+/*
+ * Insert rq into dispatch queue of q. Queue lock must be held on
+ * entry. If sort != 0, rq is sort-inserted; otherwise, rq will be
+ * appended to the dispatch queue. To be used by specific elevators.
+ */
+void elv_dispatch_sort(request_queue_t *q, struct request *rq)
+{
+ sector_t boundary;
+ struct list_head *entry;
+
+ if (q->last_merge == rq)
+ q->last_merge = NULL;
+
+ boundary = q->end_sector;
+
+ list_for_each_prev(entry, &q->queue_head) {
+ struct request *pos = list_entry_rq(entry);
+
+ if (pos->flags & (REQ_SOFTBARRIER|REQ_HARDBARRIER|REQ_STARTED))
+ break;
+ if (rq->sector >= boundary) {
+ if (pos->sector < boundary)
+ continue;
+ } else {
+ if (pos->sector >= boundary)
+ break;
+ }
+ if (rq->sector >= pos->sector)
+ break;
+ }
+
+ list_add(&rq->queuelist, entry);
+}
+