are already tons of call sites doing that manually, there is no
need to do that in a helper.

Remove btrfs_bio_alloc() helper, and enhance btrfs_io_bio_alloc()
function to provide a fail-safe value for its @nr_iovecs.

And then replace all btrfs_bio_alloc() callers with
btrfs_io_bio_alloc().

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:02 +02:00
Qu Wenruo 4c66461179 btrfs: rename btrfs_bio to btrfs_io_context 
The structure btrfs_bio is used by two different sites:

- bio->bi_private for mirror based profiles
  For those profiles (SINGLE/DUP/RAID1*/RAID10), this structures records
  how many mirrors are still pending, and save the original endio
  function of the bio.

- RAID56 code
  In that case, RAID56 only utilize the stripes info, and no long uses
  that to trace the pending mirrors.

So btrfs_bio is not always bind to a bio, and contains more info for IO
context, thus renaming it will make the naming less confusing.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:02 +02:00
Filipe Manana dc2872247e btrfs: keep track of the last logged keys when logging a directory 
After the first time we log a directory in the current transaction, for
each directory item in a changed leaf of the subvolume tree, we have to
check if we previously logged the item, in order to overwrite it in case
its data changed or skip it in case its data hasn't changed.

Checking if we have logged each item before not only wastes times, but it
also adds lock contention on the log tree. So in order to minimize the
number of times we do such checks, keep track of the offset of the last
key we logged for a directory and, on the next time we log the directory,
skip the checks for any new keys that have an offset greater than the
offset we have previously saved. This is specially effective for index
keys, because the offset for these keys comes from a monotonically
increasing counter.

This patch is part of a patchset comprised of the following 5 patches:

  btrfs: remove root argument from btrfs_log_inode() and its callees
  btrfs: remove redundant log root assignment from log_dir_items()
  btrfs: factor out the copying loop of dir items from log_dir_items()
  btrfs: insert items in batches when logging a directory when possible
  btrfs: keep track of the last logged keys when logging a directory

This is patch 5/5.

The following test was used on a non-debug kernel to measure the impact
it has on a directory fsync:

  $ cat test-dir-fsync.sh
  #!/bin/bash

  DEV=/dev/nvme0n1
  MNT=/mnt/nvme0n1

  NUM_NEW_FILES=100000
  NUM_FILE_DELETES=1000

  mkfs.btrfs -f $DEV
  mount -o ssd $DEV $MNT

  mkdir $MNT/testdir

  for ((i = 1; i <= $NUM_NEW_FILES; i++)); do
      echo -n > $MNT/testdir/file_$i
  done

  # fsync the directory, this will log the new dir items and the inodes
  # they point to, because these are new inodes.
  start=$(date +%s%N)
  xfs_io -c "fsync" $MNT/testdir
  end=$(date +%s%N)

  dur=$(( (end - start) / 1000000 ))
  echo "dir fsync took $dur ms after adding $NUM_NEW_FILES files"

  # sync to force transaction commit and wipeout the log.
  sync

  del_inc=$(( $NUM_NEW_FILES / $NUM_FILE_DELETES ))
  for ((i = 1; i <= $NUM_NEW_FILES; i += $del_inc)); do
      rm -f $MNT/testdir/file_$i
  done

  # fsync the directory, this will only log dir items, there are no
  # dentries pointing to new inodes.
  start=$(date +%s%N)
  xfs_io -c "fsync" $MNT/testdir
  end=$(date +%s%N)

  dur=$(( (end - start) / 1000000 ))
  echo "dir fsync took $dur ms after deleting $NUM_FILE_DELETES files"

  umount $MNT

Test results with NUM_NEW_FILES set to 100 000 and 1 000 000:

**** before patchset, 100 000 files, 1000 deletes ****

dir fsync took 848 ms after adding 100000 files
dir fsync took 175 ms after deleting 1000 files

**** after patchset, 100 000 files, 1000 deletes ****

dir fsync took 758 ms after adding 100000 files  (-11.2%)
dir fsync took 63 ms after deleting 1000 files   (-94.1%)

**** before patchset, 1 000 000 files, 1000 deletes ****

dir fsync took 9945 ms after adding 1000000 files
dir fsync took 473 ms after deleting 1000 files

**** after patchset, 1 000 000 files, 1000 deletes ****

dir fsync took 8677 ms after adding 1000000 files (-13.6%)
dir fsync took 146 ms after deleting 1000 files   (-105.6%)

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:02 +02:00
Filipe Manana 086dcbfa50 btrfs: insert items in batches when logging a directory when possible 
When logging a directory, we scan its directory items from the subvolume
tree and then copy one by one into the log tree. This is not efficient
since we generally are able to insert several items in a batch, using a
single btree operation for adding several items at once. The reason we
copy items one by one is that we must check if each item was previously
logged in the current transaction, and if it was we either overwrite it
or skip it in case its content did not change in the subvolume tree (this
can happen only for dir item keys, but not for dir index keys), and doing
such check makes it a bit cumbersome to attempt batch insertions.

However the chances for doing batch insertions are very frequent and
always happen when:

1) Logging the directory for the first time in the current transaction,
   as none of the items exist in the log tree yet;

2) Logging new dir index keys, because the offset for new dir index keys
   comes from a monotonically increasing counter. This means if we keep
   adding dentries to a directory, through creation of new files and
   sub-directories or by adding new links or renaming from some other
   directory into the one we are logging, all the new dir index keys
   have a new offset that is greater than the offset of any previously
   logged index keys, so we can insert them in batches into the log tree.

For dir item keys, since their offset depends on the result of an hash
function against the dentry's name, unless the directory is being logged
for the first time in the current transaction, the chances being able to
insert the items in the log using batches is pretty much random and not
predictable, as it depends on the names of the dentries, but still happens
often enough.

So change directory logging to keep track of consecutive directory items
that don't exist yet in the log and batch insert them.

This patch is part of a patchset comprised of the following 5 patches:

  btrfs: remove root argument from btrfs_log_inode() and its callees
  btrfs: remove redundant log root assignment from log_dir_items()
  btrfs: factor out the copying loop of dir items from log_dir_items()
  btrfs: insert items in batches when logging a directory when possible
  btrfs: keep track of the last logged keys when logging a directory

This is patch 4/5. The change log of the last patch (5/5) has performance
results.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:02 +02:00
Filipe Manana eb10d85ee7 btrfs: factor out the copying loop of dir items from log_dir_items() 
In preparation for the next change, move the loop that processes a leaf
and copies its directory items to the log, into a separate helper
function. This makes the next change simpler and it also helps making
log_dir_items() a bit shorter (specially after the next change).

This patch is part of a patchset comprised of the following 5 patches:

  btrfs: remove root argument from btrfs_log_inode() and its callees
  btrfs: remove redundant log root assignment from log_dir_items()
  btrfs: factor out the copying loop of dir items from log_dir_items()
  btrfs: insert items in batches when logging a directory when possible
  btrfs: keep track of the last logged keys when logging a directory

This is patch 3/5. The change log of the last patch (5/5) has performance
results.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:02 +02:00
Filipe Manana d46fb845af btrfs: remove redundant log root assignment from log_dir_items() 
At log_dir_items() we are assigning the exact same value to the local
variable 'log', once when it's declared and once again shortly after.
Remove the later assignment as it's pointless.

This patch is part of a patchset comprised of the following 5 patches:

  btrfs: remove root argument from btrfs_log_inode() and its callees
  btrfs: remove redundant log root assignment from log_dir_items()
  btrfs: factor out the copying loop of dir items from log_dir_items()
  btrfs: insert items in batches when logging a directory when possible
  btrfs: keep track of the last logged keys when logging a directory

This is patch 2/5. The change log of the last patch (5/5) has performance
results.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:02 +02:00
Filipe Manana 90d04510a7 btrfs: remove root argument from btrfs_log_inode() and its callees 
The root argument passed to btrfs_log_inode() is unncessary, as it is
always the root of the inode we are going to log. This root also gets
unnecessarily propagated to several functions called by btrfs_log_inode(),
and all of them take the inode as an argument as well. So just remove
the root argument from these functions and have them get the root from
the inode where needed.

This patch is part of a patchset comprised of the following 5 patches:

  btrfs: remove root argument from btrfs_log_inode() and its callees
  btrfs: remove redundant log root assignment from log_dir_items()
  btrfs: factor out the copying loop of dir items from log_dir_items()
  btrfs: insert items in batches when logging a directory when possible
  btrfs: keep track of the last logged keys when logging a directory

This is patch 1/5. The change log of the last patch (5/5) has performance
results.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:02 +02:00
Johannes Thumshirn 2d81eb1c3f btrfs: zoned: let the for_treelog test in the allocator stand out 
The statement which decides if an extent allocation on a zoned device is
for the dedicated tree-log block group or not and if we can use the block
group we picked for this allocation is not easy to read but an important
part of the allocator.

Rewrite into an if condition instead of a plain boolean test to make it
stand out more, like the version which tests for the dedicated
data-relocation block group.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:02 +02:00
Johannes Thumshirn 4b01c44f15 btrfs: rename setup_extent_mapping in relocation code 
In btrfs code we have two functions called setup_extent_mapping, one in
the extent_map code and one in the relocation code. While both are
private to their respective implementation, this can still be confusing
for the reader.

So rename the version in relocation.c to setup_relocation_extent_mapping.
No functional changes.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:01 +02:00
Johannes Thumshirn 960a3166ae btrfs: zoned: allow preallocation for relocation inodes 
Now that we use a dedicated block group and regular writes for data
relocation, we can preallocate the space needed for a relocated inode,
just like we do in regular mode.

Essentially this reverts commit 32430c6148 ("btrfs: zoned: enable
relocation on a zoned filesystem") as it is not needed anymore.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:01 +02:00
Johannes Thumshirn 2adada886b btrfs: check for relocation inodes on zoned btrfs in should_nocow 
Prepare for allowing preallocation for relocation inodes.

Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:01 +02:00
Johannes Thumshirn e6d261e3b1 btrfs: zoned: use regular writes for relocation 
Now that we have a dedicated block group for relocation, we can use
REQ_OP_WRITE instead of  REQ_OP_ZONE_APPEND for writing out the data on
relocation.

Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:01 +02:00
Johannes Thumshirn 35156d8527 btrfs: zoned: only allow one process to add pages to a relocation inode 
Don't allow more than one process to add pages to a relocation inode on
a zoned filesystem, otherwise we cannot guarantee the sequential write
rule once we're filling preallocated extents on a zoned filesystem.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:01 +02:00
Johannes Thumshirn c2707a2556 btrfs: zoned: add a dedicated data relocation block group 
Relocation in a zoned filesystem can fail with a transaction abort with
error -22 (EINVAL). This happens because the relocation code assumes that
the extents we relocated the data to have the same size the source extents
had and ensures this by preallocating the extents.

But in a zoned filesystem we currently can't preallocate the extents as
this would break the sequential write required rule. Therefore it can
happen that the writeback process kicks in while we're still adding pages
to a delalloc range and starts writing out dirty pages.

This then creates destination extents that are smaller than the source
extents, triggering the following safety check in get_new_location():

 1034         if (num_bytes != btrfs_file_extent_disk_num_bytes(leaf, fi)) {
 1035                 ret = -EINVAL;
 1036                 goto out;
 1037         }

Temporarily create a dedicated block group for the relocation process, so
no non-relocation data writes can interfere with the relocation writes.

This is needed that we can switch the relocation process on a zoned
filesystem from the REQ_OP_ZONE_APPEND writing we use for data to a scheme
like in a non-zoned filesystem using REQ_OP_WRITE and preallocation.

Fixes: 32430c6148 ("btrfs: zoned: enable relocation on a zoned filesystem")
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:01 +02:00
Johannes Thumshirn 37f00a6d2e btrfs: introduce btrfs_is_data_reloc_root 
There are several places in our codebase where we check if a root is the
root of the data reloc tree and subsequent patches will introduce more.

Factor out the check into a small helper function instead of open coding
it multiple times.

Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:01 +02:00
Qu Wenruo 38d5e541dd btrfs: unexport repair_io_failure() 
Function repair_io_failure() is no longer used out of extent_io.c since
commit 8b9b6f2554 ("btrfs: scrub: cleanup the remaining nodatasum
fixup code"), which removes the last external caller.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:01 +02:00
Filipe Manana f6df27dd27 btrfs: do not commit delayed inode when logging a file in full sync mode 
When logging a regular file in full sync mode, we are currently committing
its delayed inode item. This is to ensure that we never miss copying the
inode item, with its most up to date data, into the log tree.

However that is not necessary since commit e4545de5b0 ("Btrfs: fix fsync
data loss after append write"), because even if we don't find the leaf
with the inode item when looking for leaves that changed in the current
transaction, we end up logging the inode item later using the in-memory
content. In case we find the leaf containing the inode item, we already
end up using the in-memory inode for filling the inode item in the log
tree, and not the inode item that is in the fs/subvolume tree, as it
might be not up to date (copy_items() -> fill_inode_item()).

So don't commit the delayed inode item, which brings a couple of benefits:

1) Avoid writing the inode item to the fs/subvolume btree, saving time and
   reducing lock contention on the btree;

2) In case no other item for the inode was changed, added or deleted in
   the same leaf where the inode item is located, we ended up copying
   all the items in that leaf to the log tree - it's harmless from a
   functional point of view, but it wastes time and log tree space.

This patch is part of a patch set comprised of the following patches:

  btrfs: check if a log tree exists at inode_logged()
  btrfs: remove no longer needed checks for NULL log context
  btrfs: do not log new dentries when logging that a new name exists
  btrfs: always update the logged transaction when logging new names
  btrfs: avoid expensive search when dropping inode items from log
  btrfs: add helper to truncate inode items when logging inode
  btrfs: avoid expensive search when truncating inode items from the log
  btrfs: avoid search for logged i_size when logging inode if possible
  btrfs: avoid attempt to drop extents when logging inode for the first time
  btrfs: do not commit delayed inode when logging a file in full sync mode

This is patch 10/10 and the following test results compare a branch with
the whole patch set applied versus a branch without any of the patches
applied.

