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block: add missing blk_queue_dead() checks

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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>
This commit is contained in:
Tejun Heo 2011-12-14 00:33:37 +01:00 committed by Jens Axboe
parent 481a7d6479
commit 8ba61435d7
2 changed files with 25 additions and 2 deletions
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21
block/blk-core.c
View file

@ -1731,6 +1731,10 @@ int blk_insert_cloned_request(struct request_queue *q, struct request *rq)
return -EIO;
spin_lock_irqsave(q->queue_lock, flags);
if (unlikely(blk_queue_dead(q))) {
spin_unlock_irqrestore(q->queue_lock, flags);
return -ENODEV;
}
/*
* Submitting request must be dequeued before calling this function
@ -2704,6 +2708,14 @@ static void queue_unplugged(struct request_queue *q, unsigned int depth,
{
trace_block_unplug(q, depth, !from_schedule);
/*
* Don't mess with dead queue.
*/
if (unlikely(blk_queue_dead(q))) {
spin_unlock(q->queue_lock);
return;
}
/*
* If we are punting this to kblockd, then we can safely drop
* the queue_lock before waking kblockd (which needs to take
@ -2780,6 +2792,15 @@ void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
depth = 0;
spin_lock(q->queue_lock);
}
/*
* Short-circuit if @q is dead
*/
if (unlikely(blk_queue_dead(q))) {
__blk_end_request_all(rq, -ENODEV);
continue;
}
/*
* rq is already accounted, so use raw insert
*/

6
block/blk-exec.c
View file

@ -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 */