Since add_new_free_space() is exported, used outside block-group.c, rename
it to include the 'btrfs_' prefix.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The documentation for add_new_free_space() is stale and no longer correct:
1) It's no longer used only when caching a block group. It's also called
when creating a block group (btrfs_make_block_group()), when reading
a block group at mount time (read_one_block_group()) and when reading
the free space tree for a block group (typically the first time we
attempt to allocate from the block group);
2) It has nothing to do with pinned extents. It only deals with the
excluded extents io tree, which is used to track the locations of
super blocks in order to make sure we never add the location of a
super block to the free space cache of a block group.
So update the documention and also add a description of the arguments
and return values.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Merge tag 'for-6.5-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"More fixes, some of them going back to older releases and there are
fixes for hangs in stress tests regarding space caching:
- fixes and progress tracking for hangs in free space caching, found
by test generic/475
- writeback fixes, write pages in integrity mode and skip writing
pages that have been written meanwhile
- properly clear end of extent range after an error
- relocation fixes:
- fix race betwen qgroup tree creation and relocation
- detect and report invalid reloc roots"
* tag 'for-6.5-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: set cache_block_group_error if we find an error
btrfs: reject invalid reloc tree root keys with stack dump
btrfs: exit gracefully if reloc roots don't match
btrfs: avoid race between qgroup tree creation and relocation
btrfs: properly clear end of the unreserved range in cow_file_range
btrfs: don't wait for writeback on clean pages in extent_write_cache_pages
btrfs: don't stop integrity writeback too early
btrfs: wait for actual caching progress during allocation
Recently we've been having mysterious hangs while running generic/475 on
the CI system. This turned out to be something like this:
Task 1
dmsetup suspend --nolockfs
-> __dm_suspend
-> dm_wait_for_completion
-> dm_wait_for_bios_completion
-> Unable to complete because of IO's on a plug in Task 2
Task 2
wb_workfn
-> wb_writeback
-> blk_start_plug
-> writeback_sb_inodes
-> Infinite loop unable to make an allocation
Task 3
cache_block_group
->read_extent_buffer_pages
->Waiting for IO to complete that can't be submitted because Task 1
suspended the DM device
The problem here is that we need Task 2 to be scheduled completely for
the blk plug to flush. Normally this would happen, we normally wait for
the block group caching to finish (Task 3), and this schedule would
result in the block plug flushing.
However if there's enough free space available from the current caching
to satisfy the allocation we won't actually wait for the caching to
complete. This check however just checks that we have enough space, not
that we can make the allocation. In this particular case we were trying
to allocate 9MiB, and we had 10MiB of free space, but we didn't have
9MiB of contiguous space to allocate, and thus the allocation failed and
we looped.
We specifically don't cycle through the FFE loop until we stop finding
cached block groups because we don't want to allocate new block groups
just because we're caching, so we short circuit the normal loop once we
hit LOOP_CACHING_WAIT and we found a caching block group.
This is normally fine, except in this particular case where the caching
thread can't make progress because the DM device has been suspended.
Fix this by not only waiting for free space to >= the amount of space we
want to allocate, but also that we make some progress in caching from
the time we start waiting. This will keep us from busy looping when the
caching is taking a while but still theoretically has enough space for
us to allocate from, and fixes this particular case by forcing us to
actually sleep and wait for forward progress, which will flush the plug.
With this fix we're no longer hanging with generic/475.
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Merge tag 'for-6.5-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
- fix accounting of global block reserve size when block group tree is
enabled
- the async discard has been enabled in 6.2 unconditionally, but for
zoned mode it does not make that much sense to do it asynchronously
as the zones are reset as needed
- error handling and proper error value propagation fixes
* tag 'for-6.5-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: check for commit error at btrfs_attach_transaction_barrier()
btrfs: check if the transaction was aborted at btrfs_wait_for_commit()
btrfs: remove BUG_ON()'s in add_new_free_space()
btrfs: account block group tree when calculating global reserve size
btrfs: zoned: do not enable async discard
At add_new_free_space() we have these BUG_ON()'s that are there to deal
with any failure to add free space to the in memory free space cache.
Such failures are mostly -ENOMEM that should be very rare. However there's
no need to have these BUG_ON()'s, we can just return any error to the
caller and all callers and their upper call chain are already dealing with
errors.
So just make add_new_free_space() return any errors, while removing the
BUG_ON()'s, and returning the total amount of added free space to an
optional u64 pointer argument.
Reported-by: syzbot+3ba856e07b7127889d8c@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/000000000000e9cb8305ff4e8327@google.com/
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Merge tag 'for-6.5-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"Stable fixes:
- fix race between balance and cancel/pause
- various iput() fixes
- fix use-after-free of new block group that became unused
- fix warning when putting transaction with qgroups enabled after
abort
- fix crash in subpage mode when page could be released between map
and map read
- when scrubbing raid56 verify the P/Q stripes unconditionally
- fix minor memory leak in zoned mode when a block group with an
unexpected superblock is found
Regression fixes:
- fix ordered extent split error handling when submitting direct IO
- user irq-safe locking when adding delayed iputs"
* tag 'for-6.5-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: fix warning when putting transaction with qgroups enabled after abort
btrfs: fix ordered extent split error handling in btrfs_dio_submit_io
btrfs: set_page_extent_mapped after read_folio in btrfs_cont_expand
btrfs: raid56: always verify the P/Q contents for scrub
btrfs: use irq safe locking when running and adding delayed iputs
btrfs: fix iput() on error pointer after error during orphan cleanup
btrfs: fix double iput() on inode after an error during orphan cleanup
btrfs: zoned: fix memory leak after finding block group with super blocks
btrfs: fix use-after-free of new block group that became unused
btrfs: be a bit more careful when setting mirror_num_ret in btrfs_map_block
btrfs: fix race between balance and cancel/pause
At exclude_super_stripes(), if we happen to find a block group that has
super blocks mapped to it and we are on a zoned filesystem, we error out
as this is not supposed to happen, indicating either a bug or maybe some
memory corruption for example. However we are exiting the function without
freeing the memory allocated for the logical address of the super blocks.
Fix this by freeing the logical address.
Fixes: 12659251ca ("btrfs: implement log-structured superblock for ZONED mode")
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If a task creates a new block group and that block group becomes unused
before we finish its creation, at btrfs_create_pending_block_groups(),
then when btrfs_mark_bg_unused() is called against the block group, we
assume that the block group is currently in the list of block groups to
reclaim, and we move it out of the list of new block groups and into the
list of unused block groups. This has two consequences:
1) We move it out of the list of new block groups associated to the
current transaction. So the block group creation is not finished and
if we attempt to delete the bg because it's unused, we will not find
the block group item in the extent tree (or the new block group tree),
its device extent items in the device tree etc, resulting in the
deletion to fail due to the missing items;
2) We don't increment the reference count on the block group when we
move it to the list of unused block groups, because we assumed the
block group was on the list of block groups to reclaim, and in that
case it already has the correct reference count. However the block
group was on the list of new block groups, in which case no extra
reference was taken because it's local to the current task. This
later results in doing an extra reference count decrement when
removing the block group from the unused list, eventually leading the
reference count to 0.
This second case was caught when running generic/297 from fstests, which
produced the following assertion failure and stack trace:
[589.559] assertion failed: refcount_read(&block_group->refs) == 1, in fs/btrfs/block-group.c:4299
[589.559] ------------[ cut here ]------------
[589.559] kernel BUG at fs/btrfs/block-group.c:4299!
[589.560] invalid opcode: 0000 [#1] PREEMPT SMP PTI
[589.560] CPU: 8 PID: 2819134 Comm: umount Tainted: G W 6.4.0-rc6-btrfs-next-134+ #1
[589.560] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-0-gea1b7a073390-prebuilt.qemu.org 04/01/2014
[589.560] RIP: 0010:btrfs_free_block_groups+0x449/0x4a0 [btrfs]
[589.561] Code: 68 62 da c0 (...)