The following script was used to test dbench with 8 and 16 jobs on a
machine with 12 cores, 64G of RAM, a NVME device and using a non-debug
kernel config (Debian's default):

  $ cat test.sh
  #!/bin/bash

  if [ $# -ne 1 ]; then
      echo "Use $0 NUM_JOBS"
      exit 1
  fi

  NUM_JOBS=$1

  DEV=/dev/nvme0n1
  MNT=/mnt/nvme0n1
  MOUNT_OPTIONS="-o ssd"
  MKFS_OPTIONS="-m single -d single"

  echo "performance" | \
      tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor

  mkfs.btrfs -f $MKFS_OPTIONS $DEV
  mount $MOUNT_OPTIONS $DEV $MNT

  dbench -D $MNT -t 120 $NUM_JOBS

  umount $MNT

The results were the following:

8 jobs, before patchset:

 Operation      Count    AvgLat    MaxLat
 ----------------------------------------
 NTCreateX    4113896     0.009   238.665
 Close        3021699     0.001     0.590
 Rename        174215     0.082   238.733
 Unlink        830977     0.049   238.642
 Deltree           96     2.232     8.022
 Mkdir             48     0.003     0.005
 Qpathinfo    3729013     0.005     2.672
 Qfileinfo     653206     0.001     0.152
 Qfsinfo       683866     0.002     0.526
 Sfileinfo     335055     0.004     1.571
 Find         1441800     0.016     4.288
 WriteX       2049644     0.010     3.982
 ReadX        6449786     0.003     0.969
 LockX          13400     0.002     0.043
 UnlockX        13400     0.001     0.075
 Flush         288349     2.521   245.516

Throughput 1075.73 MB/sec  8 clients  8 procs  max_latency=245.520 ms

8 jobs, after patchset:

 Operation      Count    AvgLat    MaxLat
 ----------------------------------------
 NTCreateX    4154282     0.009   156.675
 Close        3051450     0.001     0.843
 Rename        175912     0.072     4.444
 Unlink        839067     0.048    66.050
 Deltree           96     2.131     5.979
 Mkdir             48     0.002     0.004
 Qpathinfo    3765575     0.005     3.079
 Qfileinfo     659582     0.001     0.099
 Qfsinfo       690474     0.002     0.155
 Sfileinfo     338366     0.004     1.419
 Find         1455816     0.016     3.423
 WriteX       2069538     0.010     4.328
 ReadX        6512429     0.003     0.840
 LockX          13530     0.002     0.078
 UnlockX        13530     0.001     0.051
 Flush         291158     2.500   163.468

Throughput 1105.45 MB/sec  8 clients  8 procs  max_latency=163.474 ms

+2.7% throughput, -40.1% max latency

16 jobs, before patchset:

 Operation      Count    AvgLat    MaxLat
 ----------------------------------------
 NTCreateX    5457602     0.033   337.098
 Close        4008979     0.002     2.018
 Rename        231051     0.323   254.054
 Unlink       1102209     0.202   337.243
 Deltree          160     6.521    31.720
 Mkdir             80     0.003     0.007
 Qpathinfo    4946147     0.014     6.988
 Qfileinfo     867440     0.001     1.642
 Qfsinfo       907081     0.003     1.821
 Sfileinfo     444433     0.005     2.053
 Find         1912506     0.067     7.854
 WriteX       2724852     0.018     7.428
 ReadX        8553883     0.003     2.059
 LockX          17770     0.003     0.350
 UnlockX        17770     0.002     0.627
 Flush         382533     2.810   353.691

Throughput 1413.09 MB/sec  16 clients  16 procs  max_latency=353.696 ms

16 jobs, after patchset:

 Operation      Count    AvgLat    MaxLat
 ----------------------------------------
 NTCreateX    5393156     0.034   303.181
 Close        3961986     0.002     1.502
 Rename        228359     0.320   253.379
 Unlink       1088920     0.206   303.409
 Deltree          160     6.419    30.088
 Mkdir             80     0.003     0.004
 Qpathinfo    4887967     0.015     7.722
 Qfileinfo     857408     0.001     1.651
 Qfsinfo       896343     0.002     2.147
 Sfileinfo     439317     0.005     4.298
 Find         1890018     0.073     8.347
 WriteX       2693356     0.018     6.373
 ReadX        8453485     0.003     3.836
 LockX          17562     0.003     0.486
 UnlockX        17562     0.002     0.635
 Flush         378023     2.802   315.904

Throughput 1454.46 MB/sec  16 clients  16 procs  max_latency=315.910 ms

+2.9% throughput, -11.3% max latency

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:01 +02:00
Filipe Manana 5328b2a7ff btrfs: avoid attempt to drop extents when logging inode for the first time 
When logging an extent, in the fast fsync path, we always attempt do drop
or trim any existing extents with a range that match or overlap the range
of the extent we are about to log. We do that through a call to
btrfs_drop_extents().

However this is not needed when we are logging the inode for the first
time in the current transaction, since we have no inode items of the
inode in the log tree. Calling btrfs_drop_extents() does a deletion search
on the log tree, which is expensive when we have concurrent tasks
accessing the log tree because a deletion search always acquires a write
lock on the extent buffers at levels 2, 1 and 0, adding significant lock
contention, specially taking into account the height of a log tree rarely
(if ever) goes beyond 2 or 3, due to its short life.

So skip the call to btrfs_drop_extents() when the inode was not previously
logged in the current transaction.

This patch is part of a patch set comprised of the following patches:

  btrfs: check if a log tree exists at inode_logged()
  btrfs: remove no longer needed checks for NULL log context
  btrfs: do not log new dentries when logging that a new name exists
  btrfs: always update the logged transaction when logging new names
  btrfs: avoid expensive search when dropping inode items from log
  btrfs: add helper to truncate inode items when logging inode
  btrfs: avoid expensive search when truncating inode items from the log
  btrfs: avoid search for logged i_size when logging inode if possible
  btrfs: avoid attempt to drop extents when logging inode for the first time
  btrfs: do not commit delayed inode when logging a file in full sync mode

This is patch 9/10 and test results are listed in the change log of the
last patch in the set.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:01 +02:00
Filipe Manana a5c733a4b6 btrfs: avoid search for logged i_size when logging inode if possible 
If we are logging that an inode exists and the inode was not logged
before, we can avoid searching in the log tree for the inode item since we
know it does not exists. That wastes time and adds more lock contention on
the extent buffers of the log tree when there are other tasks that are
logging other inodes.

This patch is part of a patch set comprised of the following patches:

  btrfs: check if a log tree exists at inode_logged()
  btrfs: remove no longer needed checks for NULL log context
  btrfs: do not log new dentries when logging that a new name exists
  btrfs: always update the logged transaction when logging new names
  btrfs: avoid expensive search when dropping inode items from log
  btrfs: add helper to truncate inode items when logging inode
  btrfs: avoid expensive search when truncating inode items from the log
  btrfs: avoid search for logged i_size when logging inode if possible
  btrfs: avoid attempt to drop extents when logging inode for the first time
  btrfs: do not commit delayed inode when logging a file in full sync mode

This is patch 8/10 and test results are listed in the change log of the
last patch in the set.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:01 +02:00
Filipe Manana 4934a81502 btrfs: avoid expensive search when truncating inode items from the log 
Whenever we are logging a file inode in full sync mode we call
btrfs_truncate_inode_items() to delete items of the inode we may have
previously logged.

That results in doing a btree search for deletion, which is expensive
because it always acquires write locks for extent buffers at levels 2, 1
and 0, and it balances any node that is less than half full. Acquiring
the write locks can block the task if the extent buffers are already
locked by another task or block other tasks attempting to lock them,
which is specially bad in case of log trees since they are small due to
their short life, with a root node at a level typically not greater than
level 2.

If we know that we are logging the inode for the first time in the current
transaction, we can skip the call to btrfs_truncate_inode_items(), avoiding
the deletion search. This change does that.

This patch is part of a patch set comprised of the following patches:

  btrfs: check if a log tree exists at inode_logged()
  btrfs: remove no longer needed checks for NULL log context
  btrfs: do not log new dentries when logging that a new name exists
  btrfs: always update the logged transaction when logging new names
  btrfs: avoid expensive search when dropping inode items from log
  btrfs: add helper to truncate inode items when logging inode
  btrfs: avoid expensive search when truncating inode items from the log
  btrfs: avoid search for logged i_size when logging inode if possible
  btrfs: avoid attempt to drop extents when logging inode for the first time
  btrfs: do not commit delayed inode when logging a file in full sync mode

This is patch 7/10 and test results are listed in the change log of the
last patch in the set.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:01 +02:00
Filipe Manana 8a2b3da191 btrfs: add helper to truncate inode items when logging inode 
Move the call to btrfs_truncate_inode_items(), and the surrounding retry
loop, into a local helper function. This avoids some repetition and avoids
making the next change a bit awkward due to a bit of too much indentation.

This patch is part of a patch set comprised of the following patches:

  btrfs: check if a log tree exists at inode_logged()
  btrfs: remove no longer needed checks for NULL log context
  btrfs: do not log new dentries when logging that a new name exists
  btrfs: always update the logged transaction when logging new names
  btrfs: avoid expensive search when dropping inode items from log
  btrfs: add helper to truncate inode items when logging inode
  btrfs: avoid expensive search when truncating inode items from the log
  btrfs: avoid search for logged i_size when logging inode if possible
  btrfs: avoid attempt to drop extents when logging inode for the first time
  btrfs: do not commit delayed inode when logging a file in full sync mode

This is patch 6/10 and test results are listed in the change log of the
last patch in the set.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:00 +02:00
Filipe Manana 88e221cdac btrfs: avoid expensive search when dropping inode items from log 
Whenever we are logging a directory inode, logging that an inode exists or
logging an inode that has changes in its references or xattrs, we attempt
to delete items of this inode we may have previously logged (through calls
to drop_objectid_items()).

That attempt does a btree search for deletion, which is expensive because
it always acquires write locks for extent buffers at levels 2, 1 and 0,
and it balances any node that is less than half full. Acquiring the write
locks can block the task if the extent buffers are already locked or block
other tasks attempting to lock them, which is specially bad in case of log
trees since they are small due to their short life, with a root node at a
level typically not greater than level 2.

If we know that we are logging the inode for the first time in the current
transaction, we can skip the search. This change does that.

This patch is part of a patch set comprised of the following patches:

  btrfs: check if a log tree exists at inode_logged()
  btrfs: remove no longer needed checks for NULL log context
  btrfs: do not log new dentries when logging that a new name exists
  btrfs: always update the logged transaction when logging new names
  btrfs: avoid expensive search when dropping inode items from log
  btrfs: add helper to truncate inode items when logging inode
  btrfs: avoid expensive search when truncating inode items from the log
  btrfs: avoid search for logged i_size when logging inode if possible
  btrfs: avoid attempt to drop extents when logging inode for the first time
  btrfs: do not commit delayed inode when logging a file in full sync mode

This is patch 5/10 and test results are listed in the change log of the
last patch in the set.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:00 +02:00
Filipe Manana 130341be7f btrfs: always update the logged transaction when logging new names 
When we are logging a new name for an inode, due to a link or rename
operation, if the inode has ancestor inodes that are new, created in the
current transaction, we need to log that these inodes exist. To ensure
that a subsequent explicit fsync on one of these ancestor inodes does
sync the log, we don't set the logged_trans field of these inodes.
This was done in commit 75b463d2b4 ("btrfs: do not commit logs and
transactions during link and rename operations"), to avoid syncing a
log after a rename or link operation.

In order to allow for future changes to do some optimizations, change
this behaviour to always update the logged_trans of any logged inode
and don't update the last_log_commit of the inode if we are logging
that it exists. This accomplishes that same objective with simpler
logic, allowing for some optimizations in the next patches.

So just do that simplification.

This patch is part of a patch set comprised of the following patches:

  btrfs: check if a log tree exists at inode_logged()
  btrfs: remove no longer needed checks for NULL log context
  btrfs: do not log new dentries when logging that a new name exists
  btrfs: always update the logged transaction when logging new names
  btrfs: avoid expensive search when dropping inode items from log
  btrfs: add helper to truncate inode items when logging inode
  btrfs: avoid expensive search when truncating inode items from the log
  btrfs: avoid search for logged i_size when logging inode if possible
  btrfs: avoid attempt to drop extents when logging inode for the first time
  btrfs: do not commit delayed inode when logging a file in full sync mode

This is patch 4/10 and test results are listed in the change log of the
last patch in the set.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:00 +02:00
Filipe Manana c48792c6ee btrfs: do not log new dentries when logging that a new name exists 
When logging a new name for an inode, due to a link or rename operation,
we don't need to log all new dentries of the parent directories and their
subdirectories. We only want to log the names of the inode and that any
new parent directories exist. So in this case don't trigger logging of
the new dentries, that is only need when doing an explicit fsync on a
directory or on a file which requires logging its parent directories.

This avoids unnecessary work and reduces contention on the extent buffers
of a log tree.

This patch is part of a patch set comprised of the following patches:

  btrfs: check if a log tree exists at inode_logged()
  btrfs: remove no longer needed checks for NULL log context
  btrfs: do not log new dentries when logging that a new name exists
  btrfs: always update the logged transaction when logging new names
  btrfs: avoid expensive search when dropping inode items from log
  btrfs: add helper to truncate inode items when logging inode
  btrfs: avoid expensive search when truncating inode items from the log
  btrfs: avoid search for logged i_size when logging inode if possible
  btrfs: avoid attempt to drop extents when logging inode for the first time
  btrfs: do not commit delayed inode when logging a file in full sync mode

This is patch 3/10 and test results are listed in the change log of the
last patch in the set.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:00 +02:00
Filipe Manana 289cffcb03 btrfs: remove no longer needed checks for NULL log context 
Since commit 75b463d2b4 ("btrfs: do not commit logs and transactions
during link and rename operations"), we always pass a non-NULL log context
to btrfs_log_inode_parent() and therefore to all the functions that it
calls. So remove the checks we have all over the place that test for a
NULL log context, making the code shorter and easier to read, as well as
reducing the size of the generated code.

This patch is part of a patch set comprised of the following patches:

  btrfs: check if a log tree exists at inode_logged()
  btrfs: remove no longer needed checks for NULL log context
  btrfs: do not log new dentries when logging that a new name exists
  btrfs: always update the logged transaction when logging new names
  btrfs: avoid expensive search when dropping inode items from log
  btrfs: add helper to truncate inode items when logging inode
  btrfs: avoid expensive search when truncating inode items from the log
  btrfs: avoid search for logged i_size when logging inode if possible
  btrfs: avoid attempt to drop extents when logging inode for the first time
  btrfs: do not commit delayed inode when logging a file in full sync mode

This is patch 2/10 and test results are listed in the change log of the
last patch in the set.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:00 +02:00
Filipe Manana 1e0860f3b3 btrfs: check if a log tree exists at inode_logged() 
In case an inode was never logged since it was loaded from disk and was
modified in the current transaction (its ->last_trans matches the ID of
the current transaction), inode_logged() returns true even if there's no
existing log tree. In this case we can simply check if a log tree exists
and return false if it does not. This avoids a caller of inode_logged()
doing some unnecessary, but harmless, work.

For btrfs_log_new_name() it avoids it logging an inode in case it was
never logged since it was loaded from disk and there is currently no log
tree for the inode's root. For the remaining callers of inode_logged(),
btrfs_del_dir_entries_in_log() and btrfs_del_inode_ref_in_log(), it has
no effect since they already check if a log tree exists through their
calls to join_running_log_trans().

So just add a check to inode_logged() to verify if a log tree exists, and
return false if it does not.

This patch is part of a patch set comprised of the following patches:

  btrfs: check if a log tree exists at inode_logged()
  btrfs: remove no longer needed checks for NULL log context
  btrfs: do not log new dentries when logging that a new name exists
  btrfs: always update the logged transaction when logging new names
  btrfs: avoid expensive search when dropping inode items from log
  btrfs: add helper to truncate inode items when logging inode
  btrfs: avoid expensive search when truncating inode items from the log
  btrfs: avoid search for logged i_size when logging inode if possible
  btrfs: avoid attempt to drop extents when logging inode for the first time
  btrfs: do not commit delayed inode when logging a file in full sync mode

This is patch 1/10 and test results are listed in the change log of the
last patch in the set.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:00 +02:00
Anand Jain cdccc03a8a btrfs: remove stale comment about the btrfs_show_devname 
There were few lockdep warnings because btrfs_show_devname() was using
device_list_mutex as recorded in the commits:

  0ccd05285e ("btrfs: fix a possible umount deadlock")
  779bf3fefa ("btrfs: fix lock dep warning, move scratch dev out of device_list_mutex and uuid_mutex")

And finally, commit 88c14590cd ("btrfs: use RCU in btrfs_show_devname
for device list traversal") removed the device_list_mutex from
btrfs_show_devname for performance reasons.

This patch removes a stale comment about the function
btrfs_show_devname and device_list_mutex.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:00 +02:00
Anand Jain b7cb29e666 btrfs: update latest_dev when we create a sprout device 
When we add a device to the seed filesystem (sprouting) it is a new
filesystem (and fsid) on the device added. Update the latest_dev so
that /proc/self/mounts shows the correct device.

Example:

  $ btrfstune -S1 /dev/vg/seed
  $ mount /dev/vg/seed /btrfs
  mount: /btrfs: WARNING: device write-protected, mounted read-only.

  $ cat /proc/self/mounts | grep btrfs
  /dev/mapper/vg-seed /btrfs btrfs ro,relatime,space_cache,subvolid=5,subvol=/ 0 0

  $ btrfs dev add -f /dev/vg/new /btrfs

Before:

  $ cat /proc/self/mounts | grep btrfs
  /dev/mapper/vg-seed /btrfs btrfs ro,relatime,space_cache,subvolid=5,subvol=/ 0 0

After:

  $ cat /proc/self/mounts | grep btrfs
  /dev/mapper/vg-new /btrfs btrfs ro,relatime,space_cache,subvolid=5,subvol=/ 0 0

Tested-by: Su Yue <l@damenly.su>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:00 +02:00
Anand Jain 6605fd2f39 btrfs: use latest_dev in btrfs_show_devname 
The test case btrfs/238 reports the warning below:

 WARNING: CPU: 3 PID: 481 at fs/btrfs/super.c:2509 btrfs_show_devname+0x104/0x1e8 [btrfs]
 CPU: 2 PID: 1 Comm: systemd Tainted: G        W  O 5.14.0-rc1-custom #72
 Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015
 Call trace:
   btrfs_show_devname+0x108/0x1b4 [btrfs]
   show_mountinfo+0x234/0x2c4
   m_show+0x28/0x34
   seq_read_iter+0x12c/0x3c4
   vfs_read+0x29c/0x2c8
   ksys_read+0x80/0xec
   __arm64_sys_read+0x28/0x34
   invoke_syscall+0x50/0xf8
   do_el0_svc+0x88/0x138
   el0_svc+0x2c/0x8c
   el0t_64_sync_handler+0x84/0xe4
   el0t_64_sync+0x198/0x19c

Reason:
While btrfs_prepare_sprout() moves the fs_devices::devices into
fs_devices::seed_list, the btrfs_show_devname() searches for the devices
and found none, leading to the warning as in above.

