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2026-05-08btrfs: fix check_chunk_block_group_mappings() to iterate all chunk mapsZhengYuan Huang1-15/+8
[BUG] A corrupted image with a chunk present in the chunk tree but whose corresponding block group item is missing from the extent tree can be mounted successfully, even though check_chunk_block_group_mappings() is supposed to catch exactly this corruption at mount time. Once mounted, running btrfs balance with a usage filter (-dusage=N or -dusage=min..max) triggers a null-ptr-deref: KASAN: null-ptr-deref in range [0x0000000000000070-0x0000000000000077] RIP: 0010:chunk_usage_filter fs/btrfs/volumes.c:3874 [inline] RIP: 0010:should_balance_chunk fs/btrfs/volumes.c:4018 [inline] RIP: 0010:__btrfs_balance fs/btrfs/volumes.c:4172 [inline] RIP: 0010:btrfs_balance+0x2024/0x42b0 fs/btrfs/volumes.c:4604 [CAUSE] The crash occurs because __btrfs_balance() iterates the on-disk chunk tree, finds the orphaned chunk, calls chunk_usage_filter() (or chunk_usage_range_filter()), which queries the in-memory block group cache via btrfs_lookup_block_group(). Since no block group was ever inserted for this chunk, the lookup returns NULL, and the subsequent dereference of cache->used crashes. check_chunk_block_group_mappings() uses btrfs_find_chunk_map() to iterate the in-memory chunk map (fs_info->mapping_tree): map = btrfs_find_chunk_map(fs_info, start, 1); With @start = 0 and @length = 1, btrfs_find_chunk_map() looks for a chunk map that *contains* the logical address 0. If no chunk contains logical address 0, btrfs_find_chunk_map(fs_info, 0, 1) returns NULL immediately and the loop breaks after the very first iteration, having checked zero chunks. The entire verification function is therefore a no-op, and the corrupted image passes the mount-time check undetected. [FIX] Replace the btrfs_find_chunk_map() based loop with a direct in-order walk of fs_info->mapping_tree using rb_first_cached() + rb_next(). This guarantees that every chunk map in the tree is visited regardless of the logical addresses involved. No lock is taken around the traversal. This function is called during mount from btrfs_read_block_groups(), which is invoked from open_ctree() before any background threads (cleaner, transaction kthread, etc.) are started. There are therefore no concurrent writers that could modify mapping_tree at this point. An analogous lockless direct traversal of mapping_tree already exists in fill_dummy_bgs() in the same file. Since we walk the rb-tree directly via rb_entry() without going through btrfs_find_chunk_map(), no reference is taken on each map entry, so the btrfs_free_chunk_map() calls are also removed. Signed-off-by: ZhengYuan Huang <gality369@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-04-07btrfs: replace BUG_ON() with error return in cache_save_setup()Teng Liu1-1/+7
In cache_save_setup(), if create_free_space_inode() succeeds but the subsequent lookup_free_space_inode() still fails on retry, the BUG_ON(retries) will crash the kernel. This can happen due to I/O errors or transient failures, not just programming bugs. Replace the BUG_ON with proper error handling that returns the original error code through the existing cleanup path. The callers already handle this gracefully: disk_cache_state defaults to BTRFS_DC_ERROR, so the space cache simply won't be written for that block group. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Teng Liu <27rabbitlt@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-04-07btrfs: zoned: limit number of zones reclaimed in flush_space()Johannes Thumshirn1-4/+9
Limit the number of zones reclaimed in flush_space()'s RECLAIM_ZONES state. This prevents possibly long running reclaim sweeps to block other tasks in the system, while the system is under pressure anyways, causing the tasks to hang. An example of this can be seen here, triggered by fstests generic/551: generic/551 [ 27.042349] run fstests generic/551 at 2026-02-27 11:05:30 BTRFS: device fsid 78c16e29-20d9-4c8e-bc04-7ba431be38ff devid 1 transid 8 /dev/vdb (254:16) scanned by mount (806) BTRFS info (device vdb): first mount of filesystem 78c16e29-20d9-4c8e-bc04-7ba431be38ff BTRFS info (device vdb): using crc32c checksum algorithm BTRFS info (device vdb): host-managed zoned block device /dev/vdb, 64 zones of 268435456 bytes BTRFS info (device vdb): zoned mode enabled with zone size 268435456 BTRFS info (device vdb): checking UUID tree BTRFS info (device vdb): enabling free space tree INFO: task kworker/u38:1:90 blocked for more than 120 seconds. Not tainted 7.0.0-rc1+ #345 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u38:1 state:D stack:0 pid:90 tgid:90 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_unbound btrfs_async_reclaim_data_space Call Trace: <TASK> __schedule+0x34f/0xe70 