kernel/git/stable/linux.git/fs/btrfs/file-item.c, branch master

btrfs: fallback to transaction csum tree on a commit root csum miss

2026-06-29T23:59:20+00:00

We have been running with commit root csums enabled for some time and have noticed a slight uptick in zero csum errors. Investigating those revealed that they were same transaction reads of extents that were just relocated, but the extent map generation was long ago. It turns out that relocation intentionally does not update the extent generation (replace_file_extents()), but must write a new csum since the data has moved, so we must account for this with commit root csum reading. Luckily this is a short lived condition: after the relocation transaction the commit root will once again have the csum. So we can add a generic fallback to the lookup to try again with the transaction csum root. Fixes: f07b855c56b1 ("btrfs: try to search for data csums in commit root") Reviewed-by: Filipe Manana Signed-off-by: Boris Burkov Signed-off-by: David Sterba

btrfs: use shifts for sectorsize and nodesize

2026-06-09T16:22:45+00:00

Convert more multiplications of sectorsize or nodesize to use the shifts. The remaining cases are multiplications by constants that compiler can optimize by itself, and in tests. Reviewed-by: Qu Wenruo Reviewed-by: Boris Burkov Signed-off-by: David Sterba

btrfs: make more ASSERTs verbose, part 3

2026-06-08T13:53:28+00:00

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. Try to finish what was left after 1c094e6ccead7a ("btrfs: make a few more ASSERTs verbose"). Signed-off-by: David Sterba

btrfs: rename btrfs_csum_file_blocks() to btrfs_insert_data_csums()

2026-04-07T16:55:56+00:00

The function btrfs_csum_file_blocks() is a little confusing, unlike btrfs_csum_one_bio(), it is not calculating the checksum of some file blocks. Instead it's just inserting the already calculated checksums into a given root (can be a csum root or a log tree). So rename it to btrfs_insert_data_csums() to reflect its behavior better. Reviewed-by: Filipe Manana Signed-off-by: Qu Wenruo Signed-off-by: David Sterba

Merge tag 'for-7.0-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

2026-03-21T15:42:17+00:00

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()

btrfs: check for NULL root after calls to btrfs_csum_root()

2026-03-17T10:29:32+00:00

btrfs_csum_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. Reported-by: Chris Mason Link: https://lore.kernel.org/linux-btrfs/20260208161657.3972997-1-clm@meta.com/ Reviewed-by: Boris Burkov Signed-off-by: Filipe Manana Reviewed-by: David Sterba 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: remove out label in btrfs_csum_file_blocks()

2026-02-03T06:56:22+00:00

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 Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: switch to library APIs for checksums

2026-02-03T05:38:32+00:00

Make btrfs use the library APIs instead of crypto_shash, for all checksum computations. This has many benefits: - Allows future checksum types, e.g. XXH3 or CRC64, to be more easily supported. Only a library API will be needed, not crypto_shash too. - Eliminates the overhead of the generic crypto layer, including an indirect call for every function call and other API overhead. A microbenchmark of btrfs_check_read_bio() with crc32c checksums shows a speedup from 658 cycles to 608 cycles per 4096-byte block. - Decreases the stack usage of btrfs by reducing the size of checksum contexts from 384 bytes to 240 bytes, and by eliminating the need for some functions to declare a checksum context at all. - Increases reliability. The library functions always succeed and return void. In contrast, crypto_shash can fail and return errors. Also, the library functions are guaranteed to be available when btrfs is loaded; there's no longer any need to use module softdeps to try to work around the crypto modules sometimes not being loaded. - Fixes a bug where blake2b checksums didn't work on kernels booted with fips=1. Since btrfs checksums are for integrity only, it's fine for them to use non-FIPS-approved algorithms. Note that with having to handle 4 algorithms instead of just 1-2, this commit does result in a slightly positive diffstat. That being said, this wouldn't have been the case if btrfs had actually checked for errors from crypto_shash, which technically it should have been doing. Reviewed-by: Ard Biesheuvel Reviewed-by: Neal Gompa Signed-off-by: Eric Biggers Reviewed-by: David Sterba 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