block: optionally merge discontiguous discard bios into a single request

[mirror_ubuntu-artful-kernel.git] / block / blk-mq.c

diff --git a/block/blk-mq.c b/block/blk-mq.c
index dd9722df4afe7820e5be50f9dd770f0204739112..7412191aee5762d89a0b2dcce10aefbbe89784d5 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -780,6 +780,9 @@ static bool blk_mq_attempt_merge(struct request_queue *q,
                        if (blk_mq_sched_allow_merge(q, rq, bio))
                                merged = bio_attempt_front_merge(q, rq, bio);
                        break;
+               case ELEVATOR_DISCARD_MERGE:
+                       merged = bio_attempt_discard_merge(q, rq, bio);
+                       break;
                default:
                        continue;
                }