schedule+0x41/0x140 schedule_timeout+0xa3/0x110 ? mark_held_locks+0x40/0x70 ? lockdep_hardirqs_on_prepare+0xd8/0x1c0 ? trace_hardirqs_on+0x18/0x100 ? lockdep_hardirqs_on+0x84/0x130 ? _raw_spin_unlock_irq+0x33/0x50 wait_for_completion+0xa4/0x150 ? __flush_work+0x24c/0x550 __flush_work+0x339/0x550 ? __pfx_wq_barrier_func+0x10/0x10 ? wait_for_completion+0x39/0x150 flush_space+0x243/0x660 ? find_held_lock+0x2b/0x80 ? kvm_sched_clock_read+0x11/0x20 ? local_clock_noinstr+0x17/0x110 ? local_clock+0x15/0x30 ? lock_release+0x1b7/0x4b0 do_async_reclaim_data_space+0xe8/0x160 btrfs_async_reclaim_data_space+0x19/0x30 process_one_work+0x20a/0x5f0 ? lock_is_held_type+0xcd/0x130 worker_thread+0x1e2/0x3c0 ? __pfx_worker_thread+0x10/0x10 kthread+0x103/0x150 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x20d/0x320 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Showing all locks held in the system: 1 lock held by khungtaskd/67: #0: ffffffff824d58e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x194 2 locks held by kworker/u38:1/90: #0: ffff8881000aa158 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x3c4/0x5f0 #1: ffffc90000c17e58 ((work_completion)(&fs_info->async_data_reclaim_work)){+.+.}-{0:0}, at: process_one_work+0x1c0/0x5f0 5 locks held by kworker/u39:1/191: #0: ffff8881000aa158 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x3c4/0x5f0 #1: ffffc90000dfbe58 ((work_completion)(&fs_info->reclaim_bgs_work)){+.+.}-{0:0}, at: process_one_work+0x1c0/0x5f0 #2: ffff888101da0420 (sb_writers#9){.+.+}-{0:0}, at: process_one_work+0x20a/0x5f0 #3: ffff88811040a648 (&fs_info->reclaim_bgs_lock){+.+.}-{4:4}, at: btrfs_reclaim_bgs_work+0x1de/0x770 #4: ffff888110408a18 (&fs_info->cleaner_mutex){+.+.}-{4:4}, at: btrfs_relocate_block_group+0x95a/0x20f0 1 lock held by aio-dio-write-v/980: #0: ffff888110093008 (&sb->s_type->i_mutex_key#15){++++}-{4:4}, at: btrfs_inode_lock+0x51/0xb0 ============================================= To prevent these long running reclaims from blocking the system, only reclaim 5 block_groups in the RECLAIM_ZONES state of flush_space(). Also as these reclaims are now constrained, it opens up the use for a synchronous call to brtfs_reclaim_block_groups(), eliminating the need to place the reclaim task on a workqueue and then flushing the workqueue again. Reviewed-by: Boris Burkov <boris@bur.io> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-04-07btrfs: create btrfs_reclaim_block_groups()Johannes Thumshirn1-3/+9
Create a function btrfs_reclaim_block_groups() that gets called from the block-group reclaim worker. This allows creating synchronous block_group reclaim later on. Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Boris Burkov <boris@bur.io> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-04-07btrfs: move reclaiming of a single block group into its own functionJohannes Thumshirn1-123/+133
The main work of reclaiming a single block-group in btrfs_reclaim_bgs_work() is done inside the loop iterating over all the block_groups in the fs_info->reclaim_bgs list. Factor out reclaim of a single block group from the loop to improve readability. No functional change intended. Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Boris Burkov <boris@bur.io> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-04-07btrfs: replace kcalloc() calls to kzalloc_objs()Miquel Sabaté Solà1-1/+1
Commit 2932ba8d9c99 ("slab: Introduce kmalloc_obj() and family") introduced, among many others, the kzalloc_objs() helper, which has some benefits over kcalloc(). Namely, internal introspection of the allocated type now becomes possible, allowing for future alignment-aware choices to be made by the allocator and future hardening work that can be type sensitive. Dropping 'sizeof' comes also as a nice side-effect. Moreover, this also allows us to be in line with the recent tree-wide migration to the kmalloc_obj() and family of helpers. See commit 69050f8d6d07 ("treewide: Replace kmalloc with kmalloc_obj for non-scalar types"). Reviewed-by: Kees Cook <kees@kernel.org> Signed-off-by: Miquel Sabaté Solà <mssola@mssola.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-04-07btrfs: remove bogus root search condition in load_extent_tree_free()Filipe Manana1-2/+1
There's no need to pass the maximum between the block group's start offset and BTRFS_SUPER_INFO_OFFSET (64K) since we can't have any block groups allocated in the first megabyte, as that's reserved space. Furthermore, even if we could, the correct thing to do was to pass the block group's start offset anyway - and that's precisely what we do for block groups hat happen to contain a superblock mirror (the range for the super block is never marked as free and it's marked as dirty in the fs_info->excluded_extents io tree). So simplify this and get rid of that maximum expression. Reviewed-by: Boris Burkov <boris@bur.io> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-04-07btrfs: change return type of cache_save_setup to voidJohannes Thumshirn1-10/+7
