From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Mon, 21 Jul 2008 19:23:00 -0700 (PDT) Received: from cuda.sgi.com (cuda1.sgi.com [192.48.168.28]) by oss.sgi.com (8.12.11.20060308/8.12.11/SuSE Linux 0.7) with ESMTP id m6M2MwDV001009 for ; Mon, 21 Jul 2008 19:22:58 -0700 Received: from ipmail01.adl6.internode.on.net (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 4E245E78DB2 for ; Mon, 21 Jul 2008 19:24:07 -0700 (PDT) Received: from ipmail01.adl6.internode.on.net (ipmail01.adl6.internode.on.net [203.16.214.146]) by cuda.sgi.com with ESMTP id TKFUJuMXHBvGz4r4 for ; Mon, 21 Jul 2008 19:24:07 -0700 (PDT) Date: Tue, 22 Jul 2008 12:24:04 +1000 From: Dave Chinner Subject: Re: [PATCH] Do not access buffers after dropping reference count Message-ID: <20080722022404.GH6761@disturbed> References: <4885430D.7000506@sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4885430D.7000506@sgi.com> Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: Lachlan McIlroy Cc: xfs-dev , xfs-oss On Tue, Jul 22, 2008 at 12:16:45PM +1000, Lachlan McIlroy wrote: > We should not access a buffer after dropping it's reference count otherwise > we could race with another thread that releases the final reference count > and frees the buffer causing us to access potentially unmapped memory. Looks OK. The commit message should point out this is a problem only for DEBUG kernels, though. Cheers, Dave. -- Dave Chinner david@fromorbit.com