1 files changed, 10 insertions, 2 deletions

diff --git a/block/elevator.c b/block/elevator.c
index ed6f8f32d27e..4f5127054e3f 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -75,6 +75,12 @@ int elv_rq_merge_ok(struct request *rq, struct bio *bio)
                 return 0;
 
         /*
+         * Don't merge file system requests and discard requests
+         */
+        if (bio_discard(bio) != bio_discard(rq->bio))
+                return 0;
+
+        /*
          * different data direction or already started, don't merge
          */
         if (bio_data_dir(bio) != rq_data_dir(rq))
@@ -438,6 +444,8 @@ void elv_dispatch_sort(struct request_queue *q, struct request *rq)
         list_for_each_prev(entry, &q->queue_head) {
                 struct request *pos = list_entry_rq(entry);
 
+                if (blk_discard_rq(rq) != blk_discard_rq(pos))
+                        break;
                 if (rq_data_dir(rq) != rq_data_dir(pos))
                         break;
                 if (pos->cmd_flags & stop_flags)
@@ -607,7 +615,7 @@ void elv_insert(struct request_queue *q, struct request *rq, int where)
                 break;
 
         case ELEVATOR_INSERT_SORT:
-                BUG_ON(!blk_fs_request(rq));
+                BUG_ON(!blk_fs_request(rq) && !blk_discard_rq(rq));
                 rq->cmd_flags |= REQ_SORTED;
                 q->nr_sorted++;
                 if (rq_mergeable(rq)) {
@@ -692,7 +700,7 @@ void __elv_add_request(struct request_queue *q, struct request *rq, int where,
                  * this request is scheduling boundary, update
                  * end_sector
                  */
-                if (blk_fs_request(rq)) {
+                if (blk_fs_request(rq) || blk_discard_rq(rq)) {
                         q->end_sector = rq_end_sector(rq);
                         q->boundary_rq = rq;
                 }