kernel.git/fs/btrfs/subpage.c, branch master

Merge tag 'for-6.19-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

2025-12-04T04:03:46Z

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 ...

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: subpage: simplify the PAGECACHE_TAG_TOWRITE handling

2025-11-24T21:03:38Z

In function btrfs_subpage_set_writeback() we need to keep the PAGECACHE_TAG_TOWRITE tag if the folio is still dirty. This is a needed quirk for support async extents, as a subpage range can almost suddenly go writeback, without touching other subpage ranges in the same folio. However we can simplify the handling by replace the open-coded tag clearing by passing the @keep_write flag depending on if the folio is dirty. Since we're holding the subpage lock already, no one is able to change the dirty/writeback flag, thus it's safe to check the folio dirty before calling __folio_start_writeback(). Reviewed-by: Filipe Manana Reviewed-by: Boris Burkov Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: subpage: rename macro variables to avoid shadowing

2025-11-24T20:37:36Z

When compiling with -Wshadow there are warnings in the subpage helper macros that are used in functions like btrfs_subpage_dump_bitmap() or btrfs_subpage_clear_and_test_dirty() that also use 'bfs' (for struct btrfs_folio_state) or blocks_per_folio. Add '__' to the macro variables and unify naming in all subpage macros. Signed-off-by: David Sterba

btrfs: fix trivial -Wshadow warnings

2025-11-24T20:37:36Z

When compiling with -Wshadow (also in 'make W=2' build) there are several reports of shadowed variables that seem to be harmless: - btrfs_do_encoded_write() - we can reuse 'ordered', there's no previous value that would need to be preserved - scrub_write_endio() - we need a standalone 'i' for bio iteration - scrub_stripe() - duplicate ret2 for errors that must not overwrite 'ret' - btrfs_subpage_set_writeback() - 'flags' is used for another irqsave lock but is not overwritten when reused for xarray due to scoping, but for clarity let's rename it - process_dir_items_leaf() - duplicate 'ret', used only for immediate checks Reviewed-by: Qu Wenruo Signed-off-by: David Sterba

btrfs: Use folio_next_pos()

2025-10-31T12:11:37Z

btrfs defined its own variant of folio_next_pos() called folio_end(). This is an ambiguous name as 'end' might be exclusive or inclusive. Switch to the new folio_next_pos(). Signed-off-by: Matthew Wilcox (Oracle) Link: https://patch.msgid.link/20251024170822.1427218-3-willy@infradead.org Acked-by: David Sterba Cc: Chris Mason Cc: David Sterba Cc: linux-btrfs@vger.kernel.org Signed-off-by: Christian Brauner

btrfs: fix typos in comments and strings

2025-09-23T06:49:16Z

Annual typo fixing pass. Strangely codespell found only about 30% of what is in this patch, the rest was done manually using text spellchecker with a custom dictionary of acceptable terms. Reviewed-by: Neal Gompa Signed-off-by: David Sterba

