Return-Path: linux-nfs-owner@vger.kernel.org Received: from fieldses.org ([173.255.197.46]:47456 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751063AbbBRByf (ORCPT ); Tue, 17 Feb 2015 20:54:35 -0500 Date: Tue, 17 Feb 2015 20:54:32 -0500 From: "J. Bruce Fields" To: NeilBrown Cc: Steve Dickson , NFS Subject: Re: [PATCH/RFC nfs-utils] exports.man: improve documentation of 'nohide' and 'crossmnt' Message-ID: <20150218015432.GA4148@fieldses.org> References: <20150216122107.4bfd4225@notabene.brown> <20150216201751.GB22154@fieldses.org> <20150218124101.0c1cebfe@notabene.brown> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20150218124101.0c1cebfe@notabene.brown> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Wed, Feb 18, 2015 at 12:41:01PM +1100, NeilBrown wrote: > On Mon, 16 Feb 2015 15:17:51 -0500 bfields@fieldses.org (J. Bruce Fields) > wrote: > > > On Mon, Feb 16, 2015 at 12:21:07PM +1100, NeilBrown wrote: > > > > > > > > > - note that 'nohide' is irrelevant for NFSv4 > > > - note that children on a 'crossmnt' filesystem cannot be unexported > > > - note that 'nocrossmnt' is a valid option, but probably not useful. > > > > > > Signed-off-by: NeilBrown > > > > > > --- > > > > > > I wonder if we should add a new option, e.g. "noaccess" so that children > > > of a "crossmnt" filesystem can be hidden. The kernel wouldn't need to > > > know about this. It would just tell mountd to refuse to export that > > > filesystem even if the parent was "crossmnt". > > > ?? > > > > Seems logical enough, but I can't recall seeing requests for it, and > > the options here already seem complicated enough. > > I haven't seem requests myself. Just rumours of 'nohide' not working with > NFSv4, which seems to suggest that someone wants something like that. > But I cannot find a clear source. > > Maybe: > > http://ubuntuforums.org/showthread.php?t=2152643 > http://ubuntuforums.org/showthread.php?t=1603881 > > > > > > In theory something like that could also be done with namespaces. (So, > > run mountd in a separate mount namespace that lacks those children.) > > Do any of the NFS man pages need to be updated to say something about > namespaces? Maybe just a note in the rpc.mountd man page that export paths are all with respect to the mount namespace rpc.mountd is running in? --b.