Fix:
latest_dev is updated according to the changes to the device list.
That means we could use the latest_dev->name to show the device name in
/proc/self/mounts, the pointer will be always valid as it's assigned
before the device is deleted from the list in remove or replace.
The RCU protection is sufficient as the device structure is freed after
synchronization.

Reported-by: Su Yue <l@damenly.su>
Tested-by: Su Yue <l@damenly.su>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:00 +02:00
Anand Jain d24fa5c1da btrfs: convert latest_bdev type to btrfs_device and rename 
In preparation to fix a bug in btrfs_show_devname().

Convert fs_devices::latest_bdev type from struct block_device to struct
btrfs_device and, rename the member to fs_devices::latest_dev.
So that btrfs_show_devname() can use fs_devices::latest_dev::name.

Tested-by: Su Yue <l@damenly.su>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:00 +02:00
Naohiro Aota 7ae9bd1803 btrfs: zoned: finish relocating block group 
We will no longer write to a relocating block group. So, we can finish it
now.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:00 +02:00
Naohiro Aota be1a1d7a5d btrfs: zoned: finish fully written block group 
If we have written to the zone capacity, the device automatically
deactivates the zone. Sync up block group side (the active BG list and
zone_is_active flag) with it.

We need to do it both on data BGs and metadata BGs. On data side, we add a
hook to btrfs_finish_ordered_io(). On metadata side, we use
end_extent_buffer_writeback().

To reduce excess lookup of a block group, we mark the last extent buffer in
a block group with EXTENT_BUFFER_ZONE_FINISH flag. This cannot be done for
data (ordered_extent), because the address may change due to
REQ_OP_ZONE_APPEND.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:08:00 +02:00
Naohiro Aota a85f05e59b btrfs: zoned: avoid chunk allocation if active block group has enough space 
The current extent allocator tries to allocate a new block group when the
existing block groups do not have enough space. On a ZNS device, a new
block group means a new active zone. If the number of active zones has
already reached the max_active_zones, activating a new zone needs to finish
an existing zone, leading to wasting the free space there.

So, instead, it should reuse the existing active block groups as much as
possible when we can't activate any other zones without sacrificing an
already activated block group.

While at it, I converted find_free_extent_update_loop() to check the
found_extent() case early and made the other conditions simpler.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:07:59 +02:00
Naohiro Aota a12b0dc0aa btrfs: move ffe_ctl one level up 
We are passing too many variables as it is from btrfs_reserve_extent() to
find_free_extent(). The next commit will add min_alloc_size to ffe_ctl, and
that means another pass-through argument. Take this opportunity to move
ffe_ctl one level up and drop the redundant arguments.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:07:59 +02:00
Naohiro Aota eb66a010d5 btrfs: zoned: activate new block group 
Activate new block group at btrfs_make_block_group(). We do not check the
return value. If failed, we can try again later at the actual extent
allocation phase.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:07:59 +02:00
Naohiro Aota 2e654e4bb9 btrfs: zoned: activate block group on allocation 
Activate a block group when trying to allocate an extent from it. We check
read-only case and no space left case before trying to activate a block
group not to consume the number of active zones uselessly.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:07:59 +02:00
Naohiro Aota 68a384b5ab btrfs: zoned: load active zone info for block group 
Load activeness of underlying zones of a block group. When underlying zones
are active, we add the block group to the fs_info->zone_active_bgs list.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:07:59 +02:00
Naohiro Aota afba2bc036 btrfs: zoned: implement active zone tracking 
Add zone_is_active flag to btrfs_block_group. This flag indicates the
underlying zones are all active. Such zone active block groups are tracked
by fs_info->active_bg_list.

btrfs_dev_{set,clear}_active_zone() take responsibility for the underlying
device part. They set/clear the bitmap to indicate zone activeness and
count the number of zones we can activate left.

btrfs_zone_{activate,finish}() take responsibility for the logical part and
the list management. In addition, btrfs_zone_finish() wait for any writes
on it and send REQ_OP_ZONE_FINISH to the zone.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:07:59 +02:00
Naohiro Aota dafc340dbd btrfs: zoned: introduce physical_map to btrfs_block_group 
We will use a block group's physical location to track active zones and
finish fully written zones in the following commits. Since the zone
activation is done in the extent allocation context which already holding
the tree locks, we can't query the chunk tree for the physical locations.
So, copy the location info into a block group and use it for activation.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:07:59 +02:00
Naohiro Aota ea6f8ddcde btrfs: zoned: load active zone information from devices 
The ZNS specification defines a limit on the number of zones that can be in
the implicit open, explicit open or closed conditions. Any zone with such
condition is defined as an active zone and correspond to any zone that is
being written or that has been only partially written. If the maximum
number of active zones is reached, we must either reset or finish some
active zones before being able to chose other zones for storing data.

Load queue_max_active_zones() and track the number of active zones left on
the device.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:07:59 +02:00
Naohiro Aota 8376d9e1ed btrfs: zoned: finish superblock zone once no space left for new SB 
If there is no more space left for a new superblock in a superblock zone,
then it is better to ZONE_FINISH the zone and frees up the active zone
count.

Since btrfs_advance_sb_log() can now issue REQ_OP_ZONE_FINISH, we also need
to convert it to return int for the error case.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:07:59 +02:00
Naohiro Aota 9658b72ef3 btrfs: zoned: locate superblock position using zone capacity 
sb_write_pointer() returns the write position of next superblock. For READ,
we need a previous location. When the pointer is at the head, the previous
one is the last one of the other zone. Calculate the last one's position
from zone capacity.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:07:59 +02:00
Naohiro Aota 5daaf552d1 btrfs: zoned: consider zone as full when no more SB can be written 
We cannot write beyond zone capacity. So, we should consider a zone as
"full" when the write pointer goes beyond capacity - the size of super
info.

Also, take this opportunity to replace a subtle duplicated code with a loop
and fix a typo in comment.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:07:59 +02:00
Naohiro Aota d8da0e8567 btrfs: zoned: tweak reclaim threshold for zone capacity 
With the introduction of zone capacity, the range [capacity, length] is
always zone unusable. Counting this region as a reclaim target will
cause reclaiming too early. Reclaim block groups based on bytes that can
be usable after resetting.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:07:59 +02:00
Naohiro Aota 98173255bd btrfs: zoned: calculate free space from zone capacity 
Now that we introduced capacity in a block group, we need to calculate free
space using the capacity instead of the length. Thus, bytes we account
capacity - alloc_pointer as free, and account bytes [capacity, length] as
zone unusable.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:07:58 +02:00
Naohiro Aota c46c4247ab btrfs: zoned: move btrfs_free_excluded_extents out of btrfs_calc_zone_unusable 
btrfs_free_excluded_extents() is not neccessary for
btrfs_calc_zone_unusable() and it makes btrfs_calc_zone_unusable()
difficult to reuse. Move it out and call btrfs_free_excluded_extents()
in proper context.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:07:58 +02:00
Naohiro Aota 8eae532be7 btrfs: zoned: load zone capacity information from devices 
The ZNS specification introduces the concept of a Zone Capacity.  A zone
capacity is an additional per-zone attribute that indicates the number of
usable logical blocks within each zone, starting from the first logical
block of each zone. It is always smaller or equal to the zone size.

With the SINGLE profile, we can set a block group's "capacity" as the same
as the underlying zone's Zone Capacity. We will limit the allocation not
to exceed in a following commit.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:07:58 +02:00
Qu Wenruo c22a3572cb btrfs: defrag: enable defrag for subpage case 
With the new infrastructure which has taken subpage into consideration,
now we should be safe to allow defrag to work for subpage case.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:07:58 +02:00
Qu Wenruo c635757365 btrfs: defrag: remove the old infrastructure 
Now the old infrastructure can all be removed, defrag

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:07:58 +02:00
Qu Wenruo 7b508037d4 btrfs: defrag: use defrag_one_cluster() to implement btrfs_defrag_file() 
The function defrag_one_cluster() is able to defrag one range well
enough, we only need to do preparation for it, including:

- Clamp and align the defrag range
- Exclude invalid cases
- Proper inode locking

The old infrastructures will not be removed in this patch, as it would
be too noisy to review.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:07:58 +02:00
Qu Wenruo b18c3ab234 btrfs: defrag: introduce helper to defrag one cluster 
This new helper, defrag_one_cluster(), will defrag one cluster (at most
256K):

- Collect all initial targets

- Kick in readahead when possible

- Call defrag_one_range() on each initial target
  With some extra range clamping.

- Update @sectors_defragged parameter

This involves one behavior change, the defragged sectors accounting is
no longer as accurate as old behavior, as the initial targets are not
consistent.

We can have new holes punched inside the initial target, and we will
skip such holes later.
But the defragged sectors accounting doesn't need to be that accurate
anyway, thus I don't want to pass those extra accounting burden into
defrag_one_range().

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:07:57 +02:00
Qu Wenruo e9eec72151 btrfs: defrag: introduce helper to defrag a range 
A new helper, defrag_one_range(), is introduced to defrag one range.

This function will mostly prepare the needed pages and extent status for
defrag_one_locked_target().

As we can only have a consistent view of extent map with page and extent
bits locked, we need to re-check the range passed in to get a real
target list for defrag_one_locked_target().

Since defrag_collect_targets() will call defrag_lookup_extent() and lock
extent range, we also need to teach those two functions to skip extent
lock.  Thus new parameter, @locked, is introduced to skip extent lock if
the caller has already locked the range.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:07:57 +02:00
Qu Wenruo 22b398eeee btrfs: defrag: introduce helper to defrag a contiguous prepared range 
A new helper, defrag_one_locked_target(), introduced to do the real part
of defrag.

The caller needs to ensure both page and extents bits are locked, and no
ordered extent exists for the range, and all writeback is finished.

The core defrag part is pretty straight-forward:

- Reserve space
- Set extent bits to defrag
- Update involved pages to be dirty

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:07:13 +02:00
Qu Wenruo eb793cf857 btrfs: defrag: introduce helper to collect target file extents 
Introduce a helper, defrag_collect_targets(), to collect all possible
targets to be defragged.

This function will not consider things like max_sectors_to_defrag, thus
caller should be responsible to ensure we don't exceed the limit.

This function will be the first stage of later defrag rework.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:06:53 +02:00
Qu Wenruo 5767b50c00 btrfs: defrag: factor out page preparation into a helper 
In cluster_pages_for_defrag(), we have complex code block inside one
for() loop.

The code block is to prepare one page for defrag, this will ensure:

- The page is locked and set up properly.
- No ordered extent exists in the page range.
- The page is uptodate.

This behavior is pretty common and will be reused by later defrag
rework.

So factor out the code into its own helper, defrag_prepare_one_page(),
for later usage, and cleanup the code by a little.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:06:34 +02:00
Qu Wenruo 76068cae63 btrfs: defrag: replace hard coded PAGE_SIZE with sectorsize 
When testing subpage defrag support, I always find some strange inode
nbytes error, after a lot of debugging, it turns out that
defrag_lookup_extent() is using PAGE_SIZE as size for
lookup_extent_mapping().

Since lookup_extent_mapping() is calling __lookup_extent_mapping() with
@strict == 1, this means any extent map smaller than one page will be
ignored, prevent subpage defrag to grab a correct extent map.

There are quite some PAGE_SIZE usage in ioctl.c, but most of them are
correct usages, and can be one of the following cases:

- ioctl structure size check
  We want ioctl structure to be contained inside one page.

- real page operations

The remaining cases in defrag_lookup_extent() and
check_defrag_in_cache() will be addressed in this patch.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:06:15 +02:00
Qu Wenruo cae7968680 btrfs: defrag: also check PagePrivate for subpage cases in cluster_pages_for_defrag() 
In function cluster_pages_for_defrag() we have a window where we unlock
page, either start the ordered range or read the content from disk.

When we re-lock the page, we need to make sure it still has the correct
page->private for subpage.

Thus add the extra PagePrivate check here to handle subpage cases
properly.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:05:18 +02:00
Qu Wenruo 1ccc2e8a86 btrfs: defrag: pass file_ra_state instead of file to btrfs_defrag_file() 
Currently btrfs_defrag_file() accepts both "struct inode" and "struct
file" as parameter.  We can easily grab "struct inode" from "struct
file" using file_inode() helper.

The reason why we need "struct file" is just to re-use its f_ra.

Change this to pass "struct file_ra_state" parameter, so that it's more
clear what we really want.  Since we're here, also add some comments on
the function btrfs_defrag_file().

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:04:39 +02:00
Anand Jain a09f23c355 btrfs: rename and switch to bool btrfs_chunk_readonly 
btrfs_chunk_readonly() checks if the given chunk is writeable. It
returns 1 for readonly, and 0 for writeable. So the return argument type
bool shall suffice instead of the current type int.

Also, rename btrfs_chunk_readonly() to btrfs_chunk_writeable() as we
check if the bg is writeable, and helps to keep the logic at the parent
function simpler to understand.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:03:57 +02:00
Sidong Yang 44bee215f7 btrfs: reflink: initialize return value to 0 in btrfs_extent_same() 
Fix a warning reported by smatch that ret could be returned without
initialized.  The dedupe operations are supposed to to return 0 for a 0
length range but the caller does not pass olen == 0. To keep this
behaviour and also fix the warning initialize ret to 0.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Sidong Yang <realwakka@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:03:57 +02:00
Qu Wenruo 72a69cd030 btrfs: subpage: pack all subpage bitmaps into a larger bitmap 
Currently we use u16 bitmap to make 4k sectorsize work for 64K page
size.

But this u16 bitmap is not large enough to contain larger page size like
128K, nor is space efficient for 16K page size.

To handle both cases, here we pack all subpage bitmaps into a larger
bitmap, now btrfs_subpage::bitmaps[] will be the ultimate bitmap for
subpage usage.

Each sub-bitmap will has its start bit number recorded in
btrfs_subpage_info::*_start, and its bitmap length will be recorded in
btrfs_subpage_info::bitmap_nr_bits.

All subpage bitmap operations will be converted from using direct u16
operations to bitmap operations, with above *_start calculated.

For 64K page size with 4K sectorsize, this should not cause much
difference.

While for 16K page size, we will only need 1 unsigned long (u32) to
store all the bitmaps, which saves quite some space.

Furthermore, this allows us to support larger page size like 128K and
258K.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-26 19:03:55 +02:00
Qu Wenruo 8481dd80ab btrfs: subpage: introduce btrfs_subpage_bitmap_info 
Currently we use fixed size u16 bitmap for subpage bitmap.  This is fine
for 4K sectorsize with 64K page size.

But for 4K sectorsize and larger page size, the bitmap is too small,
while for smaller page size like 16K, u16 bitmaps waste too much space.

Here we introduce a new helper structure, btrfs_subpage_bitmap_info, to
record the proper bitmap size, and where each bitmap should start at.

By this, we can later compact all subpage bitmaps into one u32 bitmap.
This patch is the first step.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-25 21:17:16 +02:00
Qu Wenruo 651fb41927 btrfs: subpage: make btrfs_alloc_subpage() return btrfs_subpage directly 
The existing calling convention of btrfs_alloc_subpage() is pretty
awful.  Change it to a more common pattern by returning struct
btrfs_subpage directly and let the caller to determine if the call
succeeded.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-25 21:17:16 +02:00
Qu Wenruo fdf250db89 btrfs: subpage: only call btrfs_alloc_subpage() when sectorsize is smaller than PAGE_SIZE 
There are two call sites of btrfs_alloc_subpage():

- btrfs_attach_subpage()
  We have ensured sectorsize is smaller than PAGE_SIZE

- alloc_extent_buffer()
  We call btrfs_alloc_subpage() unconditionally.

