block: Convert drivers to immutable biovecs

Now that we've got a mechanism for immutable biovecs -
bi_iter.bi_bvec_done - we need to convert drivers to use primitives that
respect it instead of using the bvec array directly.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: NeilBrown <neilb@suse.de>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: dm-devel@redhat.com

1 files changed, 17 insertions, 14 deletions

diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c
index 01558b093307..b2b8a10e8427 100644
--- a/drivers/md/dm-io.c
+++ b/drivers/md/dm-io.c
@@ -201,26 +201,29 @@ static void list_dp_init(struct dpages *dp, struct page_list *pl, unsigned offse
 /*
  * Functions for getting the pages from a bvec.
  */
-static void bvec_get_page(struct dpages *dp,
+static void bio_get_page(struct dpages *dp,
                   struct page **p, unsigned long *len, unsigned *offset)
 {
-        struct bio_vec *bvec = (struct bio_vec *) dp->context_ptr;
-        *p = bvec->bv_page;
-        *len = bvec->bv_len;
-        *offset = bvec->bv_offset;
+        struct bio *bio = dp->context_ptr;
+        struct bio_vec bvec = bio_iovec(bio);
+        *p = bvec.bv_page;
+        *len = bvec.bv_len;
+        *offset = bvec.bv_offset;
 }
 
-static void bvec_next_page(struct dpages *dp)
+static void bio_next_page(struct dpages *dp)
 {
-        struct bio_vec *bvec = (struct bio_vec *) dp->context_ptr;
-        dp->context_ptr = bvec + 1;
+        struct bio *bio = dp->context_ptr;
+        struct bio_vec bvec = bio_iovec(bio);
+
+        bio_advance(bio, bvec.bv_len);
 }
 
-static void bvec_dp_init(struct dpages *dp, struct bio_vec *bvec)
+static void bio_dp_init(struct dpages *dp, struct bio *bio)
 {
-        dp->get_page = bvec_get_page;
-        dp->next_page = bvec_next_page;
-        dp->context_ptr = bvec;
+        dp->get_page = bio_get_page;
+        dp->next_page = bio_next_page;
+        dp->context_ptr = bio;
 }
 
 /*
@@ -457,8 +460,8 @@ static int dp_init(struct dm_io_request *io_req, struct dpages *dp,
                 list_dp_init(dp, io_req->mem.ptr.pl, io_req->mem.offset);
                 break;
 
-        case DM_IO_BVEC:
-                bvec_dp_init(dp, io_req->mem.ptr.bvec);
+        case DM_IO_BIO:
+                bio_dp_init(dp, io_req->mem.ptr.bio);
                 break;
 
         case DM_IO_VMA: