Commit 0a58e077 authored May 18, 2011 by James Bottomley Committed by Jens Axboe May 18, 2011

block: add proper state guards to __elv_next_request



blk_cleanup_queue() calls elevator_exit() and after this, we can't
touch the elevator without oopsing.  __elv_next_request() must check
for this state because in the refcounted queue model, we can still
call it after blk_cleanup_queue() has been called.

This was reported as causing an oops attributable to scsi.

Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

parent a2b9c1f6

block/blk.h

+2 −1

Original line number	Diff line number	Diff line
		@@ -62,7 +62,8 @@ static inline struct request __elv_next_request(struct request_queue q)
		return rq;
		}

		if (!q->elevator->ops->elevator_dispatch_fn(q, 0))
		if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags) \|\|
		!q->elevator->ops->elevator_dispatch_fn(q, 0))
		return NULL;
		}
		}

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