Return-Path: Received: from mail-qy0-f183.google.com ([209.85.221.183]:60670 "EHLO mail-qy0-f183.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756493Ab0EYOKc convert rfc822-to-8bit (ORCPT ); Tue, 25 May 2010 10:10:32 -0400 In-Reply-To: <20100525140240.GG9731@ics.muni.cz> References: <20100507153920.GP28167@ics.muni.cz> <20100525140240.GG9731@ics.muni.cz> Date: Tue, 25 May 2010 10:10:28 -0400 Message-ID: Subject: Re: Deadlock in NFSv4 in all kernels From: "William A. (Andy) Adamson" To: Lukas Hejtmanek Cc: linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, salvet@ics.muni.cz Content-Type: text/plain; charset=ISO-8859-2 Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 2010/5/25 Lukas Hejtmanek : > 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. True - but this will be the case no matter what scheme is in place. The above is to handle the normal working situation. When this fails due to network, server overload, server reboot, i.e. not-normal situation, then use the machine credential. -->Andy > > -- > Luk?? Hejtm?nek >