kernel/linux.git/fs/btrfs/extent_map.c, branch linux-7.1.y

Merge tag 'for-7.1-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

2026-05-23T23:54:48+00:00

Pull btrfs fixes from David Sterba: "A batch of fixes to simple quotas: - add conditional rescheduling point not dependent on the lock during inode iterations to avoid delays with PREEMPT_NONE enabled - fix subvolume deletion so it does not break the squota invariants - properly handle enabling squota, tracking extents in the initial transaction - catch and warn about underflows, clamp to zero to avoid further problems And one fix to inode size handling: - fix handling of preallocated extents beyond i_size when not using the no-holes feature" * tag 'for-7.1-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: swallow btrfs_record_squota_delta() ENOENT btrfs: clamp to avoid squota underflow btrfs: fix squota accounting during enable generation btrfs: check for subvolume before deleting squota qgroup btrfs: always drop root->inodes lock before cond_resched() btrfs: mark file extent range dirty after converting prealloc extents

btrfs: always drop root->inodes lock before cond_resched()

2026-05-16T01:06:56+00:00

find_first_inode() and find_first_inode_to_shrink() lock root->inodes, then loop over them, occasionally skipping some inodes. When they skip an inode, they attempt to share the cpu/lock with cond_resched_lock(). However, that has a subtle problem associated with it. cond_resched_lock() only drops the lock if it needs to actually call schedule(). With CONFIG_PREEMPT_NONE, this means the full timeslice as detected at ticks. With 8+ cpus and default tunables, this is 2.8ms. So regardless of HZ, we will run for at least 2.8ms in this loop without dropping the lock, assuming it finds no suitable inodes. If HZ is small enough, it might be even worse as the tick granularity becomes bigger than the timeslice. The knock-on effect of this is that callers to btrfs_del_inode_from_root() like kswapd trying to shrink the inode slab or userspace threads calling evict() will spin on xa_lock(&root->inodes) for 2.8ms, so the extent map shrinker dominates the lock even though ostensibly it is intending to share it. This produces memory pressure as there is only one kswapd and it runs sequentially so it can get stuck in the inode slab shrinking. To fix it, simply replace cond_resched_lock() with an open coded variant which unconditionally does unlock/lock around cond_resched. Sharing the lock is decoupled from sharing the CPU, and all the users of the lock now share it fairly. I was able to reproduce this on test systems by producing a lot of empty files (to make a big root->inodes xarray), then producing memory pressure by reading large files larger than ram, triggering kswapd and the extent_map shrinker. The lock contention is visible with perf or lockstat. This patch also relieved a user-apparent bottleneck on a production system from the original report. Tested-by: Rik van Riel Reviewed-by: Filipe Manana Signed-off-by: Boris Burkov Signed-off-by: David Sterba

btrfs: Use trace_call__##name() at guarded tracepoint call sites

2026-03-26T14:24:40+00:00

Replace trace_foo() with the new trace_call__foo() at sites already guarded by trace_foo_enabled(), avoiding a redundant static_branch_unlikely() re-evaluation inside the tracepoint. trace_call__foo() calls the tracepoint callbacks directly without utilizing the static branch again. Cc: Chris Mason Link: https://patch.msgid.link/20260323160052.17528-16-vineeth@bitbyteword.org Suggested-by: Steven Rostedt Suggested-by: Peter Zijlstra Signed-off-by: Vineeth Pillai (Google) Assisted-by: Claude:claude-sonnet-4-6 Acked-by: David Sterba Signed-off-by: Steven Rostedt (Google)

btrfs: add strict extent map alignment checks

2026-02-03T06:56:19+00:00

Currently we do not check the alignment of extent_map structure. The reasons are the inode and extent-map tests use unaligned values for start offsets and lengths. Thankfully those legacy problems are properly addressed by previous patches, now we can finally put the alignment checks into validate_extent_map(). Reviewed-by: Filipe Manana Signed-off-by: Qu Wenruo Signed-off-by: David Sterba

