block: add missing blk_queue_dead() checks

blk_insert_cloned_request(), blk_execute_rq_nowait() and
blk_flush_plug_list() either didn't check whether the queue was dead
or did it without holding queue_lock.  Update them so that dead state
is checked while holding queue_lock.

AFAICS, this plugs all holes (requeue doesn't matter as the request is
transitioning atomically from in_flight to queued).

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 4 insertions, 2 deletions

diff --git a/block/blk-exec.c b/block/blk-exec.c
index 60532852b3ab..fb2cbd551621 100644
--- a/block/blk-exec.c
+++ b/block/blk-exec.c
@@ -50,7 +50,11 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
 {
         int where = at_head ? ELEVATOR_INSERT_FRONT : ELEVATOR_INSERT_BACK;
 
+        WARN_ON(irqs_disabled());
+        spin_lock_irq(q->queue_lock);
+
         if (unlikely(blk_queue_dead(q))) {
+                spin_unlock_irq(q->queue_lock);
                 rq->errors = -ENXIO;
                 if (rq->end_io)
                         rq->end_io(rq, rq->errors);
@@ -59,8 +63,6 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
 
         rq->rq_disk = bd_disk;
         rq->end_io = done;
-        WARN_ON(irqs_disabled());
-        spin_lock_irq(q->queue_lock);
         __elv_add_request(q, rq, where);
         __blk_run_queue(q);
         /* the queue is stopped so it won't be run */