None of the callers of `cache_save_setup` care about the return type as the space cache is purely and optimization. Also the free space cache is a deprecated feature that is being phased out. Change the return type of `cache_save_setup` to void to reflect this. Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-04-07btrfs: zoned: move partially zone_unusable block groups to reclaim listJohannes Thumshirn1-0/+18
On zoned block devices, block groups accumulate zone_unusable space (space between the write pointer and zone end that cannot be allocated until the zone is reset). When a block group becomes mostly zone_unusable but still contains some valid data and it gets added to the unused_bgs list it can never be deleted because it's not actually empty. The deletion code (btrfs_delete_unused_bgs) skips these block groups due to the btrfs_is_block_group_used() check, leaving them on the unused_bgs list indefinitely. This causes two problems: 1. The block groups are never reclaimed, permanently wasting space 2. Eventually leads to ENOSPC even though reclaimable space exists Fix by detecting block groups where zone_unusable exceeds 50% of the block group size. Move these to the reclaim_bgs list instead of skipping them. This triggers btrfs_reclaim_bgs_work() which: 1. Marks the block group read-only 2. Relocates the remaining valid data via btrfs_relocate_chunk() 3. Removes the emptied block group 4. Resets the zones, converting zone_unusable back to usable space The 50% threshold ensures we only reclaim block groups where most space is unusable, making relocation worthwhile. Block groups with less zone_unusable are left on unused_bgs to potentially become fully empty through normal deletion. Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-04-07btrfs: pass boolean literals as the last argument to inc_block_group_ro()Filipe Manana1-8/+8
The last argument of inc_block_group_ro() is defined as a boolean, but every caller is passing an integer literal, 0 or 1 for false and true respectively. While this is not incorrect, as 0 and 1 are converted to false and true, it's less readable and somewhat awkward since the argument is defined as boolean. Replace 0 and 1 with false and true. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Qu Wenruo <wqu@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>
2026-03-28Merge tag 'for-7.0-rc5-tag' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: "A few more fixes. There's one that stands out in size as it fixes an edge case in fsync. - fix issue on fsync where file with zero size appears as a non-zero after log replay - in zlib compression, handle a crash when data alignment causes folio reference issues - fix possible crash with enabled tracepoints on a overlayfs mount - handle device stats update error - on zoned filesystems, fix kobject leak on sub-block groups - fix super block offset in an error message in validation" * tag 'for-7.0-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: fix lost error when running device stats on multiple devices fs btrfs: tracepoints: get correct superblock from dentry in event btrfs_sync_file() btrfs: zlib: handle page aligned compressed size correctly btrfs: fix leak of kobject name for sub-group space_info btrfs: fix zero size inode with non-zero size after log replay btrfs: fix super block offset in error message in btrfs_validate_super()
2026-03-23btrfs: fix leak of kobject name for sub-group space_infoShin'ichiro Kawasaki1-1/+1
When create_space_info_sub_group() allocates elements of space_info->sub_group[], kobject_init_and_add() is called for each element via btrfs_sysfs_add_space_info_type(). However, when check_removing_space_info() frees these elements, it does not call btrfs_sysfs_remove_space_info() on them. As a result, kobject_put() is not called and the associated kobj->name objects are leaked. This memory leak is reproduced by running the blktests test case zbd/009 on kernels built with CONFIG_DEBUG_KMEMLEAK. The kmemleak feature reports the following error: unreferenced object 0xffff888112877d40 (size 16): comm "mount", pid 1244, jiffies 4294996972 hex dump (first 16 bytes): 64 61 74 61 2d 72 65 6c 6f 63 00 c4 c6 a7 cb 7f data-reloc...... backtrace (crc 53ffde4d): __kmalloc_node_track_caller_noprof+0x619/0x870 kstrdup+0x42/0xc0 kobject_set_name_vargs+0x44/0x110 kobject_init_and_add+0xcf/0x150 btrfs_sysfs_add_space_info_type+0xfc/0x210 [btrfs] create_space_info_sub_group.constprop.0+0xfb/0x1b0 [btrfs] create_space_info+0x211/0x320 [btrfs] btrfs_init_space_info+0x15a/0x1b0 [btrfs] open_ctree+0x33c7/0x4a50 [btrfs] btrfs_get_tree.cold+0x9f/0x1ee [btrfs] vfs_get_tree+0x87/0x2f0 vfs_cmd_create+0xbd/0x280 __do_sys_fsconfig+0x3df/0x990 do_syscall_64+0x136/0x1540 entry_SYSCALL_64_after_hwframe+0x76/0x7e To avoid the leak, call btrfs_sysfs_remove_space_info() instead of kfree() for the elements. Fixes: f92ee31e031c ("btrfs: introduce btrfs_space_info sub-group") Link: https://lore.kernel.org/linux-block/b9488881-f18d-4f47-91a5-3c9bf63955a5@wdc.com/ Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-03-21Merge tag 'for-7.0-rc4-tag' of ↵Linus Torvalds1-0/+36
