kernel/git/stable/linux.git/fs/btrfs/bio.c, branch master

btrfs: btrfs_log_dev_io_error() on all bio errors

2026-04-07T18:00:29+00:00

As far as I can tell, we never intentionally constrained ourselves to these status codes, and it is misleading and surprising to lack the bdev error logging when we get a different error code from the block layer. This can lead to jumping to a wrong conclusion like "this system didn't see any bio failures but aborted with EIO". For example on nvme devices, I observe many failures coming back as BLK_STS_MEDIUM. It is apparent that the nvme driver returns a variety of BLK_STS_* status values in nvme_error_status(). So handle the known expected errors and make some noise on the rest which we expect won't really happen. Reviewed-by: Christoph Hellwig Reviewed-by: Anand Jain Signed-off-by: Boris Burkov Signed-off-by: David Sterba

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

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

btrfs: do not ASSERT() when the fs flips RO inside btrfs_repair_io_failure()

2026-02-18T14:25:53+00:00

[BUG] There is a bug report that when btrfs hits ENOSPC error in a critical path, btrfs flips RO (this part is expected, although the ENOSPC bug still needs to be addressed). The problem is after the RO flip, if there is a read repair pending, we can hit the ASSERT() inside btrfs_repair_io_failure() like the following: BTRFS info (device vdc): relocating block group 30408704 flags metadata|raid1 ------------[ cut here ]------------ BTRFS: Transaction aborted (error -28) WARNING: fs/btrfs/extent-tree.c:3235 at __btrfs_free_extent.isra.0+0x453/0xfd0, CPU#1: btrfs/383844 Modules linked in: kvm_intel kvm irqbypass [...] ---[ end trace 0000000000000000 ]--- BTRFS info (device vdc state EA): 2 enospc errors during balance BTRFS info (device vdc state EA): balance: ended with status: -30 BTRFS error (device vdc state EA): parent transid verify failed on logical 30556160 mirror 2 wanted 8 found 6 BTRFS error (device vdc state EA): bdev /dev/nvme0n1 errs: wr 0, rd 0, flush 0, corrupt 10, gen 0 [...] assertion failed: !(fs_info->sb->s_flags & SB_RDONLY) :: 0, in fs/btrfs/bio.c:938 ------------[ cut here ]------------ assertion failed: !(fs_info->sb->s_flags & SB_RDONLY) :: 0, in fs/btrfs/bio.c:938 kernel BUG at fs/btrfs/bio.c:938! Oops: invalid opcode: 0000 [#1] SMP NOPTI CPU: 0 UID: 0 PID: 868 Comm: kworker/u8:13 Tainted: G W N 6.19.0-rc6+ #4788 PREEMPT(full) Tainted: [W]=WARN, [N]=TEST Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014 Workqueue: btrfs-endio simple_end_io_work RIP: 0010:btrfs_repair_io_failure.cold+0xb2/0x120 RSP: 0000:ffffc90001d2bcf0 EFLAGS: 00010246 RAX: 0000000000000051 RBX: 0000000000001000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8305cf42 RDI: 00000000ffffffff RBP: 0000000000000002 R08: 00000000fffeffff R09: ffffffff837fa988 R10: ffffffff8327a9e0 R11: 6f69747265737361 R12: ffff88813018d310 R13: ffff888168b8a000 R14: ffffc90001d2bd90 R15: ffff88810a169000 FS: 0000000000000000(0000) GS:ffff8885e752c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 ------------[ cut here ]------------ [CAUSE] The cause of -ENOSPC error during the test case btrfs/124 is still unknown, although it's known that we still have cases where metadata can be over-committed but can not be fulfilled correctly, thus if we hit such ENOSPC error inside a critical path, we have no choice but abort the current transaction. This will mark the fs read-only. The problem is inside the btrfs_repair_io_failure() path that we require the fs not to be mount read-only. This is normally fine, but if we are doing a read-repair meanwhile the fs flips RO due to a critical error, we can enter btrfs_repair_io_failure() with super block set to read-only, thus triggering the above crash. [FIX] Just replace the ASSERT() with a proper return if the fs is already read-only. Reported-by: Christoph Hellwig Link: https://lore.kernel.org/linux-btrfs/20260126045555.GB31641@lst.de/ Tested-by: Christoph Hellwig Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: fix copying the flags of btrfs_bio after split

2026-02-03T06:56:24+00:00

When a btrfs_bio gets split, only 'bbio->csum_search_commit_root' gets copied to the new btrfs_bio, all the other flags don't. When a bio is split in btrfs_submit_chunk(), btrfs_split_bio() creates the new split bio via btrfs_bio_init() which zeroes the struct with memset. Looking at btrfs_split_bio(), it copies csum_search_commit_root from the original but does not copy can_use_append. After the split, the code does: bbio = split; bio = &bbio->bio; This means the split bio (with can_use_append = false) gets submitted, not the original. In btrfs_submit_dev_bio(), the condition: if (btrfs_bio(bio)->can_use_append && btrfs_dev_is_sequential(...)) Will be false for the split bio even when writing to a sequential zone. Does the split bio need to inherit can_use_append from the original? The old code used a local variable use_append which persisted across the split. Copy the rest of the flags as well. Link: https://lore.kernel.org/linux-btrfs/20260125132120.2525146-1-clm@meta.com/ Reported-by: Chris Mason Reviewed-by: Qu Wenruo Reviewed-by: Boris Burkov Signed-off-by: Johannes Thumshirn Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: move existing remaps before relocating block group

