kernel/linux.git/fs/crypto, branch master

Merge tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/linux

2026-04-14T00:29:12+00:00

Pull fscrypt updates from Eric Biggers: - Various cleanups for the interface between fs/crypto/ and filesystems, from Christoph Hellwig - Simplify and optimize the implementation of v1 key derivation by using the AES library instead of the crypto_skcipher API * tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/linux: fscrypt: use AES library for v1 key derivation ext4: use a byte granularity cursor in ext4_mpage_readpages fscrypt: pass a real sector_t to fscrypt_zeroout_range fscrypt: pass a byte length to fscrypt_zeroout_range fscrypt: pass a byte offset to fscrypt_zeroout_range fscrypt: pass a byte length to fscrypt_zeroout_range_inline_crypt fscrypt: pass a byte offset to fscrypt_zeroout_range_inline_crypt fscrypt: pass a byte offset to fscrypt_set_bio_crypt_ctx fscrypt: pass a byte offset to fscrypt_mergeable_bio fscrypt: pass a byte offset to fscrypt_generate_dun fscrypt: move fscrypt_set_bio_crypt_ctx_bh to buffer.c ext4, fscrypt: merge fscrypt_mergeable_bio_bh into io_submit_need_new_bio ext4: factor out a io_submit_need_new_bio helper ext4: open code fscrypt_set_bio_crypt_ctx_bh ext4: initialize the write hint in io_submit_init_bio

fscrypt: use AES library for v1 key derivation

2026-03-25T19:06:33+00:00

Convert the implementation of the v1 (original / deprecated) fscrypt per-file key derivation algorithm to use the AES library instead of an "ecb(aes)" crypto_skcipher. This is much simpler. While the AES library doesn't support AES-ECB directly yet, we can still simply call aes_encrypt() in a loop. While that doesn't explicitly parallelize the AES encryptions, it doesn't really matter in this case, where a new key is used each time and only 16 to 64 bytes are encrypted. In fact, a quick benchmark (AMD Ryzen 9 9950X) shows that this commit actually greatly improves performance, from ~7000 cycles per key derived to ~1500. The times don't differ much between 32 bytes and 64 bytes either, so clearly the bottleneck is API stuff and key expansion. Granted, performance of the v1 key derivation is no longer very relevant: most users have moved onto v2 encryption policies. The v2 key derivation uses HKDF-SHA512 (which is ~3500 cycles on the same CPU). Still, it's nice that the simpler solution is much faster as well. Compatibility verified with xfstests generic/548. Link: https://lore.kernel.org/r/20260321075338.99809-1-ebiggers@kernel.org Signed-off-by: Eric Biggers

fscrypt: pass a real sector_t to fscrypt_zeroout_range

2026-03-09T20:34:21+00:00

While the pblk argument to fscrypt_zeroout_range is declared as a sector_t, it actually is interpreted as a logical block size unit, which is highly unusual. Switch to passing the 512 byte units that sector_t is defined for. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20260302141922.370070-14-hch@lst.de Signed-off-by: Eric Biggers

fscrypt: pass a byte length to fscrypt_zeroout_range

2026-03-09T20:34:18+00:00

Range lengths are usually expressed as bytes in the VFS, switch fscrypt_zeroout_range to this convention. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20260302141922.370070-13-hch@lst.de Signed-off-by: Eric Biggers

fscrypt: pass a byte offset to fscrypt_zeroout_range

2026-03-09T20:31:51+00:00

Logical offsets into an inode are usually expressed as bytes in the VFS. Switch fscrypt_zeroout_range to that convention. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20260302141922.370070-12-hch@lst.de Signed-off-by: Eric Biggers

fscrypt: pass a byte length to fscrypt_zeroout_range_inline_crypt

2026-03-09T20:31:51+00:00

Range lengths are usually expressed as bytes in the VFS, switch fscrypt_zeroout_range_inline_crypt to this convention. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20260302141922.370070-11-hch@lst.de Signed-off-by: Eric Biggers

fscrypt: pass a byte offset to fscrypt_zeroout_range_inline_crypt

2026-03-09T20:31:51+00:00

Logical offsets into an inode are usually expressed as bytes in the VFS. Switch fscrypt_zeroout_range_inline_crypt to that convention. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20260302141922.370070-10-hch@lst.de Signed-off-by: Eric Biggers

fscrypt: pass a byte offset to fscrypt_set_bio_crypt_ctx

2026-03-09T20:31:50+00:00

Logical offsets into an inode are usually expressed as bytes in the VFS. Switch fscrypt_set_bio_crypt_ctx to that convention. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20260302141922.370070-9-hch@lst.de Signed-off-by: Eric Biggers

fscrypt: pass a byte offset to fscrypt_mergeable_bio

2026-03-09T20:31:50+00:00

Logical offsets into an inode are usually expressed as bytes in the VFS. Switch fscrypt_mergeable_bio to that convention. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20260302141922.370070-8-hch@lst.de Signed-off-by: Eric Biggers

fscrypt: pass a byte offset to fscrypt_generate_dun

2026-03-09T20:31:50+00:00

Logical offsets into an inode are usually expressed as bytes in the VFS. Switch fscrypt_generate_dun to that convention and remove the ci_data_units_per_block_bits member in struct fscrypt_inode_info that was only used to cache the DUN shift based on the logical block size granularity. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20260302141922.370070-7-hch@lst.de Signed-off-by: Eric Biggers