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-target.c b/drivers/md/dm-verity-target.c
index 7e200ba631fb4c36af65fdda913a9b96d4f62fb8..2b0ee52d1ad87294f6b2a830a245c73a4ee43eac 100644 (file)
--- 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 c7ad4fd0518860e36c73dad1502688adc0109c4d..f5af52df8e381b9d9e2d3746b8931fd54e00fed1 100644 (file)
--- 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);