The alloc_extent_buffer() forces us to check the sectorsize size against
page size inside btrfs_alloc_subpage().

Since the function name, btrfs_alloc_subpage(), already indicates it
should only get called for subpage cases, do the check in
alloc_extent_buffer() and add an ASSERT() in btrfs_alloc_subpage().

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-25 21:17:16 +02:00
Su Yue 9675ea8c9d btrfs: update comment for fs_devices::seed_list in btrfs_rm_device 
Update it since commit 944d3f9fac ("btrfs: switch seed device to
list api") did conversion from fs_devices::seed to fs_devices::seed_list.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Su Yue <l@damenly.su>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-25 21:17:16 +02:00
Anand Jain 991a3daeda btrfs: drop unnecessary ret in ioctl_quota_rescan_status 
There is no need for the variable ret after d66105cfa873 ("btrfs:
allocate btrfs_ioctl_quota_rescan_args on stack"), remove it.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-25 21:17:16 +02:00
Marcos Paulo de Souza 0e3dd5bce8 btrfs: send: simplify send_create_inode_if_needed 
The out label is being overused, we can simply return if the condition
permits.

No functional changes.

Reviewed-by: Su Yue <l@damenly.su>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-25 21:17:16 +02:00
Nikolay Borisov f6f39f7a0a btrfs: rename btrfs_alloc_chunk to btrfs_create_chunk 
The user facing function used to allocate new chunks is
btrfs_chunk_alloc, unfortunately there is yet another similar sounding
function - btrfs_alloc_chunk. This creates confusion, especially since
the latter function can be considered "private" in the sense that it
implements the first stage of chunk creation and as such is called by
btrfs_chunk_alloc.

To avoid the awkwardness that comes with having similarly named but
distinctly different in their purpose function rename btrfs_alloc_chunk
to btrfs_create_chunk, given that the main purpose of this function is
to orchestrate the whole process of allocating a chunk - reserving space
into devices, deciding on characteristics of the stripe size and
creating the in-memory structures.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-25 21:17:16 +02:00
Andreas Gruenbacher 4fdccaa0d1 iomap: Add done_before argument to iomap_dio_rw 
Add a done_before argument to iomap_dio_rw that indicates how much of
the request has already been transferred.  When the request succeeds, we
report that done_before additional bytes were tranferred.  This is
useful for finishing a request asynchronously when part of the request
has already been completed synchronously.

We'll use that to allow iomap_dio_rw to be used with page faults
disabled: when a page fault occurs while submitting a request, we
synchronously complete the part of the request that has already been
submitted.  The caller can then take care of the page fault and call
iomap_dio_rw again for the rest of the request, passing in the number of
bytes already tranferred.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
 2021-10-24 15:26:05 +02:00
Christoph Hellwig 1226dfff57 btrfs: use sync_blockdev 
Use sync_blockdev instead of opencoding it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Acked-by: David Sterba <dsterba@suse.com>
Link: https://lore.kernel.org/r/20211019062530.2174626-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
 2021-10-22 08:36:55 -06:00
Christoph Hellwig cda00eba02 btrfs: use bdev_nr_bytes instead of open coding it 
Use the proper helper to read the block device size.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Acked-by: David Sterba <dsterba@suse.com>
Link: https://lore.kernel.org/r/20211018101130.1838532-13-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
 2021-10-18 14:43:22 -06:00
Kees Cook a2c5062f39 btrfs: Use memset_startat() to clear end of struct 
In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Use memset_startat() so memset() doesn't get confused about writing
beyond the destination member that is intended to be the starting point
of zeroing through the end of the struct.

Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: David Sterba <dsterba@suse.com>
Cc: linux-btrfs@vger.kernel.org
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Acked-by: David Sterba <dsterba@suse.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
 2021-10-18 12:28:52 -07:00
Andreas Gruenbacher a6294593e8 iov_iter: Turn iov_iter_fault_in_readable into fault_in_iov_iter_readable 
Turn iov_iter_fault_in_readable into a function that returns the number
of bytes not faulted in, similar to copy_to_user, instead of returning a
non-zero value when any of the requested pages couldn't be faulted in.
This supports the existing users that require all pages to be faulted in
as well as new users that are happy if any pages can be faulted in.

Rename iov_iter_fault_in_readable to fault_in_iov_iter_readable to make
sure this change doesn't silently break things.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
 2021-10-18 16:35:06 +02:00
Andreas Gruenbacher bb523b406c gup: Turn fault_in_pages_{readable,writeable} into fault_in_{readable,writeable} 
Turn fault_in_pages_{readable,writeable} into versions that return the
number of bytes not faulted in, similar to copy_to_user, instead of
returning a non-zero value when any of the requested pages couldn't be
faulted in.  This supports the existing users that require all pages to
be faulted in as well as new users that are happy if any pages can be
faulted in.

Rename the functions to fault_in_{readable,writeable} to make sure
this change doesn't silently break things.

Neither of these functions is entirely trivial and it doesn't seem
useful to inline them, so move them to mm/gup.c.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
 2021-10-18 16:33:03 +02:00
Christoph Hellwig 3e08773c38 block: switch polling to be bio based 
Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

 - the cookie construction can made entirely private in blk-mq.c
 - the caller does not need to remember the request_queue and cookie
   separately and thus sidesteps their lifetime issues
 - keeping the device and the cookie inside the bio allows to trivially
   support polling BIOs remapping by stacking drivers
 - a lot of code to propagate the cookie back up the submission path can
   be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
 2021-10-18 06:17:36 -06:00
Christoph Hellwig e41d12f539 mm: don't include <linux/blk-cgroup.h> in <linux/backing-dev.h> 
There is no need to pull blk-cgroup.h and thus blkdev.h in here, so
break the include chain.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210920123328.1399408-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
 2021-10-18 06:17:01 -06:00
Christoph Hellwig 348332e000 mm: don't include <linux/blk-cgroup.h> in <linux/writeback.h> 
blk-cgroup.h pulls in blkdev.h and thus pretty much all the block
headers.  Break this dependency chain by turning wbc_blkcg_css into a
macro and dropping the blk-cgroup.h include.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210920123328.1399408-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
 2021-10-18 06:17:01 -06:00
Linus Torvalds 1986c10acc for-5.15-rc5-tag 
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmFkq/oACgkQxWXV+ddt
 WDs10g//Qx27foBu0U3ovvsla0t8GgcqgzUyOx3zxed0MbOEQCtK6kqRHQ/I+9ap
 1Ec5y4qQqBwfp1NKlYdU/EiKBQIYbJO/nYhVIrFI/EZL/7qJTwyjYjrOjG9zIMvy
 2ekxuF/XVnM6p3hyRcuWMCxsossuK4XIkb0bSZrwk/nFA6nt+gbXR1oE94JitM8p
 0pwjvSVqpdTmOAIU5+oQldqL/By7un/rv+o6OTD9sJqTdQ1UMlHVDaa9mD8aCsYk
 XIiCYfkyo9rlbSAB5wmWuiAhske2xh7IXSr4l9mKxGOA0egbQAgmS1Zw3+Km7vFM
 t+ji/4rTFPFd2yv/sLCEnMinuwvBr3mnEh6pDHR76RNrI4CoK/GHmZSf7XyqzV8W
 QOftznNA9/nJInTULdhCDvNxbKhKKb+xeSP1L4uytnWc5am+WKOPLNkfczJUh3sq
 WUORpaUxByDol6BMsdQJqPVJ7CH5YI8lQzuQFoUTXDCgeQUBE2wE1s3q+5Ma+dNZ
 mamkfQim2R42nPk7RSQlFBeIyDBVBXWfSNvXNovrPFJyRmZqRWzh0nb3PS9VNnUy
 6oCOCIT7XlM4Jwh4ZR21OT66RNQQ/2sLUOU/4838TOOdn00UVBrFObHQ+ll8rq74
 Va9j0atj6iIn9c8lDQkqTek0pMDcmVGzb2MV6JA4BCbCL/lcGk8=
 =u3qV
 -----END PGP SIGNATURE-----

Merge tag 'for-5.15-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "A few more error handling fixes, stemming from code inspection, error
  injection or fuzzing"

* tag 'for-5.15-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: fix abort logic in btrfs_replace_file_extents
  btrfs: check for error when looking up inode during dir entry replay
  btrfs: unify lookup return value when dir entry is missing
  btrfs: deal with errors when adding inode reference during log replay
  btrfs: deal with errors when replaying dir entry during log replay
  btrfs: deal with errors when checking if a dir entry exists during log replay
  btrfs: update refs for any root except tree log roots
  btrfs: unlock newly allocated extent buffer after error
 2021-10-11 16:48:19 -07:00
Josef Bacik 4afb912f43 btrfs: fix abort logic in btrfs_replace_file_extents 
Error injection testing uncovered a case where we'd end up with a
corrupt file system with a missing extent in the middle of a file.  This
occurs because the if statement to decide if we should abort is wrong.

The only way we would abort in this case is if we got a ret !=
-EOPNOTSUPP and we called from the file clone code.  However the
prealloc code uses this path too.  Instead we need to abort if there is
an error, and the only error we _don't_ abort on is -EOPNOTSUPP and only
if we came from the clone file code.

CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-07 22:08:06 +02:00
Filipe Manana cfd312695b btrfs: check for error when looking up inode during dir entry replay 
At replay_one_name(), we are treating any error from btrfs_lookup_inode()
as if the inode does not exists. Fix this by checking for an error and
returning it to the caller.

CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-07 22:06:34 +02:00
Filipe Manana 8dcbc26194 btrfs: unify lookup return value when dir entry is missing 
btrfs_lookup_dir_index_item() and btrfs_lookup_dir_item() lookup for dir
entries and both are used during log replay or when updating a log tree
during an unlink.

However when the dir item does not exists, btrfs_lookup_dir_item() returns
NULL while btrfs_lookup_dir_index_item() returns PTR_ERR(-ENOENT), and if
the dir item exists but there is no matching entry for a given name or
index, both return NULL. This makes the call sites during log replay to
be more verbose than necessary and it makes it easy to miss this slight
difference. Since we don't need to distinguish between those two cases,
make btrfs_lookup_dir_index_item() always return NULL when there is no
matching directory entry - either because there isn't any dir entry or
because there is one but it does not match the given name and index.

Also rename the argument 'objectid' of btrfs_lookup_dir_index_item() to
'index' since it is supposed to match an index number, and the name
'objectid' is not very good because it can easily be confused with an
inode number (like the inode number a dir entry points to).

CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-07 22:06:32 +02:00
Filipe Manana 52db77791f btrfs: deal with errors when adding inode reference during log replay 
At __inode_add_ref(), we treating any error returned from
btrfs_lookup_dir_item() or from btrfs_lookup_dir_index_item() as meaning
that there is no existing directory entry in the fs/subvolume tree.
This is not correct since we can get errors such as, for example, -EIO
when reading extent buffers while searching the fs/subvolume's btree.

So fix that and return the error to the caller when it is not -ENOENT.

CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-07 22:06:30 +02:00
Filipe Manana e15ac64137 btrfs: deal with errors when replaying dir entry during log replay 
At replay_one_one(), we are treating any error returned from
btrfs_lookup_dir_item() or from btrfs_lookup_dir_index_item() as meaning
that there is no existing directory entry in the fs/subvolume tree.
This is not correct since we can get errors such as, for example, -EIO
when reading extent buffers while searching the fs/subvolume's btree.

So fix that and return the error to the caller when it is not -ENOENT.

CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-07 22:06:23 +02:00
Filipe Manana 77a5b9e3d1 btrfs: deal with errors when checking if a dir entry exists during log replay 
Currently inode_in_dir() ignores errors returned from
btrfs_lookup_dir_index_item() and from btrfs_lookup_dir_item(), treating
any errors as if the directory entry does not exists in the fs/subvolume
tree, which is obviously not correct, as we can get errors such as -EIO
when reading extent buffers while searching the fs/subvolume's tree.

Fix that by making inode_in_dir() return the errors and making its only
caller, add_inode_ref(), deal with returned errors as well.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-07 22:06:22 +02:00
Josef Bacik d175209be0 btrfs: update refs for any root except tree log roots 
I hit a stuck relocation on btrfs/061 during my overnight testing.  This
turned out to be because we had left over extent entries in our extent
root for a data reloc inode that no longer existed.  This happened
because in btrfs_drop_extents() we only update refs if we have SHAREABLE
set or we are the tree_root.  This regression was introduced by
aeb935a455 ("btrfs: don't set SHAREABLE flag for data reloc tree")
where we stopped setting SHAREABLE for the data reloc tree.

The problem here is we actually do want to update extent references for
data extents in the data reloc tree, in fact we only don't want to
update extent references if the file extents are in the log tree.
Update this check to only skip updating references in the case of the
log tree.

This is relatively rare, because you have to be running scrub at the
same time, which is what btrfs/061 does.  The data reloc inode has its
extents pre-allocated, and then we copy the extent into the
pre-allocated chunks.  We theoretically should never be calling
btrfs_drop_extents() on a data reloc inode.  The exception of course is
with scrub, if our pre-allocated extent falls inside of the block group
we are scrubbing, then the block group will be marked read only and we
will be forced to cow that extent.  This means we will call
btrfs_drop_extents() on that range when we COW that file extent.

This isn't really problematic if we do this, the data reloc inode
requires that our extent lengths match exactly with the extent we are
copying, thankfully we validate the extent is correct with
get_new_location(), so if we happen to COW only part of the extent we
won't link it in when we do the relocation, so we are safe from any
other shenanigans that arise because of this interaction with scrub.

Fixes: aeb935a455 ("btrfs: don't set SHAREABLE flag for data reloc tree")
CC: stable@vger.kernel.org # 5.8+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-07 22:04:36 +02:00
Qu Wenruo 19ea40dddf btrfs: unlock newly allocated extent buffer after error 
[BUG]
There is a bug report that injected ENOMEM error could leave a tree
block locked while we return to user-space:

  BTRFS info (device loop0): enabling ssd optimizations
  FAULT_INJECTION: forcing a failure.
  name failslab, interval 1, probability 0, space 0, times 0
  CPU: 0 PID: 7579 Comm: syz-executor Not tainted 5.15.0-rc1 #16
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
  rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
  Call Trace:
   __dump_stack lib/dump_stack.c:88 [inline]
   dump_stack_lvl+0x8d/0xcf lib/dump_stack.c:106
   fail_dump lib/fault-inject.c:52 [inline]
   should_fail+0x13c/0x160 lib/fault-inject.c:146
   should_failslab+0x5/0x10 mm/slab_common.c:1328
   slab_pre_alloc_hook.constprop.99+0x4e/0xc0 mm/slab.h:494
   slab_alloc_node mm/slub.c:3120 [inline]
   slab_alloc mm/slub.c:3214 [inline]
   kmem_cache_alloc+0x44/0x280 mm/slub.c:3219
   btrfs_alloc_delayed_extent_op fs/btrfs/delayed-ref.h:299 [inline]
   btrfs_alloc_tree_block+0x38c/0x670 fs/btrfs/extent-tree.c:4833
   __btrfs_cow_block+0x16f/0x7d0 fs/btrfs/ctree.c:415
   btrfs_cow_block+0x12a/0x300 fs/btrfs/ctree.c:570
   btrfs_search_slot+0x6b0/0xee0 fs/btrfs/ctree.c:1768
   btrfs_insert_empty_items+0x80/0xf0 fs/btrfs/ctree.c:3905
   btrfs_new_inode+0x311/0xa60 fs/btrfs/inode.c:6530
   btrfs_create+0x12b/0x270 fs/btrfs/inode.c:6783
   lookup_open+0x660/0x780 fs/namei.c:3282
   open_last_lookups fs/namei.c:3352 [inline]
   path_openat+0x465/0xe20 fs/namei.c:3557
   do_filp_open+0xe3/0x170 fs/namei.c:3588
   do_sys_openat2+0x357/0x4a0 fs/open.c:1200
   do_sys_open+0x87/0xd0 fs/open.c:1216
   do_syscall_x64 arch/x86/entry/common.c:50 [inline]
   do_syscall_64+0x34/0xb0 arch/x86/entry/common.c:80
   entry_SYSCALL_64_after_hwframe+0x44/0xae
  RIP: 0033:0x46ae99
  Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 48 89 f8 48
  89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d
  01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
  RSP: 002b:00007f46711b9c48 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
  RAX: ffffffffffffffda RBX: 000000000078c0a0 RCX: 000000000046ae99
  RDX: 0000000000000000 RSI: 00000000000000a1 RDI: 0000000020005800
  RBP: 00007f46711b9c80 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000017
  R13: 0000000000000000 R14: 000000000078c0a0 R15: 00007ffc129da6e0

  ================================================
  WARNING: lock held when returning to user space!
  5.15.0-rc1 #16 Not tainted
  ------------------------------------------------
  syz-executor/7579 is leaving the kernel with locks still held!
  1 lock held by syz-executor/7579:
   #0: ffff888104b73da8 (btrfs-tree-01/1){+.+.}-{3:3}, at:
  __btrfs_tree_lock+0x2e/0x1a0 fs/btrfs/locking.c:112

[CAUSE]
In btrfs_alloc_tree_block(), after btrfs_init_new_buffer(), the new
extent buffer @buf is locked, but if later operations like adding
delayed tree ref fail, we just free @buf without unlocking it,
resulting above warning.

