From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262349AbTJTA0M (ORCPT ); Sun, 19 Oct 2003 20:26:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262351AbTJTA0M (ORCPT ); Sun, 19 Oct 2003 20:26:12 -0400 Received: from dyn-ctb-210-9-246-209.webone.com.au ([210.9.246.209]:15108 "EHLO chimp.local.net") by vger.kernel.org with ESMTP id S262349AbTJTA0J (ORCPT ); Sun, 19 Oct 2003 20:26:09 -0400 Message-ID: <3F932B81.2040202@cyberone.com.au> Date: Mon, 20 Oct 2003 10:25:37 +1000 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4) Gecko/20030827 Debian/1.4-3 X-Accept-Language: en MIME-Version: 1.0 To: Andrew Morton CC: Peter Osterlund , axboe@suse.de, linux-kernel@vger.kernel.org Subject: Re: 2.6.0-test8, DEBUG_SLAB, oops in as_latter_request() References: <20031019142042.2f41eb68.akpm@osdl.org> In-Reply-To: <20031019142042.2f41eb68.akpm@osdl.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andrew Morton wrote: >Peter Osterlund wrote: > >>I was running 2.6.0-test8 compiled with CONFIG_DEBUG_SLAB=y. When >> testing the CDRW packet writing driver, I got an oops in >> as_latter_request. (Full oops at the end of this message.) It is >> repeatable and happens because arq->rb_node.rb_right is uninitialized. >> > >deadline seems to have the same problem. > >We may as well squish this with the big hammer? > Thanks for the report, Peter. The request is a special request, so either blk_attempt_remerge should never be called on it, or blk_attempt_remerge (or as_latter_request) should check for this. Its up to Jens. I would say to stick something like if (!rq_mergeable(rq)) return; into blk_attempt_remerge. I'd say we shouldn't expect drivers to try to get this right.