kernel/linux.git/fs/btrfs/ordered-data.h, branch v6.12.97

btrfs: fix false IO failure after falling back to buffered write

2026-07-24T14:11:54+00:00

[ Upstream commit 66ff4d366e7eb4d31813d2acabf3af512ce03aa5 ] [BUG] The test case generic/362 will fail with "nodatasum" mount option (*): MOUNT_OPTIONS -- -o nodatasum /dev/mapper/test-scratch1 /mnt/scratch # generic/362 0s ... - output mismatch (see /home/adam/xfstests/results//generic/362.out.bad) # --- tests/generic/362.out 2024-08-24 15:31:37.200000000 +0930 # +++ /home/adam/xfstests/results//generic/362.out.bad 2026-05-27 10:21:17.574771567 +0930 # @@ -1,2 +1,3 @@ # QA output created by 362 # +First write failed: Input/output error # Silence is golden # ... *: If the test case has been executed before with default data checksum, the failure will not reproduce. Need the following fix to make it reliably reproducible: https://lore.kernel.org/linux-btrfs/20260528111659.87113-1-wqu@suse.com/ [CAUSE] Inside __iomap_dio_rw(), the -EFAULT/-ENOTBLK error is not directly returned. Thus we never got an error pointer from __iomap_dio_rw(). The call chain looks like this: btrfs_direct_write() |- btrfs_dio_write() |- __iomap_dio_rw() | |- iomap_iter() | | |- btrfs_dio_iomap_begin() | | Now an ordered extent is allocated for the 4K write. | | | |- iomi.status = iomap_dio_iter() | | Where iomap_dio_iter() returned -EFAULT. | | | |- ret = iomap_iter() | | |- btrfs_dio_iomap_end() | | | |- btrfs_finish_ordered_extent(uptodate = false) | | | | |- can_finish_ordered_extent() | | | | |- btrfs_mark_ordered_extent_error() | | | | |- mapping_set_error() | | | | Now the address space is marked error. | | | | return -ENOTBLK | | |- return -ENOTBLK | |- if (ret == -ENOTBLK) { ret = 0; } | Now the return value is reset to 0. | Thus no error pointer will be returned. | |- ret = iomap_dio_complete() | Since no byte is submitted, @ret is 0. | |- Fallback to buffered IO | And the buffered write finished without error | |- filemap_fdatawait_range() |- filemap_check_errors() The previous error is recorded, thus an error is returned However the buffered write is properly submitted and finished, the error is from the btrfs_finish_ordered_extent() call with @uptodate = false. [FIX] When a short dio write happened, any range that is submitted will have btrfs_extract_ordered_extent() to be called, thus the submitted range will always have an OE just covering the submitted range. The remaining OE range is never submitted, thus they should be treated as truncated, not an error. So that we can properly reclaim and not insert an unnecessary file extent item, without marking the mapping as error. Extract a helper, btrfs_mark_ordered_extent_truncated(), and utilize that helper to mark the direct IO ordered extent as truncated, so it won't cause failure for the later buffered fallback. [REASON FOR NO FIXES TAG] The bug itself is pretty old, at commit f85781fb505e ("btrfs: switch to iomap for direct IO") we're already passing @uptodate=false finishing the OE. But at that time OE with IOERR won't call mapping_set_error(), so it's not exposed. Later commit d61bec08b904 ("btrfs: mark ordered extent and inode with error if we fail to finish") finally exposed the bug, but that commit is doing a correct job, not the root cause. Anyway the bug is very old, dating back to 5.1x days, thus only CC to stable. CC: stable@vger.kernel.org # 5.15+ Reviewed-by: Boris Burkov Signed-off-by: Qu Wenruo Signed-off-by: David Sterba Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