[FIX]
Unlock @buf in out_free_buf: label.

Reported-by: Hao Sun <sunhao.th@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/CACkBjsZ9O6Zr0KK1yGn=1rQi6Crh1yeCRdTSBxx9R99L4xdn-Q@mail.gmail.com/
CC: stable@vger.kernel.org # 5.4+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-10-07 22:04:20 +02:00
Linus Torvalds f9e36107ec for-5.15-rc2-tag 
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmFM79wACgkQxWXV+ddt
 WDtdZQ/+K7NNEutg4JEH7n2KiXxwj8P23NwVK66a+XwH6/ZBe9xz5TQpnTJQ+D13
 +3mhthTJG7Wbcv+FlUVbfTSp5q8m2IH7CKox43o4JCZEEGtFfRPHrBGHLlGKMk3P
 ap2TZ3rvo0Sb21rx978HCQY824wdJvhv0SmWSScmvWzlTQEKaJHz1OFJgFxhUsMp
 Cy9y7mtIy+Ei4qJglU88iFNXhNL6YvwqXxDFY5LwN9rlCaV+rLk476aPfIBvvyf8
 4f34FHJOe1w9Jlk3KfydIwWefRBbq2dm0zNqNrMHNjl8zXbvfn8+ETOvf54HbjIz
 GGgKiZlBgNh2Na+p0SLoloEvBUdD5lSUCXis8099oUWZ+MporIwsyy4jAvtAeWR/
 QxBkZyxvTNFlXLamSo6oS58K9BNuxFYO7nLGSXQFEoYvb8/fu18rRt/A/rmNS8TU
 2vxpYacNKbggoULiGDzB74JY7MHdHRcMcAhmfDeG1bvNESPHfyLnpHfWamBVoUO6
 0eQOr78f1UpBlqJAGAGtfBefN1kMDnORyX0npGkGLFrKYiZbMgsxdjkNhiHnsufl
 9gsNVJ6baCeB1d5qS2vpZXeOLw0ln5iYZa5Yqz0eh/yc/9Wlj/YCsKRuAbaPMR1i
 i2ppHo3/na4K6L0EgSi6SU3xaUT+4LLzEEcBlJJuWZEwUTeYwiM=
 =VJFC
 -----END PGP SIGNATURE-----

Merge tag 'for-5.15-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:

 - regression fix for leak of transaction handle after verity rollback
   failure

 - properly reset device last error between mounts

 - improve one error handling case when checksumming bios

 - fixup confusing displayed size of space info free space

* tag 'for-5.15-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: prevent __btrfs_dump_space_info() to underflow its free space
  btrfs: fix mount failure due to past and transient device flush error
  btrfs: fix transaction handle leak after verity rollback failure
  btrfs: replace BUG_ON() in btrfs_csum_one_bio() with proper error handling
 2021-09-23 14:39:41 -07:00
Qu Wenruo 0619b79014 btrfs: prevent __btrfs_dump_space_info() to underflow its free space 
It's not uncommon where __btrfs_dump_space_info() gets called
under over-commit situations.

In that case free space would underflow as total allocated space is not
enough to handle all the over-committed space.

Such underflow values can sometimes cause confusion for users enabled
enospc_debug mount option, and takes some seconds for developers to
convert the underflow value to signed result.

Just output the free space as s64 to avoid such problem.

Reported-by: Eli V <eliventer@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/CAJtFHUSy4zgyhf-4d9T+KdJp9w=UgzC2A0V=VtmaeEpcGgm1-Q@mail.gmail.com/
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-09-17 19:29:54 +02:00
Filipe Manana 6b225baaba btrfs: fix mount failure due to past and transient device flush error 
When we get an error flushing one device, during a super block commit, we
record the error in the device structure, in the field 'last_flush_error'.
This is used to later check if we should error out the super block commit,
depending on whether the number of flush errors is greater than or equals
to the maximum tolerated device failures for a raid profile.

However if we get a transient device flush error, unmount the filesystem
and later try to mount it, we can fail the mount because we treat that
past error as critical and consider the device is missing. Even if it's
very likely that the error will happen again, as it's probably due to a
hardware related problem, there may be cases where the error might not
happen again. One example is during testing, and a test case like the
new generic/648 from fstests always triggers this. The test cases
generic/019 and generic/475 also trigger this scenario, but very
sporadically.

When this happens we get an error like this:

  $ mount /dev/sdc /mnt
  mount: /mnt wrong fs type, bad option, bad superblock on /dev/sdc, missing codepage or helper program, or other error.

  $ dmesg
  (...)
  [12918.886926] BTRFS warning (device sdc): chunk 13631488 missing 1 devices, max tolerance is 0 for writable mount
  [12918.888293] BTRFS warning (device sdc): writable mount is not allowed due to too many missing devices
  [12918.890853] BTRFS error (device sdc): open_ctree failed

The failure happens because when btrfs_check_rw_degradable() is called at
mount time, or at remount from RO to RW time, is sees a non zero value in
a device's ->last_flush_error attribute, and therefore considers that the
device is 'missing'.

Fix this by setting a device's ->last_flush_error to zero when we close a
device, making sure the error is not seen on the next mount attempt. We
only need to track flush errors during the current mount, so that we never
commit a super block if such errors happened.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-09-17 19:29:45 +02:00
Filipe Manana acbee9aff8 btrfs: fix transaction handle leak after verity rollback failure 
During a verity rollback, if we fail to update the inode or delete the
orphan, we abort the transaction and return without releasing our
transaction handle. Fix that by releasing the handle.

Fixes: 146054090b ("btrfs: initial fsverity support")
Fixes: 705242538f ("btrfs: verity metadata orphan items")
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-09-17 19:29:41 +02:00
Qu Wenruo bbc9a6eb5e btrfs: replace BUG_ON() in btrfs_csum_one_bio() with proper error handling 
There is a BUG_ON() in btrfs_csum_one_bio() to catch code logic error.
It has indeed caught several bugs during subpage development.
But the BUG_ON() itself will bring down the whole system which is
an overkill.

Replace it with a WARN() and exit gracefully, so that it won't crash the
whole system while we can still catch the code logic error.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-09-17 19:29:38 +02:00
Linus Torvalds 8dde20867c for-5.15-tag 
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmE6BpMACgkQxWXV+ddt
 WDvXhA//aaeKQIiVbiCnmMKFVX08wU8/pUXf65TJIaaTd0KE0QMu/aW6ibOpC6QI
 auf7wTiErHoJM7A22nL+Eoic7shlPueBktt3YcmdyQ/3ZFR6Wr7Td/cby0FvTOJU
 m0bjLMLp3rWSpnbMMUlOt8VSOcA892jnp7MHVtRYGfmfslwE5iTRtnPjmVobinm7
 dfKxCXUgMG9NWINIJobn70GQsZCXipa1A+MdbkdIPyjbM+tgR0EXZBrSaEcgMVpV
 dWnwTphx0io/tsgt4ZVQzGaCWtesBAe4yhaJJK92eFMTOKlYB/8y5P31N9wBL9Uj
 AOn0ke2Uc/weah50W7AhxeU3nCSGUAl9DbGrovKEfP/p0T9NJC/l3P1gwqpeGuld
 IbrBNFGVm3Noo2ZSoZU55P17gnTFHBMnXyVsbaoEldcsBv39D8K+tZ9F2vFaAV3e
 VayZiUuw/PhEcucYCQKdUCwFqFjJJfNnYpNtMSY3aCHeTOjphrP2sWBxKNAkWChB
 n4O5IFBm5e8YjBVNItZrlXE9KtE+JuwGSbNihhQQ/wy/M1sxB76DpaKnCLgjQmF6
 peBZktTRr8X7aRs1BGQKrU7Yzq7oR1psYadUhGIrrWp/qS4UCXkvYnkMQ0FInyQH
 pYQNHTDE4PSECzEhQAj9syeVE3lnGMGIWylmniamiuDsQcvaydM=
 =RQSe
 -----END PGP SIGNATURE-----

Merge tag 'for-5.15-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:

 - fix max_inline mount option limit on 64k page system

 - lockdep fixes:
     - update bdev time in a safer way
     - move bdev put outside of sb write section when removing device
     - fix possible deadlock when mounting seed/sprout filesystem

 - zoned mode: fix split extent accounting

 - minor include fixup

* tag 'for-5.15-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: zoned: fix double counting of split ordered extent
  btrfs: fix lockdep warning while mounting sprout fs
  btrfs: delay blkdev_put until after the device remove
  btrfs: update the bdev time directly when closing
  btrfs: use correct header for div_u64 in misc.h
  btrfs: fix upper limit for max_inline for page size 64K
 2021-09-09 16:09:56 -07:00
Naohiro Aota f79645df80 btrfs: zoned: fix double counting of split ordered extent 
btrfs_add_ordered_extent_*() add num_bytes to fs_info->ordered_bytes.
Then, splitting an ordered extent will call btrfs_add_ordered_extent_*()
again for split extents, leading to double counting of the region of
a split extent. These leaked bytes are finally reported at unmount time
as follow:

  BTRFS info (device dm-1): at unmount dio bytes count 364544

Fix the double counting by subtracting split extent's size from
fs_info->ordered_bytes.

Fixes: d22002fd37 ("btrfs: zoned: split ordered extent when bio is sent")
CC: stable@vger.kernel.org # 5.12+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-09-07 14:30:41 +02:00
Anand Jain c124706900 btrfs: fix lockdep warning while mounting sprout fs 
Following test case reproduces lockdep warning.

  Test case:

  $ mkfs.btrfs -f <dev1>
  $ btrfstune -S 1 <dev1>
  $ mount <dev1> <mnt>
  $ btrfs device add <dev2> <mnt> -f
  $ umount <mnt>
  $ mount <dev2> <mnt>
  $ umount <mnt>

The warning claims a possible ABBA deadlock between the threads
initiated by [#1] btrfs device add and [#0] the mount.

  [ 540.743122] WARNING: possible circular locking dependency detected
  [ 540.743129] 5.11.0-rc7+ #5 Not tainted
  [ 540.743135] ------------------------------------------------------
  [ 540.743142] mount/2515 is trying to acquire lock:
  [ 540.743149] ffffa0c5544c2ce0 (&fs_devs->device_list_mutex){+.+.}-{4:4}, at: clone_fs_devices+0x6d/0x210 [btrfs]
  [ 540.743458] but task is already holding lock:
  [ 540.743461] ffffa0c54a7932b8 (btrfs-chunk-00){++++}-{4:4}, at: __btrfs_tree_read_lock+0x32/0x200 [btrfs]
  [ 540.743541] which lock already depends on the new lock.
  [ 540.743543] the existing dependency chain (in reverse order) is:

  [ 540.743546] -> #1 (btrfs-chunk-00){++++}-{4:4}:
  [ 540.743566] down_read_nested+0x48/0x2b0
  [ 540.743585] __btrfs_tree_read_lock+0x32/0x200 [btrfs]
  [ 540.743650] btrfs_read_lock_root_node+0x70/0x200 [btrfs]
  [ 540.743733] btrfs_search_slot+0x6c6/0xe00 [btrfs]
  [ 540.743785] btrfs_update_device+0x83/0x260 [btrfs]
  [ 540.743849] btrfs_finish_chunk_alloc+0x13f/0x660 [btrfs] <--- device_list_mutex
  [ 540.743911] btrfs_create_pending_block_groups+0x18d/0x3f0 [btrfs]
  [ 540.743982] btrfs_commit_transaction+0x86/0x1260 [btrfs]
  [ 540.744037] btrfs_init_new_device+0x1600/0x1dd0 [btrfs]
  [ 540.744101] btrfs_ioctl+0x1c77/0x24c0 [btrfs]
  [ 540.744166] __x64_sys_ioctl+0xe4/0x140
  [ 540.744170] do_syscall_64+0x4b/0x80
  [ 540.744174] entry_SYSCALL_64_after_hwframe+0x44/0xa9

  [ 540.744180] -> #0 (&fs_devs->device_list_mutex){+.+.}-{4:4}:
  [ 540.744184] __lock_acquire+0x155f/0x2360
  [ 540.744188] lock_acquire+0x10b/0x5c0
  [ 540.744190] __mutex_lock+0xb1/0xf80
  [ 540.744193] mutex_lock_nested+0x27/0x30
  [ 540.744196] clone_fs_devices+0x6d/0x210 [btrfs]
  [ 540.744270] btrfs_read_chunk_tree+0x3c7/0xbb0 [btrfs]
  [ 540.744336] open_ctree+0xf6e/0x2074 [btrfs]
  [ 540.744406] btrfs_mount_root.cold.72+0x16/0x127 [btrfs]
  [ 540.744472] legacy_get_tree+0x38/0x90
  [ 540.744475] vfs_get_tree+0x30/0x140
  [ 540.744478] fc_mount+0x16/0x60
  [ 540.744482] vfs_kern_mount+0x91/0x100
  [ 540.744484] btrfs_mount+0x1e6/0x670 [btrfs]
  [ 540.744536] legacy_get_tree+0x38/0x90
  [ 540.744537] vfs_get_tree+0x30/0x140
  [ 540.744539] path_mount+0x8d8/0x1070
  [ 540.744541] do_mount+0x8d/0xc0
  [ 540.744543] __x64_sys_mount+0x125/0x160
  [ 540.744545] do_syscall_64+0x4b/0x80
  [ 540.744547] entry_SYSCALL_64_after_hwframe+0x44/0xa9

  [ 540.744551] other info that might help us debug this:
  [ 540.744552] Possible unsafe locking scenario:

  [ 540.744553] CPU0 				CPU1
  [ 540.744554] ---- 				----
  [ 540.744555] lock(btrfs-chunk-00);
  [ 540.744557] 					lock(&fs_devs->device_list_mutex);
  [ 540.744560] 					lock(btrfs-chunk-00);
  [ 540.744562] lock(&fs_devs->device_list_mutex);
  [ 540.744564]
   *** DEADLOCK ***

  [ 540.744565] 3 locks held by mount/2515:
  [ 540.744567] #0: ffffa0c56bf7a0e0 (&type->s_umount_key#42/1){+.+.}-{4:4}, at: alloc_super.isra.16+0xdf/0x450
  [ 540.744574] #1: ffffffffc05a9628 (uuid_mutex){+.+.}-{4:4}, at: btrfs_read_chunk_tree+0x63/0xbb0 [btrfs]
  [ 540.744640] #2: ffffa0c54a7932b8 (btrfs-chunk-00){++++}-{4:4}, at: __btrfs_tree_read_lock+0x32/0x200 [btrfs]
  [ 540.744708]
   stack backtrace:
  [ 540.744712] CPU: 2 PID: 2515 Comm: mount Not tainted 5.11.0-rc7+ #5

But the device_list_mutex in clone_fs_devices() is redundant, as
explained below.  Two threads [1]  and [2] (below) could lead to
clone_fs_device().

