diff --git a/block/blk-mq.c b/block/blk-mq.c
index 383ea0cb1f0a..a13c40ca8230 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -392,6 +392,12 @@ static void blk_mq_start_request(struct request *rq, bool last)
 
 	blk_add_timer(rq);
 
+	/*
+	 * Ensure that ->deadline is visible before set the started
+	 * flag and clear the completed flag.
+	 */
+	smp_mb__before_atomic();
+
 	/*
 	 * Mark us as started and clear complete. Complete might have been
 	 * set if requeue raced with timeout, which then marked it as