Return-Path: linux-nfs-owner@vger.kernel.org Received: from fieldses.org ([174.143.236.118]:44361 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757989Ab3D2S3k (ORCPT ); Mon, 29 Apr 2013 14:29:40 -0400 Date: Mon, 29 Apr 2013 14:29:39 -0400 From: "J. Bruce Fields" To: "Myklebust, Trond" Cc: "linux-nfs@vger.kernel.org" Subject: Re: [PATCH 1/2] NFSv4: Servers should only check SETATTR stateid open mode on size change Message-ID: <20130429182939.GN17268@fieldses.org> References: <1367248534-33387-1-git-send-email-Trond.Myklebust@netapp.com> <1367259352.19515.16.camel@leira.trondhjem.org> <20130429182145.GL17268@fieldses.org> <1367260027.19515.25.camel@leira.trondhjem.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1367260027.19515.25.camel@leira.trondhjem.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Mon, Apr 29, 2013 at 06:27:07PM +0000, Myklebust, Trond wrote: > On Mon, 2013-04-29 at 14:21 -0400, J. Bruce Fields wrote: > > On Mon, Apr 29, 2013 at 06:15:52PM +0000, Myklebust, Trond wrote: > > > On Mon, 2013-04-29 at 11:15 -0400, Trond Myklebust wrote: > > > > The NFSv4 and NFSv4.1 specs are both clear that the server should only check > > > > stateid open mode if a SETATTR specifies the size attribute. If the > > > > open mode is not one that allows writing, then it returns NFS4ERR_OPENMODE. > > > > > > > > In the case where the SETATTR is not changing the size, the client will > > > > still pass it the delegation stateid to ensure that the server does not > > > > recall that delegation. In that case, the server should _ignore_ the > > > > delegation open mode, and simply apply standard permission checks. > > > > > > Bruce, what does the Linux server do when we send it a delegation > > > stateid as part of a SETATTR that just changes the mode or acl (no size > > > change)? Will it recall the delegation? How about the delegations held > > > by other clients? > > > > Yes, it breaks all delegations on any setattr. > > Do you plan to change that? I'd take patches. --b. > The main problem with the current scheme is that you can't hand out a > delegation as part of an exclusive create: the client would have to > return it immediately so that it can do the setattr to initialise the > file attributes.