Merge tag 'for-6.18-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

2025-09-30T15:14:49+00:00

Pull btrfs updates from David Sterba: "There are no new features, the changes are in the core code, notably tree-log error handling and reporting improvements, and initial support for block size > page size. Performance improvements: - search data checksums in the commit root (previous transaction) to avoid locking contention, this improves parallelism of read heavy/low write workloads, and also reduces transaction commit time; on real and reproducer workload the sync time went from minutes to tens of seconds (workload and numbers are in the changelog) Core: - tree-log updates: - error handling improvements, transaction aborts - add new error state 'O' (printed in status messages) when log replay fails and is aborted - reduced number of btrfs_path allocations when traversing the tree - 'block size > page size' support - basic implementation with limitations, under experimental build - limitations: no direct io, raid56, encoded read (standalone and in send ioctl), encoded write - preparatory work for compression, removing implicit assumptions of page and block sizes - compression workspaces are now per-filesystem, we cannot assume common block size for work memory among different filesystems - tree-checker now verifies INODE_EXTREF item (which is implementing hardlinks) - tree leaf pretty printer updates, there were missing data from items, keys/items - move config option CONFIG_BTRFS_REF_VERIFY to CONFIG_BTRFS_DEBUG, it's a debugging feature and not needed to be enabled separately - more struct btrfs_path auto free updates - use ref_tracker API for tracking delayed inodes, enabled by mount option 'ref_verify', allowing to better pinpoint leaking references - in zoned mode, avoid selecting data relocation zoned for ordinary data block groups - updated and enhanced error messages - lots of cleanups and refactoring" * tag 'for-6.18-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (113 commits) btrfs: use smp_mb__after_atomic() when forcing COW in create_pending_snapshot() btrfs: add unlikely annotations to branches leading to transaction abort btrfs: add unlikely annotations to branches leading to EIO btrfs: add unlikely annotations to branches leading to EUCLEAN btrfs: more trivial BTRFS_PATH_AUTO_FREE conversions btrfs: zoned: don't fail mount needlessly due to too many active zones btrfs: use kmalloc_array() for open-coded arithmetic in kmalloc() btrfs: enable experimental bs > ps support btrfs: add extra ASSERT()s to catch unaligned bios btrfs: fix symbolic link reading when bs > ps btrfs: prepare scrub to support bs > ps cases btrfs: prepare zlib to support bs > ps cases btrfs: prepare lzo to support bs > ps cases btrfs: prepare zstd to support bs > ps cases btrfs: prepare compression folio alloc/free for bs > ps cases btrfs: fix the incorrect max_bytes value for find_lock_delalloc_range() btrfs: remove pointless key offset setup in create_pending_snapshot() btrfs: annotate btrfs_is_testing() as unlikely and make it return bool btrfs: make the rule checking more readable for should_cow_block() btrfs: simplify inline extent end calculation at replay_one_extent() ...

btrfs: add unlikely annotations to branches leading to EIO

2025-09-23T06:49:26+00:00

The unlikely() annotation is a static prediction hint that compiler may use to reorder code out of hot path. We use it elsewhere (namely tree-checker.c) for error branches that almost never happen, where EIO is one of them. Reviewed-by: Filipe Manana Signed-off-by: David Sterba

btrfs: convert several int parameters to bool

2025-09-22T08:54:32+00:00

We're almost done cleaning misused int/bool parameters. Convert a bunch of them, found by manual grepping. Note that btrfs_sync_fs() needs an int as it's mandated by the struct super_operations prototype. Reviewed-by: Boris Burkov Signed-off-by: David Sterba

fs: replace use of system_unbound_wq with system_dfl_wq

2025-09-19T14:15:07+00:00

Currently if a user enqueue a work item using schedule_delayed_work() the used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to schedule_work() that is using system_wq and queue_work(), that makes use again of WORK_CPU_UNBOUND. This lack of consistentcy cannot be addressed without refactoring the API. system_unbound_wq should be the default workqueue so as not to enforce locality constraints for random work whenever it's not required. Adding system_dfl_wq to encourage its use when unbound work should be used. The old system_unbound_wq will be kept for a few release cycles. Suggested-by: Tejun Heo Signed-off-by: Marco Crivellari Link: https://lore.kernel.org/20250916082906.77439-2-marco.crivellari@suse.com Signed-off-by: Christian Brauner

btrfs: add btrfs prefix to is_fstree() and make it return bool

2025-07-21T21:58:04+00:00

This is an exported function and therefore it should have a 'btrfs_' prefix, to make it clear it's btrfs specific, avoid future name collisions with code outside btrfs, and make its naming consistent with most other btrfs exported functions. So add a 'btrfs_' prefix to it and make it return bool instead of int, since all we need is to return true or false. Reviewed-by: Johannes Thumshirn Reviewed-by: Qu Wenruo Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: rename __tree_search() to remove double underscore prefix

2025-05-15T12:30:45+00:00

There's no need to have a double underscore prefix as there's no variant of the function without it. Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba