From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932338Ab0EYOCj (ORCPT ); Tue, 25 May 2010 10:02:39 -0400 Received: from minas.ics.muni.cz ([147.251.4.40]:51411 "EHLO minas.ics.muni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758522Ab0EYOCh (ORCPT ); Tue, 25 May 2010 10:02:37 -0400 Date: Tue, 25 May 2010 16:02:40 +0200 From: Lukas Hejtmanek To: "William A. (Andy) Adamson" Cc: linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, salvet@ics.muni.cz Subject: Re: Deadlock in NFSv4 in all kernels Message-ID: <20100525140240.GG9731@ics.muni.cz> References: <20100507153920.GP28167@ics.muni.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-2 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-echelon: NSA, CIA, CI5, MI5, FBI, KGB, BIS, Plutonium, Bin Laden, bomb User-Agent: Mutt/1.5.20 (2009-06-14) X-Muni-Spam-TestIP: 147.251.3.109 X-Muni-Envelope-From: xhejtman@anubis.ics.muni.cz X-Muni-Virus-Test: Clean X-Greylist: Sender succeeded SMTP AUTH authentication, not delayed by milter-greylist-3.0 (minas.ics.muni.cz [147.251.4.35]); Tue, 25 May 2010 16:02:34 +0200 (CEST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 25, 2010 at 09:45:32AM -0400, William A. (Andy) Adamson wrote: > Not get into the problem in the first place: this means > > 1) determine a 'lead time' where the NFS client declares a context > expired even though it really as 'lead time' until it actually > expires. > > 2) flush all writes on any contex that will expire within the lead > time which needs to be long enough for flushes to take place. I think you cannot give any guarantees that the flush happens on time. There can be server overload, network overload, anything and you are out of luck. -- Lukáš Hejtmánek