  [1]
  open_ctree <== mount sprout fs
   btrfs_read_chunk_tree()
    mutex_lock(&uuid_mutex) <== global lock
    read_one_dev()
     open_seed_devices()
      clone_fs_devices() <== seed fs_devices
       mutex_lock(&orig->device_list_mutex) <== seed fs_devices

  [2]
  btrfs_init_new_device() <== sprouting
   mutex_lock(&uuid_mutex); <== global lock
   btrfs_prepare_sprout()
     lockdep_assert_held(&uuid_mutex)
     clone_fs_devices(seed_fs_device) <== seed fs_devices

Both of these threads hold uuid_mutex which is sufficient to protect
getting the seed device(s) freed while we are trying to clone it for
sprouting [2] or mounting a sprout [1] (as above). A mounted seed device
can not free/write/replace because it is read-only. An unmounted seed
device can be freed by btrfs_free_stale_devices(), but it needs
uuid_mutex.  So this patch removes the unnecessary device_list_mutex in
clone_fs_devices().  And adds a lockdep_assert_held(&uuid_mutex) in
clone_fs_devices().

Reported-by: Su Yue <l@damenly.su>
Tested-by: Su Yue <l@damenly.su>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-09-07 14:30:05 +02:00
Josef Bacik 3fa421dedb btrfs: delay blkdev_put until after the device remove 
When removing the device we call blkdev_put() on the device once we've
removed it, and because we have an EXCL open we need to take the
->open_mutex on the block device to clean it up.  Unfortunately during
device remove we are holding the sb writers lock, which results in the
following lockdep splat:

======================================================
WARNING: possible circular locking dependency detected
5.14.0-rc2+ #407 Not tainted
------------------------------------------------------
losetup/11595 is trying to acquire lock:
ffff973ac35dd138 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x67/0x5e0

but task is already holding lock:
ffff973ac9812c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #4 (&lo->lo_mutex){+.+.}-{3:3}:
       __mutex_lock+0x7d/0x750
       lo_open+0x28/0x60 [loop]
       blkdev_get_whole+0x25/0xf0
       blkdev_get_by_dev.part.0+0x168/0x3c0
       blkdev_open+0xd2/0xe0
       do_dentry_open+0x161/0x390
       path_openat+0x3cc/0xa20
       do_filp_open+0x96/0x120
       do_sys_openat2+0x7b/0x130
       __x64_sys_openat+0x46/0x70
       do_syscall_64+0x38/0x90
       entry_SYSCALL_64_after_hwframe+0x44/0xae

-> #3 (&disk->open_mutex){+.+.}-{3:3}:
       __mutex_lock+0x7d/0x750
       blkdev_put+0x3a/0x220
       btrfs_rm_device.cold+0x62/0xe5
       btrfs_ioctl+0x2a31/0x2e70
       __x64_sys_ioctl+0x80/0xb0
       do_syscall_64+0x38/0x90
       entry_SYSCALL_64_after_hwframe+0x44/0xae

-> #2 (sb_writers#12){.+.+}-{0:0}:
       lo_write_bvec+0xc2/0x240 [loop]
       loop_process_work+0x238/0xd00 [loop]
       process_one_work+0x26b/0x560
       worker_thread+0x55/0x3c0
       kthread+0x140/0x160
       ret_from_fork+0x1f/0x30

-> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}:
       process_one_work+0x245/0x560
       worker_thread+0x55/0x3c0
       kthread+0x140/0x160
       ret_from_fork+0x1f/0x30

-> #0 ((wq_completion)loop0){+.+.}-{0:0}:
       __lock_acquire+0x10ea/0x1d90
       lock_acquire+0xb5/0x2b0
       flush_workqueue+0x91/0x5e0
       drain_workqueue+0xa0/0x110
       destroy_workqueue+0x36/0x250
       __loop_clr_fd+0x9a/0x660 [loop]
       block_ioctl+0x3f/0x50
       __x64_sys_ioctl+0x80/0xb0
       do_syscall_64+0x38/0x90
       entry_SYSCALL_64_after_hwframe+0x44/0xae

other info that might help us debug this:

Chain exists of:
  (wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&lo->lo_mutex);
                               lock(&disk->open_mutex);
                               lock(&lo->lo_mutex);
  lock((wq_completion)loop0);

 *** DEADLOCK ***

1 lock held by losetup/11595:
 #0: ffff973ac9812c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]

stack backtrace:
CPU: 0 PID: 11595 Comm: losetup Not tainted 5.14.0-rc2+ #407
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
 dump_stack_lvl+0x57/0x72
 check_noncircular+0xcf/0xf0
 ? stack_trace_save+0x3b/0x50
 __lock_acquire+0x10ea/0x1d90
 lock_acquire+0xb5/0x2b0
 ? flush_workqueue+0x67/0x5e0
 ? lockdep_init_map_type+0x47/0x220
 flush_workqueue+0x91/0x5e0
 ? flush_workqueue+0x67/0x5e0
 ? verify_cpu+0xf0/0x100
 drain_workqueue+0xa0/0x110
 destroy_workqueue+0x36/0x250
 __loop_clr_fd+0x9a/0x660 [loop]
 ? blkdev_ioctl+0x8d/0x2a0
 block_ioctl+0x3f/0x50
 __x64_sys_ioctl+0x80/0xb0
 do_syscall_64+0x38/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fc21255d4cb

So instead save the bdev and do the put once we've dropped the sb
writers lock in order to avoid the lockdep recursion.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-09-07 14:29:59 +02:00
Josef Bacik 8f96a5bfa1 btrfs: update the bdev time directly when closing 
We update the ctime/mtime of a block device when we remove it so that
blkid knows the device changed.  However we do this by re-opening the
block device and calling filp_update_time.  This is more correct because
it'll call the inode->i_op->update_time if it exists, but the block dev
inodes do not do this.  Instead call generic_update_time() on the
bd_inode in order to avoid the blkdev_open path and get rid of the
following lockdep splat:

======================================================
WARNING: possible circular locking dependency detected
5.14.0-rc2+ #406 Not tainted
------------------------------------------------------
losetup/11596 is trying to acquire lock:
ffff939640d2f538 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x67/0x5e0

but task is already holding lock:
ffff939655510c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #4 (&lo->lo_mutex){+.+.}-{3:3}:
       __mutex_lock+0x7d/0x750
       lo_open+0x28/0x60 [loop]
       blkdev_get_whole+0x25/0xf0
       blkdev_get_by_dev.part.0+0x168/0x3c0
       blkdev_open+0xd2/0xe0
       do_dentry_open+0x161/0x390
       path_openat+0x3cc/0xa20
       do_filp_open+0x96/0x120
       do_sys_openat2+0x7b/0x130
       __x64_sys_openat+0x46/0x70
       do_syscall_64+0x38/0x90
       entry_SYSCALL_64_after_hwframe+0x44/0xae

-> #3 (&disk->open_mutex){+.+.}-{3:3}:
       __mutex_lock+0x7d/0x750
       blkdev_get_by_dev.part.0+0x56/0x3c0
       blkdev_open+0xd2/0xe0
       do_dentry_open+0x161/0x390
       path_openat+0x3cc/0xa20
       do_filp_open+0x96/0x120
       file_open_name+0xc7/0x170
       filp_open+0x2c/0x50
       btrfs_scratch_superblocks.part.0+0x10f/0x170
       btrfs_rm_device.cold+0xe8/0xed
       btrfs_ioctl+0x2a31/0x2e70
       __x64_sys_ioctl+0x80/0xb0
       do_syscall_64+0x38/0x90
       entry_SYSCALL_64_after_hwframe+0x44/0xae

-> #2 (sb_writers#12){.+.+}-{0:0}:
       lo_write_bvec+0xc2/0x240 [loop]
       loop_process_work+0x238/0xd00 [loop]
       process_one_work+0x26b/0x560
       worker_thread+0x55/0x3c0
       kthread+0x140/0x160
       ret_from_fork+0x1f/0x30

-> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}:
       process_one_work+0x245/0x560
       worker_thread+0x55/0x3c0
       kthread+0x140/0x160
       ret_from_fork+0x1f/0x30

-> #0 ((wq_completion)loop0){+.+.}-{0:0}:
       __lock_acquire+0x10ea/0x1d90
       lock_acquire+0xb5/0x2b0
       flush_workqueue+0x91/0x5e0
       drain_workqueue+0xa0/0x110
       destroy_workqueue+0x36/0x250
       __loop_clr_fd+0x9a/0x660 [loop]
       block_ioctl+0x3f/0x50
       __x64_sys_ioctl+0x80/0xb0
       do_syscall_64+0x38/0x90
       entry_SYSCALL_64_after_hwframe+0x44/0xae

other info that might help us debug this:

Chain exists of:
  (wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&lo->lo_mutex);
                               lock(&disk->open_mutex);
                               lock(&lo->lo_mutex);
  lock((wq_completion)loop0);

 *** DEADLOCK ***

1 lock held by losetup/11596:
 #0: ffff939655510c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]

stack backtrace:
CPU: 1 PID: 11596 Comm: losetup Not tainted 5.14.0-rc2+ #406
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
 dump_stack_lvl+0x57/0x72
 check_noncircular+0xcf/0xf0
 ? stack_trace_save+0x3b/0x50
 __lock_acquire+0x10ea/0x1d90
 lock_acquire+0xb5/0x2b0
 ? flush_workqueue+0x67/0x5e0
 ? lockdep_init_map_type+0x47/0x220
 flush_workqueue+0x91/0x5e0
 ? flush_workqueue+0x67/0x5e0
 ? verify_cpu+0xf0/0x100
 drain_workqueue+0xa0/0x110
 destroy_workqueue+0x36/0x250
 __loop_clr_fd+0x9a/0x660 [loop]
 ? blkdev_ioctl+0x8d/0x2a0
 block_ioctl+0x3f/0x50
 __x64_sys_ioctl+0x80/0xb0
 do_syscall_64+0x38/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-09-07 14:29:55 +02:00
Kari Argillander cde7417ce4 btrfs: use correct header for div_u64 in misc.h 
asm/do_div.h is for div_u64, but it is found in math64.h. This change
will make compiler job easier and prevent compiler errors in situation
where compiler will not find math64.h from another paths.

Signed-off-by: Kari Argillander <kari.argillander@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-09-07 14:29:50 +02:00
Anand Jain 6f93e834fa btrfs: fix upper limit for max_inline for page size 64K 
The mount option max_inline ranges from 0 to the sectorsize (which is
now equal to page size). But we parse the mount options too early and
before the actual sectorsize is read from the superblock. So the upper
limit of max_inline is unaware of the actual sectorsize and is limited
by the temporary sectorsize 4096, even on a system where the default
sectorsize is 64K.

Fix this by reading the superblock sectorsize before the mount option
parse.

Reported-by: Alexander Tsvetkov <alexander.tsvetkov@oracle.com>
CC: stable@vger.kernel.org # 5.4+
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-09-07 14:28:46 +02:00
Linus Torvalds 815409a12c overlayfs update for 5.15 
-----BEGIN PGP SIGNATURE-----
 
 iHUEABYIAB0WIQSQHSd0lITzzeNWNm3h3BK/laaZPAUCYTDKKAAKCRDh3BK/laaZ
 PG9PAQCUF0fdBlCKudwSEt5PV5xemycL9OCAlYCd7d4XbBIe9wEA6sVJL9J+OwV2
 aF0NomiXtJccE+S9+byjVCyqSzQJGQQ=
 =6L2Y
 -----END PGP SIGNATURE-----

Merge tag 'ovl-update-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs

Pull overlayfs update from Miklos Szeredi:

 - Copy up immutable/append/sync/noatime attributes (Amir Goldstein)

 - Improve performance by enabling RCU lookup.

 - Misc fixes and improvements

The reason this touches so many files is that the ->get_acl() method now
gets a "bool rcu" argument.  The ->get_acl() API was updated based on
comments from Al and Linus:

Link: https://lore.kernel.org/linux-fsdevel/CAJfpeguQxpd6Wgc0Jd3ks77zcsAv_bn0q17L3VNnnmPKu11t8A@mail.gmail.com/

* tag 'ovl-update-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ovl: enable RCU'd ->get_acl()
  vfs: add rcu argument to ->get_acl() callback
  ovl: fix BUG_ON() in may_delete() when called from ovl_cleanup()
  ovl: use kvalloc in xattr copy-up
  ovl: update ctime when changing fileattr
  ovl: skip checking lower file's i_writecount on truncate
  ovl: relax lookup error on mismatch origin ftype
  ovl: do not set overlay.opaque for new directories
  ovl: add ovl_allow_offline_changes() helper
  ovl: disable decoding null uuid with redirect_dir
  ovl: consistent behavior for immutable/append-only inodes
  ovl: copy up sync/noatime fileattr flags
  ovl: pass ovl_fs to ovl_check_setxattr()
  fs: add generic helper for filling statx attribute flags
 2021-09-02 09:21:27 -07:00
Linus Torvalds 0ee7c3e25d New code for 5.15: 
- Simplify the bio_end_page usage in the buffered IO code.
  - Support reading inline data at nonzero offsets for erofs.
  - Fix some typos and bad grammar.
  - Convert kmap_atomic usage in the inline data read path.
  - Add some extra inline data input checking.
  - Fix a memory corruption bug stemming from iomap_swapfile_activate
    trying to activate more pages than mm was expecting.
  - Pass errnos through the page writeback code so that writeback errors
    are reported correctly instead of being munged to EIO.
  - Replace iomap_apply with a open-coded iterator loops to reduce the
    number of indirect calls by a third to a half.
  - Refactor the fsdax code to use iomap iterators instead of the
    open-coded iomap_apply code that it had before.
  - Format file range iomap tracepoint data in hexadecimal and
    standardize the names used in the pretty-print string.
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEUzaAxoMeQq6m2jMV+H93GTRKtOsFAmEnwC0ACgkQ+H93GTRK
 tOtVOQ//Zu9ul2ZmPARMV8xyAfopnLpmggREOthFbPkDZ3z3ZgRpPxlbAvWEEKnj
 VDNLFNj204rDojuxP/YSdxgiawLod7dYfXIwwft8R8oI7MdgVQhpvimUi5bkz/Od
 X5pmFDe84INfFvEztOgC+sPk1RI/ToQLgrcIffWMWfF2iyVkNVMCD5MMe6LoH1la
 9GbVCfPx6Y2Nffaa8EuAEgaCo7FMPc81bvQG4qpeqXyX8qql/r5n4YENhkn3n4qa
 zI4F2lgqwbelFkamZOYNDjtLt13lb7Ze0PoFOpmTZUqlyybqhRxDvJ+OxZn8W6zH
 20pxWx/RCXhCp/sS6DRcYyf7WKoIfdGDkxed7aSuhJ+VKKtBtsjMoy7dh5IY5RJa
 8L1DMat6xtea8Glx04SF7Vib0n/An9oHOTzLEWxsUlRaPhW68uVpKgXuGLTAf+dc
 ztJhlQ9pLX0D2NmgGlkXN8d4F1XEH2BgyIrtF6UNtMbyIlCREHM9HELJs6JzKl6U
 a4ivJXyaq8o/hlXr8IMWUOTVubS0i+hgvvQjnVJmcSTJxhH10mPPJLnNsGX6heD9
 SlnnXRbD03iqsbMJP/R431VKooryOSKBc86IEECkuMz3RUfw75DGAnLtETnT1rsA
 71rSVf5NaCGZ2hV4du6jv53TS7yrPpqkxJHyDWD1WP4xGPbO1XA=
 =iVns
 -----END PGP SIGNATURE-----

Merge tag 'iomap-5.15-merge-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull iomap updates from Darrick Wong:
 "The most notable externally visible change for this cycle is the
  addition of support for reads to inline tail fragments of files, which
  was requested by the erofs developers; and a correction for a kernel
  memory corruption bug if the sysadmin tries to activate a swapfile
  with more pages than the swapfile header suggests.

  We also now report writeback completion errors to the file mapping
  correctly, instead of munging all errors into EIO.