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: "Another batch of fixes for problems that have been identified by tools analyzing code or by fuzzing. Most of them are short, two patches fix the same thing in many places so the diffs are bigger. - handle potential NULL pointer errors after attempting to read extent and checksum trees - prevent ENOSPC when creating many qgroups by ioctls in the same transaction - encoded write ioctl fixes (with 64K page and 4K block size): - fix unexpected bio length - do not let compressed bios and pages interfere with page cache - compression fixes on setups with 64K page and 4K block size: fix folio length assertions (zstd and lzo) - remap tree fixes: - make sure to hold block group reference while moving it - handle early exit when moving block group to unused list - handle deleted subvolumes with inconsistent state of deletion progress" * tag 'for-7.0-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: reject root items with drop_progress and zero drop_level btrfs: check block group before marking it unused in balance_remap_chunks() btrfs: hold block group reference during entire move_existing_remap() btrfs: fix an incorrect ASSERT() condition inside lzo_decompress_bio() btrfs: fix an incorrect ASSERT() condition inside zstd_decompress_bio() btrfs: do not touch page cache for encoded writes btrfs: fix a bug that makes encoded write bio larger than expected btrfs: reserve enough transaction items for qgroup ioctls btrfs: check for NULL root after calls to btrfs_csum_root() btrfs: check for NULL root after calls to btrfs_extent_root()
2026-03-17btrfs: check for NULL root after calls to btrfs_extent_root()Filipe Manana1-0/+36
btrfs_extent_root() can return a NULL pointer in case the root we are looking for is not in the rb tree that tracks roots. So add checks to every caller that is missing such check to log a message and return an error. The same applies to callers of btrfs_block_group_root(), since it calls btrfs_extent_root(). Reported-by: Chris Mason <clm@meta.com> Link: https://lore.kernel.org/linux-btrfs/20260208161657.3972997-1-clm@meta.com/ Reviewed-by: Boris Burkov <boris@bur.io> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-03-03Merge tag 'for-7.0-rc2-tag' of ↵Linus Torvalds1-1/+0
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: "One-liner or short fixes for minor/moderate problems reported recently: - fixes or level adjustments of error messages - fix leaked transaction handles after aborted transactions, when using the remap tree feature - fix a few leaked chunk maps after errors - fix leaked page array in io_uring encoded read if an error occurs and the 'finished' is not called - fix double release of reserved extents when doing a range COW - don't commit super block when the filesystem is in shutdown state - fix squota accounting condition when checking members vs parent usage - other error handling fixes" * tag 'for-7.0-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: check block group lookup in remove_range_from_remap_tree() btrfs: fix transaction handle leaks in btrfs_last_identity_remap_gone() btrfs: fix chunk map leak in btrfs_map_block() after btrfs_translate_remap() btrfs: fix chunk map leak in btrfs_map_block() after btrfs_chunk_map_num_copies() btrfs: fix compat mask in error messages in btrfs_check_features() btrfs: print correct subvol num if active swapfile prevents deletion btrfs: fix warning in scrub_verify_one_metadata() btrfs: fix objectid value in error message in check_extent_data_ref() btrfs: fix incorrect key offset in error message in check_dev_extent_item() btrfs: fix error message order of parameters in btrfs_delete_delayed_dir_index() btrfs: don't commit the super block when unmounting a shutdown filesystem btrfs: free pages on error in btrfs_uring_read_extent() btrfs: fix referenced/exclusive check in squota_check_parent_usage() btrfs: remove pointless WARN_ON() in cache_save_setup() btrfs: convert log messages to error level in btrfs_replay_log() btrfs: remove btrfs_handle_fs_error() after failure to recover log trees btrfs: remove redundant warning message in btrfs_check_uuid_tree() btrfs: change warning messages to error level in open_ctree() btrfs: fix a double release on reserved extents in cow_one_range() btrfs: handle discard errors in in btrfs_finish_extent_commit()
