From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932254Ab2CYWXf (ORCPT ); Sun, 25 Mar 2012 18:23:35 -0400 Received: from lennier.cc.vt.edu ([198.82.162.213]:59640 "EHLO lennier.cc.vt.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932162Ab2CYWXe (ORCPT ); Sun, 25 Mar 2012 18:23:34 -0400 X-Mailer: exmh version 2.7.2 01/07/2005 with nmh-1.4-dev To: Vasiliy Kulikov Cc: Arkadiusz =?utf-8?Q?Mi=C5=9Bkiewicz?= , Andrew Morton , linux-kernel@vger.kernel.org, Alexey Dobriyan Subject: Re: [PATCH] proc: fix mount -t proc -o AAA In-Reply-To: Your message of "Sun, 25 Mar 2012 19:36:12 +0400." <20120325153612.GC4391@albatros> From: Valdis.Kletnieks@vt.edu References: <201203220903.15360.a.miskiewicz@gmail.com> <20120323171058.GA3279@albatros> <20120323161504.dced28b9.akpm@linux-foundation.org> <201203250924.06908.a.miskiewicz@gmail.com> <20120325153612.GC4391@albatros> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="==_Exmh_1332714196_1934P"; micalg=pgp-sha1; protocol="application/pgp-signature" Content-Transfer-Encoding: 7bit Date: Sun, 25 Mar 2012 18:23:16 -0400 Message-ID: <97428.1332714196@turing-police.cc.vt.edu> X-Mirapoint-Received-SPF: 198.82.161.152 auth3.smtp.vt.edu Valdis.Kletnieks@vt.edu 2 pass X-Junkmail-Status: score=10/50, host=dagger.cc.vt.edu X-Junkmail-Signature-Raw: score=unknown, refid=str=0001.0A020206.4F6F9AD7.008D,ss=1,re=0.000,fgs=0, ip=0.0.0.0, so=2011-07-25 19:15:43, dmn=2011-05-27 18:58:46, mode=single engine X-Junkmail-IWF: false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --==_Exmh_1332714196_1934P Content-Type: text/plain; charset=us-ascii On Sun, 25 Mar 2012 19:36:12 +0400, Vasiliy Kulikov said: > On Sun, Mar 25, 2012 at 09:24 +0200, Arkadiusz Miśkiewicz wrote: > > but there is another problem - unmounting it and mounting without options > > causes old option to persist: > > > > # mount none /proc -t proc -o hidepid=2 > > # umount /proc > > # mount none /proc -t proc > > # grep "/proc" /proc/mounts > > none /proc proc rw,relatime,hidepid=2 0 0 > > > > There should be no hidepid=2 now. > > No, that's an expected behaviour. "You keep using that word. I do not think it means what you think it means". ;) > Procfs is a special filesystem. And the fact it's "special" makes this *unexpected* behavior. Are there any other filesystems where -o values will persist across an unmount and then take effect *even if no -o is given* on a subsequent mount? Yes, it may be what the code actually *does*, but it certainly violates the Principle of Least Surprise... --==_Exmh_1332714196_1934P Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) Comment: Exmh version 2.5 07/13/2001 iQIVAwUBT2+a1AdmEQWDXROgAQLnpg//XZfP9m/rCaml8IHgHOAYDjOwzSubea/m QYT9jYP2ueZIupqAC1j6vdhV948VZj6+aJrxXcloUnFP2gF25pdPV4Ar0EAi11O2 Wtsk70BbypX/k7GPDDeDbdNHe9XBOmrCKTIOhXg4UYbj2tgceJL/DJlmDhjVEzEc TPJTu1MxDCuta9Ooas2379YKBwTa/xHiOUZpHiyhgIRZgqmMb6zZfgSgKhErzHGK L87G5ayXdKzBZ4/h+yyQkZ+D8JiTJMflUSpZJLeRufQtqHUQbCcSfIzB4sMBBFFA Q4rZe9nQssqv/1Wgp/XEq+jmQQe2A46N2veHZiJk9WTxL+L5r390ZtZZuW90JqRa XYi6SIJRGfApER8ebzuOnU+7V1lSmhFwzDrWdv2+fOYmu/RjLZ0WJS6qMIDV4oky Rcsq8Wvzv41ocLjG94JXqMben8GYsEMUR2vX0FcknUzzwfT2A9ouV4MO9nbluHaK SBSxoR4PN2zfME7PpqvfDw4kVViSpr7Ok3v2dP6i8JYqlzbuRvkbQEIwOYsyFbHL VP4ttQXcGF+wrVHO8PNmw1I02XrLPgZocgoXangk75iVJpEDX/D+07HURzjncSAC MPXxiGkl6scJJhxPU8p37XB+OmvRRU2tE10Pjqm+JlRQXOAm58iR8eo8kzWbClvn OhJPei3XwY4= =GWe5 -----END PGP SIGNATURE----- --==_Exmh_1332714196_1934P--