Return-Path: linux-nfs-owner@vger.kernel.org Received: from mailhub.sw.ru ([195.214.232.25]:33661 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758305Ab1JFNOe (ORCPT ); Thu, 6 Oct 2011 09:14:34 -0400 Message-ID: <4E8DA9A9.5010205@parallels.com> Date: Thu, 06 Oct 2011 17:14:17 +0400 From: Pavel Emelyanov MIME-Version: 1.0 To: "J. Bruce Fields" CC: Stanislav Kinsbursky , "linux-nfs@vger.kernel.org" , "Kirill A. Shutemov" , "jlayton@redhat.com" Subject: Re: network-namespace-aware nfsd References: <20111005150214.GA18449@fieldses.org> <4E8C9363.9030303@parallels.com> <20111005181959.GB18449@fieldses.org> <4E8D7BED.6020705@parallels.com> <4E8D9F3F.4090004@parallels.com> <20111006131109.GB21627@fieldses.org> In-Reply-To: <20111006131109.GB21627@fieldses.org> Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-nfs-owner@vger.kernel.org List-ID: On 10/06/2011 05:11 PM, J. Bruce Fields wrote: > On Thu, Oct 06, 2011 at 04:29:51PM +0400, Pavel Emelyanov wrote: >>>> Also, do you think per-namespace version support is important? >>>> >>> >>> Actually, yes, I do. >>> As I see it, nfsd filesystem have to virtualized to provide flexible control for >>> server features. If so, then we need to virtualize program as well. >> >> ACK - per namespace version control is required as well. >> >> AFAIK it's performed via sysctl-s and this part (sysctls engine I mean) is already >> namespaces aware, thus it will not be the hard part of the implementation :) > > It's a special file in the nfsd filesystem. But I assume that won't be > a big deal either. Well, yes, you're right :) > By the way, I'm curious: as we do this virtualization step-by-step, is > there any way for userspace to tell how far we've gotten? > > So for example if you have a system that's configured to use some new > namespace-based feature, and you boot it to an old kernel, is there some > way for it to check at the start and say "sorry, this isn't going to > work"? M-m... I'd say - there's no automatic way for doing this. What we can (and probably should) do is - audit the nfs/nfsd subsystems and mark places with if (ns != &init_net_ns) return -EOPNOTSUPP and remove these parts eventually. > --b. > . >