@@ -338,6 +338,16 @@ static struct request *deadline_skip_seq_writes(struct deadline_data *dd,
return rq;
}
+/*
+ * Use write locking if either QUEUE_FLAG_NO_ZONE_WRITE_LOCK has not been set.
+ * Not using zone write locking is only safe if the block driver preserves the
+ * request order.
+ */
+static bool dd_use_zone_write_locking(struct request_queue *q)
+{
+ return blk_queue_is_zoned(q) && !blk_queue_no_zone_write_lock(q);
+}
+
/*
* For the specified data direction, return the next request to
* dispatch using arrival ordered lists.
@@ -353,7 +363,7 @@ deadline_fifo_request(struct deadline_data *dd, struct dd_per_prio *per_prio,
return NULL;
rq = rq_entry_fifo(per_prio->fifo_list[data_dir].next);
- if (data_dir == DD_READ || !blk_queue_is_zoned(rq->q))
+ if (data_dir == DD_READ || !dd_use_zone_write_locking(rq->q))
return rq;
/*
@@ -398,7 +408,7 @@ deadline_next_request(struct deadline_data *dd, struct dd_per_prio *per_prio,
if (!rq)
return NULL;
- if (data_dir == DD_READ || !blk_queue_is_zoned(rq->q))
+ if (data_dir == DD_READ || !dd_use_zone_write_locking(rq->q))
return rq;
/*
@@ -526,8 +536,9 @@ static struct request *__dd_dispatch_request(struct deadline_data *dd,
}
/*
- * For a zoned block device, if we only have writes queued and none of
- * them can be dispatched, rq will be NULL.
+ * For a zoned block device that requires write serialization, if we
+ * only have writes queued and none of them can be dispatched, rq will
+ * be NULL.
*/
if (!rq)
return NULL;
@@ -552,7 +563,8 @@ 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);
+ if (dd_use_zone_write_locking(rq->q))
+ blk_req_zone_write_lock(rq);
rq->rq_flags |= RQF_STARTED;
return rq;
}
@@ -933,7 +945,7 @@ static void dd_finish_request(struct request *rq)
atomic_inc(&per_prio->stats.completed);
- if (blk_queue_is_zoned(q)) {
+ if (dd_use_zone_write_locking(rq->q)) {
unsigned long flags;
spin_lock_irqsave(&dd->zone_lock, flags);