block: reuse __blk_bvec_map_sg() for mapping page sized bvec

Inside __blk_segment_map_sg(), page sized bvec mapping is optimized
a bit with one standalone branch.

So reuse __blk_bvec_map_sg() to do that.

Cc: Omar Sandoval <osandov@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-merge.c b/block/blk-merge.c
index 9ec704bb58ec67646faaac4e208f49fb1910f036..3e934ee9a907c30994a67ffe0371ed83aaa34a8c 100644 (file)
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -493,6 +493,14 @@ static unsigned blk_bvec_map_sg(struct request_queue *q,
        return nsegs;
 }
 
+static inline int __blk_bvec_map_sg(struct bio_vec bv,
+               struct scatterlist *sglist, struct scatterlist **sg)
+{
+       *sg = blk_next_sg(sg, sglist);
+       sg_set_page(*sg, bv.bv_page, bv.bv_len, bv.bv_offset);
+       return 1;
+}
+
 static inline void
 __blk_segment_map_sg(struct request_queue *q, struct bio_vec *bvec,
                     struct scatterlist *sglist, struct bio_vec *bvprv,
@@ -511,23 +519,13 @@ __blk_segment_map_sg(struct request_queue *q, struct bio_vec *bvec,
        } else {
 new_segment:
                if (bvec->bv_offset + bvec->bv_len <= PAGE_SIZE) {
-                       *sg = blk_next_sg(sg, sglist);
-                       sg_set_page(*sg, bvec->bv_page, nbytes, bvec->bv_offset);
-                       (*nsegs) += 1;
+                       (*nsegs) += __blk_bvec_map_sg(*bvec, sglist, sg);
                } else
                        (*nsegs) += blk_bvec_map_sg(q, bvec, sglist, sg);
        }
        *bvprv = *bvec;
 }
 
-static inline int __blk_bvec_map_sg(struct bio_vec bv,
-               struct scatterlist *sglist, struct scatterlist **sg)
-{
-       *sg = sglist;
-       sg_set_page(*sg, bv.bv_page, bv.bv_len, bv.bv_offset);
-       return 1;
-}
-
 static int __blk_bios_map_sg(struct request_queue *q, struct bio *bio,
                             struct scatterlist *sglist,
                             struct scatterlist **sg)