+ /*
+ * Reset private fields. In case of a requeue, this allows
+ * this function to correctly do nothing if it is spuriously
+ * invoked again on this same request (see the check at the
+ * beginning of the function). Probably, a better general
+ * design would be to prevent blk-mq from invoking the requeue
+ * or finish hooks of an elevator, for a request that is not
+ * referred by that elevator.
+ *
+ * Resetting the following fields would break the
+ * request-insertion logic if rq is re-inserted into a bfq
+ * internal queue, without a re-preparation. Here we assume
+ * that re-insertions of requeued requests, without
+ * re-preparation, can happen only for pass_through or at_head
+ * requests (which are not re-inserted into bfq internal
+ * queues).
+ */