Re: [PATCH 07/13] iomap: align the direct I/O bios of encrypted files to the block size

[sashiko-bot@kernel.org]

> A bio that carries an encryption context must cover a whole number of
> data units: its data unit number is generated from its first data unit
> (see bio_crypt_set_ctx()), and it is only split at data unit
> boundaries.
> 
> iomap attaches the encryption context of an encrypted file to the bios
> that it builds for direct I/O, but it only cuts them at the logical
> block size of the device.  A bio ends where the bio_vecs that fit into
> it end, not at a fixed number of bytes: the extraction stops when the
> bio is out of bio_vecs or when the iterator is exhausted, and a
> bio_vec can cover a whole folio.
> 
> A bio can end in the middle of a data unit, and a data unit that is
> larger than a page makes this reachable without any misaligned input
> at all: the extraction then stops in the middle of a folio, and a cut
> [ ... ]
> the logical block size of the device on to iomap expecting it to fail
> with -EINVAL, while iomap checks only the file position and the
> length, so such a request can reach bio submission.
> 
> Signed-off-by: Baokun Li <libaokun@linux.alibaba.com>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20261011170958.1759230-1-libaokun@linux.alibaba.com?part=7