From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Brown Subject: Re: [nfs-utils PATCH] retry on EPERM from NFSv4 mount attempt Date: Tue, 1 Dec 2009 08:59:16 +1100 Message-ID: <20091201085916.7c1bb644@notabene.brown> References: <19211.7054.291514.185591@notabene.brown> <4B0BEDDB.1010203@RedHat.com> <4B13C48E.5020009@RedHat.com> <20091130181858.GA6348@fieldses.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Cc: Steve Dickson , linux-nfs@vger.kernel.org To: "J. Bruce Fields" Return-path: Received: from cantor2.suse.de ([195.135.220.15]:39316 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752196AbZK3V5m (ORCPT ); Mon, 30 Nov 2009 16:57:42 -0500 In-Reply-To: <20091130181858.GA6348@fieldses.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Mon, 30 Nov 2009 13:18:58 -0500 "J. Bruce Fields" wrote: > Note we want to do more than one of these; in particular: > > > 1) Start servers with '-N 4' when there is no root configured. > > This is required. The current behavior is a bug, and we must not > start servers with v4 support without having a pseudoroot. Yes, you could describe the current behaviour as a bug, but I don't think it necessarily follows than encouraging the use of "-N 4" is an appropriate resolution to the bug. I agree with Steve that that would seem like a backwards step. Completing the auto-pseudo-root work and getting that active would also fix the bug, and would do it in a more forward-looking way. So while there may be a case of advising people (in a FAQ?) that using -N4 might be appropriate if no fsid=root is configured, I don't think there is any point in trying to make it a default through making any changes to the nfs-utils packages. > > 2) Change the kernel to return NFS4ERR_SERVERFAULT when there is no > > root configured. > > * I see this is yet another errno the mounting code has to deal with.. > > We are up to two errnos, do we really want to add a third? > > I think SERVERFAULT is a little more accurate, but I'm open to argument. I think SERVERFAULT is the only vaguely relevant error permitted by the RFC, so it think that should be returned. As I said previously, I think mount.nfs should fall-back from v4 to v3 on any error when no specific version has been requested. NeilBrown