1 files changed, 34 insertions, 14 deletions

diff --git a/block/blk-rq-qos.h b/block/blk-rq-qos.h
index 37245c97ee61..b538f2c0febc 100644
--- a/block/blk-rq-qos.h
+++ b/block/blk-rq-qos.h
@@ -112,41 +112,58 @@ void __rq_qos_queue_depth_changed(struct rq_qos *rqos);
 
 static inline void rq_qos_cleanup(struct request_queue *q, struct bio *bio)
 {
-	if (q->rq_qos)
+	if (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) &&
+			q->rq_qos)
 		__rq_qos_cleanup(q->rq_qos, bio);
 }
 
 static inline void rq_qos_done(struct request_queue *q, struct request *rq)
 {
-	if (q->rq_qos && !blk_rq_is_passthrough(rq))
+	if (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) &&
+			q->rq_qos && !blk_rq_is_passthrough(rq))
 		__rq_qos_done(q->rq_qos, rq);
 }
 
 static inline void rq_qos_issue(struct request_queue *q, struct request *rq)
 {
-	if (q->rq_qos)
+	if (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) &&
+			q->rq_qos)
 		__rq_qos_issue(q->rq_qos, rq);
 }
 
 static inline void rq_qos_requeue(struct request_queue *q, struct request *rq)
 {
-	if (q->rq_qos)
+	if (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) &&
+			q->rq_qos)
 		__rq_qos_requeue(q->rq_qos, rq);
 }
 
 static inline void rq_qos_done_bio(struct bio *bio)
 {
-	if (bio->bi_bdev && (bio_flagged(bio, BIO_QOS_THROTTLED) ||
-			     bio_flagged(bio, BIO_QOS_MERGED))) {
-		struct request_queue *q = bdev_get_queue(bio->bi_bdev);
-		if (q->rq_qos)
-			__rq_qos_done_bio(q->rq_qos, bio);
-	}
+	struct request_queue *q;
+
+	if (!bio->bi_bdev || (!bio_flagged(bio, BIO_QOS_THROTTLED) &&
+			     !bio_flagged(bio, BIO_QOS_MERGED)))
+		return;
+
+	q = bdev_get_queue(bio->bi_bdev);
+
+	/*
+	 * A BIO may carry BIO_QOS_* flags even if the associated request_queue
+	 * does not have rq_qos enabled. This can happen with stacked block
+	 * devices — for example, NVMe multipath, where it's possible that the
+	 * bottom device has QoS enabled but the top device does not. Therefore,
+	 * always verify that q->rq_qos is present and QoS is enabled before
+	 * calling __rq_qos_done_bio().
+	 */
+	if (test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags) && q->rq_qos)
+		__rq_qos_done_bio(q->rq_qos, bio);
 }
 
 static inline void rq_qos_throttle(struct request_queue *q, struct bio *bio)
 {
-	if (q->rq_qos) {
+	if (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) &&
+			q->rq_qos) {
 		bio_set_flag(bio, BIO_QOS_THROTTLED);
 		__rq_qos_throttle(q->rq_qos, bio);
 	}
@@ -155,14 +172,16 @@ static inline void rq_qos_throttle(struct request_queue *q, struct bio *bio)
 static inline void rq_qos_track(struct request_queue *q, struct request *rq,
 				struct bio *bio)
 {
-	if (q->rq_qos)
+	if (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) &&
+			q->rq_qos)
 		__rq_qos_track(q->rq_qos, rq, bio);
 }
 
 static inline void rq_qos_merge(struct request_queue *q, struct request *rq,
 				struct bio *bio)
 {
-	if (q->rq_qos) {
+	if (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) &&
+			q->rq_qos) {
 		bio_set_flag(bio, BIO_QOS_MERGED);
 		__rq_qos_merge(q->rq_qos, rq, bio);
 	}
@@ -170,7 +189,8 @@ static inline void rq_qos_merge(struct request_queue *q, struct request *rq,
 
 static inline void rq_qos_queue_depth_changed(struct request_queue *q)
 {
-	if (q->rq_qos)
+	if (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) &&
+			q->rq_qos)
 		__rq_qos_queue_depth_changed(q->rq_qos);
 }