| Date | Wed, 01 Jun 2011 17:09:58 +0900 | From | Greg KH <> | Subject | [028/165] block: add proper state guards to __elv_next_request |
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2.6.39-stable review patch. If anyone has any objections, please let us know.
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From: James Bottomley <James.Bottomley@suse.de>
commit 0a58e077eb600d1efd7e54ad9926a75a39d7f8ae upstream.
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> Signed-off-by: Jens Axboe <jaxboe@fusionio.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- block/blk.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/block/blk.h +++ b/block/blk.h @@ -81,7 +81,8 @@ static inline struct request *__elv_next q->flush_queue_delayed = 1; return NULL; } - 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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