mirror of https://github.com/torvalds/linux.git
263 Commits
| Author | SHA1 | Message | Date |
|---|---|---|---|
Christoph Hellwig
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d8e1ea43e5 |
xfs: return the allocated transaction from xfs_trans_alloc_empty
xfs_trans_alloc_empty can't return errors, so return the allocated transaction directly instead of an output double pointer argument. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Carlos Maiolino <cem@kernel.org> |
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Dave Chinner
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09234a632b |
xfs: xfs_ifree_cluster vs xfs_iflush_shutdown_abort deadlock
Lock order of xfs_ifree_cluster() is cluster buffer -> try ILOCK -> IFLUSHING, except for the last inode in the cluster that is triggering the free. In that case, the lock order is ILOCK -> cluster buffer -> IFLUSHING. xfs_iflush_cluster() uses cluster buffer -> try ILOCK -> IFLUSHING, so this can safely run concurrently with xfs_ifree_cluster(). xfs_inode_item_precommit() uses ILOCK -> cluster buffer, but this cannot race with xfs_ifree_cluster() so being in a different order will not trigger a deadlock. xfs_reclaim_inode() during a filesystem shutdown uses ILOCK -> IFLUSHING -> cluster buffer via xfs_iflush_shutdown_abort(), and this deadlocks against xfs_ifree_cluster() like so: sysrq: Show Blocked State task:kworker/10:37 state:D stack:12560 pid:276182 tgid:276182 ppid:2 flags:0x00004000 Workqueue: xfs-inodegc/dm-3 xfs_inodegc_worker Call Trace: <TASK> __schedule+0x650/0xb10 schedule+0x6d/0xf0 schedule_timeout+0x8b/0x180 schedule_timeout_uninterruptible+0x1e/0x30 xfs_ifree+0x326/0x730 xfs_inactive_ifree+0xcb/0x230 xfs_inactive+0x2c8/0x380 xfs_inodegc_worker+0xaa/0x180 process_scheduled_works+0x1d4/0x400 worker_thread+0x234/0x2e0 kthread+0x147/0x170 ret_from_fork+0x3e/0x50 ret_from_fork_asm+0x1a/0x30 </TASK> task:fsync-tester state:D stack:12160 pid:2255943 tgid:2255943 ppid:3988702 flags:0x00004006 Call Trace: <TASK> __schedule+0x650/0xb10 schedule+0x6d/0xf0 schedule_timeout+0x31/0x180 __down_common+0xbe/0x1f0 __down+0x1d/0x30 down+0x48/0x50 xfs_buf_lock+0x3d/0xe0 xfs_iflush_shutdown_abort+0x51/0x1e0 xfs_icwalk_ag+0x386/0x690 xfs_reclaim_inodes_nr+0x114/0x160 xfs_fs_free_cached_objects+0x19/0x20 super_cache_scan+0x17b/0x1a0 do_shrink_slab+0x180/0x350 shrink_slab+0xf8/0x430 drop_slab+0x97/0xf0 drop_caches_sysctl_handler+0x59/0xc0 proc_sys_call_handler+0x189/0x280 proc_sys_write+0x13/0x20 vfs_write+0x33d/0x3f0 ksys_write+0x7c/0xf0 __x64_sys_write+0x1b/0x30 x64_sys_call+0x271d/0x2ee0 do_syscall_64+0x68/0x130 entry_SYSCALL_64_after_hwframe+0x76/0x7e We can't change the lock order of xfs_ifree_cluster() - XFS_ISTALE and XFS_IFLUSHING are serialised through to journal IO completion by the cluster buffer lock being held. There's quite a few asserts in the code that check that XFS_ISTALE does not occur out of sync with buffer locking (e.g. in xfs_iflush_cluster). There's also a dependency on the inode log item being removed from the buffer before XFS_IFLUSHING is cleared, also with asserts that trigger on this. Further, we don't have a requirement for the inode to be locked when completing or aborting inode flushing because all the inode state updates are serialised by holding the cluster buffer lock across the IO to completion. We can't check for XFS_IRECLAIM in xfs_ifree_mark_inode_stale() and skip the inode, because there is no guarantee that the inode will be reclaimed. Hence it *must* be marked XFS_ISTALE regardless of whether reclaim is preparing to free that inode. Similarly, we can't check for IFLUSHING before locking the inode because that would result in dirty inodes not being marked with ISTALE in the event of racing with XFS_IRECLAIM. Hence we have to address this issue from the xfs_reclaim_inode() side. It is clear that we cannot hold the inode locked here when calling xfs_iflush_shutdown_abort() because it is the inode->buffer lock order that causes the deadlock against xfs_ifree_cluster(). Hence we need to drop the ILOCK before aborting the inode in the shutdown case. Once we've aborted the inode, we can grab the ILOCK again and then immediately reclaim it as it is now guaranteed to be clean. Note that dropping the ILOCK in xfs_reclaim_inode() means that it can now be locked by xfs_ifree_mark_inode_stale() and seen whilst in this state. This is safe because we have left the XFS_IFLUSHING flag on the inode and so xfs_ifree_mark_inode_stale() will simply set XFS_ISTALE and move to the next inode. An ASSERT check in this path needs to be tweaked to take into account this new shutdown interaction. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com> Signed-off-by: Carlos Maiolino <cem@kernel.org> |
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Linus Torvalds
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d6b02199cd |
- The 7 patch series "powerpc/crash: use generic crashkernel
reservation" from Sourabh Jain changes powerpc's kexec code to use more of the generic layers. - The 2 patch series "get_maintainer: report subsystem status separately" from Vlastimil Babka makes some long-requested improvements to the get_maintainer output. - The 4 patch series "ucount: Simplify refcounting with rcuref_t" from Sebastian Siewior cleans up and optimizing the refcounting in the ucount code. - The 12 patch series "reboot: support runtime configuration of emergency hw_protection action" from Ahmad Fatoum improves the ability for a driver to perform an emergency system shutdown or reboot. - The 16 patch series "Converge on using secs_to_jiffies() part two" from Easwar Hariharan performs further migrations from msecs_to_jiffies() to secs_to_jiffies(). - The 7 patch series "lib/interval_tree: add some test cases and cleanup" from Wei Yang permits more userspace testing of kernel library code, adds some more tests and performs some cleanups. - The 2 patch series "hung_task: Dump the blocking task stacktrace" from Masami Hiramatsu arranges for the hung_task detector to dump the stack of the blocking task and not just that of the blocked task. - The 4 patch series "resource: Split and use DEFINE_RES*() macros" from Andy Shevchenko provides some cleanups to the resource definition macros. - Plus the usual shower of singleton patches - please see the individual changelogs for details. -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZ+nuqwAKCRDdBJ7gKXxA jtNqAQDxqJpjWkzn4yN9CNSs1ivVx3fr6SqazlYCrt3u89WQvwEA1oRrGpETzUGq r6khQUIcQImPPcjFqEFpuiSOU0MBZA0= =Kii8 -----END PGP SIGNATURE----- Merge tag 'mm-nonmm-stable-2025-03-30-18-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-MM updates from Andrew Morton: - The series "powerpc/crash: use generic crashkernel reservation" from Sourabh Jain changes powerpc's kexec code to use more of the generic layers. - The series "get_maintainer: report subsystem status separately" from Vlastimil Babka makes some long-requested improvements to the get_maintainer output. - The series "ucount: Simplify refcounting with rcuref_t" from Sebastian Siewior cleans up and optimizing the refcounting in the ucount code. - The series "reboot: support runtime configuration of emergency hw_protection action" from Ahmad Fatoum improves the ability for a driver to perform an emergency system shutdown or reboot. - The series "Converge on using secs_to_jiffies() part two" from Easwar Hariharan performs further migrations from msecs_to_jiffies() to secs_to_jiffies(). - The series "lib/interval_tree: add some test cases and cleanup" from Wei Yang permits more userspace testing of kernel library code, adds some more tests and performs some cleanups. - The series "hung_task: Dump the blocking task stacktrace" from Masami Hiramatsu arranges for the hung_task detector to dump the stack of the blocking task and not just that of the blocked task. - The series "resource: Split and use DEFINE_RES*() macros" from Andy Shevchenko provides some cleanups to the resource definition macros. - Plus the usual shower of singleton patches - please see the individual changelogs for details. * tag 'mm-nonmm-stable-2025-03-30-18-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (77 commits) mailmap: consolidate email addresses of Alexander Sverdlin fs/procfs: fix the comment above proc_pid_wchan() relay: use kasprintf() instead of fixed buffer formatting resource: replace open coded variant of DEFINE_RES() resource: replace open coded variants of DEFINE_RES_*_NAMED() resource: replace open coded variant of DEFINE_RES_NAMED_DESC() resource: split DEFINE_RES_NAMED_DESC() out of DEFINE_RES_NAMED() samples: add hung_task detector mutex blocking sample hung_task: show the blocker task if the task is hung on mutex kexec_core: accept unaccepted kexec segments' destination addresses watchdog/perf: optimize bytes copied and remove manual NUL-termination lib/interval_tree: fix the comment of interval_tree_span_iter_next_gap() lib/interval_tree: skip the check before go to the right subtree lib/interval_tree: add test case for span iteration lib/interval_tree: add test case for interval_tree_iter_xxx() helpers lib/rbtree: add random seed lib/rbtree: split tests lib/rbtree: enable userland test suite for rbtree related data structure checkpatch: describe --min-conf-desc-length scripts/gdb/symbols: determine KASLR offset on s390 ... |
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Easwar Hariharan
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a877cd2a64 |
xfs: convert timeouts to secs_to_jiffies()
Commit
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Christoph Hellwig
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0cb53d773b |
xfs: skip zoned RT inodes in xfs_inodegc_want_queue_rt_file
The zoned allocator never performs speculative preallocations, so don't bother queueing up zoned inodes here. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> |
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Christoph Hellwig
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712bae9663 |
xfs: generalize the freespace and reserved blocks handling
xfs_{add,dec}_freecounter already handles the block and RT extent
percpu counters, but it currently hardcodes the passed in counter.
