Return-Path: Received: from fieldses.org ([174.143.236.118]:53741 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756699Ab0ITS1R (ORCPT ); Mon, 20 Sep 2010 14:27:17 -0400 Date: Mon, 20 Sep 2010 14:25:36 -0400 From: "J. Bruce Fields" To: Chuck Lever Cc: Trond Myklebust , Jeff Layton , Sachin Prabhu , linux-nfs Subject: Re: Should we be aggressively invalidating cache when using -onolock? Message-ID: <20100920182536.GA17543@fieldses.org> References: <1103741.22.1284726314119.JavaMail.sprabhu@dhcp-1-233.fab.redhat.com> <29790688.25.1284726394683.JavaMail.sprabhu@dhcp-1-233.fab.redhat.com> <20100917174644.GD25515@fieldses.org> <20100918070932.1c1bb700@corrin.poochiereds.net> <20100919185318.GE32071@fieldses.org> <88791E8C-1109-480A-A3FA-E9DBA1DBF75D@oracle.com> Content-Type: text/plain; charset=us-ascii In-Reply-To: <88791E8C-1109-480A-A3FA-E9DBA1DBF75D@oracle.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 On Mon, Sep 20, 2010 at 10:41:59AM -0400, Chuck Lever wrote: > At one point long ago, I had asked Trond if we could get rid of the > cache-invalidation-on-lock behavior if "-onolock" was in effect. He > said at the time that this would eliminate the only recourse > applications have for invalidating the data cache in case it was > stale, and NACK'd the request. Argh. I guess I can see the argument, though. > I suggested introducing a new mount option called "llock" that would > be semantically the same as "llock" on other operating systems, to do > this. It never went anywhere. > > We now seem to have a fresh opportunity to address this issue with the > recent addition of "local_lock". Can we augment this option or add > another which allows better control of caching behavior during a file > lock? I wouldn't stand in the way, but it does start to sound like a rather confusing array of choices. --b. > > It also seems to me that if RHEL 4 is _not_ invalidating on lock, then > it is not working as designed. AFAIK the Linux NFS client has always > invalidated a file's data cache on lock. Did I misread something?