[PATCH V4 28/45] block: loop: pass segments to iov_iter

Ming Lei
2017-12-18T12:30:06Z

iov_iter is implemented with bvec itererator, so it is safe to pass
segment to it, and this way is much more efficient than passing one
page in each bvec.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
drivers/block/loop.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 8e30d081ad2a..90e3f402af62 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -499,7 +499,7 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd,
struct bio_vec tmp;

__rq_for_each_bio(bio, rq)
- segments += bio_pages(bio);
+ segments += bio_segments(bio);
bvec = kmalloc(sizeof(struct bio_vec) * segments, GFP_NOIO);
if (!bvec)
return -EIO;
@@ -511,7 +511,7 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd,
* copy bio->bi_iov_vec to new bvec. The rq_for_each_page
* API will take care of all details for us.
*/
- rq_for_each_page(tmp, rq, iter) {
+ rq_for_each_segment(tmp, rq, iter) {
*bvec = tmp;
bvec++;
}
@@ -525,7 +525,7 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd,
*/
offset = bio->bi_iter.bi_bvec_done;
bvec = __bvec_iter_bvec(bio->bi_io_vec, bio->bi_iter);
- segments = bio_pages(bio);
+ segments = bio_segments(bio);
}
atomic_set(&cmd->ref, 2);

--
2.9.5