Add a freecounter abstraction that uses an enum to designate the counter
and add wrappers that hide the actual percpu_counters. This will allow
expanding the reserved block handling to the RT extent counter in the
next step, and also prepares for adding yet another such counter that
can share the code. Both these additions will be needed for the zoned
allocator.
Also switch the flooring of the frextents counter to 0 in statfs for the
rthinherit case to a manual min_t call to match the handling of the
fdblocks counter for normal file systems.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
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Darrick J. Wong
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be42fc1393 |
xfs: record health problems with the metadata directory
Make a report to the health monitoring subsystem any time we encounter something in the metadata directory tree that looks like corruption. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> |
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Darrick J. Wong
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5d9b54a4ef |
xfs: read and write metadata inode directory tree
Plumb in the bits we need to load metadata inodes from a named entry in a metadir directory, create (or hardlink) inodes into a metadir directory, create metadir directories, and flag inodes as being metadata files. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> |
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Darrick J. Wong
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7297fd0beb |
xfs: enforce metadata inode flag
Add checks for the metadata inode flag so that we don't ever leak metadata inodes out to userspace, and we don't ever try to read a regular inode as metadata. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> |
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Darrick J. Wong
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dcf6069143 |
xfs: iget for metadata inodes
Create a xfs_trans_metafile_iget function for metadata inodes to ensure that when we try to iget a metadata file, the inode is allocated and its file mode matches the metadata file type the caller expects. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> |
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Christoph Hellwig
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86437e6abb |
xfs: switch perag iteration from the for_each macros to a while based iterator
The current for_each_perag* macros are a bit annoying in that they
require the caller to both provide an object and an index iterator, and
also somewhat obsfucate the underlying control flow mechanism.
Switch to open coded while loops using new xfs_perag_next{,_from,_range}
helpers that return the next pag structure to iterate on based on the
previous one or NULL for the loop start.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Christoph Hellwig
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e9c4d8bfb2 |
xfs: factor out a generic xfs_group structure
Split the lookup and refcount handling of struct xfs_perag into an embedded xfs_group structure that can be reused for the upcoming realtime groups. It will be extended with more features later. Note that he xg_type field will only need a single bit even with realtime group support. For now it fills a hole, but it might be worth to fold it into another field if we can use this space better. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org> |
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Brian Foster
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4390f019ad |
xfs: don't free cowblocks from under dirty pagecache on unshare
fallocate unshare mode explicitly breaks extent sharing. When a
command completes, it checks the data fork for any remaining shared
extents to determine whether the reflink inode flag and COW fork
preallocation can be removed. This logic doesn't consider in-core
pagecache and I/O state, however, which means we can unsafely remove
COW fork blocks that are still needed under certain conditions.
For example, consider the following command sequence:
xfs_io -fc "pwrite 0 1k" -c "reflink <file> 0 256k 1k" \
-c "pwrite 0 32k" -c "funshare 0 1k" <file>
This allocates a data block at offset 0, shares it, and then
overwrites it with a larger buffered write. The overwrite triggers
COW fork preallocation, 32 blocks by default, which maps the entire
32k write to delalloc in the COW fork. All but the shared block at
offset 0 remains hole mapped in the data fork. The unshare command
redirties and flushes the folio at offset 0, removing the only
shared extent from the inode. Since the inode no longer maps shared
extents, unshare purges the COW fork before the remaining 28k may
have written back.
This leaves dirty pagecache backed by holes, which writeback quietly
skips, thus leaving clean, non-zeroed pagecache over holes in the
file. To verify, fiemap shows holes in the first 32k of the file and
reads return different data across a remount:
$ xfs_io -c "fiemap -v" <file>
<file>:
EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS
...
1: [8..511]: hole 504
...
$ xfs_io -c "pread -v 4k 8" <file>
00001000: cd cd cd cd cd cd cd cd ........
$ umount <mnt>; mount <dev> <mnt>
$ xfs_io -c "pread -v 4k 8" <file>
00001000: 00 00 00 00 00 00 00 00 ........
To avoid this problem, make unshare follow the same rules used for
background cowblock scanning and never purge the COW fork for inodes
with dirty pagecache or in-flight I/O.