2026-02-26btrfs: remove pointless WARN_ON() in cache_save_setup()Filipe Manana1-1/+0
This WARN_ON(ret) is never executed since the previous if statement makes us jump into the 'out_put' label when ret is not zero. The existing transaction abort inside the if statement also gives us a stack trace, so we don't need to move the WARN_ON(ret) into the if statement either. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-21treewide: Replace kmalloc with kmalloc_obj for non-scalar typesKees Cook1-4/+3
This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook <kees@kernel.org>
2026-02-18btrfs: reset block group size class when it becomes emptyJiasheng Jiang1-0/+10
Block group size classes are managed consistently everywhere. Currently, btrfs_use_block_group_size_class() sets a block group's size class to specialize it for a specific allocation size. However, this size class remains "stale" even if the block group becomes completely empty (both used and reserved bytes reach zero). This happens in two scenarios: 1. When space reservations are freed (e.g., due to errors or transaction aborts) via btrfs_free_reserved_bytes(). 2. When the last extent in a block group is freed via btrfs_update_block_group(). While size classes are advisory, a stale size class can cause find_free_extent to unnecessarily skip candidate block groups during initial search loops. This undermines the purpose of size classes to reduce fragmentation by keeping block groups restricted to a specific size class when they could be reused for any size. Fix this by resetting the size class to BTRFS_BG_SZ_NONE whenever a block group's used and reserved counts both reach zero. This ensures that empty block groups are fully available for any allocation size in the next cycle. Fixes: 52bb7a2166af ("btrfs: introduce size class to block group allocator") Reviewed-by: Boris Burkov <boris@bur.io> Signed-off-by: Jiasheng Jiang <jiashengjiangcool@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03btrfs: do not BUG_ON() in btrfs_remove_block_group()Filipe Manana1-1/+6
There's no need to BUG_ON(), we can just abort the transaction and return an error. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03btrfs: abort transaction on error in btrfs_remove_block_group()Filipe Manana1-5/+14
When btrfs_remove_block_group() fails we abort the transaction in its single caller (btrfs_remove_chunk()). This makes it harder to find out where exactly the failure happened, as several steps inside btrfs_remove_block_group() can fail. So make btrfs_remove_block_group() abort the transaction whenever an error happens, instead of aborting in its caller. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03btrfs: remove out label in load_extent_tree_free()Filipe Manana1-6/+4
There is no point in having the label since all it does is return the value in the 'ret' variable. Instead make every goto return directly and remove the label. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03btrfs: deal with missing root in sample_block_group_extent_item()Filipe Manana1-0/+6
In case the root does not exists, which is unexpected, btrfs_extent_root() returns NULL, but we ignore that and so if it happens we can trigger a NULL pointer dereference later. So verify if we found the root and log an error message in case it's missing. Reviewed-by: Boris Burkov <boris@bur.io> Reviewed-by: Qu Wenruo <wqu@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>
2026-02-03btrfs: remove bogus root search condition in sample_block_group_extent_item()Filipe Manana1-2/+1
There's no need to pass the maximum between the block group's start offset and BTRFS_SUPER_INFO_OFFSET (64K) since we can't have any block groups allocated in the first megabyte, as that's reserved space. Furthermore, even if we could, the correct thing to do was to pass the block group's start offset anyway - and that's precisely what we do for block groups that happen to contain superblock mirror (the range for the super block is never marked as free and it's marked as dirty in the fs_info->excluded_extents io tree). So simplify this and get rid of that maximum expression. Reviewed-by: Boris Burkov <boris@bur.io> Reviewed-by: Qu Wenruo <wqu@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>
2026-02-03btrfs: assert block group is locked in btrfs_use_block_group_size_class()Filipe Manana1-0/+1
It's supposed to be called with the block group locked, in order to read and set its size_class member, so assert it's locked. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Qu Wenruo <wqu@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>
2026-02-03btrfs: don't pass block group argument to load_block_group_size_class()Filipe Manana1-7/+6
