From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266196AbUG0A63 (ORCPT ); Mon, 26 Jul 2004 20:58:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266197AbUG0A63 (ORCPT ); Mon, 26 Jul 2004 20:58:29 -0400 Received: from nwkea-mail-2.sun.com ([192.18.42.14]:51917 "EHLO nwkea-mail-2.sun.com") by vger.kernel.org with ESMTP id S266196AbUG0A60 (ORCPT ); Mon, 26 Jul 2004 20:58:26 -0400 Date: Mon, 26 Jul 2004 20:56:56 -0400 From: Mike Waychison Subject: Re: bug with multiple mounts of filesystems in 2.6 In-reply-to: <1090881327.6809.111.camel@lade.trondhjem.org> To: Trond Myklebust Cc: John S J Anderson , linux-kernel@vger.kernel.org, Alexander Viro , Herbert Poetzl Message-id: <4105A858.7090209@sun.com> MIME-version: 1.0 Content-type: text/plain; charset=ISO-8859-1 Content-transfer-encoding: 8BIT X-Accept-Language: en-us, en User-Agent: Mozilla Thunderbird 0.5 (X11/20040208) X-Enigmail-Version: 0.83.3.0 X-Enigmail-Supports: pgp-inline, pgp-mime References: <86oem2hgv8.fsf@mendel.genehack.org> <1090870651.6809.62.camel@lade.trondhjem.org> <41057893.1030006@sun.com> <1090881327.6809.111.camel@lade.trondhjem.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Trond Myklebust wrote: > På må , 26/07/2004 klokka 17:33, skreiv Mike Waychison: > > >>How is this any different than having two seperate nfs clients accessing >>the same nfs export? > > > It isn't, but why do you think that should be a reason for allowing it? > > By all means feel free to add "mount --bind -oro" capabilities, but it > is neither useful nor is it necessary to break the NFS caching model in > order to do so. > Agreed. The two problems are orthogonal. [1] As an example where sharing the super_block is wrong (albeit probably just an oversight) is that the protocols (udp vs tcp) are not compared in nfs_compare_super. You could argue that the client fhandles should be different though, I'm not sure.. Another 'bind mount extension' that would be nice to change at the vfsmount level may be w/rsize, but that is probably a very intrusive change for nfs and probably not possible. Thoughts? [1] - I haven't tested mounting nfs ro, and then mounting nfs rw using the bind extensions. Does nfs make any assumptions about the mount being ro? - -- Mike Waychison Sun Microsystems, Inc. 1 (650) 352-5299 voice 1 (416) 202-8336 voice http://www.sun.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ NOTICE: The opinions expressed in this email are held by me, and may not represent the views of Sun Microsystems, Inc. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (GNU/Linux) iD8DBQFBBahXdQs4kOxk3/MRAhTCAKCJGOaemEdeDrmtp/tG5Y6fHe+BTgCgkh8v 312wdekZsxms1ShJciogYRQ= =7Hm7 -----END PGP SIGNATURE-----