From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752661Ab1GXMRU (ORCPT ); Sun, 24 Jul 2011 08:17:20 -0400 Received: from 173-166-109-252-newengland.hfc.comcastbusiness.net ([173.166.109.252]:42315 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752515Ab1GXMRQ (ORCPT ); Sun, 24 Jul 2011 08:17:16 -0400 Date: Sun, 24 Jul 2011 08:17:14 -0400 From: Christoph Hellwig To: T?r?k Edwin Cc: xfs-masters@oss.sgi.com, xfs@oss.sgi.com, Linux Kernel Mailing List Subject: Re: BUG: unable to handle kernel paging request xfs_is_delayed_page Message-ID: <20110724121714.GA22065@infradead.org> References: <4E289228.4000208@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4E289228.4000208@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 21, 2011 at 11:55:04PM +0300, T?r?k Edwin wrote: > Not sure what the BUG means: did XFS ran out of memory when trying to write the 4GB coredump, as it wanted to allocate an extra 4G temporarely to hold it? > It means we dereferenced an invalid pointer in xfs_is_delayed_page, which is called from the writeback code, which is pretty odd. We haven't really touched that particular piece of code for a long time, and it really doesn't derefence many pointers, basically just page->mapping, page->private and the flags and b_this_page fields in the buffer head.