There's no need to pass the block group since we can extract it from the given caching control structure. Same goes for its helper function sample_block_group_extent_item(). Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Qu Wenruo <wqu@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>
2026-02-03btrfs: allocate path on stack in load_block_group_size_class()Filipe Manana1-13/+19
Instead of allocating and freeing a path in every iteration of load_block_group_size_class(), through its helper function sample_block_group_extent_item(), allocate the path in the former and pass it to the later. The path is allocated on stack since it's short and we are in a workqueue context so there's not much stack usage. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Qu Wenruo <wqu@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>
2026-02-03btrfs: make load_block_group_size_class() return voidFilipe Manana1-8/+8
There's no point in returning anything since determining and setting a size class for a block group is an optimization, not something critical. The only caller of load_block_group_size_class() (the caching thread) does not do anything with the return value anyway, exactly because having a size class is just an optimization and it can always be set later when adding reserved bytes to a block group (btrfs_add_reserved_bytes()). Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Qu Wenruo <wqu@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>
2026-02-03btrfs: consolidate reclaim readiness checks in btrfs_should_reclaim()Sun YangKai1-6/+6
Move the filesystem state validation from btrfs_reclaim_bgs_work() into btrfs_should_reclaim() to centralize the reclaim eligibility logic. Since it is the only caller of btrfs_should_reclaim(), there's no functional change. Reviewed-by: Boris Burkov <boris@bur.io> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Sun YangKai <sunk67188@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03btrfs: fix periodic reclaim conditionSun YangKai1-2/+4
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 <boris@bur.io> Reviewed-by: Boris Burkov <boris@bur.io> Signed-off-by: Sun YangKai <sunk67188@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03btrfs: use the btrfs_block_group_end() helper everywhereFilipe Manana1-11/+10
We have a helper to calculate a block group's exclusive end offset, but we only use it in some places. Update every site that open codes the calculation to use the helper. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03btrfs: populate fully_remapped_bgs_list on mountMark Harmstone1-0/+75
Add a function btrfs_populate_fully_remapped_bgs_list() which gets called on mount, which looks for fully remapped block groups (i.e. identity_remap_count == 0) which haven't yet had their chunk stripes and device extents removed. This happens when a filesystem is unmounted while async discard has not yet finished, as otherwise the data range occupied by the chunk stripes would be permanently unusable. Reviewed-by: Boris Burkov <boris@bur.io> Signed-off-by: Mark Harmstone <mark@harmstone.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03btrfs: handle discarding fully-remapped block groupsMark Harmstone1-13/+17
Discard normally works by iterating over the free-space entries of a block group. This doesn't work for fully-remapped block groups, as we removed their free-space entries when we started relocation. For sync discard, call btrfs_discard_extent() when we commit the transaction in which the last identity remap was removed. For async discard, add a new function btrfs_trim_fully_remapped_block_group() to be called by the discard worker, which iterates over the block group's range using the normal async discard rules. Once we reach the end, remove the chunk's stripes and device extents to get back its free space. Reviewed-by: Boris Burkov <boris@bur.io> Signed-off-by: Mark Harmstone <mark@harmstone.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03btrfs: handle setting up relocation of block group with remap-treeMark Harmstone1-1/+5
Handle the preliminary work for relocating a block group in a filesystem with the remap-tree flag set. If the block group is SYSTEM btrfs_relocate_block_group() proceeds as it does already, as bootstrapping issues mean that these block groups have to be processed the existing way. Similarly with METADATA_REMAP blocks, which are dealt with in a later patch. Otherwise we walk the free-space tree for the block group in question, recording any holes. These get converted into identity remaps and placed in the remap tree, and the block group's REMAPPED flag is set. From now on no new allocations are possible within this block group, and any I/O to it will be funnelled through btrfs_translate_remap(). We store the number of identity remaps in `identity_remap_count`, so that we know when we've removed the last one and the block group is fully remapped. The change in btrfs_read_roots() is because data relocations no longer rely on the data reloc tree as a hidden subvolume in which to do snapshots. (Thanks to Sun YangKai for his suggestions.) Reviewed-by: Boris Burkov <boris@bur.io> Signed-off-by: Mark Harmstone <mark@harmstone.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03btrfs: handle deletions from remapped block groupMark Harmstone1-26/+61