[589.561] RSP: 0018:ffffa55a8c3b3d98 EFLAGS: 00010246
[589.561] RAX: 0000000000000058 RBX: ffff8f030d7f2000 RCX: 0000000000000000
[589.562] RDX: 0000000000000000 RSI: ffffffff953f0878 RDI: 00000000ffffffff
[589.562] RBP: ffff8f030d7f2088 R08: 0000000000000000 R09: ffffa55a8c3b3c50
[589.562] R10: 0000000000000001 R11: 0000000000000001 R12: ffff8f05850b4c00
[589.562] R13: ffff8f030d7f2090 R14: ffff8f05850b4cd8 R15: dead000000000100
[589.563] FS: 00007f497fd2e840(0000) GS:ffff8f09dfc00000(0000) knlGS:0000000000000000
[589.563] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[589.563] CR2: 00007f497ff8ec10 CR3: 0000000271472006 CR4: 0000000000370ee0
[589.563] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[589.564] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[589.564] Call Trace:
[589.564] <TASK>
[589.565] ? __die_body+0x1b/0x60
[589.565] ? die+0x39/0x60
[589.565] ? do_trap+0xeb/0x110
[589.565] ? btrfs_free_block_groups+0x449/0x4a0 [btrfs]
[589.566] ? do_error_trap+0x6a/0x90
[589.566] ? btrfs_free_block_groups+0x449/0x4a0 [btrfs]
[589.566] ? exc_invalid_op+0x4e/0x70
[589.566] ? btrfs_free_block_groups+0x449/0x4a0 [btrfs]
[589.567] ? asm_exc_invalid_op+0x16/0x20
[589.567] ? btrfs_free_block_groups+0x449/0x4a0 [btrfs]
[589.567] ? btrfs_free_block_groups+0x449/0x4a0 [btrfs]
[589.567] close_ctree+0x35d/0x560 [btrfs]
[589.568] ? fsnotify_sb_delete+0x13e/0x1d0
[589.568] ? dispose_list+0x3a/0x50
[589.568] ? evict_inodes+0x151/0x1a0
[589.568] generic_shutdown_super+0x73/0x1a0
[589.569] kill_anon_super+0x14/0x30
[589.569] btrfs_kill_super+0x12/0x20 [btrfs]
[589.569] deactivate_locked_super+0x2e/0x70
[589.569] cleanup_mnt+0x104/0x160
[589.570] task_work_run+0x56/0x90
[589.570] exit_to_user_mode_prepare+0x160/0x170
[589.570] syscall_exit_to_user_mode+0x22/0x50
[589.570] ? __x64_sys_umount+0x12/0x20
[589.571] do_syscall_64+0x48/0x90
[589.571] entry_SYSCALL_64_after_hwframe+0x72/0xdc
[589.571] RIP: 0033:0x7f497ff0a567
[589.571] Code: af 98 0e (...)
[589.572] RSP: 002b:00007ffc98347358 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
[589.572] RAX: 0000000000000000 RBX: 00007f49800b8264 RCX: 00007f497ff0a567
[589.572] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000557f558abfa0
[589.573] RBP: 0000557f558a6ba0 R08: 0000000000000000 R09: 00007ffc98346100
[589.573] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
[589.573] R13: 0000557f558abfa0 R14: 0000557f558a6cb0 R15: 0000557f558a6dd0
[589.573] </TASK>
[589.574] Modules linked in: dm_snapshot dm_thin_pool (...)
[589.576] ---[ end trace 0000000000000000 ]---
Fix this by adding a runtime flag to the block group to tell that the
block group is still in the list of new block groups, and therefore it
should not be moved to the list of unused block groups, at
btrfs_mark_bg_unused(), until the flag is cleared, when we finish the
creation of the block group at btrfs_create_pending_block_groups().
Fixes: a9f189716c ("btrfs: move out now unused BG from the reclaim list")
CC: stable@vger.kernel.org # 5.15+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Merge tag 'for-6.5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs updates from David Sterba:
"Mainly core changes, refactoring and optimizations.
Performance is improved in some areas, overall there may be a
cumulative improvement due to refactoring that removed lookups in the
IO path or simplified IO submission tracking.
Core:
- submit IO synchronously for fast checksums (crc32c and xxhash),
remove high priority worker kthread
- read extent buffer in one go, simplify IO tracking, bio submission
and locking
- remove additional tracking of redirtied extent buffers, originally
added for zoned mode but actually not needed
- track ordered extent pointer in bio to avoid rbtree lookups during
IO
- scrub, use recovered data stripes as cache to avoid unnecessary
read
- in zoned mode, optimize logical to physical mappings of extents
- remove PageError handling, not set by VFS nor writeback
- cleanups, refactoring, better structure packing
- lots of error handling improvements
- more assertions, lockdep annotations
- print assertion failure with the exact line where it happens
- tracepoint updates
- more debugging prints
Performance:
- speedup in fsync(), better tracking of inode logged status can
avoid transaction commit
- IO path structures track logical offsets in data structures and
does not need to look it up
User visible changes:
- don't commit transaction for every created subvolume, this can
reduce time when many subvolumes are created in a batch
- print affected files when relocation fails
- trigger orphan file cleanup during START_SYNC ioctl
Notable fixes:
- fix crash when disabling quota and relocation
- fix crashes when removing roots from drity list
- fix transacion abort during relocation when converting from newer
profiles not covered by fallback
- in zoned mode, stop reclaiming block groups if filesystem becomes
read-only
- fix rare race condition in tree mod log rewind that can miss some
btree node slots
- with enabled fsverity, drop up-to-date page bit in case the
verification fails"
* tag 'for-6.5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (194 commits)
btrfs: fix race between quota disable and relocation
btrfs: add comment to struct btrfs_fs_info::dirty_cowonly_roots
btrfs: fix race when deleting free space root from the dirty cow roots list
btrfs: fix race when deleting quota root from the dirty cow roots list
btrfs: tracepoints: also show actual number of the outstanding extents
btrfs: update i_version in update_dev_time
btrfs: make btrfs_compressed_bioset static
btrfs: add handling for RAID1C23/DUP to btrfs_reduce_alloc_profile
btrfs: scrub: remove btrfs_fs_info::scrub_wr_completion_workers
btrfs: scrub: remove scrub_ctx::csum_list member
btrfs: do not BUG_ON after failure to migrate space during truncation
btrfs: do not BUG_ON on failure to get dir index for new snapshot
btrfs: send: do not BUG_ON() on unexpected symlink data extent
btrfs: do not BUG_ON() when dropping inode items from log root
btrfs: replace BUG_ON() at split_item() with proper error handling
btrfs: do not BUG_ON() on tree mod log failures at btrfs_del_ptr()
btrfs: do not BUG_ON() on tree mod log failures at insert_ptr()
btrfs: do not BUG_ON() on tree mod log failure at insert_new_root()
btrfs: do not BUG_ON() on tree mod log failures at push_nodes_for_insert()
btrfs: abort transaction at update_ref_for_cow() when ref count is zero
...
There was regression caused by a97699d1d6 ("btrfs: replace
map_lookup->stripe_len by BTRFS_STRIPE_LEN") and supposedly fixed by
a7299a18a1 ("btrfs: fix u32 overflows when left shifting stripe_nr").
To avoid code churn the fix was open coding the type casts but
unfortunately missed one which was still possible to hit [1].
The missing place was assignment of bioc->full_stripe_logical inside
btrfs_map_block().
Fix it by adding a helper that does the safe calculation of the offset
and use it everywhere even though it may not be strictly necessary due
to already using u64 types. This replaces all remaining
"<< BTRFS_STRIPE_LEN_SHIFT" calls.
[1] https://lore.kernel.org/linux-btrfs/20230622065438.86402-1-wqu@suse.com/
Fixes: a7299a18a1 ("btrfs: fix u32 overflows when left shifting stripe_nr")
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
Callers of `btrfs_reduce_alloc_profile` expect it to return exactly
one allocation profile flag, and failing to do so may ultimately
result in a WARN_ON and remount-ro when allocating new blocks, like
the below transaction abort on 6.1.
`btrfs_reduce_alloc_profile` has two ways of determining the profile,
first it checks if a conversion balance is currently running and
uses the profile we're converting to. If no balance is currently
running, it returns the max-redundancy profile which at least one
block in the selected block group has.
This works by simply checking each known allocation profile bit in
redundancy order. However, `btrfs_reduce_alloc_profile` has not been
updated as new flags have been added - first with the `DUP` profile
and later with the RAID1C34 profiles.
Because of the way it checks, if we have blocks with different
profiles and at least one is known, that profile will be selected.
However, if none are known we may return a flag set with multiple
allocation profiles set.
This is currently only possible when a balance from one of the three
unhandled profiles to another of the unhandled profiles is canceled
after allocating at least one block using the new profile.
In that case, a transaction abort like the below will occur and the
filesystem will need to be mounted with -o skip_balance to get it
mounted rw again (but the balance cannot be resumed without a
similar abort).
