diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index bb109bb0a055..3772671cf2bc 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -453,9 +453,26 @@ static ssize_t queue_wb_lat_store(struct request_queue *q, const char *page,
 	else if (val >= 0)
 		val *= 1000ULL;
 
-	wbt_set_min_lat(q, val);
+	/*
+	 * Ensure that the queue is idled, in case the latency update
+	 * ends up either enabling or disabling wbt completely. We can't
+	 * have IO inflight if that happens.
+	 */
+	if (q->mq_ops) {
+		blk_mq_freeze_queue(q);
+		blk_mq_quiesce_queue(q);
+	} else
+		blk_queue_bypass_start(q);
 
+	wbt_set_min_lat(q, val);
 	wbt_update_limits(q);
+
+	if (q->mq_ops) {
+		blk_mq_unquiesce_queue(q);
+		blk_mq_unfreeze_queue(q);
+	} else
+		blk_queue_bypass_end(q);
+
 	return count;
 }
 
diff --git a/block/blk-wbt.c b/block/blk-wbt.c
index c9358f1981fb..84507d3e9a98 100644
--- a/block/blk-wbt.c
+++ b/block/blk-wbt.c
@@ -540,6 +540,9 @@ static enum wbt_flags bio_to_wbt_flags(struct rq_wb *rwb, struct bio *bio)
 {
 	enum wbt_flags flags = 0;
 
+	if (!rwb_enabled(rwb))
+		return 0;
+
 	if (bio_op(bio) == REQ_OP_READ) {
 		flags = WBT_READ;
 	} else if (wbt_should_throttle(rwb, bio)) {