From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755162AbYD2EhP (ORCPT ); Tue, 29 Apr 2008 00:37:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752004AbYD2EhD (ORCPT ); Tue, 29 Apr 2008 00:37:03 -0400 Received: from hobbit.corpit.ru ([81.13.94.6]:23031 "EHLO hobbit.corpit.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751542AbYD2EhB (ORCPT ); Tue, 29 Apr 2008 00:37:01 -0400 Message-ID: <4816A5EB.5090402@msgid.tls.msk.ru> Date: Tue, 29 Apr 2008 08:36:59 +0400 From: Michael Tokarev Organization: Telecom Service, JSC User-Agent: Mozilla-Thunderbird 2.0.0.12 (X11/20080406) MIME-Version: 1.0 To: Al Viro CC: Linux-kernel Subject: Re: umount(/proc) after CLONE_NEWNS in 2.6.25? References: <481609A5.1080905@msgid.tls.msk.ru> <20080428182759.GF5882@ZenIV.linux.org.uk> <20080429014718.GI5882@ZenIV.linux.org.uk> <20080429020638.GJ5882@ZenIV.linux.org.uk> <20080429021228.GK5882@ZenIV.linux.org.uk> In-Reply-To: <20080429021228.GK5882@ZenIV.linux.org.uk> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Al Viro wrote: > On Tue, Apr 29, 2008 at 03:06:38AM +0100, Al Viro wrote: > >>> Check the version of umount(8) you've got. And see if that strace happens >>> to have open of /proc/mounts, without matching close by the time it calls >>> umount(). util-linux-ng 2.13.1 is _that_ dumb... >> Umm... Looks like something more odd is going on... > > ... or something much simpler: > > ; cat /proc/mounts |grep proc > proc /proc proc rw,nosuid,nodev,noexec 0 0 > usbfs /proc/bus/usb usbfs rw 0 0 > ; > > and unmounting the stuff mounted under /proc before doing umount /proc > works as expected. Amazing how well the first cup of coffee helps... Hey. Don't paint ME *that* dumb... ;) It was indeed the case here. I never tried those things on my home machine before, and decided to experiment, but I forgot that it has /proc/bus/usb mounted. And for comparison I used another machine which does NOT have that filesystem mounted. How.. dum^Wodd... ;) Please excuse me for the noise. /mj