It is required to hold the queue lock when calling blk_run_queue_async()
to avoid that a race between blk_run_queue_async() and
blk_cleanup_queue() is triggered.
Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxxxxxx>
---
drivers/md/dm-rq.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c
index f9f37ad..7df7948 100644
--- a/drivers/md/dm-rq.c
+++ b/drivers/md/dm-rq.c
@@ -210,6 +210,9 @@ static void rq_end_stats(struct mapped_device *md, struct request *orig)
*/
static void rq_completed(struct mapped_device *md, int rw, bool run_queue)
{
+ struct request_queue *q = md->queue;
+ unsigned long flags;
+
atomic_dec(&md->pending[rw]);
/* nudge anyone waiting on suspend queue */
@@ -222,8 +225,11 @@ static void rq_completed(struct mapped_device *md, int rw, bool run_queue)
* back into ->request_fn() could deadlock attempting to grab the
* queue lock again.
*/
- if (!md->queue->mq_ops && run_queue)
- blk_run_queue_async(md->queue);
+ if (!q->mq_ops && run_queue) {
+ spin_lock_irqsave(q->queue_lock, flags);
+ blk_run_queue_async(q);
+ spin_unlock_irqrestore(q->queue_lock, flags);
+ }
/*
* dm_put() must be at the end of this function. See the comment above
--
2.10.1
--
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