btrfs: subpage: keep TOWRITE tag until folio is cleaned

2025-08-13T12:08:45Z

btrfs_subpage_set_writeback() calls folio_start_writeback() the first time a folio is written back, and it also clears the PAGECACHE_TAG_TOWRITE tag even if there are still dirty blocks in the folio. This can break ordering guarantees, such as those required by btrfs_wait_ordered_extents(). That ordering breakage leads to a real failure. For example, running generic/464 on a zoned setup will hit the following ASSERT. This happens because the broken ordering fails to flush existing dirty pages before the file size is truncated. assertion failed: !list_empty(&ordered->list) :: 0, in fs/btrfs/zoned.c:1899 ------------[ cut here ]------------ kernel BUG at fs/btrfs/zoned.c:1899! Oops: invalid opcode: 0000 [#1] SMP NOPTI CPU: 2 UID: 0 PID: 1906169 Comm: kworker/u130:2 Kdump: loaded Not tainted 6.16.0-rc6-BTRFS-ZNS+ #554 PREEMPT(voluntary) Hardware name: Supermicro Super Server/H12SSL-NT, BIOS 2.0 02/22/2021 Workqueue: btrfs-endio-write btrfs_work_helper [btrfs] RIP: 0010:btrfs_finish_ordered_zoned.cold+0x50/0x52 [btrfs] RSP: 0018:ffffc9002efdbd60 EFLAGS: 00010246 RAX: 000000000000004c RBX: ffff88811923c4e0 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff827e38b1 RDI: 00000000ffffffff RBP: ffff88810005d000 R08: 00000000ffffdfff R09: ffffffff831051c8 R10: ffffffff83055220 R11: 0000000000000000 R12: ffff8881c2458c00 R13: ffff88811923c540 R14: ffff88811923c5e8 R15: ffff8881c1bd9680 FS: 0000000000000000(0000) GS:ffff88a04acd0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f907c7a918c CR3: 0000000004024000 CR4: 0000000000350ef0 Call Trace: ? srso_return_thunk+0x5/0x5f btrfs_finish_ordered_io+0x4a/0x60 [btrfs] btrfs_work_helper+0xf9/0x490 [btrfs] process_one_work+0x204/0x590 ? srso_return_thunk+0x5/0x5f worker_thread+0x1d6/0x3d0 ? __pfx_worker_thread+0x10/0x10 kthread+0x118/0x230 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x205/0x260 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 Consider process A calling writepages() with WB_SYNC_NONE. In zoned mode or for compressed writes, it locks several folios for delalloc and starts writing them out. Let's call the last locked folio folio X. Suppose the write range only partially covers folio X, leaving some pages dirty. Process A calls btrfs_subpage_set_writeback() when building a bio. This function call clears the TOWRITE tag of folio X, whose size = 8K and the block size = 4K. It is following state. 0 4K 8K |/////|/////| (flag: DIRTY, tag: DIRTY) <-----> Process A will write this range. Now suppose process B concurrently calls writepages() with WB_SYNC_ALL. It calls tag_pages_for_writeback() to tag dirty folios with PAGECACHE_TAG_TOWRITE. Since folio X is still dirty, it gets tagged. Then, B collects tagged folios using filemap_get_folios_tag() and must wait for folio X to be written before returning from writepages(). 0 4K 8K |/////|/////| (flag: DIRTY, tag: DIRTY|TOWRITE) However, between tagging and collecting, process A may call btrfs_subpage_set_writeback() and clear folio X's TOWRITE tag. 0 4K 8K | |/////| (flag: DIRTY|WRITEBACK, tag: DIRTY) As a result, process B won't see folio X in its batch, and returns without waiting for it. This breaks the WB_SYNC_ALL ordering requirement. Fix this by using btrfs_subpage_set_writeback_keepwrite(), which retains the TOWRITE tag. We now manually clear the tag only after the folio becomes clean, via the xas operation. Fixes: 3470da3b7d87 ("btrfs: subpage: introduce helpers for writeback status") CC: stable@vger.kernel.org # 6.12+ Reviewed-by: Qu Wenruo Reviewed-by: Johannes Thumshirn Signed-off-by: Naohiro Aota Signed-off-by: David Sterba

btrfs: output more info when btrfs_subpage_assert() failed

2025-07-21T23:13:03Z

The function btrfs_subpage_assert() is a very commonly utilized assert to make sure the range passed in is correct inside the folio. And when some code is not properly subpage/large folio compatible btrfs_subpage_assert() will be the first to be triggered. E.g. when I incorrectly enabled large folios for data reloc inodes, it immediately triggered btrfs_subpage_assert(). In that case, outputting all the involved members will be very helpful, this includes: - start - len - folio position inside the mapping - folio size Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: use folio_end() where appropriate

2025-07-21T21:58:01Z

Simplify folio_pos() + folio_size() and use the new helper. Reviewed-by: Johannes Thumshirn Signed-off-by: David Sterba