block: get the 1st and last bvec via helpers
authorMing Lei <ming.lei@canonical.com>
Fri, 26 Feb 2016 15:40:52 +0000 (23:40 +0800)
committerJens Axboe <axboe@fb.com>
Thu, 3 Mar 2016 21:42:49 +0000 (14:42 -0700)
This patch applies the two introduced helpers to
figure out the 1st and last bvec, and fixes the
original way after bio splitting.

Cc: stable@vger.kernel.org
Reported-by: Sagi Grimberg <sagig@dev.mellanox.co.il>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
include/linux/blkdev.h

index cd06a41581b321094928569da4814cef74b3f0ae..d7f6bca707ef39101e2fad5e035c66d316eeb875 100644 (file)
@@ -1394,11 +1394,16 @@ static inline bool bvec_gap_to_prev(struct request_queue *q,
 static inline bool bio_will_gap(struct request_queue *q, struct bio *prev,
                         struct bio *next)
 {
-       if (!bio_has_data(prev) || !queue_virt_boundary(q))
-               return false;
+       if (bio_has_data(prev) && queue_virt_boundary(q)) {
+               struct bio_vec pb, nb;
+
+               bio_get_last_bvec(prev, &pb);
+               bio_get_first_bvec(next, &nb);
 
-       return __bvec_gap_to_prev(q, &prev->bi_io_vec[prev->bi_vcnt - 1],
-                                 next->bi_io_vec[0].bv_offset);
+               return __bvec_gap_to_prev(q, &pb, nb.bv_offset);
+       }
+
+       return false;
 }
 
 static inline bool req_gap_back_merge(struct request *req, struct bio *bio)