[770.648] ------------[ cut here ]------------
[770.648] BTRFS: Transaction aborted (error -22)
[770.648] WARNING: CPU: 43 PID: 1159593 at fs/btrfs/extent-tree.c:4122 find_free_extent+0x1d94/0x1e00 [btrfs]
[770.648] CPU: 43 PID: 1159593 Comm: btrfs Tainted: G W 6.1.0-0.deb11.7-powerpc64le #1 Debian 6.1.20-2~bpo11+1a~test
[770.648] Hardware name: T2P9D01 REV 1.00 POWER9 0x4e1202 opal:skiboot-bc106a0 PowerNV
[770.648] NIP: c00800000f6784fc LR: c00800000f6784f8 CTR: c000000000d746c0
[770.648] REGS: c000200089afe9a0 TRAP: 0700 Tainted: G W (6.1.0-0.deb11.7-powerpc64le Debian 6.1.20-2~bpo11+1a~test)
[770.648] MSR: 9000000002029033 <SF,HV,VEC,EE,ME,IR,DR,RI,LE> CR: 28848282 XER: 20040000
[770.648] CFAR: c000000000135110 IRQMASK: 0
GPR00: c00800000f6784f8 c000200089afec40 c00800000f7ea800 0000000000000026
GPR04: 00000001004820c2 c000200089afea00 c000200089afe9f8 0000000000000027
GPR08: c000200ffbfe7f98 c000000002127f90 ffffffffffffffd8 0000000026d6a6e8
GPR12: 0000000028848282 c000200fff7f3800 5deadbeef0000122 c00000002269d000
GPR16: c0002008c7797c40 c000200089afef17 0000000000000000 0000000000000000
GPR20: 0000000000000000 0000000000000001 c000200008bc5a98 0000000000000001
GPR24: 0000000000000000 c0000003c73088d0 c000200089afef17 c000000016d3a800
GPR28: c0000003c7308800 c00000002269d000 ffffffffffffffea 0000000000000001
[770.648] NIP [c00800000f6784fc] find_free_extent+0x1d94/0x1e00 [btrfs]
[770.648] LR [c00800000f6784f8] find_free_extent+0x1d90/0x1e00 [btrfs]
[770.648] Call Trace:
[770.648] [c000200089afec40] [c00800000f6784f8] find_free_extent+0x1d90/0x1e00 [btrfs] (unreliable)
[770.648] [c000200089afed30] [c00800000f681398] btrfs_reserve_extent+0x1a0/0x2f0 [btrfs]
[770.648] [c000200089afeea0] [c00800000f681bf0] btrfs_alloc_tree_block+0x108/0x670 [btrfs]
[770.648] [c000200089afeff0] [c00800000f66bd68] __btrfs_cow_block+0x170/0x850 [btrfs]
[770.648] [c000200089aff100] [c00800000f66c58c] btrfs_cow_block+0x144/0x288 [btrfs]
[770.648] [c000200089aff1b0] [c00800000f67113c] btrfs_search_slot+0x6b4/0xcb0 [btrfs]
[770.648] [c000200089aff2a0] [c00800000f679f60] lookup_inline_extent_backref+0x128/0x7c0 [btrfs]
[770.648] [c000200089aff3b0] [c00800000f67b338] lookup_extent_backref+0x70/0x190 [btrfs]
[770.648] [c000200089aff470] [c00800000f67b54c] __btrfs_free_extent+0xf4/0x1490 [btrfs]
[770.648] [c000200089aff5a0] [c00800000f67d770] __btrfs_run_delayed_refs+0x328/0x1530 [btrfs]
[770.648] [c000200089aff740] [c00800000f67ea2c] btrfs_run_delayed_refs+0xb4/0x3e0 [btrfs]
[770.648] [c000200089aff800] [c00800000f699aa4] btrfs_commit_transaction+0x8c/0x12b0 [btrfs]
[770.648] [c000200089aff8f0] [c00800000f6dc628] reset_balance_state+0x1c0/0x290 [btrfs]
[770.648] [c000200089aff9a0] [c00800000f6e2f7c] btrfs_balance+0x1164/0x1500 [btrfs]
[770.648] [c000200089affb40] [c00800000f6f8e4c] btrfs_ioctl+0x2b54/0x3100 [btrfs]
[770.648] [c000200089affc80] [c00000000053be14] sys_ioctl+0x794/0x1310
[770.648] [c000200089affd70] [c00000000002af98] system_call_exception+0x138/0x250
[770.648] [c000200089affe10] [c00000000000c654] system_call_common+0xf4/0x258
[770.648] --- interrupt: c00 at 0x7fff94126800
[770.648] NIP: 00007fff94126800 LR: 0000000107e0b594 CTR: 0000000000000000
[770.648] REGS: c000200089affe80 TRAP: 0c00 Tainted: G W (6.1.0-0.deb11.7-powerpc64le Debian 6.1.20-2~bpo11+1a~test)
[770.648] MSR: 900000000000d033 <SF,HV,EE,PR,ME,IR,DR,RI,LE> CR: 24002848 XER: 00000000
[770.648] IRQMASK: 0
GPR00: 0000000000000036 00007fffc9439da0 00007fff94217100 0000000000000003
GPR04: 00000000c4009420 00007fffc9439ee8 0000000000000000 0000000000000000
GPR08: 00000000803c7416 0000000000000000 0000000000000000 0000000000000000
GPR12: 0000000000000000 00007fff9467d120 0000000107e64c9c 0000000107e64d0a
GPR16: 0000000107e64d06 0000000107e64cf1 0000000107e64cc4 0000000107e64c73
GPR20: 0000000107e64c31 0000000107e64bf1 0000000107e64be7 0000000000000000
GPR24: 0000000000000000 00007fffc9439ee0 0000000000000003 0000000000000001
GPR28: 00007fffc943f713 0000000000000000 00007fffc9439ee8 0000000000000000
[770.648] NIP [00007fff94126800] 0x7fff94126800
[770.648] LR [0000000107e0b594] 0x107e0b594
[770.648] --- interrupt: c00
[770.648] Instruction dump:
[770.648] 3b00ffe4 e8898828 481175f5 60000000 4bfff4fc 3be00000 4bfff570 3d220000
[770.648] 7fc4f378 e8698830 4811cd95 e8410018 <0fe00000> f9c10060 f9e10068 fa010070
[770.648] ---[ end trace 0000000000000000 ]---
[770.648] BTRFS: error (device dm-2: state A) in find_free_extent_update_loop:4122: errno=-22 unknown
[770.648] BTRFS info (device dm-2: state EA): forced readonly
[770.648] BTRFS: error (device dm-2: state EA) in __btrfs_free_extent:3070: errno=-22 unknown
[770.648] BTRFS error (device dm-2: state EA): failed to run delayed ref for logical 17838685708288 num_bytes 24576 type 184 action 2 ref_mod 1: -22
[770.648] BTRFS: error (device dm-2: state EA) in btrfs_run_delayed_refs:2144: errno=-22 unknown
[770.648] BTRFS: error (device dm-2: state EA) in reset_balance_state:3599: errno=-22 unknown
Fixes: 47e6f7423b ("btrfs: add support for 3-copy replication (raid1c3)")
Fixes: 8d6fac0087 ("btrfs: add support for 4-copy replication (raid1c4)")
CC: stable@vger.kernel.org # 5.10+
Signed-off-by: Matt Corallo <blnxfsl@bluematt.me>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The reclaim process can temporarily fail. For example, if the space is
getting tight, it fails to make the block group read-only. If there are no
further writes on that block group, the block group will never get back to
the reclaim list, and the BG never gets reclaimed. In a certain workload,
we can leave many such block groups never reclaimed.
So, let's get it back to the list and give it a chance to be reclaimed.
Fixes: 18bb8bbf13 ("btrfs: zoned: automatically reclaim zones")
CC: stable@vger.kernel.org # 5.15+
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When a filesystem is read-only, we cannot reclaim a block group as it
cannot rewrite the data. Just bail out in that case.
Note that it can drop block groups in this case. As we did
sb_start_write(), read-only filesystem means we got a fatal error and
forced read-only. There is no chance to reclaim them again.
Fixes: 18bb8bbf13 ("btrfs: zoned: automatically reclaim zones")
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
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>
An unused block group is easy to remove to free up space and should be
reclaimed fast. Such block group can often already be a target of the
reclaim process. As we check list_empty(&bg->bg_list), we keep it in the
reclaim list. That block group is never reclaimed until the file system
is filled e.g. up to 75%.
Instead, we can move unused block group to the unused list and delete it
fast.
Fixes: 18bb8bbf13 ("btrfs: zoned: automatically reclaim zones")
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
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>
The reclaiming process only starts after the filesystem volumes are
allocated to a certain level (75% by default). Thus, the list of
reclaiming target block groups can build up so huge at the time the
reclaim process kicks in. On a test run, there were over 1000 BGs in the
reclaim list.
As the reclaim involves rewriting the data, it takes really long time to
reclaim the BGs. While the reclaim is running, btrfs_delete_unused_bgs()
won't proceed because the reclaim side is holding
fs_info->reclaim_bgs_lock. As a result, we will have a large number of
unused BGs kept in the unused list. On my test run, I got 1057 unused BGs.
Since deleting a block group is relatively easy and fast work, we can call
btrfs_delete_unused_bgs() while it reclaims BGs, to avoid building up
unused BGs.
Fixes: 18bb8bbf13 ("btrfs: zoned: automatically reclaim zones")
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
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>
Now that all extent state bit helpers effectively take the GFP_NOFS mask
(and GFP_NOWAIT is encoded in the bits) we can remove the parameter.
This reduces stack consumption in many functions and simplifies a lot of
code.
Net effect on module on a release build:
text data bss dec hex filename
1250432 20985 16088 1287505 13a551 pre/btrfs.ko
1247074 20985 16088 1284147 139833 post/btrfs.ko
DELTA: -3358
Signed-off-by: David Sterba <dsterba@suse.com>
The __GFP_NOFAIL passed to set_extent_bit first appeared in 2010
(commit f0486c68e4 ("Btrfs: Introduce contexts for metadata
reservation")), without any explanation why it would be needed.
Meanwhile we've updated the semantics of set_extent_bit to handle failed
allocations and do unlock, sleep and retry if needed. The use of the
NOFAIL flag is also an outlier, we never want any of the set/clear
extent bit helpers to fail, they're used for many critical changes like
extent locking, besides the extent state bit changes.
Signed-off-by: David Sterba <dsterba@suse.com>
The helper is used a few times, that it's setting the DIRTY extent bit
is still clear.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently we allow a block group not to be marked read-only for scrub.
But for RAID56 block groups if we require the block group to be
read-only, then we're allowed to use cached content from scrub stripe to
reduce unnecessary RAID56 reads.
So this patch would:
- Make btrfs_inc_block_group_ro() try harder
During my tests, for cases like btrfs/061 and btrfs/064, we can hit
ENOSPC from btrfs_inc_block_group_ro() calls during scrub.