Fixes:
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Brian Foster
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90a71daaf7 |
xfs: skip background cowblock trims on inodes open for write
The background blockgc scanner runs on a 5m interval by default and trims preallocation (post-eof and cow fork) from inodes that are otherwise idle. Idle effectively means that iolock can be acquired without blocking and that the inode has no dirty pagecache or I/O in flight. This simple mechanism and heuristic has worked fairly well for post-eof speculative preallocations. Support for reflink and COW fork preallocations came sometime later and plugged into the same mechanism, with similar heuristics. Some recent testing has shown that COW fork preallocation may be notably more sensitive to blockgc processing than post-eof preallocation, however. For example, consider an 8GB reflinked file with a COW extent size hint of 1MB. A worst case fully randomized overwrite of this file results in ~8k extents of an average size of ~1MB. If the same workload is interrupted a couple times for blockgc processing (assuming the file goes idle), the resulting extent count explodes to over 100k extents with an average size <100kB. This is significantly worse than ideal and essentially defeats the COW extent size hint mechanism. While this particular test is instrumented, it reflects a fairly reasonable pattern in practice where random I/Os might spread out over a large period of time with varying periods of (in)activity. For example, consider a cloned disk image file for a VM or container with long uptime and variable and bursty usage. A background blockgc scan that races and processes the image file when it happens to be clean and idle can have a significant effect on the future fragmentation level of the file, even when still in use. To help combat this, update the heuristic to skip cowblocks inodes that are currently opened for write access during non-sync blockgc scans. This allows COW fork preallocations to persist for as long as possible unless otherwise needed for functional purposes (i.e. a sync scan), the file is idle and closed, or the inode is being evicted from cache. While here, update the comments to help distinguish performance oriented heuristics from the logic that exists to maintain functional correctness. Suggested-by: Darrick Wong <djwong@kernel.org> Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Carlos Maiolino <cem@kernel.org> |
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Linus Torvalds
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171754c380 |
vfs-6.12.blocksize
-----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZuQEvwAKCRCRxhvAZXjc ohg3APwJWQnqFlBddcRl4yrPJ/cgcYSYAOdHb+E+blomSwdxcwEAmwsnLPNQOtw2 rxKvQfZqhVT437bl7RpPPZrHGxwTng8= =6v1r -----END PGP SIGNATURE----- Merge tag 'vfs-6.12.blocksize' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs Pull vfs blocksize updates from Christian Brauner: "This contains the vfs infrastructure as well as the xfs bits to enable support for block sizes (bs) larger than page sizes (ps) plus a few fixes to related infrastructure. There has been efforts over the last 16 years to enable enable Large Block Sizes (LBS), that is block sizes in filesystems where bs > page size. Through these efforts we have learned that one of the main blockers to supporting bs > ps in filesystems has been a way to allocate pages that are at least the filesystem block size on the page cache where bs > ps. Thanks to various previous efforts it is possible to support bs > ps in XFS with only a few changes in XFS itself. Most changes are to the page cache to support minimum order folio support for the target block size on the filesystem. A motivation for Large Block Sizes today is to support high-capacity (large amount of Terabytes) QLC SSDs where the internal Indirection Unit (IU) are typically greater than 4k to help reduce DRAM and so in turn cost and space. In practice this then allows different architectures to use a base page size of 4k while still enabling support for block sizes aligned to the larger IUs by relying on high order folios on the page cache when needed. It also allows to take advantage of the drive's support for atomics larger than 4k with buffered IO support in Linux. As described this year at LSFMM, supporting large atomics greater than 4k enables databases to remove the need to rely on their own journaling, so they can disable double buffered writes, which is a feature different cloud providers are already enabling through custom storage solutions" * tag 'vfs-6.12.blocksize' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs: (22 commits) Documentation: iomap: fix a typo iomap: remove the iomap_file_buffered_write_punch_delalloc return value iomap: pass the iomap to the punch callback iomap: pass flags to iomap_file_buffered_write_punch_delalloc iomap: improve shared block detection in iomap_unshare_iter iomap: handle a post-direct I/O invalidate race in iomap_write_delalloc_release docs:filesystems: fix spelling and grammar mistakes in iomap design page filemap: fix htmldoc warning for mapping_align_index() iomap: make zero range flush conditional on unwritten mappings iomap: fix handling of dirty folios over unwritten extents iomap: add a private argument for iomap_file_buffered_write iomap: remove set_memor_ro() on zero page xfs: enable block size larger than page size support xfs: make the calculation generic in xfs_sb_validate_fsb_count() xfs: expose block size in stat xfs: use kvmalloc for xattr buffers iomap: fix iomap_dio_zero() for fs bs > system page size filemap: cap PTE range to be created to allowed zero fill in folio_map_range() mm: split a folio in minimum folio order chunks readahead: allocate folios with mapping_min_order in readahead ... |
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Pankaj Raghav
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7df7c204c6 |
xfs: enable block size larger than page size support
Page cache now has the ability to have a minimum order when allocating a folio which is a prerequisite to add support for block size > page size. Signed-off-by: Pankaj Raghav <p.raghav@samsung.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Link: https://lore.kernel.org/r/20240827-xfs-fix-wformat-bs-gt-ps-v1-1-aec6717609e0@kernel.org # fix folded Link: https://lore.kernel.org/r/20240822135018.1931258-11-kernel@pankajraghav.com Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Christian Brauner <brauner@kernel.org> |
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Christoph Hellwig
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866cf1dd3d |
xfs: use xas_for_each_marked in xfs_reclaim_inodes_count
xfs_reclaim_inodes_count iterates over all AGs to sum up the reclaimable inodes counts. There is no point in grabbing a reference to the them or unlock the RCU critical section for each iteration, so switch to the more efficient xas_for_each_marked iterator. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org> |
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Christoph Hellwig
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32fa4059fe |
xfs: convert perag lookup to xarray
Convert the perag lookup from the legacy radix tree to the xarray, which allows for much nicer iteration and bulk lookup semantics. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org> |
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Christoph Hellwig
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f9ffd095c8 |
xfs: simplify tagged perag iteration
Pass the old perag structure to the tagged loop helpers so that they can grab the old agno before releasing the reference. This removes the need to separately track the agno and the iterator macro, and thus also obsoletes the for_each_perag_tag syntactic sugar. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org> |
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Christoph Hellwig
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f48f0a8e00 |
xfs: move the tagged perag lookup helpers to xfs_icache.c
The tagged perag helpers are only used in xfs_icache.c in the kernel code and not at all in xfsprogs. Move them to xfs_icache.c in preparation for switching to an xarray, for which I have no plan to implement the tagged lookup functions for userspace. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org> |
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Christoph Hellwig
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9372dce08b |
xfs: reclaim speculative preallocations for append only files
The XFS XFS_DIFLAG_APPEND maps to the VFS S_APPEND flag, which forbids
writes that don't append at the current EOF.
But the commit originally adding XFS_DIFLAG_APPEND support (commit
a23321e766d in xfs xfs-import repository) also checked it to skip
releasing speculative preallocations, which doesn't make any sense.
Another commit (
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Darrick J. Wong
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05aba1953f |
xfs: validate inumber in xfs_iget
Actually use the inumber validator to check the argument passed in here. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> |
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Linus Torvalds
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2aae1d67fd |
vfs-6.11.inode
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Merge tag 'vfs-6.11.inode' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs inode / dentry updates from Christian Brauner:
"This contains smaller performance improvements to inodes and dentries:
inode:
- Add rcu based inode lookup variants.
They avoid one inode hash lock acquire in the common case thereby
significantly reducing contention. We already support RCU-based
operations but didn't take advantage of them during inode
insertion.
Callers of iget_locked() get the improvement without any code
changes. Callers that need a custom callback can switch to
iget5_locked_rcu() as e.g., did btrfs.
With 20 threads each walking a dedicated 1000 dirs * 1000 files
directory tree to stat(2) on a 32 core + 24GB ram vm:
before: 3.54s user 892.30s system 1966% cpu 45.549 total
after: 3.28s user 738.66s system 1955% cpu 37.932 total (-16.7%)
Long-term we should pick up the effort to introduce more
fine-grained locking and possibly improve on the currently used
hash implementation.
- Start zeroing i_state in inode_init_always() instead of doing it in
individual filesystems.
This allows us to remove an unneeded lock acquire in new_inode()
and not burden individual filesystems with this.
dcache:
- Move d_lockref out of the area used by RCU lookup to avoid
cacheline ping poing because the embedded name is sharing a
cacheline with d_lockref.
