EXPORT_SYMBOL_GPL(bio_associate_blkcg);
 
 /**
- * bio_associate_blkg - associate a bio with the a blkg
+ * bio_has_queue - required check for blkg association
+ * @bio: target bio
+ *
+ * A blkg represents the relationship between a blkcg and a request_queue.
+ * If there is no request_queue, there is no blkg and therefore nothing to
+ * associate with.
+ */
+static inline bool bio_has_queue(struct bio *bio)
+{
+	return bio->bi_disk && bio->bi_disk->queue;
+}

How do you ever see a bio without a queue?  We can't even do I/O in
that case.