kernel/fs/btrfs/space-info.c, branch linux-rolling-stable

btrfs: hold space_info->lock when clearing periodic reclaim ready

2026-03-19T15:14:48Z

[ Upstream commit b8883b61f2fc50dcf22938cbed40fec05020552f ] btrfs_set_periodic_reclaim_ready() requires space_info->lock to be held, as enforced by lockdep_assert_held(). However, btrfs_reclaim_sweep() was calling it after do_reclaim_sweep() returns, at which point space_info->lock is no longer held. Fix this by explicitly acquiring space_info->lock before clearing the periodic reclaim ready flag in btrfs_reclaim_sweep(). Reported-by: Chris Mason Link: https://lore.kernel.org/linux-btrfs/20260208182556.891815-1-clm@meta.com/ Fixes: 19eff93dc738 ("btrfs: fix periodic reclaim condition") Reviewed-by: Boris Burkov Signed-off-by: Sun YangKai Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Sasha Levin

btrfs: fix periodic reclaim condition

2026-03-04T12:21:31Z

[ Upstream commit 19eff93dc738e8afaa59cb374b44bb5a162e6c2d ] Problems with current implementation: 1. reclaimable_bytes is signed while chunk_sz is unsigned, causing negative reclaimable_bytes to trigger reclaim unexpectedly 2. The "space must be freed between scans" assumption breaks the two-scan requirement: first scan marks block groups, second scan reclaims them. Without the second scan, no reclamation occurs. Instead, track actual reclaim progress: pause reclaim when block groups will be reclaimed, and resume only when progress is made. This ensures reclaim continues until no further progress can be made. And resume periodic reclaim when there's enough free space. And we take care if reclaim is making any progress now, so it's unnecessary to set periodic_reclaim_ready to false when failed to reclaim a block group. Fixes: 813d4c6422516 ("btrfs: prevent pathological periodic reclaim loops") CC: stable@vger.kernel.org # 6.12+ Suggested-by: Boris Burkov Reviewed-by: Boris Burkov Signed-off-by: Sun YangKai Signed-off-by: David Sterba Signed-off-by: Sasha Levin

btrfs: fix memory leaks in create_space_info() error paths

2026-01-12T15:21:55Z

In create_space_info(), the 'space_info' object is allocated at the beginning of the function. However, there are two error paths where the function returns an error code without freeing the allocated memory: 1. When create_space_info_sub_group() fails in zoned mode. 2. When btrfs_sysfs_add_space_info_type() fails. In both cases, 'space_info' has not yet been added to the fs_info->space_info list, resulting in a memory leak. Fix this by adding an error handling label to kfree(space_info) before returning. Fixes: 2be12ef79fe9 ("btrfs: Separate space_info create/update") Reviewed-by: Qu Wenruo Signed-off-by: Jiasheng Jiang Signed-off-by: David Sterba

btrfs: make a few more ASSERTs verbose

2025-11-24T21:42:24Z

We have support for optional string to be printed in ASSERT() (added in 19468a623a9109 ("btrfs: enhance ASSERT() to take optional format string")), it's not yet everywhere it could be so add a few more files. Signed-off-by: David Sterba

btrfs: move struct reserve_ticket definition to space-info.c

2025-11-24T21:42:23Z

It's not used anywhere outside space-info.c so move it from space-info.h into space-info.c. Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: headers cleanup to remove unnecessary local includes

2025-11-24T21:34:52Z

[BUG] When I tried to remove btrfs_bio::fs_info and use btrfs_bio::inode to grab the fs_info, the header "btrfs_inode.h" is needed to access the full btrfs_inode structure. Then btrfs will fail to compile. [CAUSE] There is a recursive including chain: "bio.h" -> "btrfs_inode.h" -> "extent_map.h" -> "compression.h" -> "bio.h" That recursive including is causing problems for btrfs. [ENHANCEMENT] To reduce the risk of recursive including: - Remove unnecessary local includes from btrfs headers Either the included header is pulled in by other headers, or is completely unnecessary. - Remove btrfs local includes if the header only requires a pointer In that case let the implementing C file to pull the required header. This is especially important for headers like "btrfs_inode.h" which pulls in a lot of other btrfs headers, thus it's a mine field of recursive including. - Remove unnecessary temporary structure definition Either if we have included the header defining the structure, or completely unused. Now including "btrfs_inode.h" inside "bio.h" is completely fine, although "btrfs_inode.h" still includes "extent_map.h", but that header only includes "fs.h", no more chain back to "bio.h". Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: annotate as unlikely fs aborted checks in space flushing code

2025-11-24T21:20:29Z

It's not expected to have the fs in an aborted state, so surround the abortion checks with unlikely to make it clear it's unexpected and to hint the compiler to generate better code. Also at maybe_fail_all_tickets() untangle all repeated checks for the abortion into a single if-then-else. This makes things more readable and makes the compiler generate less code. On x86_64 with gcc 14.2.0-19 from Debian I got the following object size differences. Before this change: $ size fs/btrfs/btrfs.ko text data bss dec hex filename 2021606 179704 25088 2226398 21f8de fs/btrfs/btrfs.ko After this change: $ size fs/btrfs/btrfs.ko text data bss dec hex filename 2021458 179704 25088 2226250 21f84a fs/btrfs/btrfs.ko Reviewed-by: Johannes Thumshirn Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: avoid space_info locking when checking if tickets are served

2025-11-24T21:18:21Z

When checking if a ticket was served, we take the space_info's spinlock. If the ticket was served (its ->bytes is 0) or had an error (its ->error it not 0) then we just unlock the space_info and return. This however causes contention on the space_info's spinlock, which is heavily used (space reservation, space flushing, allocating and deallocating an extent from a block group (btrfs_update_block_group()), etc). Instead of using the space_info's spinlock to check if a ticket was served, use a per ticket spinlock which isn't used by anyone other than the task that created the ticket (stack allocated) and the task that serves the ticket (a reclaim task or any task deallocating space that ends up at btrfs_try_granting_tickets()). After applying this patch and all previous patches from the same patchset (many attempt to reduce space_info critical sections), lockstat showed some improvements for a fs_mark test regarding the space_info's spinlock 'lock'. The lockstat results: Before patchset: con-bounces: 13733858 contentions: 15902322 waittime-total: 264902529.72 acq-bounces: 28161791 acquisitions: 38679282 After patchset: con-bounces: 12032220 contentions: 13598034 waittime-total: 221806127.28 acq-bounces: 24717947 acquisitions: 34103281 Reviewed-by: Johannes Thumshirn Signed-off-by: Filipe Manana Signed-off-by: David Sterba

btrfs: move ticket wakeup and finalization to remove_ticket()

2025-11-24T21:18:17Z

Instead of repeating the wakeup and setup of the ->bytes or ->error field, move those steps to remove_ticket() to avoid duplication. This is also needed for the next patch in the series, so that we avoid duplicating more logic. Reviewed-by: Johannes Thumshirn Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: add data_race() in btrfs_account_ro_block_groups_free_space()

2025-11-24T21:16:27Z

Surround the intentional empty list check with the data_race() annotation so that tools like KCSAN don't report a data race. The race is intentional as it's harmless and we want to avoid lock contention of the space_info since its lock is heavily used (space reservation, space flushing, extent allocation and deallocation, etc). Reviewed-by: Johannes Thumshirn Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba