diff --git a/block/blk-mq.c b/block/blk-mq.c
index 5a9c02d0199cb2296ec1e70ab4243be0676d1a84..05694bd216d18dd95b798cff393ac8c9b3da89f3 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -141,7 +141,9 @@ static bool blk_mq_check_inflight_with_stat(struct blk_mq_hw_ctx *hctx,
 				rq->part->stat_time - stat_time :
 				rq->part->stat_time - rq->start_time_ns;
 
+			part_stat_lock();
 			part_stat_add(rq->part, nsecs[sgrp], duation);
+			part_stat_unlock();
 		}
 	}
 
diff --git a/block/genhd.c b/block/genhd.c
index 1f358495e21820aa24b308b1986f474b1f9abd70..b2b33ac21a4a08be108c6088d7a45750e1d8e77b 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1432,10 +1432,8 @@ static void part_get_stat_info(struct hd_struct *hd, struct disk_stats *stat,
 	struct request_queue *q = part_to_disk(hd)->queue;
 	if (queue_is_mq(q)) {
 		mutex_lock(&part_to_dev(hd)->mutex);
-		part_stat_lock();
 		part_set_stat_time(hd);
 		*inflight = blk_mq_in_flight_with_stat(q, hd);
-		part_stat_unlock();
 		mutex_unlock(&part_to_dev(hd)->mutex);
 	} else {
 		*inflight = part_in_flight(hd);