Handle the case where we free an extent from a block group that has the REMAPPED flag set. Because the remap tree is orthogonal to the extent tree, for data this may be within any number of identity remaps or actual remaps. If we're freeing a metadata node, this will be wholly inside one or the other. btrfs_remove_extent_from_remap_tree() searches the remap tree for the remaps that cover the range in question, then calls remove_range_from_remap_tree() for each one, to punch a hole in the remap and adjust the free-space tree. For an identity remap, remove_range_from_remap_tree() will adjust the block group's `identity_remap_count` if this changes. If it reaches zero we mark the block group as fully remapped. For an identity remap, remove_range_from_remap_tree() will adjust the block group's `identity_remap_count` if this changes. If it reaches zero we mark the block group as fully remapped. Fully remapped block groups have their chunk stripes removed and their device extents freed, which makes the disk space available again to the chunk allocator. This happens asynchronously: in the cleaner thread for sync discard and nodiscard, and (in a later patch) in the discard worker for async discard. Reviewed-by: Boris Burkov <boris@bur.io> Signed-off-by: Mark Harmstone <mark@harmstone.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03btrfs: add extended version of struct block_group_itemMark Harmstone1-24/+68
Add a struct btrfs_block_group_item_v2, which is used in the block group tree if the remap-tree incompat flag is set. This adds two new fields to the block group item: `remap_bytes` and `identity_remap_count`. `remap_bytes` records the amount of data that's physically within this block group, but nominally in another, remapped block group. This is necessary because this data will need to be moved first if this block group is itself relocated. If `remap_bytes` > 0, this is an indicator to the relocation thread that it will need to search the remap-tree for backrefs. A block group must also have `remap_bytes` == 0 before it can be dropped. `identity_remap_count` records how many identity remap items are located in the remap tree for this block group. When relocation is begun for this block group, this is set to the number of holes in the free-space tree for this range. As identity remaps are converted into actual remaps by the relocation process, this number is decreased. Once it reaches 0, either because of relocation or because extents have been deleted, the block group has been fully remapped and its chunk's device extents are removed. Reviewed-by: Boris Burkov <boris@bur.io> Signed-off-by: Mark Harmstone <mark@harmstone.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03btrfs: rename struct btrfs_block_group field commit_used to last_usedMark Harmstone1-12/+12
Rename the field commit_used in struct btrfs_block_group to last_used, for clarity and consistency with the similar fields we're about to add. It's not obvious that commit_flags means "flags as of the last commit" rather than "flags related to a commit". Signed-off-by: Mark Harmstone <mark@harmstone.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03btrfs: remove remapped block groups from the free-space-treeMark Harmstone1-3/+16
No new allocations can be done from block groups that have the REMAPPED flag set, so there's no value in their having entries in the free-space tree. Prevent a search through the free-space tree being scheduled for such a block group, and prevent any additions to the in-memory free-space tree. Reviewed-by: Boris Burkov <boris@bur.io> Signed-off-by: Mark Harmstone <mark@harmstone.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03btrfs: add and use helper to compute the available space for a block groupFilipe Manana1-7/+2
We have currently three places that compute how much available space a block group has. Add a helper function for this and use it in those places. Reviewed-by: Boris Burkov <boris@bur.io> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Qu Wenruo <wqu@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>
2026-02-03btrfs: split btrfs_fs_closing() and change return type to boolDavid Sterba1-1/+1
