From: "J. Bruce Fields" Subject: Re: [RFC][PATCH 2/4] sunrpc: Use utsnamespaces Date: Tue, 6 Jan 2009 19:20:24 -0500 Message-ID: <20090107002024.GJ13785@fieldses.org> References: <20090106011314.534653345@us.ibm.com> <20090106011314.961946803@us.ibm.com> <20090106200229.GA17031@us.ibm.com> <1231274682.20316.65.camel@heimdal.trondhjem.org> <20090106215831.GE18147@us.ibm.com> <1231281732.4173.6.camel@heimdal.trondhjem.org> <1231286930.14345.196.camel@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Trond Myklebust , "Serge E. Hallyn" , Linux Containers , linux-nfs@vger.kernel.org, Linux Kernel Mailing List , Chuck Lever , "Eric W. Biederman" , Linux Containers , Cedric Le Goater To: Matt Helsley Return-path: Received: from mail.fieldses.org ([141.211.133.115]:38249 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754002AbZAGAUb (ORCPT ); Tue, 6 Jan 2009 19:20:31 -0500 In-Reply-To: <1231286930.14345.196.camel@localhost> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Tue, Jan 06, 2009 at 04:08:50PM -0800, Matt Helsley wrote: > On Tue, 2009-01-06 at 17:42 -0500, Trond Myklebust wrote: > > On Tue, 2009-01-06 at 15:58 -0600, Serge E. Hallyn wrote: > > > > > So should we use patch 2/4, plus (as someone - was it you? - suggested) > > > using a DEFAULT instead of init_utsname()->nodename when > > > current->utsname() == NULL? > > > > No. I'm don't think that 2/4 is correct either. Basically, 2/4 is saying > > that the container that first mounts the filesystem 'owns' it. However > > at the same time we know that the lifetime of the filesystem is in no > > way bounded by the lifetime of the container, and that's what gets you > > into trouble with 'umount' in the first place. > > > > IMO, the current code is the most correct approach, in that it assumes > > that the filesystems are owned by the 'init' namespace. > > IMHO This seems more incorrect than trying to use a more proximal > namespace. If it would be possible, for example, for the 'init' namespace to have no network interfaces at all, then it would be nicer to use a name that's at least been used with nfs at *some* point--just on the general principle of not leaking information to a domain that the user wouldn't expect it to. (Assuming it's unlikely anyone would consider init's utsname to be sensitive information, that's a minor point.) --b.