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Commit 42e8a0d2 authored by Sami Tolvanen's avatar Sami Tolvanen
Browse files

UPSTREAM: dm verity: factor out verity_for_bv_block() 



(cherry-picked from bb4d73ac5e4f0a6c4853f35824f6cb2d396a2f9c)

verity_for_bv_block() will be re-used by optional dm-verity object.

Bug: 21893453
Change-Id: Ia7782db8077bcc46fd000f5be1919942c28b03db
Signed-off-by: default avatarSami Tolvanen <samitolvanen@google.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent 83ab4db9

drivers/md/dm-verity-target.c

+49 −23
Original line number Diff line number Diff line
@@ -333,19 +333,61 @@ int verity_hash_for_block(struct dm_verity *v, struct dm_verity_io *io, 
	return 0;

}



/*

 * Calls function process for 1 << v->data_dev_block_bits bytes in the bio_vec

 * starting from iter.

 */

int verity_for_bv_block(struct dm_verity *v, struct dm_verity_io *io,

			struct bvec_iter *iter,

			int (*process)(struct dm_verity *v,

				       struct dm_verity_io *io, u8 *data,

				       size_t len))

{

	unsigned todo = 1 << v->data_dev_block_bits;

	struct bio *bio = dm_bio_from_per_bio_data(io, v->ti->per_bio_data_size);



	do {

		int r;

		u8 *page;

		unsigned len;

		struct bio_vec bv = bio_iter_iovec(bio, *iter);



		page = kmap_atomic(bv.bv_page);

		len = bv.bv_len;



		if (likely(len >= todo))

			len = todo;



		r = process(v, io, page + bv.bv_offset, len);

		kunmap_atomic(page);



		if (r < 0)

			return r;



		bio_advance_iter(bio, iter, len);

		todo -= len;

	} while (todo);



	return 0;

}



static int verity_bv_hash_update(struct dm_verity *v, struct dm_verity_io *io,

				 u8 *data, size_t len)

{

	return verity_hash_update(v, verity_io_hash_desc(v, io), data, len);

}



/*

 * Verify one "dm_verity_io" structure.

 */

static int verity_verify_io(struct dm_verity_io *io)

{

	struct dm_verity *v = io->v;

	struct bio *bio = dm_bio_from_per_bio_data(io,

						   v->ti->per_bio_data_size);

	struct bvec_iter start;

	unsigned b;



	for (b = 0; b < io->n_blocks; b++) {

		int r;

		unsigned todo;

		struct shash_desc *desc = verity_io_hash_desc(v, io);



		r = verity_hash_for_block(v, io, io->block + b,
@@ -357,27 +399,11 @@ static int verity_verify_io(struct dm_verity_io *io) 
		if (unlikely(r < 0))

			return r;



		todo = 1 << v->data_dev_block_bits;

		do {

			u8 *page;

			unsigned len;

			struct bio_vec bv = bio_iter_iovec(bio, io->iter);



			page = kmap_atomic(bv.bv_page);

			len = bv.bv_len;

			if (likely(len >= todo))

				len = todo;

			r = verity_hash_update(v, desc,  page + bv.bv_offset,

					       len);

			kunmap_atomic(page);



		start = io->iter;

		r = verity_for_bv_block(v, io, &io->iter, verity_bv_hash_update);

		if (unlikely(r < 0))

			return r;



			bio_advance_iter(bio, &io->iter, len);

			todo -= len;

		} while (todo);



		r = verity_hash_final(v, desc, verity_io_real_digest(v, io));

		if (unlikely(r < 0))

			return r;

drivers/md/dm-verity.h

+6 −0
Original line number Diff line number Diff line
@@ -104,6 +104,12 @@ static inline u8 *verity_io_want_digest(struct dm_verity *v, 
	return (u8 *)(io + 1) + v->shash_descsize + v->digest_size;

}



extern int verity_for_bv_block(struct dm_verity *v, struct dm_verity_io *io,

			       struct bvec_iter *iter,

			       int (*process)(struct dm_verity *v,

					      struct dm_verity_io *io,

					      u8 *data, size_t len));



extern int verity_hash(struct dm_verity *v, struct shash_desc *desc,

		       const u8 *data, size_t len, u8 *digest);