- Fix dentry size on 32bit with CONFIG_SMP=y so it does actually end
up with 128 bytes in total"
* tag 'vfs-6.11.inode' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
fs: fix dentry size
vfs: move d_lockref out of the area used by RCU lookup
bcachefs: remove now spurious i_state initialization
xfs: remove now spurious i_state initialization in xfs_inode_alloc
vfs: partially sanitize i_state zeroing on inode creation
xfs: preserve i_state around inode_init_always in xfs_reinit_inode
btrfs: use iget5_locked_rcu
vfs: add rcu-based find_inode variants for iget ops
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Christoph Hellwig
|
610b29161b |
xfs: fix freeing speculative preallocations for preallocated files
xfs_can_free_eofblocks returns false for files that have persistent preallocations unless the force flag is passed and there are delayed blocks. This means it won't free delalloc reservations for files with persistent preallocations unless the force flag is set, and it will also free the persistent preallocations if the force flag is set and the file happens to have delayed allocations. Both of these are bad, so do away with the force flag and always free only post-EOF delayed allocations for files with the XFS_DIFLAG_PREALLOC or APPEND flags set. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org> |
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Mateusz Guzik
|
e9dae2fb99 |
xfs: remove now spurious i_state initialization in xfs_inode_alloc
inode_init_always started setting the field to 0. Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> Link: https://lore.kernel.org/r/20240611120626.513952-4-mjguzik@gmail.com Signed-off-by: Christian Brauner <brauner@kernel.org> |
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Mateusz Guzik
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ddd4cd4824 |
xfs: preserve i_state around inode_init_always in xfs_reinit_inode
This is in preparation for the routine starting to zero the field. De facto coded by Dave Chinner, see: https://lore.kernel.org/linux-fsdevel/ZmgtaGglOL33Wkzr@dread.disaster.area/ Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> Link: https://lore.kernel.org/r/20240611120626.513952-2-mjguzik@gmail.com Signed-off-by: Christian Brauner <brauner@kernel.org> |
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Darrick J. Wong
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1a3f1afb25 |
xfs: widen flags argument to the xfs_iflags_* helpers
xfs_inode.i_flags is an unsigned long, so make these helpers take that as the flags argument instead of unsigned short. This is needed for the next patch. While we're at it, remove the iflags variable from xfs_iget_cache_miss because we no longer need it. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Andrey Albershteyn <aalbersh@redhat.com> |
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Dave Chinner
|
f2e812c152 |
xfs: don't use current->journal_info
syzbot reported an ext4 panic during a page fault where found a journal handle when it didn't expect to find one. The structure it tripped over had a value of 'TRAN' in the first entry in the structure, and that indicates it tripped over a struct xfs_trans instead of a jbd2 handle. The reason for this is that the page fault was taken during a copy-out to a user buffer from an xfs bulkstat operation. XFS uses an "empty" transaction context for bulkstat to do automated metadata buffer cleanup, and so the transaction context is valid across the copyout of the bulkstat info into the user buffer. We are using empty transaction contexts like this in XFS to reduce the risk of failing to release objects we reference during the operation, especially during error handling. Hence we really need to ensure that we can take page faults from these contexts without leaving landmines for the code processing the page fault to trip over. However, this same behaviour could happen from any other filesystem that triggers a page fault or any other exception that is handled on-stack from within a task context that has current->journal_info set. Having a page fault from some other filesystem bounce into XFS where we have to run a transaction isn't a bug at all, but the usage of current->journal_info means that this could result corruption of the outer task's journal_info structure. The problem is purely that we now have two different contexts that now think they own current->journal_info. IOWs, no filesystem can allow page faults or on-stack exceptions while current->journal_info is set by the filesystem because the exception processing might use current->journal_info itself. If we end up with nested XFS transactions whilst holding an empty transaction, then it isn't an issue as the outer transaction does not hold a log reservation. If we ignore the current->journal_info usage, then the only problem that might occur is a deadlock if the exception tries to take the same locks the upper context holds. That, however, is not a problem that setting current->journal_info would solve, so it's largely an irrelevant concern here. IOWs, we really only use current->journal_info for a warning check in xfs_vm_writepages() to ensure we aren't doing writeback from a transaction context. Writeback might need to do allocation, so it can need to run transactions itself. Hence it's a debug check to warn us that we've done something silly, and largely it is not all that useful. So let's just remove all the use of current->journal_info in XFS and get rid of all the potential issues from nested contexts where current->journal_info might get misused by another filesystem context. Reported-by: syzbot+cdee56dbcdf0096ef605@syzkaller.appspotmail.com Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Reviewed-by: Mark Tinguely <mark.tinguely@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org> |
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Darrick J. Wong
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baf44fa5c3 |
xfs: report inode corruption errors to the health system
Whenever we encounter corrupt inode records, we should report that to the health monitoring system for later reporting. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> |
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Dave Chinner
|
94a69db236 |
xfs: use __GFP_NOLOCKDEP instead of GFP_NOFS
In the past we've had problems with lockdep false positives stemming from inode locking occurring in memory reclaim contexts (e.g. from superblock shrinkers). Lockdep doesn't know that inodes access from above memory reclaim cannot be accessed from below memory reclaim (and vice versa) but there has never been a good solution to solving this problem with lockdep annotations. This situation isn't unique to inode locks - buffers are also locked above and below memory reclaim, and we have to maintain lock ordering for them - and against inodes - appropriately. IOWs, the same code paths and locks are taken both above and below memory reclaim and so we always need to make sure the lock orders are consistent. We are spared the lockdep problems this might cause by the fact that semaphores and bit locks aren't covered by lockdep. In general, this sort of lockdep false positive detection is cause by code that runs GFP_KERNEL memory allocation with an actively referenced inode locked. When it is run from a transaction, memory allocation is automatically GFP_NOFS, so we don't have reclaim recursion issues. So in the places where we do memory allocation with inodes locked outside of a transaction, we have explicitly set them to use GFP_NOFS allocations to prevent lockdep false positives from being reported if the allocation dips into direct memory reclaim. More recently, __GFP_NOLOCKDEP was added to the memory allocation flags to tell lockdep not to track that particular allocation for the purposes of reclaim recursion detection. This is a much better way of preventing false positives - it allows us to use GFP_KERNEL context outside of transactions, and allows direct memory reclaim to proceed normally without throwing out false positive deadlock warnings. The obvious places that lock inodes and do memory allocation are the lookup paths and inode extent list initialisation. These occur in non-transactional GFP_KERNEL contexts, and so can run direct reclaim and lock inodes. This patch makes a first path through all the explicit GFP_NOFS allocations in XFS and converts the obvious ones to GFP_KERNEL | __GFP_NOLOCKDEP as a first step towards removing explicit GFP_NOFS allocations from the XFS code. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org> |
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Qi Zheng
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1a86a53da4 |
xfs: dynamically allocate the xfs-inodegc shrinker
In preparation for implementing lockless slab shrink, use new APIs to dynamically allocate the xfs-inodegc shrinker, so that it can be freed asynchronously via RCU. Then it doesn't need to wait for RCU read-side critical section when releasing the struct xfs_mount. Link: https://lkml.kernel.org/r/20230911094444.68966-36-zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Chandan Babu R <chandan.babu@oracle.com> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Abhinav Kumar <quic_abhinavk@quicinc.com> Cc: Alasdair Kergon <agk@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Andreas Gruenbacher <agruenba@redhat.com> Cc: Anna Schumaker <anna@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bob Peterson <rpeterso@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Carlos Llamas <cmllamas@google.com> Cc: Chao Yu <chao@kernel.org> Cc: Chris Mason <clm@fb.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Christian Koenig <christian.koenig@amd.com> Cc: Chuck Lever <cel@kernel.org> Cc: Coly Li <colyli@suse.de> Cc: Dai Ngo <Dai.Ngo@oracle.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Airlie <airlied@gmail.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Sterba <dsterba@suse.com> Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Cc: Gao Xiang <hsiangkao@linux.alibaba.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Huang Rui <ray.huang@amd.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jaegeuk Kim <jaegeuk@kernel.org> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Wang <jasowang@redhat.com> Cc: Jeff Layton <jlayton@kernel.org> Cc: Jeffle Xu <jefflexu@linux.alibaba.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Kirill Tkhai <tkhai@ya.ru> Cc: Marijn Suijten <marijn.suijten@somainline.org> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Mike Snitzer <snitzer@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nadav Amit <namit@vmware.com> Cc: Neil Brown <neilb@suse.de> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Olga Kornievskaia <kolga@netapp.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Richard Weinberger <richard@nod.at> Cc: Rob Clark <robdclark@gmail.com> Cc: Rob Herring <robh@kernel.org> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Sean Paul <sean@poorly.run> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Song Liu <song@kernel.org> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Steven Price <steven.price@arm.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com> Cc: Tom Talpey <tom@talpey.com> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: Yue Hu <huyue2@coolpad.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Darrick J. Wong
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f12b96683d |
xfs: use i_prev_unlinked to distinguish inodes that are not on the unlinked list
Alter the definition of i_prev_unlinked slightly to make it more obvious when an inode with 0 link count is not part of the iunlink bucket lists rooted in the AGI. This distinction is necessary because it is not sufficient to check inode.i_nlink to decide if an inode is on the unlinked list. Updates to i_nlink can happen while holding only ILOCK_EXCL, but updates to an inode's position in the AGI unlinked list (which happen after the nlink update) requires both ILOCK_EXCL and the AGI buffer lock. The next few patches will make it possible to reload an entire unlinked bucket list when we're walking the inode table or performing handle operations and need more than the ability to iget the last inode in the chain. The upcoming directory repair code also needs to be able to make this distinction to decide if a zero link count directory should be moved to the orphanage or allowed to inactivate. An upcoming enhancement to the online AGI fsck code will need this distinction to check and rebuild the AGI unlinked buckets. Signed-off-by: Darrick J. Wong <djwong@kernel.org> |
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Darrick J. Wong
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62334fab47 |
xfs: use per-mount cpumask to track nonempty percpu inodegc lists
Directly track which CPUs have contributed to the inodegc percpu lists
instead of trusting the cpu online mask. This eliminates a theoretical
problem where the inodegc flush functions might fail to flush a CPU's
inodes if that CPU happened to be dying at exactly the same time. Most
likely nobody's noticed this because the CPU dead hook moves the percpu
inodegc list to another CPU and schedules that worker immediately. But
it's quite possible that this is a subtle race leading to UAF if the
inodegc flush were part of an unmount.
