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>
diff --git a/drivers/md/dm-verity.h b/drivers/md/dm-verity.h
index c7ad4fd..f5af52d 100644
--- a/drivers/md/dm-verity.h
+++ b/drivers/md/dm-verity.h
@@ -103,6 +103,12 @@
 	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);