btrfs: remove folio parameter from ordered io related functions

2026-07-24T14:11:53+00:00

[ Upstream commit a11d6912fdd9e57aff889ec97256b1d6b4e5bf06 ] Both functions btrfs_finish_ordered_extent() and btrfs_mark_ordered_io_finished() are accepting an optional folio parameter. That @folio is passed into can_finish_ordered_extent(), which later will test and clear the ordered flag for the involved range. However I do not think there is any other call site that can clear ordered flags of an page cache folio and can affect can_finish_ordered_extent(). There are limited *_clear_ordered() callers out of can_finish_ordered_extent() function: - btrfs_migrate_folio() This is completely unrelated, it's just migrating the ordered flag to the new folio. - btrfs_cleanup_ordered_extents() We manually clean the ordered flags of all involved folios, then call btrfs_mark_ordered_io_finished() without a @folio parameter. So it doesn't need and didn't pass a @folio parameter in the first place. - btrfs_writepage_fixup_worker() This function is going to be removed soon, and we should not hit that function anymore. - btrfs_invalidate_folio() This is the real call site we need to bother with. If we already have a bio running, btrfs_finish_ordered_extent() in end_bbio_data_write() will be executed first, as btrfs_invalidate_folio() will wait for the writeback to finish. Thus if there is a running bio, it will not see the range has ordered flags, and just skip to the next range. If there is no bio running, meaning the ordered extent is created but the folio is not yet submitted. In that case btrfs_invalidate_folio() will manually clear the folio ordered range, but then manually finish the ordered extent with btrfs_dec_test_ordered_pending() without bothering the folio ordered flags. Meaning if the OE range with folio ordered flags will be finished manually without the need to call can_finish_ordered_extent(). This means all can_finish_ordered_extent() call sites should get a range that has folio ordered flag set, thus the old "return false" branch should never be triggered. Now we can: - Remove the @folio parameter from involved functions * btrfs_mark_ordered_io_finished() * btrfs_finish_ordered_extent() For call sites passing a @folio into those functions, let them manually clear the ordered flag of involved folios. - Move btrfs_finish_ordered_extent() out of the loop in end_bbio_data_write() We only need to call btrfs_finish_ordered_extent() once per bbio, not per folio. - Add an ASSERT() to make sure all folio ranges have ordered flags It's only for end_bbio_data_write(). And we already have enough safe nets to catch over-accounting of ordered extents. Reviewed-by: Filipe Manana Signed-off-by: Qu Wenruo Signed-off-by: David Sterba Stable-dep-of: 66ff4d366e7e ("btrfs: fix false IO failure after falling back to buffered write") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

btrfs: convert btrfs_mark_ordered_io_finished() to take a folio

2024-09-10T14:51:14+00:00

We only need a folio now, make it take a folio as an argument and update all of the callers. Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: convert btrfs_finish_ordered_extent() to take a folio

2024-09-10T14:51:14+00:00

The callers and callee's of this now all use folios, update it to take a folio as well. Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: switch btrfs_ordered_extent::inode to struct btrfs_inode

2024-07-11T13:33:28+00:00

The structure is internal so we should use struct btrfs_inode for that, allowing to remove some use of BTRFS_I. Reviewed-by: Boris Burkov Signed-off-by: David Sterba

btrfs: cleanup duplicated parameters related to create_io_em()

2024-07-11T13:33:21+00:00

Most parameters of create_io_em() can be replaced by the members with the same name inside btrfs_file_extent. Do a direct parameters cleanup here. Reviewed-by: Johannes Thumshirn Reviewed-by: Filipe Manana Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: cleanup duplicated parameters related to btrfs_alloc_ordered_extent

2024-07-11T13:33:21+00:00

All parameters after @filepos of btrfs_alloc_ordered_extent() can be replaced with btrfs_file_extent structure. This patch does the cleanup, meanwhile some points to note: - Move btrfs_file_extent structure to ordered-data.h The structure is needed by both btrfs_alloc_ordered_extent() and can_nocow_extent(), but since btrfs_inode.h includes ordered-data.h, so we need to move the structure to ordered-data.h. - Move the special handling of NOCOW/PREALLOC into btrfs_alloc_ordered_extent() This is to allow btrfs_split_ordered_extent() to properly split them for DIO. For now just move the handling into btrfs_alloc_ordered_extent() to simplify the callers. Reviewed-by: Johannes Thumshirn Reviewed-by: Filipe Manana Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: simplify range parameters of btrfs_wait_ordered_roots()

2024-07-11T13:33:19+00:00

The range is specified only in two ways, we can simplify the case for the whole filesystem range as a NULL block group parameter. Signed-off-by: David Sterba

btrfs: pass a btrfs_inode to btrfs_wait_ordered_range()

2024-07-11T13:33:18+00:00

Instead of passing a (VFS) inode pointer argument, pass a btrfs_inode instead, as this is generally what we do for internal APIs, making it more consistent with most of the code base. This will later allow to help to remove a lot of BTRFS_I() calls in btrfs_sync_file(). Reviewed-by: Qu Wenruo Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: make btrfs_finish_ordered_extent() return void

2024-07-11T13:33:18+00:00

Currently btrfs_finish_ordered_extent() returns a boolean indicating if the ordered extent was added to the work queue for completion, but none of its callers cares about it, so make it return void. Reviewed-by: Qu Wenruo Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba