Make sure that ->request_fn() really isn't called on queues that are
supposed to be stopped. While at it, don't remove the plug in
__blk_run_queue() unconditionally since this might lead to system hangs.
Signed-off-by: Elias Oltmanns <eo@nebensachen.de>
---
Applies to your devel tree.
block/blk-core.c | 6 +++---
block/elevator.c | 12 +++++++-----
2 files changed, 10 insertions(+), 8 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index 2d053b5..ecc5443 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -404,14 +404,14 @@ EXPORT_SYMBOL(blk_sync_queue);
*/
void __blk_run_queue(struct request_queue *q)
{
- blk_remove_plug(q);
-
/*
* Only recurse once to avoid overrunning the stack, let the unplug
* handling reinvoke the handler shortly if we already got there.
*/
- if (!elv_queue_empty(q))
+ if (!elv_queue_empty(q) && likely(!blk_queue_stopped(q))) {
+ blk_remove_plug(q);
blk_invoke_request_fn(q);
+ }
}
EXPORT_SYMBOL(__blk_run_queue);
diff --git a/block/elevator.c b/block/elevator.c
index 0451892..43a4257 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -611,8 +611,10 @@ void elv_insert(struct request_queue *q, struct request *rq, int where)
* with anything. There's no point in delaying queue
* processing.
*/
- blk_remove_plug(q);
- q->request_fn(q);
+ if (likely(!blk_queue_stopped(q))) {
+ blk_remove_plug(q);
+ q->request_fn(q);
+ }
break;
case ELEVATOR_INSERT_SORT:
@@ -950,7 +952,8 @@ void elv_completed_request(struct request_queue *q, struct request *rq)
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);
+ if (likely(!blk_queue_stopped(q)))
+ q->request_fn(q);
}
}
}
@@ -1109,8 +1112,7 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e)
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);
--
