Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751397Ab3F3DJY (ORCPT ); Sat, 29 Jun 2013 23:09:24 -0400 Received: from mail-ie0-f171.google.com ([209.85.223.171]:63552 "EHLO mail-ie0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750798Ab3F3DJW convert rfc822-to-8bit (ORCPT ); Sat, 29 Jun 2013 23:09:22 -0400 Date: Sat, 29 Jun 2013 22:09:20 -0500 From: Rob Landley Subject: Re: [PATCH 1/5] initmpfs: replace MS_NOUSER in initramfs To: "Eric W. Biederman" Cc: linux-kernel@vger.kernel.org, Al Viro References: <1372536729.850656@landley.net> <87y59swg8z.fsf@xmission.com> In-Reply-To: <87y59swg8z.fsf@xmission.com> (from ebiederm@xmission.com on Sat Jun 29 20:15:40 2013) X-Mailer: Balsa 2.4.11 Message-Id: <1372561760.2776.161@driftwood> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; DelSp=Yes; Format=Flowed Content-Disposition: inline Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 899 Lines: 25 On 06/29/2013 08:15:40 PM, Eric W. Biederman wrote: > Rob Landley writes: > > > From: Rob Landley > > > > Mounting MS_NOUSER prevents --bind mounts from rootfs. Prevent new > rootfs > > mounts with a different mechanism that doesn't affect bind mounts. > > I don't see patches 4 and 5 so I don't know if you have covered this > elsewhere but a very important part of the reason for MS_NOUSER is to > prevent unmounting of rootfs. > > The entire vfs breaks if you are allowed to unmount rootfs, and it > appears this patch is allowing that. I mean I tried "mount --move / home". (--bind worked.) Long day... Rob-- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/