The reason is if we only have one single data chunk, and trying to
scrub it, we won't have any space left for any newer data writes.
But this check should be done by the caller, especially for scrub
cases we only temporarily mark the chunk read-only.
And newer data writes would always try to allocate a new data chunk
when needed.
- Return error for scrub if we failed to mark a RAID56 chunk read-only
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The old scrub code has different entrance to verify the content, and
since we have removed the writeback path, now we can start removing the
re-check part, including:
- scrub_recover structure
- scrub_sector::recover member
- function scrub_setup_recheck_block()
- function scrub_recheck_block()
- function scrub_recheck_block_checksum()
- function scrub_repair_block_group_good_copy()
- function scrub_repair_sector_from_good_copy()
- function scrub_is_page_on_raid56()
- function full_stripe_lock()
- function search_full_stripe_lock()
- function get_full_stripe_logical()
- function insert_full_stripe_lock()
- function lock_full_stripe()
- function unlock_full_stripe()
- btrfs_block_group::full_stripe_locks_root member
- btrfs_full_stripe_locks_tree structure
This infrastructure is to ensure RAID56 scrub is properly handling
recovery and P/Q scrub correctly.
This is no longer needed, before P/Q scrub we will wait for all
the involved data stripes to be scrubbed first, and RAID56 code has
internal lock to ensure no race in the same full stripe.
- function scrub_print_warning()
- function scrub_get_recover()
- function scrub_put_recover()
- function scrub_handle_errored_block()
- function scrub_setup_recheck_block()
- function scrub_bio_wait_endio()
- function scrub_submit_raid56_bio_wait()
- function scrub_recheck_block_on_raid56()
- function scrub_recheck_block()
- function scrub_recheck_block_checksum()
- function scrub_repair_block_from_good_copy()
- function scrub_repair_sector_from_good_copy()
And two more functions exported temporarily for later cleanup:
- alloc_scrub_sector()
- alloc_scrub_block()
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The only caller of btrfs_make_block_group() always passes 0 as the value
for the bytes_used argument, so 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>
There are quite some div64 calls inside btrfs_map_block() and its
variants.
Such calls are for @stripe_nr, where @stripe_nr is the number of
stripes before our logical bytenr inside a chunk.
However we can eliminate such div64 calls by just reducing the width of
@stripe_nr from 64 to 32.
This can be done because our chunk size limit is already 10G, with fixed
stripe length 64K.
Thus a U32 is definitely enough to contain the number of stripes.
With such width reduction, we can get rid of slower div64, and extra
warning for certain 32bit arch.
This patch would do:
- Add a new tree-checker chunk validation on chunk length
Make sure no chunk can reach 256G, which can also act as a bitflip
checker.
- Reduce the width from u64 to u32 for @stripe_nr variables
- Replace unnecessary div64 calls with regular modulo and division
32bit division and modulo are much faster than 64bit operations, and
we are finally free of the div64 fear at least in those involved
functions.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently btrfs doesn't support stripe lengths other than 64KiB.
This is already set in the tree-checker.
There is really no meaning to record that fixed value in map_lookup for
now, and can all be replaced with BTRFS_STRIPE_LEN.
Furthermore we can use the fix stripe length to do the following
optimization:
- Use BTRFS_STRIPE_LEN_SHIFT to replace some 64bit division
Now we only need to do a right shift.
And the value of BTRFS_STRIPE_LEN itself is already too large for bit
shift, thus if we accidentally use BTRFS_STRIPE_LEN to do bit shift,
a compiler warning would be triggered.
Thus this bit shift optimization would be safe.
- Use BTRFS_STRIPE_LEN_MASK to calculate the offset inside a stripe
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The space_info->active_total_bytes is no longer necessary as we now
count the region of newly allocated block group as zone_unusable. Drop
its usage.
Fixes: 6a921de589 ("btrfs: zoned: introduce space_info->active_total_bytes")
CC: stable@vger.kernel.org # 6.1+
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We do
cache->space_info->counter += num_bytes;
everywhere in here. This is makes the lines longer than they need to
be, and will be especially noticeable when we add the active tracking in,
so add a temp variable for the space_info so this is cleaner.
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
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>
We can often end up inserting a block group item, for a new block group,
with a wrong value for the used bytes field.
This happens if for the new allocated block group, in the same transaction
that created the block group, we have tasks allocating extents from it as
well as tasks removing extents from it.
For example:
1) Task A creates a metadata block group X;
2) Two extents are allocated from block group X, so its "used" field is
updated to 32K, and its "commit_used" field remains as 0;
3) Transaction commit starts, by some task B, and it enters
btrfs_start_dirty_block_groups(). There it tries to update the block
group item for block group X, which currently has its "used" field with
a value of 32K. But that fails since the block group item was not yet
inserted, and so on failure update_block_group_item() sets the
"commit_used" field of the block group back to 0;
4) The block group item is inserted by task A, when for example
btrfs_create_pending_block_groups() is called when releasing its
transaction handle. This results in insert_block_group_item() inserting
the block group item in the extent tree (or block group tree), with a
"used" field having a value of 32K, but without updating the
"commit_used" field in the block group, which remains with value of 0;
5) The two extents are freed from block X, so its "used" field changes
from 32K to 0;
6) The transaction commit by task B continues, it enters
btrfs_write_dirty_block_groups() which calls update_block_group_item()
for block group X, and there it decides to skip the block group item
update, because "used" has a value of 0 and "commit_used" has a value
of 0 too.
As a result, we end up with a block item having a 32K "used" field but
no extents allocated from it.
When this issue happens, a btrfs check reports an error like this:
[1/7] checking root items
[2/7] checking extents
block group [1104150528 1073741824] used 39796736 but extent items used 0
ERROR: errors found in extent allocation tree or chunk allocation
(...)
Fix this by making insert_block_group_item() update the block group's
"commit_used" field.
Fixes: 7248e0cebb ("btrfs: skip update of block group item if used bytes are the same")
CC: stable@vger.kernel.org # 6.2+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We have a report, that the info message for block-group reclaim is
crossing the 100% used mark.
This is happening as we were truncating the divisor for the division
(the block_group->length) to a 32bit value.
Fix this by using div64_u64() to not truncate the divisor.
In the worst case, it can lead to a div by zero error and should be
possible to trigger on 4 disks RAID0, and each device is large enough:
$ mkfs.btrfs -f /dev/test/scratch[1234] -m raid1 -d raid0
btrfs-progs v6.1
[...]
Filesystem size: 40.00GiB
Block group profiles:
Data: RAID0 4.00GiB <<<
Metadata: RAID1 256.00MiB
System: RAID1 8.00MiB
Reported-by: Forza <forza@tnonline.net>
Link: https://lore.kernel.org/linux-btrfs/e99483.c11a58d.1863591ca52@tnonline.net/
Fixes: 5f93e776c6 ("btrfs: zoned: print unusable percentage when reclaiming block groups")
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add Qu's note ]
Signed-off-by: David Sterba <dsterba@suse.com>
The only user in the zoned remap code is gone now, so remove the argument.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When a file system has ZNS devices which are constrained by a maximum
number of active block groups, then not being able to use all the block
groups for every allocation is not ideal, and could cause us to loop a
ton with mixed size allocations.
In general, since zoned doesn't write into gaps behind where block
groups are writing, it is not susceptible to the same sort of
fragmentation that size classes are designed to solve, so we can skip
size classes for zoned file systems in general, even though there would
probably be no harm for SMR devices.
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Since the size class is an artifact of an arbitrary anti fragmentation
strategy, it doesn't really make sense to persist it. Furthermore, most
of the size class logic assumes fresh block groups. That is of course
not a reasonable assumption -- we will be upgrading kernels with
existing filesystems whose block groups are not classified.
To work around those issues, implement logic to compute the size class
of the block groups as we cache them in. To perfectly assess the state
of a block group, we would have to read the entire extent tree (since
the free space cache mashes together contiguous extent items) which
would be prohibitively expensive for larger file systems with more
extents.
We can do it relatively cheaply by implementing a simple heuristic of
sampling a handful of extents and picking the smallest one we see. In
the happy case where the block group was classified, we will only see
extents of the correct size. In the unhappy case, we will hopefully find
one of the smaller extents, but there is no perfect answer anyway.
Autorelocation will eventually churn up the block group if there is
significant freeing anyway.
There was no regression in mount performance at end state of the fsperf
test suite, and the delay until the block group is marked cached is
minimized by the constant number of extent samples.
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
The aim of this patch is to reduce the fragmentation of block groups
under certain unhappy workloads. It is particularly effective when the
size of extents correlates with their lifetime, which is something we
have observed causing fragmentation in the fleet at Meta.
This patch categorizes extents into size classes:
- x < 128KiB: "small"
- 128KiB < x < 8MiB: "medium"
- x > 8MiB: "large"
and as much as possible reduces allocations of extents into block groups
that don't match the size class. This takes advantage of any (possible)
correlation between size and lifetime and also leaves behind predictable
re-usable gaps when extents are freed; small writes don't gum up bigger
holes.
Size classes are implemented in the following way:
- Mark each new block group with a size class of the first allocation
that goes into it.
- Add two new passes to ffe: "unset size class" and "wrong size class".
First, try only matching block groups, then try unset ones, then allow
allocation of new ones, and finally allow mismatched block groups.
- Filtering is done just by skipping inappropriate ones, there is no
special size class indexing.