Further benefits: This reduces the overhead of the inodegc flush code
slightly by allowing us to ignore CPUs that have empty lists. Better
yet, it reduces our dependence on the cpu online masks, which have been
the cause of confusion and drama lately.
Fixes:
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Darrick J. Wong
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0d29663453 |
xfs: hide xfs_inode_is_allocated in scrub common code
This function is only used by online fsck, so let's move it there. In the next patch, we'll fix it to work properly and to require that the caller hold the AGI buffer locked. No major changes aside from adjusting the signature a bit. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> |
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Dave Chinner
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d4d12c02bf |
xfs: collect errors from inodegc for unlinked inode recovery
Unlinked list recovery requires errors removing the inode the from the unlinked list get fed back to the main recovery loop. Now that we offload the unlinking to the inodegc work, we don't get errors being fed back when we trip over a corruption that prevents the inode from being removed from the unlinked list. This means we never clear the corrupt unlinked list bucket, resulting in runtime operations eventually tripping over it and shutting down. Fix this by collecting inodegc worker errors and feed them back to the flush caller. This is largely best effort - the only context that really cares is log recovery, and it only flushes a single inode at a time so we don't need complex synchronised handling. Essentially the inodegc workers will capture the first error that occurs and the next flush will gather them and clear them. The flush itself will only report the first gathered error. In the cases where callers can return errors, propagate the collected inodegc flush error up the error handling chain. In the case of inode unlinked list recovery, there are several superfluous calls to flush queued unlinked inodes - xlog_recover_iunlink_bucket() guarantees that it has flushed the inodegc and collected errors before it returns. Hence nothing in the calling path needs to run a flush, even when an error is returned. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Dave Chinner <david@fromorbit.com> |
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Darrick J. Wong
|
2254a7396a |
xfs: fix xfs_inodegc_stop racing with mod_delayed_work
syzbot reported this warning from the faux inodegc shrinker that tries
to kick off inodegc work:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 102 at kernel/workqueue.c:1445 __queue_work+0xd44/0x1120 kernel/workqueue.c:1444
RIP: 0010:__queue_work+0xd44/0x1120 kernel/workqueue.c:1444
Call Trace:
__queue_delayed_work+0x1c8/0x270 kernel/workqueue.c:1672
mod_delayed_work_on+0xe1/0x220 kernel/workqueue.c:1746
xfs_inodegc_shrinker_scan fs/xfs/xfs_icache.c:2212 [inline]
xfs_inodegc_shrinker_scan+0x250/0x4f0 fs/xfs/xfs_icache.c:2191
do_shrink_slab+0x428/0xaa0 mm/vmscan.c:853
shrink_slab+0x175/0x660 mm/vmscan.c:1013
shrink_one+0x502/0x810 mm/vmscan.c:5343
shrink_many mm/vmscan.c:5394 [inline]
lru_gen_shrink_node mm/vmscan.c:5511 [inline]
shrink_node+0x2064/0x35f0 mm/vmscan.c:6459
kswapd_shrink_node mm/vmscan.c:7262 [inline]
balance_pgdat+0xa02/0x1ac0 mm/vmscan.c:7452
kswapd+0x677/0xd60 mm/vmscan.c:7712
kthread+0x2e8/0x3a0 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
This warning corresponds to this code in __queue_work:
/*
* For a draining wq, only works from the same workqueue are
* allowed. The __WQ_DESTROYING helps to spot the issue that
* queues a new work item to a wq after destroy_workqueue(wq).
*/
if (unlikely(wq->flags & (__WQ_DESTROYING | __WQ_DRAINING) &&
WARN_ON_ONCE(!is_chained_work(wq))))
return;
For this to trip, we must have a thread draining the inodedgc workqueue
and a second thread trying to queue inodegc work to that workqueue.
This can happen if freezing or a ro remount race with reclaim poking our
faux inodegc shrinker and another thread dropping an unlinked O_RDONLY
file:
Thread 0 Thread 1 Thread 2
xfs_inodegc_stop
xfs_inodegc_shrinker_scan
xfs_is_inodegc_enabled
<yes, will continue>
xfs_clear_inodegc_enabled
xfs_inodegc_queue_all
<list empty, do not queue inodegc worker>
xfs_inodegc_queue
<add to list>
xfs_is_inodegc_enabled
<no, returns>
drain_workqueue
<set WQ_DRAINING>
llist_empty
<no, will queue list>
mod_delayed_work_on(..., 0)
__queue_work
<sees WQ_DRAINING, kaboom>
In other words, everything between the access to inodegc_enabled state
and the decision to poke the inodegc workqueue requires some kind of
coordination to avoid the WQ_DRAINING state. We could perhaps introduce
a lock here, but we could also try to eliminate WQ_DRAINING from the
picture.
We could replace the drain_workqueue call with a loop that flushes the
workqueue and queues workers as long as there is at least one inode
present in the per-cpu inodegc llists. We've disabled inodegc at this
point, so we know that the number of queued inodes will eventually hit
zero as long as xfs_inodegc_start cannot reactivate the workers.
There are four callers of xfs_inodegc_start. Three of them come from the
VFS with s_umount held: filesystem thawing, failed filesystem freezing,
and the rw remount transition. The fourth caller is mounting rw (no
remount or freezing possible).
There are three callers ofs xfs_inodegc_stop. One is unmounting (no
remount or thaw possible). Two of them come from the VFS with s_umount
held: fs freezing and ro remount transition.
Hence, it is correct to replace the drain_workqueue call with a loop
that drains the inodegc llists.
Fixes:
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Darrick J. Wong
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b37c4c8339 |
xfs: check that per-cpu inodegc workers actually run on that cpu
Now that we've allegedly worked out the problem of the per-cpu inodegc workers being scheduled on the wrong cpu, let's put in a debugging knob to let us know if a worker ever gets mis-scheduled again. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com> |
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Darrick J. Wong
|
03e0add80f |
xfs: explicitly specify cpu when forcing inodegc delayed work to run immediately
I've been noticing odd racing behavior in the inodegc code that could
only be explained by one cpu adding an inode to its inactivation llist
at the same time that another cpu is processing that cpu's llist.
