From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Mason Subject: Re: lockdep warning with LTP dio test (v2.6.24-rc6-125-g5356f66) Date: Fri, 25 Jan 2008 11:16:13 -0500 Message-ID: <200801251116.13690.chris.mason@oracle.com> References: <200712242302.lBON2O8s011190@agora.fsl.cs.sunysb.edu> <20080114131454.37eb7c12@think.oraclecorp.com> <20080125160931.GC1767@duck.suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Cc: Zach Brown , Erez Zadok , linux-kernel@vger.kernel.org, ext3-users@redhat.com, Peter Zijlstra , linux-fsdevel@vger.kernel.org To: Jan Kara Return-path: Received: from agminet01.oracle.com ([141.146.126.228]:62256 "EHLO agminet01.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752006AbYAYQRv (ORCPT ); Fri, 25 Jan 2008 11:17:51 -0500 In-Reply-To: <20080125160931.GC1767@duck.suse.cz> Content-Disposition: inline Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Friday 25 January 2008, Jan Kara wrote: > > If ext3's DIO code only touches transactions in get_block, then it can > > violate data=ordered rules. Basically the transaction that allocates > > the blocks might commit before the DIO code gets around to writing them. > > > > A crash in the wrong place will expose stale data on disk. > > Hmm, I've looked at it and I don't think so - look at the rationale in > the patch below... That patch should fix the lock-inversion problem (at > least I see no lockdep warnings on my test machine). > Ah ok, when I was looking at this I was allowing holes to get filled without falling back to buffered. But, with the orphan inode entry protecting things I see how you're safe with this patch. -chris