Re: [PATCH 05/13] blk-crypto: encrypt one data unit per crypto request

[sashiko-bot@kernel.org]

> __blk_crypto_fallback_encrypt_bio() encrypts the source bio one bio_vec
> at a time: it walks the bio with bio_iter_iovec(), which clamps each
> bio_vec to a single page, encrypts all the data units of that bio_vec
> into its bounce page with one crypto request per data unit, and starts a
> new encrypted bio when all of its pages are in use.
> 
> That structure cannot express a data unit that spans more than a page.
> In preparation for supporting such data units, restructure the loop
> around the data unit, the same way as the decryption path: collect the
> bio_vecs that make up one data unit in blk_crypto_du_bvecs(), encrypt it
> with a single crypto request whose scatterlist covers exactly those
> bio_vecs, and advance the source bio by one data unit.
> 
> Unlike the decryption path, which decrypts in place using one
> scatterlist for both sides, the encryption path writes the ciphertext
> to the bounce pages, so it fills the scatterlist for each side of the
> crypto request, and calls the same blk_crypto_crypt_du() helper, with
> the encryption direction and the bounce page scatterlist as the
> destination.
> 
> A data unit is now encrypted as soon as it is complete instead of when
> all the data units of its bio_vec are, and the first bio_vec of a data
> unit is added to the encrypted bio with the whole length of the source
> bio_vec it starts in, as the data units that follow it in that bio_vec
> share its bounce page.
> 
> No functional change intended.
> 
> 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=5