There are two tests in btrfs_fs_closing() but checking the BTRFS_FS_CLOSING_DONE bit is done only in one place load_extent_tree_free(). As this is an inline we can reduce size of the generated code. The types can be also changed to bool as this becomes a simple condition. text data bss dec hex filename 1674006 146704 15560 1836270 1c04ee pre/btrfs.ko 1673772 146704 15560 1836036 1c0404 post/btrfs.ko DELTA: -234 Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03btrfs: rename btrfs_create_block_group_cache to btrfs_create_block_groupJohannes Thumshirn1-4/+4
struct btrfs_block_group used to be called struct btrfs_block_group_cache but got renamed to btrfs_block_group with commit 32da5386d9a4 ("btrfs: rename btrfs_block_group_cache"). Rename btrfs_create_block_group_cache() to btrfs_create_block_group() to reflect that change. Reviewed-by: Filipe Manana <fdmanana@suse.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>
2026-02-03btrfs: merge setting ret and return retDavid Sterba1-2/+1
In many places we have pattern: ret = ...; return ret; This can be simplified to a direct return, removing 'ret' if not otherwise needed. The places in self tests are not converted so we can add more test cases without changing surrounding code (extent-map-tests.c:test_case_4()). Signed-off-by: David Sterba <dsterba@suse.com>
2025-12-03Merge tag 'for-6.19-tag' of ↵Linus Torvalds1-35/+44
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs updates from David Sterba: "Features: - shutdown ioctl support (needs CONFIG_BTRFS_EXPERIMENTAL for now): - set filesystem state as being shut down (also named going down in other filesystems), where all active operations return EIO and this cannot be changed until unmount - pending operations are attempted to be finished but error messages may still show up depending on where exactly the shutdown happened - scrub (and device replace) vs suspend/hibernate: - a running scrub will prevent suspend, which can be annoying as suspend is an immediate request and scrub is not critical - filesystem freezing before suspend was not sufficient as the problem was in process freezing - behaviour change: on suspend scrub and device replace are cancelled, where scrub can record the last state and continue from there; the device replace has to be restarted from the beginning - zone stats exported in sysfs, from the perspective of the filesystem this includes active, reclaimable, relocation etc zones Performance: - improvements when processing space reservation tickets by optimizing locking and shrinking critical sections, cumulative improvements in lockstat numbers show +15% Notable fixes: - use vmalloc fallback when allocating bios as high order allocations can happen with wide checksums (like sha256) - scrub will always track the last position of progress so it's not starting from zero after an error Core: - under experimental config, checksum calculations are offloaded to process context, simplifies locking and allows to remove compression write worker kthread(s): - speed improvement in direct IO throughput with buffered IO fallback is +15% when not offloaded but this is more related to internal crypto subsystem improvements - this will be probably default in the future removing the sysfs tunable - (experimental) block size > page size updates: - support more operations when not using large folios (encoded read/write and send) - raid56 - more preparations for fscrypt support Other: - more conversions to auto-cleaned variables - parameter cleanups and removals - extended warning fixes - improved printing of structured values like keys - lots of other cleanups and refactoring" * tag 'for-6.19-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (147 commits) btrfs: remove unnecessary inode key in btrfs_log_all_parents() btrfs: remove redundant zero/NULL initializations in btrfs_alloc_root() btrfs: remaining BTRFS_PATH_AUTO_FREE conversions btrfs: send: do not allocate memory for xattr data when checking it exists btrfs: send: add unlikely to all unexpected overflow checks btrfs: reduce arguments to btrfs_del_inode_ref_in_log() btrfs: remove root argument from btrfs_del_dir_entries_in_log() btrfs: use test_and_set_bit() in btrfs_delayed_delete_inode_ref() btrfs: don't search back for dir inode item in INO_LOOKUP_USER btrfs: don't rewrite ret from inode_permission btrfs: add orig_logical to btrfs_bio for encryption btrfs: disable verity on encrypted inodes btrfs: disable various operations on encrypted inodes btrfs: remove redundant level reset in btrfs_del_items() btrfs: simplify leaf traversal after path release in btrfs_next_old_leaf() btrfs: optimize balance_level() path reference handling btrfs: factor out root promotion logic into promote_child_to_root() btrfs: raid56: remove the "_step" infix btrfs: raid56: enable bs > ps support btrfs: raid56: prepare finish_parity_scrub() to support bs > ps cases ...
2025-11-25btrfs: remaining BTRFS_PATH_AUTO_FREE conversionsDavid Sterba1-2/+1