blk-mq: don't allow queue entering for a dying queue

If the queue is going away, don't let new allocs or queueing
happen on it. Go through the normal wait process, and exit with
ENODEV in that case.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/block/blk-mq.c b/block/blk-mq.c
index a6ee74e27957..75fc33f34251 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -82,8 +82,10 @@ static int blk_mq_queue_enter(struct request_queue *q)
 
         __percpu_counter_add(&q->mq_usage_counter, 1, 1000000);
         smp_wmb();
-        /* we have problems to freeze the queue if it's initializing */
-        if (!blk_queue_bypass(q) || !blk_queue_init_done(q))
+
+        /* we have problems freezing the queue if it's initializing */
+        if (!blk_queue_dying(q) &&
+            (!blk_queue_bypass(q) || !blk_queue_init_done(q)))
                 return 0;
 
         __percpu_counter_add(&q->mq_usage_counter, -1, 1000000);