Preemption is disabled between get/put_cpu_ptr, so the only explanation
is scheduler mayhem. I inserted the following debug code into
xfs_inodegc_worker (see the next patch):
ASSERT(gc->cpu == smp_processor_id());
This assertion tripped during overnight tests on the arm64 machines, but
curiously not on x86_64. I think we haven't observed any resource leaks
here because the lockfree list code can handle simultaneous llist_add
and llist_del_all functions operating on the same list. However, the
whole point of having percpu inodegc lists is to take advantage of warm
memory caches by inactivating inodes on the last processor to touch the
inode.
The incorrect scheduling seems to occur after an inodegc worker is
subjected to mod_delayed_work(). This wraps mod_delayed_work_on with
WORK_CPU_UNBOUND specified as the cpu number. Unbound allows for
scheduling on any cpu, not necessarily the same one that scheduled the
work.
Because preemption is disabled for as long as we have the gc pointer, I
think it's safe to use current_cpu() (aka smp_processor_id) to queue the
delayed work item on the correct cpu.
Fixes:
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|
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Darrick J. Wong
|
302436c27c |
xfs: fix an inode lookup race in xchk_get_inode
In commit d658e, we tried to improve the robustnes of xchk_get_inode in
the face of EINVAL returns from iget by calling xfs_imap to see if the
inobt itself thinks that the inode is allocated. Unfortunately, that
commit didn't consider the possibility that the inode gets allocated
after iget but before imap. In this case, the imap call will succeed,
but we turn that into a corruption error and tell userspace the inode is
corrupt.
Avoid this false corruption report by grabbing the AGI header and
retrying the iget before calling imap. If the iget succeeds, we can
proceed with the usual scrub-by-handle code. Fix all the incorrect
comments too, since unreadable/corrupt inodes no longer result in EINVAL
returns.
Fixes:
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|
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Dave Chinner
|
498f0adbcd |
xfs: convert xfs_imap() to take a perag
Callers have referenced perags but they don't pass it into xfs_imap() so it takes it's own reference. Fix that so we can change inode allocation over to using active references. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> |
|
|
Dave Chinner
|
368e2d09b4 |
xfs: rework the perag trace points to be perag centric
So that they all output the same information in the traces to make debugging refcount issues easier. This means that all the lookup/drop functions no longer need to use the full memory barrier atomic operations (atomic*_return()) so will have less overhead when tracing is off. The set/clear tag tracepoints no longer abuse the reference count to pass the tag - the tag being cleared is obvious from the _RET_IP_ that is recorded in the trace point. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> |
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Dave Chinner
|
c4d5660afb |
xfs: active perag reference counting
We need to be able to dynamically remove instantiated AGs from memory safely, either for shrinking the filesystem or paging AG state in and out of memory (e.g. supporting millions of AGs). This means we need to be able to safely exclude operations from accessing perags while dynamic removal is in progress. To do this, introduce the concept of active and passive references. Active references are required for high level operations that make use of an AG for a given operation (e.g. allocation) and pin the perag in memory for the duration of the operation that is operating on the perag (e.g. transaction scope). This means we can fail to get an active reference to an AG, hence callers of the new active reference API must be able to handle lookup failure gracefully. Passive references are used in low level code, where we might need to access the perag structure for the purposes of completing high level operations. For example, buffers need to use passive references because: - we need to be able to do metadata IO during operations like grow and shrink transactions where high level active references to the AG have already been blocked - buffers need to pin the perag until they are reclaimed from memory, something that high level code has no direct control over. - unused cached buffers should not prevent a shrink from being started. Hence we have active references that will form exclusion barriers for operations to be performed on an AG, and passive references that will prevent reclaim of the perag until all objects with passive references have been reclaimed themselves. This patch introduce xfs_perag_grab()/xfs_perag_rele() as the API for active AG reference functionality. We also need to convert the for_each_perag*() iterators to use active references, which will start the process of converting high level code over to using active references. Conversion of non-iterator based code to active references will be done in followup patches. Note that the implementation using reference counting is really just a development vehicle for the API to ensure we don't have any leaks in the callers. Once we need to remove perag structures from memory dyanmically, we will need a much more robust per-ag state transition mechanism for preventing new references from being taken while we wait for existing references to drain before removal from memory can occur.... Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> |
|
Wu Guanghao
|
4da112513c |
xfs: Fix deadlock on xfs_inodegc_worker
We are doing a test about deleting a large number of files when memory is low. A deadlock problem was found. [ 1240.279183] -> #1 (fs_reclaim){+.+.}-{0:0}: [ 1240.280450] lock_acquire+0x197/0x460 [ 1240.281548] fs_reclaim_acquire.part.0+0x20/0x30 [ 1240.282625] kmem_cache_alloc+0x2b/0x940 [ 1240.283816] xfs_trans_alloc+0x8a/0x8b0 [ 1240.284757] xfs_inactive_ifree+0xe4/0x4e0 [ 1240.285935] xfs_inactive+0x4e9/0x8a0 [ 1240.286836] xfs_inodegc_worker+0x160/0x5e0 [ 1240.287969] process_one_work+0xa19/0x16b0 [ 1240.289030] worker_thread+0x9e/0x1050 [ 1240.290131] kthread+0x34f/0x460 [ 1240.290999] ret_from_fork+0x22/0x30 [ 1240.291905] [ 1240.291905] -> #0 ((work_completion)(&gc->work)){+.+.