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 Content-Length: 849 Lines: 22 > 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/