dm crypt: leverage immutable biovecs when decrypting on read (59779079) · Commits · 戴 / test

Commit ("block: Convert drivers to immutable biovecs") stopped short of changing dm-crypt to leverage the fact that the biovec array of a bio will no longer be modified. Switch to using bio_clone_fast() when cloning bios for decryption after read. Signed-off-by:

Mike Snitzer <snitzer@redhat.com>

drivers/md/dm-crypt.c

+5 −5

Original line number	Diff line number	Diff line
		@@ -1124,15 +1124,15 @@ static void clone_init(struct dm_crypt_io io, struct bio clone)
		static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
		{
		struct crypt_config *cc = io->cc;
		struct bio *base_bio = io->base_bio;
		struct bio *clone;

		/*
		* The block layer might modify the bvec array, so always
		* copy the required bvecs because we need the original
		* one in order to decrypt the whole bio data afterwards.
		* We need the original biovec array in order to decrypt
		* the whole bio data afterwards -- thanks to immutable
		* biovecs we don't need to worry about the block layer
		* modifying the biovec array; so leverage bio_clone_fast().
		*/
		clone = bio_clone_bioset(base_bio, gfp, cc->bs);
		clone = bio_clone_fast(io->base_bio, gfp, cc->bs);
		if (!clone)
		return 1;

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