2026-02-03T06:54:35+00:00

If when relocating a block group we find that `remap_bytes` > 0 in its block group item, that means that it has been the destination block group for another that has been remapped. We need to search the remap tree for any remap backrefs within this range, and move the data to a third block group. This is because otherwise btrfs_translate_remap() could end up following an unbounded chain of remaps, which would only get worse over time. We only relocate one block group at a time, so `remap_bytes` will only ever go down while we are doing this. Once we're finished we set the REMAPPED flag on the block group, which will permanently prevent any other data from being moved to within it. Reviewed-by: Boris Burkov Signed-off-by: Mark Harmstone Signed-off-by: David Sterba

btrfs: remove experimental offload csum mode

2026-02-03T06:51:43+00:00

The offload csum mode was introduced to allow developers to compare the performance of generating checksum for data writes at different timings: - During btrfs_submit_chunk() This is the most common one, if any of the following condition is met we go this path: * The csum is fast For now it's CRC32C and xxhash. * It's a synchronous write * Zoned - Delay the checksum generation to a workqueue However since commit dd57c78aec39 ("btrfs: introduce btrfs_bio::async_csum") we no longer need to bother any of them. As if it's an experimental build, async checksum generation at the background will be faster anyway. And if not an experimental build, we won't even have the offload csum mode support. Considering the async csum will be the new default, let's remove the offload csum mode code. There will be no impact to end users, and offload csum mode is still under experimental features. Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: simplify check for zoned NODATASUM writes in btrfs_submit_chunk()

2026-02-03T06:50:26+00:00

This function already dereferences 'inode' multiple times earlier, making the additional NULL check at line 840 redundant since the function would have crashed already if inode were NULL. After commit 81cea6cd7041 ("btrfs: remove btrfs_bio::fs_info by extracting it from btrfs_bio::inode"), the btrfs_bio::inode field is mandatory for all btrfs_bio allocations and is guaranteed to be non-NULL. Simplify the condition for allocating dummy checksums for zoned NODATASUM data by removing the unnecessary 'inode &&' check. Reviewed-by: Johannes Thumshirn Signed-off-by: Zhen Ni Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: zoned: don't zone append to conventional zone

2026-02-03T05:38:31+00:00

In case of a zoned RAID, it can happen that a data write is targeting a sequential write required zone and a conventional zone. In this case the bio will be marked as REQ_OP_ZONE_APPEND but for the conventional zone, this needs to be REQ_OP_WRITE. The setting of REQ_OP_ZONE_APPEND is deferred to the last possible time in btrfs_submit_dev_bio(), but the decision if we can use zone append is cached in btrfs_bio. CC: Naohiro Aota Fixes: e9b9b911e03c ("btrfs: add raid stripe tree to features enabled with debug config") Reviewed-by: Christoph Hellwig Reviewed-by: Naohiro Aota Signed-off-by: Johannes Thumshirn Signed-off-by: David Sterba

btrfs: add orig_logical to btrfs_bio for encryption

2025-11-25T00:52:23+00:00

When checksumming the encrypted bio on writes we need to know which logical address this checksum is for. At the point where we get the encrypted bio the bi_sector is the physical location on the target disk, so we need to save the original logical offset in the btrfs_bio. Then we can use this when checksumming the bio instead of the bio->iter.bi_sector. Note: The patch was taken from v5 of fscrypt patchset (https://lore.kernel.org/linux-btrfs/cover.1706116485.git.josef@toxicpanda.com/) which was handled over time by various people: Omar Sandoval, Sweet Tea Dorminy, Josef Bacik. Signed-off-by: Josef Bacik Signed-off-by: Daniel Vacek Reviewed-by: David Sterba [ add note ] Signed-off-by: David Sterba

btrfs: enable encoded read/write/send for bs > ps cases

2025-11-24T21:42:24+00:00

Since the read verification and read repair are all supporting bs > ps without large folios now, we can enable encoded read/write/send. Now we can relax the alignment in assert_bbio_alignment() to min(blocksize, PAGE_SIZE). But also add the extra blocksize based alignment check for the logical and length of the bbio. There is a pitfall in btrfs_add_compress_bio_folios(), which relies on the folios passed in to meet the minimal folio order. But now we can pass regular page sized folios in, update it to check each folio's size instead of using the minimal folio size. This allows btrfs_add_compress_bio_folios() to even handle folios array with different sizes, thankfully we don't yet need to handle such crazy situation. Signed-off-by: Qu Wenruo Signed-off-by: David Sterba