Return-Path: linux-nfs-owner@vger.kernel.org Received: from fieldses.org ([174.143.236.118]:60181 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758284Ab1JFNLK (ORCPT ); Thu, 6 Oct 2011 09:11:10 -0400 Date: Thu, 6 Oct 2011 09:11:09 -0400 From: "J. Bruce Fields" To: Pavel Emelyanov Cc: Stanislav Kinsbursky , "linux-nfs@vger.kernel.org" , "Kirill A. Shutemov" , "jlayton@redhat.com" Subject: Re: network-namespace-aware nfsd Message-ID: <20111006131109.GB21627@fieldses.org> References: <20111005150214.GA18449@fieldses.org> <4E8C9363.9030303@parallels.com> <20111005181959.GB18449@fieldses.org> <4E8D7BED.6020705@parallels.com> <4E8D9F3F.4090004@parallels.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <4E8D9F3F.4090004@parallels.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: 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. 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"? --b.