}-{0:0}: [ 1240.293569] check_prev_add+0x160/0x2490 [ 1240.294473] __lock_acquire+0x2c4d/0x5160 [ 1240.295544] lock_acquire+0x197/0x460 [ 1240.296403] __flush_work+0x6bc/0xa20 [ 1240.297522] xfs_inode_mark_reclaimable+0x6f0/0xdc0 [ 1240.298649] destroy_inode+0xc6/0x1b0 [ 1240.299677] dispose_list+0xe1/0x1d0 [ 1240.300567] prune_icache_sb+0xec/0x150 [ 1240.301794] super_cache_scan+0x2c9/0x480 [ 1240.302776] do_shrink_slab+0x3f0/0xaa0 [ 1240.303671] shrink_slab+0x170/0x660 [ 1240.304601] shrink_node+0x7f7/0x1df0 [ 1240.305515] balance_pgdat+0x766/0xf50 [ 1240.306657] kswapd+0x5bd/0xd20 [ 1240.307551] kthread+0x34f/0x460 [ 1240.308346] ret_from_fork+0x22/0x30 [ 1240.309247] [ 1240.309247] other info that might help us debug this: [ 1240.309247] [ 1240.310944] Possible unsafe locking scenario: [ 1240.310944] [ 1240.312379] CPU0 CPU1 [ 1240.313363] ---- ---- [ 1240.314433] lock(fs_reclaim); [ 1240.315107] lock((work_completion)(&gc->work)); [ 1240.316828] lock(fs_reclaim); [ 1240.318088] lock((work_completion)(&gc->work)); [ 1240.319203] [ 1240.319203] *** DEADLOCK *** ... [ 2438.431081] Workqueue: xfs-inodegc/sda xfs_inodegc_worker [ 2438.432089] Call Trace: [ 2438.432562] __schedule+0xa94/0x1d20 [ 2438.435787] schedule+0xbf/0x270 [ 2438.436397] schedule_timeout+0x6f8/0x8b0 [ 2438.445126] wait_for_completion+0x163/0x260 [ 2438.448610] __flush_work+0x4c4/0xa40 [ 2438.455011] xfs_inode_mark_reclaimable+0x6ef/0xda0 [ 2438.456695] destroy_inode+0xc6/0x1b0 [ 2438.457375] dispose_list+0xe1/0x1d0 [ 2438.458834] prune_icache_sb+0xe8/0x150 [ 2438.461181] super_cache_scan+0x2b3/0x470 [ 2438.461950] do_shrink_slab+0x3cf/0xa50 [ 2438.462687] shrink_slab+0x17d/0x660 [ 2438.466392] shrink_node+0x87e/0x1d40 [ 2438.467894] do_try_to_free_pages+0x364/0x1300 [ 2438.471188] try_to_free_pages+0x26c/0x5b0 [ 2438.473567] __alloc_pages_slowpath.constprop.136+0x7aa/0x2100 [ 2438.482577] __alloc_pages+0x5db/0x710 [ 2438.485231] alloc_pages+0x100/0x200 [ 2438.485923] allocate_slab+0x2c0/0x380 [ 2438.486623] ___slab_alloc+0x41f/0x690 [ 2438.490254] __slab_alloc+0x54/0x70 [ 2438.491692] kmem_cache_alloc+0x23e/0x270 [ 2438.492437] xfs_trans_alloc+0x88/0x880 [ 2438.493168] xfs_inactive_ifree+0xe2/0x4e0 [ 2438.496419] xfs_inactive+0x4eb/0x8b0 [ 2438.497123] xfs_inodegc_worker+0x16b/0x5e0 [ 2438.497918] process_one_work+0xbf7/0x1a20 [ 2438.500316] worker_thread+0x8c/0x1060 [ 2438.504938] ret_from_fork+0x22/0x30 When the memory is insufficient, xfs_inonodegc_worker will trigger memory reclamation when memory is allocated, then flush_work() may be called to wait for the work to complete. This causes a deadlock. So use memalloc_nofs_save() to avoid triggering memory reclamation in xfs_inodegc_worker. Signed-off-by: Wu Guanghao <wuguanghao3@huawei.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org> |
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Long Li
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28b4b05963 |
xfs: fix incorrect i_nlink caused by inode racing
The following error occurred during the fsstress test:
XFS: Assertion failed: VFS_I(ip)->i_nlink >= 2, file: fs/xfs/xfs_inode.c, line: 2452
The problem was that inode race condition causes incorrect i_nlink to be
written to disk, and then it is read into memory. Consider the following
call graph, inodes that are marked as both XFS_IFLUSHING and
XFS_IRECLAIMABLE, i_nlink will be reset to 1 and then restored to original
value in xfs_reinit_inode(). Therefore, the i_nlink of directory on disk
may be set to 1.
xfsaild
xfs_inode_item_push
xfs_iflush_cluster
xfs_iflush
xfs_inode_to_disk
xfs_iget
xfs_iget_cache_hit
xfs_iget_recycle
xfs_reinit_inode
inode_init_always
xfs_reinit_inode() needs to hold the ILOCK_EXCL as it is changing internal
inode state and can race with other RCU protected inode lookups. On the
read side, xfs_iflush_cluster() grabs the ILOCK_SHARED while under rcu +
ip->i_flags_lock, and so xfs_iflush/xfs_inode_to_disk() are protected from
racing inode updates (during transactions) by that lock.
Fixes:
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Jason A. Donenfeld
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a251c17aa5 |
treewide: use get_random_u32() when possible
The prandom_u32() function has been a deprecated inline wrapper around get_random_u32() for several releases now, and compiles down to the exact same code. Replace the deprecated wrapper with a direct call to the real function. The same also applies to get_random_int(), which is just a wrapper around get_random_u32(). This was done as a basic find and replace. Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Yury Norov <yury.norov@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> # for ext4 Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> # for sch_cake Acked-by: Chuck Lever <chuck.lever@oracle.com> # for nfsd Acked-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> # for thunderbolt Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs Acked-by: Helge Deller <deller@gmx.de> # for parisc Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390 Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> |
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Linus Torvalds
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6614a3c316 |
- The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe
Lin, Yang Shi, Anshuman Khandual and Mike Rapoport
- Some kmemleak fixes from Patrick Wang and Waiman Long
- DAMON updates from SeongJae Park
- memcg debug/visibility work from Roman Gushchin
- vmalloc speedup from Uladzislau Rezki
- more folio conversion work from Matthew Wilcox
- enhancements for coherent device memory mapping from Alex Sierra
- addition of shared pages tracking and CoW support for fsdax, from
Shiyang Ruan
- hugetlb optimizations from Mike Kravetz
- Mel Gorman has contributed some pagealloc changes to improve latency
and realtime behaviour.
- mprotect soft-dirty checking has been improved by Peter Xu
- Many other singleton patches all over the place
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Merge tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
"Most of the MM queue. A few things are still pending.
Liam's maple tree rework didn't make it. This has resulted in a few
other minor patch series being held over for next time.
Multi-gen LRU still isn't merged as we were waiting for mapletree to
stabilize. The current plan is to merge MGLRU into -mm soon and to
later reintroduce mapletree, with a view to hopefully getting both
into 6.1-rc1.
Summary:
- The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe
Lin, Yang Shi, Anshuman Khandual and Mike Rapoport
- Some kmemleak fixes from Patrick Wang and Waiman Long
- DAMON updates from SeongJae Park
- memcg debug/visibility work from Roman Gushchin
- vmalloc speedup from Uladzislau Rezki
- more folio conversion work from Matthew Wilcox
- enhancements for coherent device memory mapping from Alex Sierra
- addition of shared pages tracking and CoW support for fsdax, from
Shiyang Ruan
- hugetlb optimizations from Mike Kravetz
- Mel Gorman has contributed some pagealloc changes to improve
latency and realtime behaviour.
- mprotect soft-dirty checking has been improved by Peter Xu
- Many other singleton patches all over the place"
[ XFS merge from hell as per Darrick Wong in
https://lore.kernel.org/all/YshKnxb4VwXycPO8@magnolia/ ]
* tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (282 commits)
tools/testing/selftests/vm/hmm-tests.c: fix build
mm: Kconfig: fix typo
mm: memory-failure: convert to pr_fmt()
mm: use is_zone_movable_page() helper
hugetlbfs: fix inaccurate comment in hugetlbfs_statfs()
hugetlbfs: cleanup some comments in inode.c
hugetlbfs: remove unneeded header file
hugetlbfs: remove unneeded hugetlbfs_ops forward declaration
hugetlbfs: use helper macro SZ_1{K,M}
mm: cleanup is_highmem()
mm/hmm: add a test for cross device private faults
selftests: add soft-dirty into run_vmtests.sh
selftests: soft-dirty: add test for mprotect
mm/mprotect: fix soft-dirty check in can_change_pte_writable()
mm: memcontrol: fix potential oom_lock recursion deadlock
mm/gup.c: fix formatting in check_and_migrate_movable_page()
xfs: fail dax mount if reflink is enabled on a partition
mm/memcontrol.c: remove the redundant updating of stats_flush_threshold
userfaultfd: don't fail on unrecognized features
hugetlb_cgroup: fix wrong hugetlb cgroup numa stat
...
