block: only call ->request_fn when the queue is not stopped
Callers should use either blk_run_queue/__blk_run_queue, or
blk_start_queueing() to invoke request handling instead of calling
->request_fn() directly as that does not take the queue stopped
flag into account.
Also add appropriate comments on the above functions to detail
their usage.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/block/elevator.c b/block/elevator.c
index 9482ffa..59173a6 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -612,7 +612,7 @@
* processing.
*/
blk_remove_plug(q);
- q->request_fn(q);
+ blk_start_queueing(q);
break;
case ELEVATOR_INSERT_SORT:
@@ -950,7 +950,7 @@
blk_ordered_cur_seq(q) == QUEUE_ORDSEQ_DRAIN &&
blk_ordered_req_seq(first_rq) > QUEUE_ORDSEQ_DRAIN) {
blk_ordered_complete_seq(q, QUEUE_ORDSEQ_DRAIN, 0);
- q->request_fn(q);
+ blk_start_queueing(q);
}
}
}
@@ -1109,8 +1109,7 @@
elv_drain_elevator(q);
while (q->rq.elvpriv) {
- blk_remove_plug(q);
- q->request_fn(q);
+ blk_start_queueing(q);
spin_unlock_irq(q->queue_lock);
msleep(10);
spin_lock_irq(q->queue_lock);