  Internally, the bulk of the changes are Christoph's patchset to reduce
  the indirect function call count by a third to a half by converting
  iomap iteration from a loop pattern to a generator/consumer pattern.
  As an added bonus, fsdax no longer open-codes iomap apply loops.

  Summary:

   - Simplify the bio_end_page usage in the buffered IO code.

   - Support reading inline data at nonzero offsets for erofs.

   - Fix some typos and bad grammar.

   - Convert kmap_atomic usage in the inline data read path.

   - Add some extra inline data input checking.

   - Fix a memory corruption bug stemming from iomap_swapfile_activate
     trying to activate more pages than mm was expecting.

   - Pass errnos through the page writeback code so that writeback
     errors are reported correctly instead of being munged to EIO.

   - Replace iomap_apply with a open-coded iterator loops to reduce the
     number of indirect calls by a third to a half.

   - Refactor the fsdax code to use iomap iterators instead of the
     open-coded iomap_apply code that it had before.

   - Format file range iomap tracepoint data in hexadecimal and
     standardize the names used in the pretty-print string"

* tag 'iomap-5.15-merge-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (41 commits)
  iomap: standardize tracepoint formatting and storage
  mm/swap: consider max pages in iomap_swapfile_add_extent
  iomap: move loop control code to iter.c
  iomap: constify iomap_iter_srcmap
  fsdax: switch the fault handlers to use iomap_iter
  fsdax: factor out a dax_fault_actor() helper
  fsdax: factor out helpers to simplify the dax fault code
  iomap: rework unshare flag
  iomap: pass an iomap_iter to various buffered I/O helpers
  iomap: remove iomap_apply
  fsdax: switch dax_iomap_rw to use iomap_iter
  iomap: switch iomap_swapfile_activate to use iomap_iter
  iomap: switch iomap_seek_data to use iomap_iter
  iomap: switch iomap_seek_hole to use iomap_iter
  iomap: switch iomap_bmap to use iomap_iter
  iomap: switch iomap_fiemap to use iomap_iter
  iomap: switch __iomap_dio_rw to use iomap_iter
  iomap: switch iomap_page_mkwrite to use iomap_iter
  iomap: switch iomap_zero_range to use iomap_iter
  iomap: switch iomap_file_unshare to use iomap_iter
  ...
 2021-08-31 11:13:35 -07:00
Linus Torvalds 87045e6546 for-5.15-tag 
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmEs2NIACgkQxWXV+ddt
 WDsJMQ/+PJ/yXfI85mAeAzTJLWQ0zD6YO3iBhf3wOeyychWC4on435pj+zW8zR/U
 /bix25ygoWF4MvGF6p0uyv4Z5mnvkZXE5lapUcJu6wXG7se1QRPH0broTh05IBXK
 SnT93Eb9RexaiNFk7DVma9XkviqZ/ZISPtkJ9wYrfIba7j/U/wa+PtEFS7wk58hP
 rFQXgV64xm/pcP28YYHfOkCjdyUMdJrnBUvfKOlX6d94lmYbP5lyiTL+XJEXExzN
 wPakD0UsnXPr4TRvf+YRTPeFHPPUgyORII7otVUOKmGywWtcJrELX8rXFoW+6GwB
 dzZIcSYXHUxU5UrtMbZgiztVBJ+bQY5juYMIrj13eYOMYkijxAqPP84iDO15+TSV
 zNqyAVjUglHCGUGjhSpAxnAmtp+IJTZfVAWcvIKq3VqvJtb8tssQsk9bqFjH1xlH
 qNJLE57CYe3tjw05K9y0keMh2iJWRWkXZYkgI/zjwo5nreemobpN+3fO4yneVLh7
 ecdBmSl/JVSzAB1NamLOCZNGZLUqiiuTvZlJtI6ZsekrN1+4A6QzVcU/MGjSYL1v
 C7W0hK0LF+e3xIBkxTKVq8noolsgbmlWacxJq8fZq9HwZy5IVJOVm9STDlCuLaIo
 gPr0V0itkclcsMU0CHTyCjMsfuHYUwJZXwg93wKfJf5UCzS4OWU=
 =ALO9
 -----END PGP SIGNATURE-----

Merge tag 'for-5.15-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs updates from David Sterba:
 "The highlights of this round are integrations with fs-verity and
  idmapped mounts, the rest is usual mix of minor improvements, speedups
  and cleanups.

  There are some patches outside of btrfs, namely updating some VFS
  interfaces, all straightforward and acked.

  Features:

   - fs-verity support, using standard ioctls, backward compatible with
     read-only limitation on inodes with previously enabled fs-verity

   - idmapped mount support

   - make mount with rescue=ibadroots more tolerant to partially damaged
     trees

   - allow raid0 on a single device and raid10 on two devices,
     degenerate cases but might be useful as an intermediate step during
     conversion to other profiles

   - zoned mode block group auto reclaim can be disabled via sysfs knob

  Performance improvements:

   - continue readahead of node siblings even if target node is in
     memory, could speed up full send (on sample test +11%)

   - batching of delayed items can speed up creating many files

   - fsync/tree-log speedups
       - avoid unnecessary work (gains +2% throughput, -2% run time on
         sample load)
       - reduced lock contention on renames (on dbench +4% throughput,
         up to -30% latency)

  Fixes:

   - various zoned mode fixes

   - preemptive flushing threshold tuning, avoid excessive work on
     almost full filesystems

  Core:

   - continued subpage support, preparation for implementing remaining
     features like compression and defragmentation; with some
     limitations, write is now enabled on 64K page systems with 4K
     sectors, still considered experimental
       - no readahead on compressed reads
       - inline extents disabled
       - disabled raid56 profile conversion and mount

   - improved flushing logic, fixing early ENOSPC on some workloads

   - inode flags have been internally split to read-only and read-write
     incompat bit parts, used by fs-verity

   - new tree items for fs-verity
       - descriptor item
       - Merkle tree item

   - inode operations extended to be namespace-aware

   - cleanups and refactoring

  Generic code changes:

   - fs: new export filemap_fdatawrite_wbc

   - fs: removed sync_inode

   - block: bio_trim argument type fixups

   - vfs: add namespace-aware lookup"

* tag 'for-5.15-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (114 commits)
  btrfs: reset replace target device to allocation state on close
  btrfs: zoned: fix ordered extent boundary calculation
  btrfs: do not do preemptive flushing if the majority is global rsv
  btrfs: reduce the preemptive flushing threshold to 90%
  btrfs: tree-log: check btrfs_lookup_data_extent return value
  btrfs: avoid unnecessarily logging directories that had no changes
  btrfs: allow idmapped mount
  btrfs: handle ACLs on idmapped mounts
  btrfs: allow idmapped INO_LOOKUP_USER ioctl
  btrfs: allow idmapped SUBVOL_SETFLAGS ioctl
  btrfs: allow idmapped SET_RECEIVED_SUBVOL ioctls
  btrfs: relax restrictions for SNAP_DESTROY_V2 with subvolids
  btrfs: allow idmapped SNAP_DESTROY ioctls
  btrfs: allow idmapped SNAP_CREATE/SUBVOL_CREATE ioctls
  btrfs: check whether fsgid/fsuid are mapped during subvolume creation
  btrfs: allow idmapped permission inode op
  btrfs: allow idmapped setattr inode op
  btrfs: allow idmapped tmpfile inode op
  btrfs: allow idmapped symlink inode op
  btrfs: allow idmapped mkdir inode op
  ...
 2021-08-31 09:41:22 -07:00
Linus Torvalds 9b49ceb854 for-5.14-rc7-tag 
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmEmQy4ACgkQxWXV+ddt
 WDuCRRAAmuO+6Zsl5MSq0hBnpec/VBN6lTi9VPt184BjW1IWsqwR1Ax8dVQEKgCm
 gzkGYEuVq2L5p+/ugWKKftAbmUU85Jf3AIsv81SCJQosRkxVXAdbrZOv00yUZy6/
 5YOdO+9u61otvtO6LcZz9l+0LcpSmrBwEszluyIS+nArgQyZwX2aZTjcScDJvB9+
 1y7Eo6eIbqbcJOf4mLDIJh0bHaiA7HB6jYJkbsnz51wBU2ETATzNzAoyP5ReTPGc
 1s0uxrpY37kHcUUTd6q8VLDTM6Ei4vF2zQm0jWcrw0K3hM6yPuH+GiEADoV/xsls
 6pbtss1E81rHEQjcK8brf6CxbOak8/WXV0gRia/3avkFteVlax+NJxRdVhksuJln
 siGlQqASX3vYdNL0nG+U0ml1Y9C1ZXTXu4lGjS6rtT9oeV+YSccG2UjIT9LEtuON
 W/zE4bUMqCddcZFEPH5jNK+ChGS8mmfs+UFFR+W/JzMIO8Uji5/K44FZDFBo0Oc/
 3JEgk7ZV4D+8SblBPMxJx0fZqbE8ggKM+IN5CAyscINOWOxrmRiaFFRygRX0TLDB
 2uts9owItW6zvaTRY6RclVeCvJ6ARQli4pv7YxZmH85hhtCbn515imWvLWw4+tSg
 QwrtDnPVMSJTdzFHvsmeE9lM6Vaw0ur70Ysyd29k/XJu3WwRdkM=
 =jN7s
 -----END PGP SIGNATURE-----

Merge tag 'for-5.14-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fix from David Sterba:
 "One more fix that I think qualifies for a late merge. It's a revert of
  a one-liner fix that meanwhile got backported to stable kernels and we
  got reports from users.

  The broken fix prevents creating compressed inline extents, which
  could be noticeable on space consumption.

  Technically it's a regression as the patch was merged in 5.14-rc1 but
  got propagated to several stable kernels and has higher exposure than
  a 'typical' development cycle bug"

* tag 'for-5.14-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Revert "btrfs: compression: don't try to compress if we don't have enough pages"
 2021-08-26 11:05:11 -07:00
Qu Wenruo 4e9655763b Revert "btrfs: compression: don't try to compress if we don't have enough pages" 
This reverts commit f216562731.

[BUG]
It's no longer possible to create compressed inline extent after commit
f216562731 ("btrfs: compression: don't try to compress if we don't
have enough pages").

[CAUSE]
For compression code, there are several possible reasons we have a range
that needs to be compressed while it's no more than one page.

- Compressed inline write
  The data is always smaller than one sector and the test lacks the
  condition to properly recognize a non-inline extent.

- Compressed subpage write
  For the incoming subpage compressed write support, we require page
  alignment of the delalloc range.
  And for 64K page size, we can compress just one page into smaller
  sectors.

For those reasons, the requirement for the data to be more than one page
is not correct, and is already causing regression for compressed inline
data writeback.  The idea of skipping one page to avoid wasting CPU time
could be revisited in the future.

[FIX]
Fix it by reverting the offending commit.

Reported-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
Link: https://lore.kernel.org/linux-btrfs/afa2742.c084f5d6.17b6b08dffc@tnonline.net
Fixes: f216562731 ("btrfs: compression: don't try to compress if we don't have enough pages")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-08-25 15:08:19 +02:00
Desmond Cheong Zhi Xi 0d977e0eba btrfs: reset replace target device to allocation state on close 
This crash was observed with a failed assertion on device close:

  BTRFS: Transaction aborted (error -28)
  WARNING: CPU: 1 PID: 3902 at fs/btrfs/extent-tree.c:2150 btrfs_run_delayed_refs+0x1d2/0x1e0 [btrfs]
  Modules linked in: btrfs blake2b_generic libcrc32c crc32c_intel xor zstd_decompress zstd_compress xxhash lzo_compress lzo_decompress raid6_pq loop
  CPU: 1 PID: 3902 Comm: kworker/u8:4 Not tainted 5.14.0-rc5-default+ #1532
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba527-rebuilt.opensuse.org 04/01/2014
  Workqueue: events_unbound btrfs_async_reclaim_metadata_space [btrfs]
  RIP: 0010:btrfs_run_delayed_refs+0x1d2/0x1e0 [btrfs]
  RSP: 0018:ffffb7a5452d7d80 EFLAGS: 00010282
  RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000
  RDX: 0000000000000001 RSI: ffffffffabee13c4 RDI: 00000000ffffffff
  RBP: ffff97834176a378 R08: 0000000000000001 R09: 0000000000000001
  R10: 0000000000000000 R11: 0000000000000001 R12: ffff97835195d388
  R13: 0000000005b08000 R14: ffff978385484000 R15: 000000000000016c
  FS:  0000000000000000(0000) GS:ffff9783bd800000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 000056190d003fe8 CR3: 000000002a81e005 CR4: 0000000000170ea0
  Call Trace:
   flush_space+0x197/0x2f0 [btrfs]
   btrfs_async_reclaim_metadata_space+0x139/0x300 [btrfs]
   process_one_work+0x262/0x5e0
   worker_thread+0x4c/0x320
   ? process_one_work+0x5e0/0x5e0
   kthread+0x144/0x170
   ? set_kthread_struct+0x40/0x40
   ret_from_fork+0x1f/0x30
  irq event stamp: 19334989
  hardirqs last  enabled at (19334997): [<ffffffffab0e0c87>] console_unlock+0x2b7/0x400
  hardirqs last disabled at (19335006): [<ffffffffab0e0d0d>] console_unlock+0x33d/0x400
  softirqs last  enabled at (19334900): [<ffffffffaba0030d>] __do_softirq+0x30d/0x574
  softirqs last disabled at (19334893): [<ffffffffab0721ec>] irq_exit_rcu+0x12c/0x140
  ---[ end trace 45939e308e0dd3c7 ]---
  BTRFS: error (device vdd) in btrfs_run_delayed_refs:2150: errno=-28 No space left
  BTRFS info (device vdd): forced readonly
  BTRFS warning (device vdd): failed setting block group ro: -30
  BTRFS info (device vdd): suspending dev_replace for unmount
  assertion failed: !test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state), in fs/btrfs/volumes.c:1150
  ------------[ cut here ]------------
  kernel BUG at fs/btrfs/ctree.h:3431!
  invalid opcode: 0000 [#1] PREEMPT SMP
  CPU: 1 PID: 3982 Comm: umount Tainted: G        W         5.14.0-rc5-default+ #1532
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba527-rebuilt.opensuse.org 04/01/2014
  RIP: 0010:assertfail.constprop.0+0x18/0x1a [btrfs]
  RSP: 0018:ffffb7a5454c7db8 EFLAGS: 00010246
  RAX: 0000000000000068 RBX: ffff978364b91c00 RCX: 0000000000000000
  RDX: 0000000000000000 RSI: ffffffffabee13c4 RDI: 00000000ffffffff
  RBP: ffff9783523a4c00 R08: 0000000000000001 R09: 0000000000000001
  R10: 0000000000000000 R11: 0000000000000001 R12: ffff9783523a4d18
  R13: 0000000000000000 R14: 0000000000000004 R15: 0000000000000003
  FS:  00007f61c8f42800(0000) GS:ffff9783bd800000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 000056190cffa810 CR3: 0000000030b96002 CR4: 0000000000170ea0
  Call Trace:
   btrfs_close_one_device.cold+0x11/0x55 [btrfs]
   close_fs_devices+0x44/0xb0 [btrfs]
   btrfs_close_devices+0x48/0x160 [btrfs]
   generic_shutdown_super+0x69/0x100
   kill_anon_super+0x14/0x30
   btrfs_kill_super+0x12/0x20 [btrfs]
   deactivate_locked_super+0x2c/0xa0
   cleanup_mnt+0x144/0x1b0
   task_work_run+0x59/0xa0
   exit_to_user_mode_loop+0xe7/0xf0
   exit_to_user_mode_prepare+0xaf/0xf0
   syscall_exit_to_user_mode+0x19/0x50
   do_syscall_64+0x4a/0x90
   entry_SYSCALL_64_after_hwframe+0x44/0xae

This happens when close_ctree is called while a dev_replace hasn't
completed. In close_ctree, we suspend the dev_replace, but keep the
replace target around so that we can resume the dev_replace procedure
when we mount the root again. This is the call trace:

  close_ctree():
    btrfs_dev_replace_suspend_for_unmount();
    btrfs_close_devices():
      btrfs_close_fs_devices():
        btrfs_close_one_device():
          ASSERT(!test_bit(BTRFS_DEV_STATE_REPLACE_TGT,
                 &device->dev_state));

However, since the replace target sticks around, there is a device
with BTRFS_DEV_STATE_REPLACE_TGT set on close, and we fail the
assertion in btrfs_close_one_device.

