If a request times out the .completed_request() method is not called
and the .finish_request() method is only called if RQF_ELVPRIV has
been set. Hence this patch that sets RQF_ELVPRIV and that adds a
.finish_request() method. Without this patch, if a request times out
the zone that request applies to remains locked forever and no further
writes are accepted for that zone.
Fixes: 5700f69178e9 ("mq-deadline: Introduce zone locking support")
Signed-off-by: Damien Le Moal <damien.lemoal@xxxxxxx>
Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxx>
Cc: Hannes Reinecke <hare@xxxxxxxx>
Cc: Ming Lei <ming.lei@xxxxxxxxxx>
---
block/mq-deadline.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/block/mq-deadline.c b/block/mq-deadline.c
index c56f211c8440..55d5b7a02d62 100644
--- a/block/mq-deadline.c
+++ b/block/mq-deadline.c
@@ -367,7 +367,8 @@ static struct request *__dd_dispatch_request(struct deadline_data *dd)
* If the request needs its target zone locked, do it.
*/
blk_req_zone_write_lock(rq);
- rq->rq_flags |= RQF_STARTED;
+ /* Set RQF_ELVPRIV to ensure that .finish_request() gets called */
+ rq->rq_flags |= RQF_STARTED | RQF_ELVPRIV;
return rq;
}
@@ -539,7 +540,9 @@ static void dd_insert_requests(struct blk_mq_hw_ctx *hctx,
* For zoned block devices, write unlock the target zone of
* completed write requests. Do this while holding the zone lock
* spinlock so that the zone is never unlocked while deadline_fifo_request()
- * while deadline_next_request() are executing.
+ * while deadline_next_request() are executing. This function is called twice
+ * for requests that complete in a normal way and once for requests that time
+ * out.
*/
static void dd_completed_request(struct request *rq)
{
@@ -757,6 +760,7 @@ static struct elevator_type mq_deadline = {
.insert_requests = dd_insert_requests,
.dispatch_request = dd_dispatch_request,
.completed_request = dd_completed_request,
+ .finish_request = dd_completed_request,
.next_request = elv_rb_latter_request,
.former_request = elv_rb_former_request,
.bio_merge = dd_bio_merge,
--
2.16.2
