dm verity: add ignore_zero_blocks feature
If ignore_zero_blocks is enabled dm-verity will return zeroes for blocks
matching a zero hash without validating the content.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
diff --git a/drivers/md/dm-verity.h b/drivers/md/dm-verity.h
index 8e85372..fb419f4 100644
--- a/drivers/md/dm-verity.h
+++ b/drivers/md/dm-verity.h
@@ -40,6 +40,7 @@
struct crypto_shash *tfm;
u8 *root_digest; /* digest of the root block */
u8 *salt; /* salt: its size is salt_size */
+ u8 *zero_digest; /* digest for a zero block */
unsigned salt_size;
sector_t data_start; /* data offset in 512-byte sectors */
sector_t hash_start; /* hash start in blocks */
@@ -123,6 +124,6 @@
const u8 *data, size_t len, u8 *digest);
extern int verity_hash_for_block(struct dm_verity *v, struct dm_verity_io *io,
- sector_t block, u8 *digest);
+ sector_t block, u8 *digest, bool *is_zero);
#endif /* DM_VERITY_H */