Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965008Ab2EOCRF (ORCPT ); Mon, 14 May 2012 22:17:05 -0400 Received: from mail1.windriver.com ([147.11.146.13]:52786 "EHLO mail1.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964857Ab2EOCQD (ORCPT ); Mon, 14 May 2012 22:16:03 -0400 From: Paul Gortmaker To: , Subject: [34-longterm 007/179] block: add proper state guards to __elv_next_request Date: Mon, 14 May 2012 22:11:43 -0400 Message-ID: <1337048075-6132-8-git-send-email-paul.gortmaker@windriver.com> X-Mailer: git-send-email 1.7.9.6 In-Reply-To: <1337048075-6132-1-git-send-email-paul.gortmaker@windriver.com> References: <1337048075-6132-1-git-send-email-paul.gortmaker@windriver.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1627 Lines: 46 From: James Bottomley ------------------- This is a commit scheduled for the next v2.6.34 longterm release. http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git If you see a problem with using this for longterm, please comment. ------------------- 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 Signed-off-by: Jens Axboe Signed-off-by: Paul Gortmaker --- block/blk.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/block/blk.h b/block/blk.h index 5ee3d7e..1414836 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; } } -- 1.7.9.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/