To fix this, if we come across the replace target device when
closing, we should properly reset it back to allocation state. This
fix also ensures that if a non-target device has a corrupted state and
has the BTRFS_DEV_STATE_REPLACE_TGT bit set, the assertion will still
catch the error.

Reported-by: David Sterba <dsterba@suse.com>
Fixes: b2a6166768 ("btrfs: fix rw device counting in __btrfs_free_extra_devids")
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-08-23 13:57:18 +02:00
Naohiro Aota 939c7feb19 btrfs: zoned: fix ordered extent boundary calculation 
btrfs_lookup_ordered_extent() is supposed to query the offset in a file
instead of the logical address. Pass the file offset from
submit_extent_page() to calc_bio_boundaries().

Also, calc_bio_boundaries() relies on the bio's operation flag, so move
the call site after setting it.

Fixes: 390ed29b81 ("btrfs: refactor submit_extent_page() to make bio and its flag tracing easier")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-08-23 13:19:16 +02:00
Josef Bacik 1146239794 btrfs: do not do preemptive flushing if the majority is global rsv 
A common characteristic of the bug report where preemptive flushing was
going full tilt was the fact that the vast majority of the free metadata
space was used up by the global reserve.  The hard 90% threshold would
cover the majority of these cases, but to be even smarter we should take
into account how much of the outstanding reservations are covered by the
global block reserve.  If the global block reserve accounts for the vast
majority of outstanding reservations, skip preemptive flushing, as it
will likely just cause churn and pain.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=212185
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-08-23 13:19:16 +02:00
Josef Bacik 93c60b17f2 btrfs: reduce the preemptive flushing threshold to 90% 
The preemptive flushing code was added in order to avoid needing to
synchronously wait for ENOSPC flushing to recover space.  Once we're
almost full however we can essentially flush constantly.  We were using
98% as a threshold to determine if we were simply full, however in
practice this is a really high bar to hit.  For example reports of
systems running into this problem had around 94% usage and thus
continued to flush.  Fix this by lowering the threshold to 90%, which is
a more sane value, especially for smaller file systems.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=212185
CC: stable@vger.kernel.org # 5.12+
Fixes: 576fa34830 ("btrfs: improve preemptive background space flushing")
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-08-23 13:19:15 +02:00
Marcos Paulo de Souza 3736127a3a btrfs: tree-log: check btrfs_lookup_data_extent return value 
Function btrfs_lookup_data_extent calls btrfs_search_slot to verify if
the EXTENT_ITEM exists in the extent tree. btrfs_search_slot can return
values bellow zero if an error happened.

Function replay_one_extent currently checks if the search found
something (0 returned) and increments the reference, and if not, it
seems to evaluate as 'not found'.

Fix the condition by checking if the value was bellow zero and return
early.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-08-23 13:19:15 +02:00
Filipe Manana 8be2ba2e0e btrfs: avoid unnecessarily logging directories that had no changes 
There are several cases where when logging an inode we need to log its
parent directories or logging subdirectories when logging a directory.

There are cases however where we end up logging a directory even if it was
not changed in the current transaction, no dentries added or removed since
the last transaction. While this is harmless from a functional point of
view, it is a waste time as it brings no advantage.

One example where this is triggered is the following:

  $ mkfs.btrfs -f /dev/sdc
  $ mount /dev/sdc /mnt

  $ mkdir /mnt/A
  $ mkdir /mnt/B
  $ mkdir /mnt/C

  $ touch /mnt/A/foo
  $ ln /mnt/A/foo /mnt/B/bar
  $ ln /mnt/A/foo /mnt/C/baz

  $ sync

  $ rm -f /mnt/A/foo
  $ xfs_io -c "fsync" /mnt/B/bar

This last fsync ends up logging directories A, B and C, however we only
need to log directory A, as B and C were not changed since the last
transaction commit.

So fix this by changing need_log_inode(), to return false in case the
given inode is a directory and has a ->last_trans value smaller than the
current transaction's ID.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-08-23 13:19:15 +02:00
Christian Brauner 5b9b26f5d0 btrfs: allow idmapped mount 
Now that we converted btrfs internally to account for idmapped mounts
allow the creation of idmapped mounts on by setting the FS_ALLOW_IDMAP
flag.  We only need to raise this flag on the btrfs_root_fs_type
filesystem since btrfs_mount_root() is ultimately responsible for
allocating the superblock and is called into from btrfs_mount()
associated with btrfs_fs_type.

The conversion of the btrfs inode operations was straightforward.
Regarding btrfs specific ioctls that perform checks based on inode
permissions only those have been allowed that are not filesystem wide
operations and hence can be reasonably charged against a specific mount.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-08-23 13:19:15 +02:00
Christian Brauner 4a8b34afa9 btrfs: handle ACLs on idmapped mounts 
Make the ACL code idmapped mount aware. The POSIX default and POSIX
access ACLs are the only ACLs other than some specific xattrs that take
DAC permissions into account. On an idmapped mount they need to be
translated according to the mount's userns. The main change is done to
__btrfs_set_acl() which is responsible for translating POSIX ACLs to
their final on-disk representation.

The btrfs_init_acl() helper does not need to take the idmapped mount
into account since it is called in the context of file creation
operations (mknod, create, mkdir, symlink, tmpfile) and is used for
btrfs_init_inode_security() to copy POSIX default and POSIX access
permissions from the parent directory. These ACLs need to be inherited
unmodified from the parent directory. This is identical to what we do
for ext4 and xfs.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-08-23 13:19:15 +02:00
Christian Brauner 6623d9a0b0 btrfs: allow idmapped INO_LOOKUP_USER ioctl 
The INO_LOOKUP_USER is an unprivileged version of the INO_LOOKUP ioctl
and has the following restrictions. The main difference between the two
is that INO_LOOKUP is filesystem wide operation wheres INO_LOOKUP_USER
is scoped beneath the file descriptor passed with the ioctl.
Specifically, INO_LOOKUP_USER must adhere to the following restrictions:

- The caller must be privileged over each inode of each path component
  for the path they are trying to lookup.

- The path for the subvolume the caller is trying to lookup must be reachable
  from the inode associated with the file descriptor passed with the ioctl.

The second condition makes it possible to scope the lookup of the path
to the mount identified by the file descriptor passed with the ioctl.
This allows us to enable this ioctl on idmapped mounts.

Specifically, this is possible because all child subvolumes of a parent
subvolume are reachable when the parent subvolume is mounted. So if the
user had access to open the parent subvolume or has been given the fd
then they can lookup the path if they had access to it provided they
were privileged over each path component.

Note, the INO_LOOKUP_USER ioctl allows a user to learn the path and name
of a subvolume even though they would otherwise be restricted from doing
so via regular VFS-based lookup.

So think about a parent subvolume with multiple child subvolumes.
Someone could mount he parent subvolume and restrict access to the child
subvolumes by overmounting them with empty directories. At this point
the user can't traverse the child subvolumes and they can't open files
in the child subvolumes.  However, they can still learn the path of
child subvolumes as long as they have access to the parent subvolume by
using the INO_LOOKUP_USER ioctl.

The underlying assumption here is that it's ok that the lookup ioctls
can't really take mounts into account other than the original mount the
fd belongs to during lookup. Since this assumption is baked into the
original INO_LOOKUP_USER ioctl we can extend it to idmapped mounts.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-08-23 13:19:15 +02:00
Christian Brauner 39e1674ff0 btrfs: allow idmapped SUBVOL_SETFLAGS ioctl 
Setting flags on subvolumes or snapshots are core features of btrfs. The
SUBVOL_SETFLAGS ioctl is especially important as it allows to make
subvolumes and snapshots read-only or read-write. Allow setting flags on
btrfs subvolumes and snapshots on idmapped mounts. This is a fairly
straightforward operation since all the permission checking helpers are
already capable of handling idmapped mounts. So we just need to pass
down the mount's userns.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-08-23 13:19:14 +02:00
Christian Brauner e4fed17a32 btrfs: allow idmapped SET_RECEIVED_SUBVOL ioctls 
The SET_RECEIVED_SUBVOL ioctls are used to set information about
a received subvolume. Make it possible to set information about a
received subvolume on idmapped mounts. This is a fairly straightforward
operation since all the permission checking helpers are already capable
of handling idmapped mounts. So we just need to pass down the mount's
userns.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-08-23 13:19:14 +02:00
Christian Brauner aabb34e7a3 btrfs: relax restrictions for SNAP_DESTROY_V2 with subvolids 
So far we prevented the deletion of subvolumes and snapshots using
subvolume ids possible with the BTRFS_SUBVOL_SPEC_BY_ID flag.

This restriction is necessary on idmapped mounts as this allows
filesystem wide subvolume and snapshot deletions and thus can escape the
scope of what's exposed under the mount identified by the fd passed with
the ioctl.

Deletion by subvolume id works by looking for an alias of the parent of
the subvolume or snapshot to be deleted. The parent alias can be
anywhere in the filesystem. However, as long as the alias of the parent
that is found is the same as the one identified by the file descriptor
passed through the ioctl we can allow the deletion.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-08-23 13:19:14 +02:00
Christian Brauner c4ed533bdc btrfs: allow idmapped SNAP_DESTROY ioctls 
Destroying subvolumes and snapshots are important features of btrfs.
Both operations are available to unprivileged users if the filesystem
has been mounted with the "user_subvol_rm_allowed" mount option. Allow
subvolume and snapshot deletion on idmapped mounts. This is a fairly
straightforward operation since all the permission checking helpers are
already capable of handling idmapped mounts. So we just need to pass
down the mount's userns.

Subvolumes and snapshots can either be deleted by specifying their name
or - if BTRFS_IOC_SNAP_DESTROY_V2 is used - by their subvolume or
snapshot id if the BTRFS_SUBVOL_SPEC_BY_ID is set.

This feature is blocked on idmapped mounts as this allows filesystem
wide subvolume deletions and thus can escape the scope of what's exposed
under the mount identified by the fd passed with the ioctl.

This means that even the root or CAP_SYS_ADMIN capable user can't delete
a subvolume via BTRFS_SUBVOL_SPEC_BY_ID. This is intentional.

The root user is currently already subject to permission checks in
btrfs_may_delete() including whether the inode's i_uid/i_gid of the
directory the subvolume is located in have a mapping in the caller's
idmapping. For this to fail isn't currently possible since a btrfs
filesystem can't be mounted with a non-initial idmapping but it shows
that even the root user would fail to delete a subvolume if the relevant
inode isn't mapped in their idmapping. The idmapped mount case is the
same in principle.

This isn't a huge problem a root user wanting to delete arbitrary
subvolumes can just always create another (even detached) mount without
an idmapping attached.

In addition, we will allow BTRFS_SUBVOL_SPEC_BY_ID for cases where the
subvolume to delete is directly located under inode referenced by the fd
passed for the ioctl() in a follow-up commit.

Here is an example where a btrfs subvolume is deleted through a
subvolume mount that does not expose the subvolume to be delete but it
can still be deleted by using the subvolume id:

  /* Compile the following program as "delete_by_spec". */

  #define _GNU_SOURCE
  #include <fcntl.h>
  #include <inttypes.h>
  #include <linux/btrfs.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <sys/ioctl.h>
  #include <sys/stat.h>
  #include <sys/types.h>
  #include <unistd.h>

  static int rm_subvolume_by_id(int fd, uint64_t subvolid)
  {
	 struct btrfs_ioctl_vol_args_v2 args = {};
	 int ret;

	 args.flags = BTRFS_SUBVOL_SPEC_BY_ID;
	 args.subvolid = subvolid;

	 ret = ioctl(fd, BTRFS_IOC_SNAP_DESTROY_V2, &args);
	 if (ret < 0)
		 return -1;

	 return 0;
  }

  int main(int argc, char *argv[])
  {
	 int subvolid = 0;

	 if (argc < 3)
		 exit(1);

	 fprintf(stderr, "Opening %s\n", argv[1]);
	 int fd = open(argv[1], O_CLOEXEC | O_DIRECTORY);
	 if (fd < 0)
		 exit(2);

	 subvolid = atoi(argv[2]);

	 fprintf(stderr, "Deleting subvolume with subvolid %d\n", subvolid);
	 int ret = rm_subvolume_by_id(fd, subvolid);
	 if (ret < 0)
		 exit(3);

	 exit(0);
  }
  #include <stdio.h>"
  #include <stdlib.h>"
  #include <linux/btrfs.h"

  truncate -s 10G btrfs.img
  mkfs.btrfs btrfs.img
  export LOOPDEV=$(sudo losetup -f --show btrfs.img)
  mount ${LOOPDEV} /mnt
  sudo chown $(id -u):$(id -g) /mnt
  btrfs subvolume create /mnt/A
  btrfs subvolume create /mnt/B/C
  # Get subvolume id via:
  sudo btrfs subvolume show /mnt/A
  # Save subvolid
  SUBVOLID=<nr>
  sudo umount /mnt
  sudo mount ${LOOPDEV} -o subvol=B/C,user_subvol_rm_allowed /mnt
  ./delete_by_spec /mnt ${SUBVOLID}

With idmapped mounts this can potentially be used by users to delete
subvolumes/snapshots they would otherwise not have access to as the
idmapping would be applied to an inode that is not exposed in the mount
of the subvolume.

The fact that this is a filesystem wide operation suggests it might be a
good idea to expose this under a separate ioctl that clearly indicates
this. In essence, the file descriptor passed with the ioctl is merely
used to identify the filesystem on which to operate when
BTRFS_SUBVOL_SPEC_BY_ID is used.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-08-23 13:19:14 +02:00
Christian Brauner 4d4340c912 btrfs: allow idmapped SNAP_CREATE/SUBVOL_CREATE ioctls 
Creating subvolumes and snapshots is one of the core features of btrfs
and is even available to unprivileged users. Make it possible to use
subvolume and snapshot creation on idmapped mounts. This is a fairly
straightforward operation since all the permission checking helpers are
already capable of handling idmapped mounts. So we just need to pass
down the mount's userns.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-08-23 13:19:14 +02:00
Christian Brauner 5474bf400f btrfs: check whether fsgid/fsuid are mapped during subvolume creation 
When a new subvolume is created btrfs currently doesn't check whether
the fsgid/fsuid of the caller actually have a mapping in the user
namespace attached to the filesystem. The VFS always checks this to make
sure that the caller's fsgid/fsuid can be represented on-disk. This is
most relevant for filesystems that can be mounted inside user namespaces
but it is in general a good hardening measure to prevent unrepresentable
gid/uid from being written to disk.

Since we want to support idmapped mounts for btrfs ioctls to create
subvolumes in follow-up patches this becomes important since we want to
make sure the fsgid/fsuid of the caller as mapped according to the
idmapped mount can be represented on-disk. Simply add the missing
fsuidgid_has_mapping() line from the VFS may_create() version to
btrfs_may_create().

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-08-23 13:19:14 +02:00
Christian Brauner 3bc71ba02c btrfs: allow idmapped permission inode op 
Enable btrfs_permission() to handle idmapped mounts. This is just a
matter of passing down the mount's userns.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-08-23 13:19:13 +02:00
Christian Brauner d4d0946461 btrfs: allow idmapped setattr inode op 
Enable btrfs_setattr() to handle idmapped mounts. This is just a matter
of passing down the mount's userns.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-08-23 13:19:13 +02:00
Christian Brauner 98b6ab5fc0 btrfs: allow idmapped tmpfile inode op 
Enable btrfs_tmpfile() to handle idmapped mounts. This is just a matter
of passing down the mount's userns.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-08-23 13:19:13 +02:00
Christian Brauner 5a0521086e btrfs: allow idmapped symlink inode op 
Enable btrfs_symlink() to handle idmapped mounts. This is just a matter
of passing down the mount's userns.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-08-23 13:19:13 +02:00
Christian Brauner b0b3e44d34 btrfs: allow idmapped mkdir inode op 
Enable btrfs_mkdir() to handle idmapped mounts. This is just a matter of
passing down the mount's userns.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 2021-08-23 13:19:13 +02:00