Other solutions I considered were:
- A best fit allocator with an rb-tree. This worked well, as small
writes didn't leak big holes from large freed extents, but led to
regressions in ffe and write performance due to lock contention on
the rb-tree with every allocation possibly updating it in parallel.
Perhaps something clever could be done to do the updates in the
background while being "right enough".
- A fixed size "working set". This prevents freeing an extent
drastically changing where writes currently land, and seems like a
good option too. Doesn't take advantage of size in any way.
- The same size class idea, but implemented with xarray marks. This
turned out to be slower than looping the linked list and skipping
wrong block groups, and is also less flexible since we must have only
3 size classes (max #marks). With the current approach we can have as
many as we like.
Performance testing was done via: https://github.com/josefbacik/fsperf
Of particular relevance are the new fragmentation specific tests.
A brief summary of the testing results:
- Neutral results on existing tests. There are some minor regressions
and improvements here and there, but nothing that truly stands out as
notable.
- Improvement on new tests where size class and extent lifetime are
correlated. Fragmentation in these cases is completely eliminated
and write performance is generally a little better. There is also
significant improvement where extent sizes are just a bit larger than
the size class boundaries.
- Regression on one new tests: where the allocations are sized
intentionally a hair under the borders of the size classes. Results
are neutral on the test that intentionally attacks this new scheme by
mixing extent size and lifetime.
The full dump of the performance results can be found here:
https://bur.io/fsperf/size-class-2022-11-15.txt
(there are ANSI escape codes, so best to curl and view in terminal)
Here is a snippet from the full results for a new test which mixes
buffered writes appending to a long lived set of files and large short
lived fallocates:
bufferedappendvsfallocate results
metric baseline current stdev diff
======================================================================================
avg_commit_ms 31.13 29.20 2.67 -6.22%
bg_count 14 15.60 0 11.43%
commits 11.10 12.20 0.32 9.91%
elapsed 27.30 26.40 2.98 -3.30%
end_state_mount_ns 11122551.90 10635118.90 851143.04 -4.38%
end_state_umount_ns 1.36e+09 1.35e+09 12248056.65 -1.07%
find_free_extent_calls 116244.30 114354.30 964.56 -1.63%
find_free_extent_ns_max 599507.20 1047168.20 103337.08 74.67%
find_free_extent_ns_mean 3607.19 3672.11 101.20 1.80%
find_free_extent_ns_min 500 512 6.67 2.40%
find_free_extent_ns_p50 2848 2876 37.65 0.98%
find_free_extent_ns_p95 4916 5000 75.45 1.71%
find_free_extent_ns_p99 20734.49 20920.48 1670.93 0.90%
frag_pct_max 61.67 0 8.05 -100.00%
frag_pct_mean 43.59 0 6.10 -100.00%
frag_pct_min 25.91 0 16.60 -100.00%
frag_pct_p50 42.53 0 7.25 -100.00%
frag_pct_p95 61.67 0 8.05 -100.00%
frag_pct_p99 61.67 0 8.05 -100.00%
fragmented_bg_count 6.10 0 1.45 -100.00%
max_commit_ms 49.80 46 5.37 -7.63%
sys_cpu 2.59 2.62 0.29 1.39%
write_bw_bytes 1.62e+08 1.68e+08 17975843.50 3.23%
write_clat_ns_mean 57426.39 54475.95 2292.72 -5.14%
write_clat_ns_p50 46950.40 42905.60 2101.35 -8.62%
write_clat_ns_p99 148070.40 143769.60 2115.17 -2.90%
write_io_kbytes 4194304 4194304 0 0.00%
write_iops 2476.15 2556.10 274.29 3.23%
write_lat_ns_max 2101667.60 2251129.50 370556.59 7.11%
write_lat_ns_mean 59374.91 55682.00 2523.09 -6.22%
write_lat_ns_min 17353.10 16250 1646.08 -6.36%
There are some mixed improvements/regressions in most metrics along with
an elimination of fragmentation in this workload.
On the balance, the drastic 1->0 improvement in the happy cases seems
worth the mix of regressions and improvements we do observe.
Some considerations for future work:
- Experimenting with more size classes
- More hinting/search ordering work to approximate a best-fit allocator
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
reclaim isn't set in the alloc case, however we only care about
reclaim in the !alloc case. This isn't an actual problem, however
-Wmaybe-uninitialized will complain, so initialize reclaim to quiet the
compiler.
Reviewed-by: Qu Wenruo <wqu@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>
We already have flags in block group to track various status bits,
convert needs_free_space as well and reduce size of btrfs_block_group.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The div_factor* helpers calculate fraction or percentage fraction. The
name is a bit confusing, we use it only for percentage calculations and
there are two helpers.
There's a helper mult_frac that's for general fractions, that tries to
be accurate but we multiply and divide by small numbers so we can use
the div_u64 helper.
Rename the div_factor* helpers and use 1..100 percentage range, also drop
the case checking for percentage == 100, it's never hit.
The conversions:
* div_factor calculates tenths and the numbers need to be adjusted
* div_factor_fine is direct replacement
Signed-off-by: David Sterba <dsterba@suse.com>
Update, reformat or reword function comments. This also removes the kdoc
marker so we don't get reports when the function name is missing.
Changes made:
- remove kdoc markers
- reformat the brief description to be a proper sentence
- reword to imperative voice
- align parameter list
- fix typos
Signed-off-by: David Sterba <dsterba@suse.com>
Move all the extent tree related prototypes to extent-tree.h out of
ctree.h, and then go include it everywhere needed so everything
compiles.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This is a large patch, but because they're all macros it's impossible to
split up. Simply copy all of the item accessors in ctree.h and paste
them in accessors.h, and then update any files to include the header so
everything compiles.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ reformat comments, style fixups ]
Signed-off-by: David Sterba <dsterba@suse.com>
We have several fs wide related helpers in ctree.h. The bulk of these
are the incompat flag test helpers, but there are things such as
btrfs_fs_closing() and the read only helpers that also aren't directly
related to the ctree code. Move these into a fs.h header, which will
serve as the location for file system wide related helpers.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
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>
[BACKGROUND]
When committing a transaction, we will update block group items for all
dirty block groups.
But in fact, dirty block groups don't always need to update their block
group items.
It's pretty common to have a metadata block group which experienced
several COW operations, but still have the same amount of used bytes.
In that case, we may unnecessarily COW a tree block doing nothing.
[ENHANCEMENT]
This patch will introduce btrfs_block_group::commit_used member to
remember the last used bytes, and use that new member to skip
unnecessary block group item update.
This would be more common for large filesystems, where metadata block
group can be as large as 1GiB, containing at most 64K metadata items.
In that case, if COW added and then deleted one metadata item near the
end of the block group, then it's completely possible we don't need to
touch the block group item at all.
[BENCHMARK]
The change itself can have quite a high chance (20~80%) to skip block
group item updates in lot of workloads.
As a result, it would result shorter time spent on
btrfs_write_dirty_block_groups(), and overall reduce the execution time
of the critical section of btrfs_commit_transaction().
Here comes a fio command, which will do random writes in 4K block size,
causing a very heavy metadata updates.
fio --filename=$mnt/file --size=512M --rw=randwrite --direct=1 --bs=4k \
--ioengine=libaio --iodepth=64 --runtime=300 --numjobs=4 \
--name=random_write --fallocate=none --time_based --fsync_on_close=1
The file size (512M) and number of threads (4) means 2GiB file size in
total, but during the full 300s run time, my dedicated SATA SSD is able
to write around 20~25GiB, which is over 10 times the file size.
Thus after we fill the initial 2G, we should not cause much block group
item updates.
Please note, the fio numbers by themselves don't have much change, but
if we look deeper, there is some reduced execution time, especially for
the critical section of btrfs_commit_transaction().
I added extra trace_printk() to measure the following per-transaction
execution time:
- Critical section of btrfs_commit_transaction()
By re-using the existing update_commit_stats() function, which
has already calculated the interval correctly.
- The while() loop for btrfs_write_dirty_block_groups()
Although this includes the execution time of btrfs_run_delayed_refs(),
it should still be representative overall.
Both result involves transid 7~30, the same amount of transaction
committed.
The result looks like this:
| Before | After | Diff
----------------------+-------------------+----------------+--------
Transaction interval | 229247198.5 | 215016933.6 | -6.2%
Block group interval | 23133.33333 | 18970.83333 | -18.0%
The change in block group item updates is more obvious, as skipped block
group item updates also mean less delayed refs.
And the overall execution time for that block group update loop is
pretty small, thus we can assume the extent tree is already mostly
cached. If we can skip an uncached tree block, it would cause more
obvious change.
Unfortunately the overall reduction in commit transaction critical
section is much smaller, as the block group item updates loop is not
really the major part, at least not for the above fio script.
But still we have a observable reduction in the critical section.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
I have observed the following case play out and lead to unnecessary
relocations:
1. write a file across multiple block groups
2. delete the file
3. several block groups fall below the reclaim threshold
4. reclaim the first, moving extents into the others
5. reclaim the others which are now actually very full, leading to poor
reclaim behavior with lots of writing, allocating new block groups,
etc.
I believe the risk of missing some reasonable reclaims is worth it
when traded off against the savings of avoiding overfull reclaims.
