diff --git a/block/blk-stat.c b/block/blk-stat.c
index e77ec52f5bb5..dde9d399f707 100644
--- a/block/blk-stat.c
+++ b/block/blk-stat.c
@@ -19,7 +19,7 @@ struct blk_queue_stats {
 	bool enable_accounting;
 };
 
-unsigned int blk_stat_rq_ddir(const struct request *rq)
+int blk_stat_rq_ddir(const struct request *rq)
 {
 	return rq_data_dir(rq);
 }
@@ -104,6 +104,8 @@ void blk_stat_add(struct request *rq)
 	list_for_each_entry_rcu(cb, &q->stats->callbacks, list) {
 		if (blk_stat_is_active(cb)) {
 			bucket = cb->bucket_fn(rq);
+			if (bucket < 0)
+				continue;
 			stat = &this_cpu_ptr(cb->cpu_stat)[bucket];
 			__blk_stat_add(stat, value);
 		}
@@ -135,7 +137,7 @@ static void blk_stat_timer_fn(unsigned long data)
 
 struct blk_stat_callback *
 blk_stat_alloc_callback(void (*timer_fn)(struct blk_stat_callback *),
-			unsigned int (*bucket_fn)(const struct request *),
+			int (*bucket_fn)(const struct request *),
 			unsigned int buckets, void *data)
 {
 	struct blk_stat_callback *cb;
diff --git a/block/blk-stat.h b/block/blk-stat.h
index 53f08a63bf15..622a62ce6213 100644
--- a/block/blk-stat.h
+++ b/block/blk-stat.h
@@ -48,9 +48,10 @@ struct blk_stat_callback {
 
 	/**
 	 * @bucket_fn: Given a request, returns which statistics bucket it
-	 * should be accounted under.
+	 * should be accounted under. Return -1 for no bucket for this
+	 * request.
 	 */
-	unsigned int (*bucket_fn)(const struct request *);
+	int (*bucket_fn)(const struct request *);
 
 	/**
 	 * @buckets: Number of statistics buckets.
@@ -120,7 +121,7 @@ void blk_stat_enable_accounting(struct request_queue *q);
  *
  * Return: Data direction of the request, either READ or WRITE.
  */
-unsigned int blk_stat_rq_ddir(const struct request *rq);
+int blk_stat_rq_ddir(const struct request *rq);
 
 /**
  * blk_stat_alloc_callback() - Allocate a block statistics callback.
@@ -135,7 +136,7 @@ unsigned int blk_stat_rq_ddir(const struct request *rq);
  */
 struct blk_stat_callback *
 blk_stat_alloc_callback(void (*timer_fn)(struct blk_stat_callback *),
-			unsigned int (*bucket_fn)(const struct request *),
+			int (*bucket_fn)(const struct request *),
 			unsigned int buckets, void *data);
 
 /**
diff --git a/block/kyber-iosched.c b/block/kyber-iosched.c
index fe4af5b97c0e..3b0090bc5dd1 100644
--- a/block/kyber-iosched.c
+++ b/block/kyber-iosched.c
@@ -102,7 +102,7 @@ struct kyber_hctx_data {
 	atomic_t wait_index[KYBER_NUM_DOMAINS];
 };
 
-static unsigned int rq_sched_domain(const struct request *rq)
+static int rq_sched_domain(const struct request *rq)
 {
 	unsigned int op = rq->cmd_flags;