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Darrick J. Wong
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c78c2d0903 |
xfs: don't leak memory when attr fork loading fails
I observed the following evidence of a memory leak while running xfs/399 from the xfs fsck test suite (edited for brevity): XFS (sde): Metadata corruption detected at xfs_attr_shortform_verify_struct.part.0+0x7b/0xb0 [xfs], inode 0x1172 attr fork XFS: Assertion failed: ip->i_af.if_u1.if_data == NULL, file: fs/xfs/libxfs/xfs_inode_fork.c, line: 315 ------------[ cut here ]------------ WARNING: CPU: 2 PID: 91635 at fs/xfs/xfs_message.c:104 assfail+0x46/0x4a [xfs] CPU: 2 PID: 91635 Comm: xfs_scrub Tainted: G W 5.19.0-rc7-xfsx #rc7 6e6475eb29fd9dda3181f81b7ca7ff961d277a40 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014 RIP: 0010:assfail+0x46/0x4a [xfs] Call Trace: <TASK> xfs_ifork_zap_attr+0x7c/0xb0 xfs_iformat_attr_fork+0x86/0x110 xfs_inode_from_disk+0x41d/0x480 xfs_iget+0x389/0xd70 xfs_bulkstat_one_int+0x5b/0x540 xfs_bulkstat_iwalk+0x1e/0x30 xfs_iwalk_ag_recs+0xd1/0x160 xfs_iwalk_run_callbacks+0xb9/0x180 xfs_iwalk_ag+0x1d8/0x2e0 xfs_iwalk+0x141/0x220 xfs_bulkstat+0x105/0x180 xfs_ioc_bulkstat.constprop.0.isra.0+0xc5/0x130 xfs_file_ioctl+0xa5f/0xef0 __x64_sys_ioctl+0x82/0xa0 do_syscall_64+0x2b/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 This newly-added assertion checks that there aren't any incore data structures hanging off the incore fork when we're trying to reset its contents. From the call trace, it is evident that iget was trying to construct an incore inode from the ondisk inode, but the attr fork verifier failed and we were trying to undo all the memory allocations that we had done earlier. The three assertions in xfs_ifork_zap_attr check that the caller has already called xfs_idestroy_fork, which clearly has not been done here. As the zap function then zeroes the pointers, we've effectively leaked the memory. The shortest change would have been to insert an extra call to xfs_idestroy_fork, but it makes more sense to bundle the _idestroy_fork call into _zap_attr, since all other callsites call _idestroy_fork immediately prior to calling _zap_attr. IOWs, it eliminates one way to fail. Note: This change only applies cleanly to |
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Darrick J. Wong
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6d200bdc01 |
xfs: make attr forks permanent
This series fixes a use-after-free bug that syzbot uncovered. The UAF itself is a result of a race condition between getxattr and removexattr because callers to getxattr do not necessarily take any sort of locks before calling into the filesystem. Although the race condition itself can be fixed through clever use of a memory barrier, further consideration of the use cases of extended attributes shows that most files always have at least one attribute, so we might as well make them permanent. v2: Minor tweaks suggested by Dave, and convert some more macros to helper functions. Signed-off-by: Darrick J. Wong <djwong@kernel.org> -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEUzaAxoMeQq6m2jMV+H93GTRKtOsFAmLQRsAACgkQ+H93GTRK tOseOw/+JdSH2MU2xx+XoE5M/fStzGpw0UsoOqDo8kUPKDt3z12NwuczlL4OAiuw XFrN/1IAnxBsTD9YxFYbqoCPNi/VR81ajfWV7JqD2B1Joj0aATsxGDdNUYJnxCdU HMlMqP5o77XvArwkxFbgxYi7UGdAeNwXxqUJcJ8FopQo2lb8+SG6XzpLgGKnyrKT FRNKXNObplhtzOs/Bv8qYAxJulmmjkktFJXhK2OAUJlIDjFwFY9Wo2T4QuOVe9w+ NXFOYyu0BqWLpDZQkYKWoCnF0GNsUavS8DP6zZYW3qJ6mX/f1jmtfbOLAkHNhlh8 uHy/3k3SeQhKztTqM28sPioe6mdj2xocorDCCVBgGXgWxVF6aWeM/PS4tMTWN/Bg TWd1egERpeVC0Ymkm0LTCIDNuLqxsknK1G6sxXhwrQ8cw/70Gl08ePwgdyZ6hpD9 Q61iJQofcI7MJX189a2VSbbHRzFnZIA+uVK4oyhmdEkQVKTHgmzwHVP660oAv9bD Y5hqkWEoyKTaaCsOWRAPVXG3k03lq+TNcaGggZgwFx11Gw4oMEx5hMUztoP54xX4 aEXb1HWcCmMxy8llnFY/82baW98ucwl8FwWF1qhNIPT40mYx9IobDmvkCtNrAoOC 41U7O8CxxPlt7XKxoRhafQOAhzp0ZzuhCdbaFIUENV7pTAJtq5Q= =W3Ad -----END PGP SIGNATURE----- Merge tag 'make-attr-fork-permanent-5.20_2022-07-14' of git://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux into xfs-5.20-mergeB xfs: make attr forks permanent This series fixes a use-after-free bug that syzbot uncovered. The UAF itself is a result of a race condition between getxattr and removexattr because callers to getxattr do not necessarily take any sort of locks before calling into the filesystem. Although the race condition itself can be fixed through clever use of a memory barrier, further consideration of the use cases of extended attributes shows that most files always have at least one attribute, so we might as well make them permanent. v2: Minor tweaks suggested by Dave, and convert some more macros to helper functions. Signed-off-by: Darrick J. Wong <djwong@kernel.org> * tag 'make-attr-fork-permanent-5.20_2022-07-14' of git://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux: xfs: replace inode fork size macros with functions xfs: replace XFS_IFORK_Q with a proper predicate function xfs: use XFS_IFORK_Q to determine the presence of an xattr fork xfs: make inode attribute forks a permanent part of struct xfs_inode xfs: convert XFS_IFORK_PTR to a static inline helper |
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Dave Chinner
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fad743d7cd |
xfs: add log item precommit operation
For inodes that are dirty, we have an attached cluster buffer that we want to use to track the dirty inode through the AIL. Unfortunately, locking the cluster buffer and adding it to the transaction when the inode is first logged in a transaction leads to buffer lock ordering inversions. The specific problem is ordering against the AGI buffer. When modifying unlinked lists, the buffer lock order is AGI -> inode cluster buffer as the AGI buffer lock serialises all access to the unlinked lists. Unfortunately, functionality like xfs_droplink() logs the inode before calling xfs_iunlink(), as do various directory manipulation functions. The inode can be logged way down in the stack as far as the bmapi routines and hence, without a major rewrite of lots of APIs there's no way we can avoid the inode being logged by something until after the AGI has been logged. As we are going to be using ordered buffers for inode AIL tracking, there isn't a need to actually lock that buffer against modification as all the modifications are captured by logging the inode item itself. Hence we don't actually need to join the cluster buffer into the transaction until just before it is committed. This means we do not perturb any of the existing buffer lock orders in transactions, and the inode cluster buffer is always locked last in a transaction that doesn't otherwise touch inode cluster buffers. We do this by introducing a precommit log item method. This commit just introduces the mechanism; the inode item implementation is in followup commits. The precommit items need to be sorted into consistent order as we may be locking multiple items here. Hence if we have two dirty inodes in cluster buffers A and B, and some other transaction has two separate dirty inodes in the same cluster buffers, locking them in different orders opens us up to ABBA deadlocks. Hence we sort the items on the transaction based on the presence of a sort log item method. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> |
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Dave Chinner
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2fd26cc07e |
xfs: double link the unlinked inode list
Now we have forwards traversal via the incore inode in place, we now need to add back pointers to the incore inode to entirely replace the back reference cache. We use the same lookup semantics and constraints as for the forwards pointer lookups during unlinks, and so we can look up any inode in the unlinked list directly and update the list pointers, forwards or backwards, at any time. The only wrinkle in converting the unlinked list manipulations to use in-core previous pointers is that log recovery doesn't have the incore inode state built up so it can't just read in an inode and release it to finish off the unlink. Hence we need to modify the traversal in recovery to read one inode ahead before we release the inode at the head of the list. This populates the next->prev relationship sufficient to be able to replay the unlinked list and hence greatly simplify the runtime code. This recovery algorithm also requires that we actually remove inodes from the unlinked list one at a time as background inode inactivation will result in unlinked list removal racing with the building of the in-memory unlinked list state. We could serialise this by holding the AGI buffer lock when constructing the in memory state, but all that does is lockstep background processing with list building. It is much simpler to flush the inodegc immediately after releasing the inode so that it is unlinked immediately and there is no races present at all. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> |