Going forward, it could be interesting to make the check more advanced
(zoned aware, fragmentation aware, etc...) so that it can be a really
strong signal both at extent delete and reclaim time.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
As we delete extents from a block group, at some deletion we cross below
the reclaim threshold. It is possible we are still in the middle of
deleting more extents and might soon hit 0. If the block group is empty
by the time the reclaim worker runs, we will still relocate it.
This works just fine, as relocating an empty block group ultimately
results in properly deleting it. However, we have more direct ways of
removing empty block groups in the cleaner thread. Those are either
async discard or the unused_bgs list. In fact, when we decide whether to
relocate a block group during extent deletion, we do check for emptiness
and prefer the discard/unused_bgs mechanisms when possible.
Not using relocation for this case reduces some modest overhead from
empty bg relocation:
- extra transactions
- extra metadata use/churn for creating relocation metadata
- trying to read the extent tree to look for extents (and in this case
finding none)
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This function uses functions that are not defined in block-group.h, move
it into block-group.c in order to keep the header clean.
Reviewed-by: Qu Wenruo <wqu@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>
There are two comments in btrfs_cache_block_group that I left when
resolving conflict between commits ced8ecf026 "btrfs: fix space cache
corruption and potential double allocations" and 527c490f44 "btrfs:
delete btrfs_wait_space_cache_v1_finished".
The former reworked the caching logic to wait until the caching ends in
btrfs_cache_block_group while the latter only open coded the waiting.
Both removed btrfs_wait_space_cache_v1_finished, the correct code is
with the waiting and returning error. Thus the conflict resolution was
OK.
Signed-off-by: David Sterba <dsterba@suse.com>
In order to accommodate NOWAIT IOCB's we need to be able to do NO_FLUSH
data reservations, so plumb this through the delalloc reservation
system.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Stefan Roesch <shr@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This is actually embedded in struct btrfs_block_group, so move this
definition to block-group.h, and then open-code the init of the tree
where we init the rest of the block group instead of using a helper.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
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>
Currently there are two corner cases not handling compat RO flags
correctly:
- Remount
We can still mount the fs RO with compat RO flags, then remount it RW.
We should not allow any write into a fs with unsupported RO flags.
- Still try to search block group items
In fact, behavior/on-disk format change to extent tree should not
need a full incompat flag.
And since we can ensure fs with unsupported RO flags never got any
writes (with above case fixed), then we can even skip block group
items search at mount time.
This patch will enhance the unsupported RO compat flags by:
- Reject read-write remount if there are unsupported RO compat flags
- Go dummy block group items directly for unsupported RO compat flags
In fact, only changes to chunk/subvolume/root/csum trees should go
incompat flags.
The latter part should allow future change to extent tree to be compat
RO flags.
Thus this patch also needs to be backported to all stable trees.
CC: stable@vger.kernel.org # 4.9+
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>
We are calling __btrfs_remove_free_space_cache everywhere to cleanup the
block group free space, however we can just use
btrfs_remove_free_space_cache and pass in the block group in all of
these places. Then we can remove __btrfs_remove_free_space_cache and
rename __btrfs_remove_free_space_cache_locked to
__btrfs_remove_free_space_cache.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
struct btrfs_caching_ctl::progress and struct
btrfs_block_group::last_byte_to_unpin were previously needed to ensure
that unpin_extent_range() didn't return a range to the free space cache
before the caching thread had a chance to cache that range. However, the
commit "btrfs: fix space cache corruption and potential double
allocations" made it so that we always synchronously cache the block
group at the time that we pin the extent, so this machinery is no longer
necessary.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We used to use this in a few spots, but now we only use it directly
inside of block-group.c, so remove the helper and just open code where
we were using it.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This is used mostly to determine if we need to look at the caching ctl
list and clean up any references to this block group. However we never
clear this flag, specifically because we need to know if we have to
remove a caching ctl we have for this block group still. This is in the
remove block group path which isn't a fast path, so the optimization
doesn't really matter, simplify this logic and 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>
We're breaking out and re-searching for the next block group while
evicting any of the block group cache inodes. This is not needed, the
block groups aren't disappearing here, we can simply loop through the
block groups like normal and iput any inode that we find.
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>
We use a bit field in the btrfs_block_group for different flags, however
this is awkward because we have to hold the block_group->lock for any
modification of any of these fields, and makes the code clunky for a few
of these flags. Convert these to a properly flags setup so we can
utilize the bit helpers.
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>
We previously had the pattern of
btrfs_update_space_info(all, the, bg, fields, &space_info);
link_block_group(bg);
bg->space_info = space_info;
Now that we're passing the bg into btrfs_add_bg_to_space_info we can do
the linking in that function, transforming this to simply
btrfs_add_bg_to_space_info(fs_info, bg);
and put the link_block_group() and bg->space_info assignment directly in
btrfs_add_bg_to_space_info.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This function has grown a bunch of new arguments, and it just boils down
to passing in all the block group fields as arguments. Simplify this by
passing in the block group itself and updating the space_info fields
based on the block group fields directly.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
For both unused bg deletion and async balance work we'll happily run if
the fs is closing. However I want to move these to their own worker
thread, and they can be long running jobs, so add a check to see if
we're closing and simply bail.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When testing space_cache v2 on a large set of machines, we encountered a
few symptoms:
1. "unable to add free space :-17" (EEXIST) errors.
2. Missing free space info items, sometimes caught with a "missing free
space info for X" error.
3. Double-accounted space: ranges that were allocated in the extent tree
and also marked as free in the free space tree, ranges that were
marked as allocated twice in the extent tree, or ranges that were
marked as free twice in the free space tree. If the latter made it
onto disk, the next reboot would hit the BUG_ON() in
add_new_free_space().
4. On some hosts with no on-disk corruption or error messages, the
in-memory space cache (dumped with drgn) disagreed with the free
space tree.
All of these symptoms have the same underlying cause: a race between
caching the free space for a block group and returning free space to the
in-memory space cache for pinned extents causes us to double-add a free
range to the space cache. This race exists when free space is cached
from the free space tree (space_cache=v2) or the extent tree
(nospace_cache, or space_cache=v1 if the cache needs to be regenerated).
struct btrfs_block_group::last_byte_to_unpin and struct
btrfs_block_group::progress are supposed to protect against this race,
but commit d0c2f4fa55 ("btrfs: make concurrent fsyncs wait less when
waiting for a transaction commit") subtly broke this by allowing
multiple transactions to be unpinning extents at the same time.
Specifically, the race is as follows:
1. An extent is deleted from an uncached block group in transaction A.
2. btrfs_commit_transaction() is called for transaction A.
3. btrfs_run_delayed_refs() -> __btrfs_free_extent() runs the delayed
ref for the deleted extent.
4. __btrfs_free_extent() -> do_free_extent_accounting() ->
add_to_free_space_tree() adds the deleted extent back to the free
space tree.
5. do_free_extent_accounting() -> btrfs_update_block_group() ->
btrfs_cache_block_group() queues up the block group to get cached.
block_group->progress is set to block_group->start.
6. btrfs_commit_transaction() for transaction A calls
switch_commit_roots(). It sets block_group->last_byte_to_unpin to
block_group->progress, which is block_group->start because the block
group hasn't been cached yet.
7. The caching thread gets to our block group. Since the commit roots
were already switched, load_free_space_tree() sees the deleted extent
as free and adds it to the space cache. It finishes caching and sets
block_group->progress to U64_MAX.
8. btrfs_commit_transaction() advances transaction A to
TRANS_STATE_SUPER_COMMITTED.
9. fsync calls btrfs_commit_transaction() for transaction B. Since
transaction A is already in TRANS_STATE_SUPER_COMMITTED and the
commit is for fsync, it advances.
10. btrfs_commit_transaction() for transaction B calls
switch_commit_roots(). This time, the block group has already been
cached, so it sets block_group->last_byte_to_unpin to U64_MAX.
11. btrfs_commit_transaction() for transaction A calls
btrfs_finish_extent_commit(), which calls unpin_extent_range() for
the deleted extent. It sees last_byte_to_unpin set to U64_MAX (by
transaction B!), so it adds the deleted extent to the space cache
again!
This explains all of our symptoms above:
* If the sequence of events is exactly as described above, when the free
space is re-added in step 11, it will fail with EEXIST.
* If another thread reallocates the deleted extent in between steps 7
and 11, then step 11 will silently re-add that space to the space
cache as free even though it is actually allocated. Then, if that
space is allocated *again*, the free space tree will be corrupted
(namely, the wrong item will be deleted).
* If we don't catch this free space tree corruption, it will continue
to get worse as extents are deleted and reallocated.
The v1 space_cache is synchronously loaded when an extent is deleted
(btrfs_update_block_group() with alloc=0 calls btrfs_cache_block_group()
with load_cache_only=1), so it is not normally affected by this bug.
However, as noted above, if we fail to load the space cache, we will
fall back to caching from the extent tree and may hit this bug.
The easiest fix for this race is to also make caching from the free
space tree or extent tree synchronous. Josef tested this and found no
performance regressions.
A few extra changes fall out of this change. Namely, this fix does the
following, with step 2 being the crucial fix:
1. Factor btrfs_caching_ctl_wait_done() out of
btrfs_wait_block_group_cache_done() to allow waiting on a caching_ctl
that we already hold a reference to.
