From bb4d73ac5e4f0a6c4853f35824f6cb2d396a2f9c Mon Sep 17 00:00:00 2001 From: Sami Tolvanen Date: Thu, 3 Dec 2015 16:30:36 -0500 Subject: [PATCH] dm verity: factor out verity_for_bv_block() verity_for_bv_block() will be re-used by optional dm-verity object. Signed-off-by: Sami Tolvanen Signed-off-by: Mike Snitzer --- drivers/md/dm-verity-target.c | 72 ++++++++++++++++++++++++----------- drivers/md/dm-verity.h | 6 +++ 2 files changed, 55 insertions(+), 23 deletions(-) diff --git a/drivers/md/dm-verity-target.c b/drivers/md/dm-verity-target.c index 7e200ba631fb..2b0ee52d1ad8 100644 --- a/drivers/md/dm-verity-target.c +++ b/drivers/md/dm-verity-target.c @@ -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, @@ -357,26 +399,10 @@ 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); - - if (unlikely(r < 0)) - return r; - - bio_advance_iter(bio, &io->iter, len); - todo -= len; - } while (todo); + start = io->iter; + r = verity_for_bv_block(v, io, &io->iter, verity_bv_hash_update); + if (unlikely(r < 0)) + return r; r = verity_hash_final(v, desc, verity_io_real_digest(v, io)); if (unlikely(r < 0)) diff --git a/drivers/md/dm-verity.h b/drivers/md/dm-verity.h index c7ad4fd05188..f5af52df8e38 100644 --- a/drivers/md/dm-verity.h +++ b/drivers/md/dm-verity.h @@ -103,6 +103,12 @@ 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); -- 2.34.1