Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262483AbVDGOrP (ORCPT ); Thu, 7 Apr 2005 10:47:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262482AbVDGOrP (ORCPT ); Thu, 7 Apr 2005 10:47:15 -0400 Received: from ns.virtualhost.dk ([195.184.98.160]:62340 "EHLO virtualhost.dk") by vger.kernel.org with ESMTP id S262481AbVDGOqF (ORCPT ); Thu, 7 Apr 2005 10:46:05 -0400 Date: Thu, 7 Apr 2005 16:45:58 +0200 From: Jens Axboe To: James Bottomley Cc: Christoph Hellwig , Chris Rankin , Linux Kernel , SCSI Mailing List Subject: Re: [OOPS] 2.6.11 - NMI lockup with CFQ scheduler Message-ID: <20050407144557.GK1847@suse.de> References: <20050406175838.GC15165@suse.de> <1112811607.5555.15.camel@mulgrave> <20050406190838.GE15165@suse.de> <1112821799.5850.19.camel@mulgrave> <20050407064934.GJ15165@suse.de> <1112879919.5842.3.camel@mulgrave> <20050407132205.GA16517@infradead.org> <1112880658.5842.10.camel@mulgrave> <20050407133222.GJ1847@suse.de> <1112881183.5842.13.camel@mulgrave> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1112881183.5842.13.camel@mulgrave> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 859 Lines: 21 On Thu, Apr 07 2005, James Bottomley wrote: > On Thu, 2005-04-07 at 15:32 +0200, Jens Axboe wrote: > > I think Christophs point is that why add sdev_lock as a pointer, instead > > of just killing it? It's only used in one location, so it's not really > > that confusing (and a comment could fix that). > > Because any use of sdev->request_queue->queue_lock would likely succeed > even after we've freed the device and released the queue. If it's a > pointer and we null it after free and release, then any later use will > trigger an immediate NULL deref oops. So clear ->request_queue instead. -- Jens Axboe - 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/