2. Change the call in btrfs_cache_block_group() of
btrfs_wait_space_cache_v1_finished() to
btrfs_caching_ctl_wait_done(), which makes us wait regardless of the
space_cache option.
3. Delete the now unused btrfs_wait_space_cache_v1_finished() and
space_cache_v1_done().
4. Change btrfs_cache_block_group()'s `int load_cache_only` parameter to
`bool wait` to more accurately describe its new meaning.
5. Change a few callers which had a separate call to
btrfs_wait_block_group_cache_done() to use wait = true instead.
6. Make btrfs_wait_block_group_cache_done() static now that it's not
used outside of block-group.c anymore.
Fixes: d0c2f4fa55 ("btrfs: make concurrent fsyncs wait less when waiting for a transaction commit")
CC: stable@vger.kernel.org # 5.12+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
With the automatic block group reclaim code we will preemptively try to
mark the block group RO before we start the relocation. We do this to
make sure we should actually try to relocate the block group.
However if we hit an error during the actual relocation we won't clean
up our RO counter and the block group will remain RO. This was observed
internally with file systems reporting less space available from df when
we had failed background relocations.
Fix this by doing the dec_ro in the error case.
Fixes: 18bb8bbf13 ("btrfs: zoned: automatically reclaim zones")
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There are two places where allocating a chunk is not enough. These two
places are trying to ensure the space by allocating a chunk. To meet the
condition for active_total_bytes, we also need to activate a block group
there.
CC: stable@vger.kernel.org # 5.16+
Fixes: afba2bc036 ("btrfs: zoned: implement active zone tracking")
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The active_total_bytes, like the total_bytes, accounts for the total bytes
of active block groups in the space_info.
With an introduction of active_total_bytes, we can check if the reserved
bytes can be written to the block groups without activating a new block
group. The check is necessary for metadata allocation on zoned
filesystem. We cannot finish a block group, which may require waiting
for the current transaction, from the metadata allocation context.
Instead, we need to ensure the ongoing allocation (reserved bytes) fits
in active block groups.
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Use the same expression for stripe_nr for RAID0 (map->sub_stripes is 1)
and RAID10 (map->sub_stripes is 2), with equivalent results.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If you try to force a chunk allocation, but you race with another chunk
allocation, you will end up waiting on the chunk allocation that just
occurred and then allocate another chunk. If you have many threads all
doing this at once you can way over-allocate chunks.
Fix this by resetting force to NO_FORCE, that way if we think we need to
allocate we can, otherwise we don't force another chunk allocation if
one is already happening.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
CC: stable@vger.kernel.org # 5.4+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
While the active zones within an active block group are reset, and their
active resource is released, the block group itself is kept in the active
block group list and marked as active. As a result, the list will contain
more than max_active_zones block groups. That itself is not fatal for the
device as the zones are properly reset.
However, that inflated list is, of course, strange. Also, a to-appear
patch series, which deactivates an active block group on demand, gets
confused with the wrong list.
So, fix the issue by finishing the unused block group once it gets
read-only, so that we can release the active resource in an early stage.
Fixes: be1a1d7a5d ("btrfs: zoned: finish fully written block group")
CC: stable@vger.kernel.org # 5.16+
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>
When doing a NOCOW write, either through direct IO or buffered IO, we do
two lookups for the block group that contains the target extent: once
when we call btrfs_inc_nocow_writers() and then later again when we call
btrfs_dec_nocow_writers() after creating the ordered extent.
The lookups require taking a lock and navigating the red black tree used
to track all block groups, which can take a non-negligible amount of time
for a large filesystem with thousands of block groups, as well as lock
contention and cache line bouncing.
Improve on this by having a single block group search: making
btrfs_inc_nocow_writers() return the block group to its caller and then
have the caller pass that block group to btrfs_dec_nocow_writers().
This is part of a patchset comprised of the following patches:
btrfs: remove search start argument from first_logical_byte()
btrfs: use rbtree with leftmost node cached for tracking lowest block group
btrfs: use a read/write lock for protecting the block groups tree
btrfs: return block group directly at btrfs_next_block_group()
btrfs: avoid double search for block group during NOCOW writes
The following test was used to test these changes from a performance
perspective:
$ cat test.sh
#!/bin/bash
modprobe null_blk nr_devices=0
NULL_DEV_PATH=/sys/kernel/config/nullb/nullb0
mkdir $NULL_DEV_PATH
if [ $? -ne 0 ]; then
echo "Failed to create nullb0 directory."
exit 1
fi
echo 2 > $NULL_DEV_PATH/submit_queues
echo 16384 > $NULL_DEV_PATH/size # 16G
echo 1 > $NULL_DEV_PATH/memory_backed
echo 1 > $NULL_DEV_PATH/power
DEV=/dev/nullb0
MNT=/mnt/nullb0
LOOP_MNT="$MNT/loop"
MOUNT_OPTIONS="-o ssd -o nodatacow"
MKFS_OPTIONS="-R free-space-tree -O no-holes"
cat <<EOF > /tmp/fio-job.ini
[io_uring_writes]
rw=randwrite
fsync=0
fallocate=posix
group_reporting=1
direct=1
ioengine=io_uring
iodepth=64
bs=64k
filesize=1g
runtime=300
time_based
directory=$LOOP_MNT
numjobs=8
thread
EOF
echo performance | \
tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
echo
echo "Using config:"
echo
cat /tmp/fio-job.ini
echo
umount $MNT &> /dev/null
mkfs.btrfs -f $MKFS_OPTIONS $DEV &> /dev/null
mount $MOUNT_OPTIONS $DEV $MNT
mkdir $LOOP_MNT
truncate -s 4T $MNT/loopfile
mkfs.btrfs -f $MKFS_OPTIONS $MNT/loopfile &> /dev/null
mount $MOUNT_OPTIONS $MNT/loopfile $LOOP_MNT
# Trigger the allocation of about 3500 data block groups, without
# actually consuming space on underlying filesystem, just to make
# the tree of block group large.
fallocate -l 3500G $LOOP_MNT/filler
fio /tmp/fio-job.ini
umount $LOOP_MNT
umount $MNT
echo 0 > $NULL_DEV_PATH/power
rmdir $NULL_DEV_PATH
The test was run on a non-debug kernel (Debian's default kernel config),
the result were the following.
Before patchset:
WRITE: bw=1455MiB/s (1526MB/s), 1455MiB/s-1455MiB/s (1526MB/s-1526MB/s), io=426GiB (458GB), run=300006-300006msec
After patchset:
WRITE: bw=1503MiB/s (1577MB/s), 1503MiB/s-1503MiB/s (1577MB/s-1577MB/s), io=440GiB (473GB), run=300006-300006msec
+3.3% write throughput and +3.3% IO done in the same time period.
The test has somewhat limited coverage scope, as with only NOCOW writes
we get less contention on the red black tree of block groups, since we
don't have the extra contention caused by COW writes, namely when
allocating data extents, pinning and unpinning data extents, but on the
hand there's access to tree in the NOCOW path, when incrementing a block
group's number of NOCOW writers.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
At btrfs_next_block_group(), we have this long line with two statements:
cache = btrfs_lookup_first_block_group(...); return cache;
This makes it a bit harder to read due to two statements on the same
line, so change that to directly return the result of the call to
btrfs_lookup_first_block_group().
Reviewed-by: Nikolay Borisov <nborisov@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>
Currently we use a spin lock to protect the red black tree that we use to
track block groups. Most accesses to that tree are actually read only and
for large filesystems, with thousands of block groups, it actually has
a bad impact on performance, as concurrent read only searches on the tree
are serialized.
Read only searches on the tree are very frequent and done when:
1) Pinning and unpinning extents, as we need to lookup the respective
block group from the tree;
2) Freeing the last reference of a tree block, regardless if we pin the
underlying extent or add it back to free space cache/tree;
3) During NOCOW writes, both buffered IO and direct IO, we need to check
if the block group that contains an extent is read only or not and to
increment the number of NOCOW writers in the block group. For those
operations we need to search for the block group in the tree.
Similarly, after creating the ordered extent for the NOCOW write, we
need to decrement the number of NOCOW writers from the same block
group, which requires searching for it in the tree;
4) Decreasing the number of extent reservations in a block group;
5) When allocating extents and freeing reserved extents;
6) Adding and removing free space to the free space tree;
7) When releasing delalloc bytes during ordered extent completion;
8) When relocating a block group;
9) During fitrim, to iterate over the block groups;
10) etc;
Write accesses to the tree, to add or remove block groups, are much less
frequent as they happen only when allocating a new block group or when
deleting a block group.
We also use the same spin lock to protect the list of currently caching
block groups. Additions to this list are made when we need to cache a
block group, because we don't have a free space cache for it (or we have
but it's invalid), and removals from this list are done when caching of
the block group's free space finishes. These cases are also not very
common, but when they happen, they happen only once when the filesystem
is mounted.
So switch the lock that protects the tree of block groups from a spinning
lock to a read/write lock.
Reviewed-by: Nikolay Borisov <nborisov@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>
We keep track of the start offset of the block group with the lowest start
offset at fs_info->first_logical_byte. This requires explicitly updating
that field every time we add, delete or lookup a block group to/from the
red black tree at fs_info->block_group_cache_tree.
