From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by oss.sgi.com (8.12.11.20060308/8.12.11/SuSE Linux 0.7) with ESMTP id mB4E9B2R005045 for ; Thu, 4 Dec 2008 08:09:14 -0600 Received: from one.firstfloor.org (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 70C101BEF682 for ; Thu, 4 Dec 2008 06:09:09 -0800 (PST) Received: from one.firstfloor.org (one.firstfloor.org [213.235.205.2]) by cuda.sgi.com with ESMTP id Xu52A9uZYDg5OA2V for ; Thu, 04 Dec 2008 06:09:09 -0800 (PST) Date: Thu, 4 Dec 2008 15:20:15 +0100 From: Andi Kleen Subject: Re: Device loses barrier support (was: Fixed patch for simple barriers.) Message-ID: <20081204142015.GQ6703@one.firstfloor.org> References: <20081204100050.GN6703@one.firstfloor.org> Mime-Version: 1.0 Content-Disposition: inline In-Reply-To: List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Mikulas Patocka Cc: Andi Kleen , linux-kernel@vger.kernel.org, xfs@oss.sgi.com, Andi Kleen , Alasdair G Kergon , Milan Broz > the 1st write request ends with success > the 2nd write request ends with -EOPNOTSUPP > the 3rd write request ends with success > > --- when you first see -EOPNOTSUPP, you have already corrupted filesystem > (the 3rd write passed while the filesystem expected that it would be There's no passing of requests during pvmove. It's a really strong barrier. > finished after the 2nd write) and you are in an interrupt context, where > you can't reissue -EOPNOTSUPP request. So what do you want to do? The barrier aware file systems I know of just resubmit synchronously when a barrier fails. -Andi _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757410AbYLDOJV (ORCPT ); Thu, 4 Dec 2008 09:09:21 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755044AbYLDOJK (ORCPT ); Thu, 4 Dec 2008 09:09:10 -0500 Received: from one.firstfloor.org ([213.235.205.2]:47378 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754562AbYLDOJJ (ORCPT ); Thu, 4 Dec 2008 09:09:09 -0500 Date: Thu, 4 Dec 2008 15:20:15 +0100 From: Andi Kleen To: Mikulas Patocka Cc: Andi Kleen , linux-kernel@vger.kernel.org, xfs@oss.sgi.com, Alasdair G Kergon , Andi Kleen , Milan Broz Subject: Re: Device loses barrier support (was: Fixed patch for simple barriers.) Message-ID: <20081204142015.GQ6703@one.firstfloor.org> References: <20081204100050.GN6703@one.firstfloor.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > the 1st write request ends with success > the 2nd write request ends with -EOPNOTSUPP > the 3rd write request ends with success > > --- when you first see -EOPNOTSUPP, you have already corrupted filesystem > (the 3rd write passed while the filesystem expected that it would be There's no passing of requests during pvmove. It's a really strong barrier. > finished after the 2nd write) and you are in an interrupt context, where > you can't reissue -EOPNOTSUPP request. So what do you want to do? The barrier aware file systems I know of just resubmit synchronously when a barrier fails. -Andi