block: add a missing BIOVEC_SEG_BOUNDARY check in bio_add_pc_page

The actual recaculation of segments in __blk_recalc_rq_segments will
do this check, so there is no point in forcing it if we know it won't
succeed.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 3 insertions, 1 deletions

diff --git a/block/bio.c b/block/bio.c
index 81d90b839e05..c254e5aa331f 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -731,7 +731,9 @@ int bio_add_pc_page(struct request_queue *q, struct bio *bio, struct page
         }
 
         /* If we may be able to merge these biovecs, force a recount */
-        if (bio->bi_vcnt > 1 && biovec_phys_mergeable(bvec-1, bvec))
+        if (bio->bi_vcnt > 1 &&
+            biovec_phys_mergeable(bvec - 1, bvec) &&
+            BIOVEC_SEG_BOUNDARY(q, bvec - 1, bvec))
                 bio_clear_flag(bio, BIO_SEG_VALID);
 
  done: