int front_merges;
};
-static void deadline_move_request(struct deadline_data *, struct request *);
-
static inline struct rb_root *
deadline_rb_root(struct deadline_data *dd, struct request *rq)
{
struct deadline_data *dd = q->elevator->elevator_data;
const int data_dir = rq_data_dir(rq);
+ /*
+ * This may be a requeue of a write request that has locked its
+ * target zone. If it is the case, this releases the zone lock.
+ */
+ blk_req_zone_write_unlock(rq);
+
deadline_add_rq_rb(dd, rq);
/*
{
struct request_queue *q = rq->q;
+ /*
+ * For a zoned block device, write requests must write lock their
+ * target zone.
+ */
+ blk_req_zone_write_lock(rq);
+
deadline_remove_request(q, rq);
elv_dispatch_add_tail(q, rq);
}
return 0;
}
+/*
+ * For the specified data direction, return the next request to dispatch using
+ * arrival ordered lists.
+ */
+static struct request *
+deadline_fifo_request(struct deadline_data *dd, int data_dir)
+{
+ struct request *rq;
+
+ if (WARN_ON_ONCE(data_dir != READ && data_dir != WRITE))
+ return NULL;
+
+ if (list_empty(&dd->fifo_list[data_dir]))
+ return NULL;
+
+ rq = rq_entry_fifo(dd->fifo_list[data_dir].next);
+ if (data_dir == READ || !blk_queue_is_zoned(rq->q))
+ return rq;
+
+ /*
+ * Look for a write request that can be dispatched, that is one with
+ * an unlocked target zone.
+ */
+ list_for_each_entry(rq, &dd->fifo_list[WRITE], queuelist) {
+ if (blk_req_can_dispatch_to_zone(rq))
+ return rq;
+ }
+
+ return NULL;
+}
+
+/*
+ * For the specified data direction, return the next request to dispatch using
+ * sector position sorted lists.
+ */
+static struct request *
+deadline_next_request(struct deadline_data *dd, int data_dir)
+{
+ struct request *rq;
+
+ if (WARN_ON_ONCE(data_dir != READ && data_dir != WRITE))
+ return NULL;
+
+ rq = dd->next_rq[data_dir];
+ if (!rq)
+ return NULL;
+
+ if (data_dir == READ || !blk_queue_is_zoned(rq->q))
+ return rq;
+
+ /*
+ * Look for a write request that can be dispatched, that is one with
+ * an unlocked target zone.
+ */
+ while (rq) {
+ if (blk_req_can_dispatch_to_zone(rq))
+ return rq;
+ rq = deadline_latter_request(rq);
+ }
+
+ return NULL;
+}
+
/*
* deadline_dispatch_requests selects the best request according to
* read/write expire, fifo_batch, etc
struct deadline_data *dd = q->elevator->elevator_data;
const int reads = !list_empty(&dd->fifo_list[READ]);
const int writes = !list_empty(&dd->fifo_list[WRITE]);
- struct request *rq;
+ struct request *rq, *next_rq;
int data_dir;
/*
* batches are currently reads XOR writes
*/
- if (dd->next_rq[WRITE])
- rq = dd->next_rq[WRITE];
- else
- rq = dd->next_rq[READ];
+ rq = deadline_next_request(dd, WRITE);
+ if (!rq)
+ rq = deadline_next_request(dd, READ);
if (rq && dd->batching < dd->fifo_batch)
/* we have a next request are still entitled to batch */
if (reads) {
BUG_ON(RB_EMPTY_ROOT(&dd->sort_list[READ]));
- if (writes && (dd->starved++ >= dd->writes_starved))
+ if (deadline_fifo_request(dd, WRITE) &&
+ (dd->starved++ >= dd->writes_starved))
goto dispatch_writes;
data_dir = READ;
/*
* we are not running a batch, find best request for selected data_dir
*/
- if (deadline_check_fifo(dd, data_dir) || !dd->next_rq[data_dir]) {
+ next_rq = deadline_next_request(dd, data_dir);
+ if (deadline_check_fifo(dd, data_dir) || !next_rq) {
/*
* A deadline has expired, the last request was in the other
* direction, or we have run out of higher-sectored requests.
* Start again from the request with the earliest expiry time.
*/
- rq = rq_entry_fifo(dd->fifo_list[data_dir].next);
+ rq = deadline_fifo_request(dd, data_dir);
} else {
/*
* The last req was the same dir and we have a next request in
* sort order. No expired requests so continue on from here.
*/
- rq = dd->next_rq[data_dir];
+ rq = next_rq;
}
+ /*
+ * For a zoned block device, if we only have writes queued and none of
+ * them can be dispatched, rq will be NULL.
+ */
+ if (!rq)
+ return 0;
+
dd->batching = 0;
dispatch_request:
return 1;
}
+/*
+ * For zoned block devices, write unlock the target zone of completed
+ * write requests.
+ */
+static void
+deadline_completed_request(struct request_queue *q, struct request *rq)
+{
+ blk_req_zone_write_unlock(rq);
+}
+
static void deadline_exit_queue(struct elevator_queue *e)
{
struct deadline_data *dd = e->elevator_data;
.elevator_merged_fn = deadline_merged_request,
.elevator_merge_req_fn = deadline_merged_requests,
.elevator_dispatch_fn = deadline_dispatch_requests,
+ .elevator_completed_req_fn = deadline_completed_request,
.elevator_add_req_fn = deadline_add_request,
.elevator_former_req_fn = elv_rb_former_request,
.elevator_latter_req_fn = elv_rb_latter_request,
git.samba.org / sfrench / cifs-2.6.git / blobdiff