Since the block group with the lowest start address happens to always be
the one that is the leftmost node of the tree, we can use a red black tree
that caches the left most node. Then when we need the start address of
that block group, we can just quickly get the leftmost node in the tree
and extract the start offset of that node's block group. This avoids the
need to explicitly keep track of that address in the dedicated member
fs_info->first_logical_byte, and it also allows the next patch in the
series to switch the lock that protects the red black tree from a spin
lock to a read/write lock - without this change it would be tricky
because block group searches also update fs_info->first_logical_byte.
Reviewed-by: Nikolay Borisov <nborisov@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>
The current auto-reclaim algorithm starts reclaiming all block groups
with a zone_unusable value above a configured threshold. This is causing
a lot of reclaim IO even if there would be enough free zones on the
device.
Instead of only accounting a block groups zone_unusable value, also take
the ratio of free and not usable (written as well as zone_unusable)
bytes a device has into account.
Tested-by: Pankaj Raghav <p.raghav@samsung.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This will allow us to set a threshold for block groups to be
automatically relocated even if we don't have zoned devices.
We have found this feature invaluable at Facebook due to how our
workload interacts with the allocator. We have been using this in
production for months with only a single problem that has already been
fixed.
Tested-by: Pankaj Raghav <p.raghav@samsung.com>
Signed-off-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>
This function can be simplified by refactoring to use the new iterator
macro. No functional changes.
Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Signed-off-by: Gabriel Niebler <gniebler@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In btrfs_make_block_group(), we activate the allocated block group,
expecting that the block group is soon used for allocation. However, the
chunk allocation from flush_space() context broke the assumption. There
can be a large time gap between the chunk allocation time and the extent
allocation time from the chunk.
Activating the empty block groups pre-allocated from flush_space()
context can exhaust the active zone counter of a device. Once we use all
the active zone counts for empty pre-allocated block groups, we cannot
activate new block group for the other things: metadata, tree-log, or
data relocation block group. That failure results in a fake -ENOSPC.
This patch introduces CHUNK_ALLOC_FORCE_FOR_EXTENT to distinguish the
chunk allocation from find_free_extent(). Now, the new block group is
activated only in that context.
Fixes: eb66a010d5 ("btrfs: zoned: activate new block group")
CC: stable@vger.kernel.org # 5.16+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Return the allocated block group from do_chunk_alloc(). This is a
preparation patch for the next patch.
CC: stable@vger.kernel.org # 5.16+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Clang's version of -Wunused-but-set-variable recently gained support for
unary operations, which reveals two unused variables:
fs/btrfs/block-group.c:2949:6: error: variable 'num_started' set but not used [-Werror,-Wunused-but-set-variable]
int num_started = 0;
^
fs/btrfs/block-group.c:3116:6: error: variable 'num_started' set but not used [-Werror,-Wunused-but-set-variable]
int num_started = 0;
^
2 errors generated.
These variables appear to be unused from their introduction, so just
remove them to silence the warnings.
Fixes: c9dc4c6578 ("Btrfs: two stage dirty block group writeout")
Fixes: 1bbc621ef2 ("Btrfs: allow block group cache writeout outside critical section in commit")
CC: stable@vger.kernel.org # 5.4+
Link: https://github.com/ClangBuiltLinux/linux/issues/1614
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: David Sterba <dsterba@suse.com>
There is a hung_task issue with running generic/068 on an SMR
device. The hang occurs while a process is trying to thaw the
filesystem. The process is trying to take sb->s_umount to thaw the
FS. The lock is held by fsstress, which calls btrfs_sync_fs() and is
waiting for an ordered extent to finish. However, as the FS is frozen,
the ordered extents never finish.
Having an ordered extent while the FS is frozen is the root cause of
the hang. The ordered extent is initiated from btrfs_relocate_chunk()
which is called from btrfs_reclaim_bgs_work().
This commit adds sb_*_write() around btrfs_relocate_chunk() call
site. For the usual "btrfs balance" command, we already call it with
mnt_want_file() in btrfs_ioctl_balance().
Fixes: 18bb8bbf13 ("btrfs: zoned: automatically reclaim zones")
CC: stable@vger.kernel.org # 5.13+
Link: https://github.com/naota/linux/issues/56
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.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>
With extent tree v2 you will be able to create multiple csum, extent,
and free space trees. They will be used based on the block group, which
will now use the block_group_item->chunk_objectid to point to the set of
global roots that it will use. When allocating new block groups we'll
simply mod the gigabyte offset of the block group against the number of
global roots we have and that will be the block groups global id.
>From there we can take the bytenr that we're modifying in the respective
tree, look up the block group and get that block groups corresponding
global root id. From there we can get to the appropriate global root
for that bytenr.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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>
[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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
btrfs_relocate_chunk() can fail with -EAGAIN when e.g. send operations are
running. The message can fail btrfs/187 and it's unnecessary because we
anyway add it back to the reclaim list.
btrfs_reclaim_bgs_work()
`-> btrfs_relocate_chunk()
`-> btrfs_relocate_block_group()
`-> reloc_chunk_start()
`-> if (fs_info->send_in_progress)
`-> return -EAGAIN
CC: stable@vger.kernel.org # 5.13+
Fixes: 18bb8bbf13 ("btrfs: zoned: automatically reclaim zones")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.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>
When extent tree gets corrupted, normally it's not extent tree root, but
one toasted tree leaf/node.
In that case, rescue=ibadroots mount option won't help as it can only
handle the extent tree root corruption.
This patch will enhance the behavior by:
- Allow fill_dummy_bgs() to ignore -EEXIST error
This means we may have some block group items read from disk, but
then hit some error halfway.
- Fallback to fill_dummy_bgs() if any error gets hit in
btrfs_read_block_groups()
Of course, this still needs rescue=ibadroots mount option.
With that, rescue=ibadroots can handle extent tree corruption more
gracefully and allow a better recover chance.
Reported-by: Zhenyu Wu <wuzy001@gmail.com>
Link: https://www.spinics.net/lists/linux-btrfs/msg114424.html
Reviewed-by: Su Yue <l@damenly.su>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
One of the final things that must be done to add a new chunk is
inserting its device extent items in the device tree. They describe
the portion of allocated device physical space during phase 1 of
chunk allocation. This is currently done in btrfs_finish_chunk_alloc
whose name isn't very informative. What's more, this function is only
used in block-group.c but is defined as public. There isn't anything
special about it that would warrant it being defined in volumes.c.
Just move btrfs_finish_chunk_alloc and alloc_chunk_dev_extent to
block-group.c, make the former static and rename both functions to
insert_dev_extents and insert_dev_extent respectively.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If we can't acquire the reclaim_bgs_lock on block group reclaim, we
block until it is free. This can potentially stall for a long time.
While reclaim of block groups is necessary for a good user experience on
a zoned file system, there still is no need to block as it is best
effort only, just like when we're deleting unused block groups.
CC: stable@vger.kernel.org # 5.13
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Commit eafa4fd0ad ("btrfs: fix exhaustion of the system chunk array
due to concurrent allocations") fixed a problem that resulted in
exhausting the system chunk array in the superblock when there are many
tasks allocating chunks in parallel. Basically too many tasks enter the
first phase of chunk allocation without previous tasks having finished
their second phase of allocation, resulting in too many system chunks
being allocated. That was originally observed when running the fallocate
tests of stress-ng on a PowerPC machine, using a node size of 64K.
However that commit also introduced a deadlock where a task in phase 1 of
the chunk allocation waited for another task that had allocated a system
chunk to finish its phase 2, but that other task was waiting on an extent
buffer lock held by the first task, therefore resulting in both tasks not
making any progress. That change was later reverted by a patch with the
subject "btrfs: fix deadlock with concurrent chunk allocations involving
system chunks", since there is no simple and short solution to address it
and the deadlock is relatively easy to trigger on zoned filesystems, while
the system chunk array exhaustion is not so common.
This change reworks the chunk allocation to avoid the system chunk array
exhaustion. It accomplishes that by making the first phase of chunk
allocation do the updates of the device items in the chunk btree and the
insertion of the new chunk item in the chunk btree. This is done while
under the protection of the chunk mutex (fs_info->chunk_mutex), in the
same critical section that checks for available system space, allocates
a new system chunk if needed and reserves system chunk space. This way
we do not have chunk space reserved until the second phase completes.
The same logic is applied to chunk removal as well, since it keeps
reserved system space long after it is done updating the chunk btree.
For direct allocation of system chunks, the previous behaviour remains,
because otherwise we would deadlock on extent buffers of the chunk btree.
Changes to the chunk btree are by large done by chunk allocation and chunk
removal, which first reserve chunk system space and then later do changes
to the chunk btree. The other remaining cases are uncommon and correspond
to adding a device, removing a device and resizing a device. All these
other cases do not pre-reserve system space, they modify the chunk btree
right away, so they don't hold reserved space for a long period like chunk
allocation and chunk removal do.
The diff of this change is huge, but more than half of it is just addition
of comments describing both how things work regarding chunk allocation and
removal, including both the new behavior and the parts of the old behavior
that did not change.
CC: stable@vger.kernel.org # 5.12+
Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Tested-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Tested-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana
Linus Torvalds
Josef Bacik
Qu Wenruo
Matt Corallo
Naohiro Aota
David Sterba
Naohiro Aota
Johannes Thumshirn
Boris Burkov
Christoph Hellwig
Omar Sandoval
Gabriel Niebler
Nathan Chancellor
Nikolay Borisov
Anand Jain