2 files changed, 8 insertions, 2 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index 9677c6525ed8..936876ab662d 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1401,13 +1401,19 @@ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
         struct blk_plug *plug;
         struct request *rq;
         bool ret = false;
+        struct list_head *plug_list;
 
         plug = current->plug;
         if (!plug)
                 goto out;
         *request_count = 0;
 
-        list_for_each_entry_reverse(rq, &plug->list, queuelist) {
+        if (q->mq_ops)
+                plug_list = &plug->mq_list;
+        else
+                plug_list = &plug->list;
+
+        list_for_each_entry_reverse(rq, plug_list, queuelist) {
                 int el_ret;
 
                 if (rq->q == q)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 2dc8de86d0d2..88d4e864d4c0 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -950,7 +950,7 @@ static void blk_mq_make_request(struct request_queue *q, struct bio *bio)
 
                 if (plug) {
                         blk_mq_bio_to_request(rq, bio);
-                        if (list_empty(&plug->list))
+                        if (list_empty(&plug->mq_list))
                                 trace_block_plug(q);
                         else if (request_count >= BLK_MAX_REQUEST_COUNT) {
                                 blk_flush_plug_list(plug, false);