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 <samitolvanen@google.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This commit is contained in:
Sami Tolvanen 2015-12-03 16:30:36 -05:00 committed by Mike Snitzer
parent ffa393807c
commit bb4d73ac5e
2 changed files with 55 additions and 23 deletions

View File

@ -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;

View File

@ -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);