kernel/linux.git/fs/btrfs/compression.c, branch v6.12.102

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: compression: adjust cb->compressed_folios allocation type

2025-05-29T09:03:12+00:00

[ Upstream commit 6f9a8ab796c6528d22de3c504c81fce7dde63d8a ] In preparation for making the kmalloc() family of allocators type aware, we need to make sure that the returned type from the allocation matches the type of the variable being assigned. (Before, the allocator would always return "void *", which can be implicitly cast to any pointer type.) The assigned type is "struct folio **" but the returned type will be "struct page **". These are the same allocation size (pointer size), but the types don't match. Adjust the allocation type to match the assignment. Reviewed-by: Qu Wenruo Signed-off-by: Kees Cook Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Sasha Levin

btrfs: rename btrfs_folio_(set|start|end)_writer_lock()

2025-02-27T12:30:14+00:00

[ Upstream commit 0f7120266584490616f031873e7148495d77dd68 ] Since there is no user of reader locks, rename the writer locks into a more generic name, by removing the "_writer" part from the name. And also rename btrfs_subpage::writer into btrfs_subpage::locked. Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba Stable-dep-of: 8bf334beb349 ("btrfs: fix double accounting race when extent_writepage_io() failed") Signed-off-by: Sasha Levin

btrfs: unify to use writer locks for subpage locking

2025-02-27T12:30:13+00:00

[ Upstream commit 336e69f3025fb70db9d0dfb7f36ac79887bf5341 ] Since commit d7172f52e993 ("btrfs: use per-buffer locking for extent_buffer reading"), metadata read no longer relies on the subpage reader locking. This means we do not need to maintain a different metadata/data split for locking, so we can convert the existing reader lock users by: - add_ra_bio_pages() Convert to btrfs_folio_set_writer_lock() - end_folio_read() Convert to btrfs_folio_end_writer_lock() - begin_folio_read() Convert to btrfs_folio_set_writer_lock() - folio_range_has_eb() Remove the subpage->readers checks, since it is always 0. - Remove btrfs_subpage_start_reader() and btrfs_subpage_end_reader() Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba Stable-dep-of: 8bf334beb349 ("btrfs: fix double accounting race when extent_writepage_io() failed") Signed-off-by: Sasha Levin

btrfs: convert btrfs_decompress() to take a folio

2024-09-10T14:51:21+00:00

The old page API is being gradually replaced and converted to use folio to improve code readability and avoid repeated conversion between page and folio. Based on the previous patch, the compression path can be directly used in folio without converting to page. Signed-off-by: Li Zetao Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: convert zstd_decompress() to take a folio

2024-09-10T14:51:21+00:00

The old page API is being gradually replaced and converted to use folio to improve code readability and avoid repeated conversion between page and folio. And memcpy_to_page() can be replaced with memcpy_to_folio(). But there is no memzero_folio(), but it can be replaced equivalently by folio_zero_range(). Signed-off-by: Li Zetao Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: convert lzo_decompress() to take a folio

2024-09-10T14:51:21+00:00

btrfs: convert zlib_decompress() to take a folio

2024-09-10T14:51:21+00:00

btrfs: do not hold the extent lock for entire read

2024-09-10T14:51:20+00:00

Historically we've held the extent lock throughout the entire read. There's been a few reasons for this, but it's mostly just caused us problems. For example, this prevents us from allowing page faults during direct io reads, because we could deadlock. This has forced us to only allow 4k reads at a time for io_uring NOWAIT requests because we have no idea if we'll be forced to page fault and thus have to do a whole lot of work. On the buffered side we are protected by the page lock, as long as we're reading things like buffered writes, punch hole, and even direct IO to a certain degree will get hung up on the page lock while the page is in flight. On the direct side we have the dio extent lock, which acts much like the way the extent lock worked previously to this patch, however just for direct reads. This protects direct reads from concurrent direct writes, while we're protected from buffered writes via the inode lock. Now that we're protected in all cases, narrow the extent lock to the part where we're getting the extent map to submit the reads, no longer holding the extent lock for the entire read operation. Push the extent lock down into do_readpage() so that we're only grabbing it when looking up the extent map. This portion was contributed by Goldwyn. Co-developed-by: Goldwyn Rodrigues Reviewed-by: Goldwyn Rodrigues Signed-off-by: Josef Bacik Signed-off-by: David Sterba

btrfs: rename btrfs_submit_bio() to btrfs_submit_bbio()

2024-09-10T14:51:19+00:00

The function name is a bit misleading as it submits the btrfs_bio (bbio), rename it so we can use btrfs_submit_bio() when an actual bio is submitted. Reviewed-by: Qu Wenruo Signed-off-by: David Sterba