From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: [PATCH 1/2] block: add proper state guards to __elv_next_request Date: Fri, 22 Apr 2011 10:38:51 -0500 Message-ID: <1303486731.2590.23.camel@mulgrave.site> References: <1303486638.2590.21.camel@mulgrave.site> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Received: from cantor2.suse.de ([195.135.220.15]:54314 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752204Ab1DVPiz (ORCPT ); Fri, 22 Apr 2011 11:38:55 -0400 In-Reply-To: <1303486638.2590.21.camel@mulgrave.site> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: linux-scsi Cc: Jens Axboe 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 --- block/blk.h | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/block/blk.h b/block/blk.h index 6126346..4df474d 100644 --- a/block/blk.h +++ b/block/blk.h @@ -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; } } -- 1.7.4.1