From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751991Ab2CHUuT (ORCPT ); Thu, 8 Mar 2012 15:50:19 -0500 Received: from mx2.netapp.com ([216.240.18.37]:31885 "EHLO mx2.netapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751146Ab2CHUuQ (ORCPT ); Thu, 8 Mar 2012 15:50:16 -0500 X-IronPort-AV: E=Sophos;i="4.73,553,1325491200"; d="scan'208";a="631884499" From: "Myklebust, Trond" To: "J. Bruce Fields" CC: Olga Kornievskaia , Miklos Szeredi , "linux-nfs@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 2/2] NFSv4: Return the delegation if the server returns NFS4ERR_OPENMODE Thread-Topic: [PATCH 2/2] NFSv4: Return the delegation if the server returns NFS4ERR_OPENMODE Thread-Index: AQHM/LNZTVOlz2021kCDLkZUy1AmJZZhNRYAgAAGfYCAACPOAIAABSyAgAACRwA= Date: Thu, 8 Mar 2012 20:50:14 +0000 Message-ID: <1331239814.11759.1.camel@lade.trondhjem.org> References: <87k42yjb0c.fsf@tucsk.pomaz.szeredi.hu> <1331160049-3842-1-git-send-email-Trond.Myklebust@netapp.com> <1331160049-3842-2-git-send-email-Trond.Myklebust@netapp.com> <1331160049-3842-3-git-send-email-Trond.Myklebust@netapp.com> <1331230525.2472.39.camel@lade.trondhjem.org> <20120308204205.GB9273@fieldses.org> In-Reply-To: <20120308204205.GB9273@fieldses.org> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.104.60.115] Content-Type: text/plain; charset="utf-8" Content-ID: <15E5548A396897479E6F835DED20EF19@tahoe.netapp.com> MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by nfs id q28KoP5w025293 On Thu, 2012-03-08 at 15:42 -0500, J. Bruce Fields wrote: > On Thu, Mar 08, 2012 at 03:23:34PM -0500, Olga Kornievskaia wrote: > > On Thu, Mar 8, 2012 at 1:15 PM, Myklebust, Trond > > wrote: > > > On Thu, 2012-03-08 at 12:52 -0500, Olga Kornievskaia wrote: > > >> wouldn't it be better for you to proactively return a read delegation > > >> then unnecessarily erroring? > > > > > > If nobody else holds a delegation, then the NFS client is actually > > > allowed to keep its read delegation while writing to the file. It does > > > admittedly need to request an OPEN stateid for write in that case... > > > (See section 10.4 of RFC3530bis draft 16) > > > > If we both agree that there has to be a request for an open stateid for > > a write, then instead of returning the read delegation if the client receives > > err_openmode (when it send the request with read delegation stateid > > as you said per 3560bis), can't the client resend the setattr with the open > > stateid? The ordering of the stateid usage is a "should" and not a "must". > > > > In rfc5661, it really doesn't make sense to ever send a setattr with > > a read delegation stateid. According to 9.1.2, the server "MUST" return > > err_open_mode" error in that case. > > > > I gather you are in this case dealing with 4.0 delegations. But I wonder > > if you'll do something else for 4.1 delegation then? > > 3530bis has the same language ("...must verify that the access mode > allows writing and return an NFS4ERR_OPENMODE error if it does not"). OK, so we shouldn't send the delegation stateid either for v4 or v4.1. However should we pre-emptively return the delegation? I've been assuming not. -- Trond Myklebust Linux NFS client maintainer NetApp Trond.Myklebust@netapp.com www.netapp.com {.n++%ݶw{.n+{G{ayʇڙ,jfhz_(階ݢj"mG?&~iOzv^m ?I