From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: matthew@linuxfromscratch.org Message-ID: <1331492786.1816.2.camel@kyoto.localdomain> Subject: Re: mount -f regression in v2.21's new-mount From: Matt Burgess To: Karel Zak Cc: util-linux Date: Sun, 11 Mar 2012 19:06:26 +0000 In-Reply-To: <20120309122926.GH17711@x2.net.home> References: <20120309105304.GF17711@x2.net.home> <5fde29ffbccb41cf5eb3a286c2f7e954@quantum.linuxfromscratch.org> <20120309122926.GH17711@x2.net.home> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 List-ID: On Fri, 2012-03-09 at 13:29 +0100, Karel Zak wrote: > On Fri, Mar 09, 2012 at 04:30:02AM -0700, Matthew Burgess wrote: > > On Fri, 9 Mar 2012 11:53:04 +0100, Karel Zak wrote: > > > On Thu, Mar 08, 2012 at 08:25:00PM +0000, Matt Burgess wrote: > > >> I've attached LIBMOUNT_DEBUG output from the 'mount -a' call that our > > >> bootscript does. Note how mount correctly detects that /proc, /sys > > > > > > No, it calls mount(2) syscall for /proc. The problem is that the > > > detection code expects /proc/self/mountinfo (used on systems with > > > mtab -> /proc/mounts symlink), but your system uses regular mtab. > > > > > > I'll fix it. Thanks. > > Fixed, try git pull. Thanks, that's sorted it! > > > Thanks! Is there a consensus opinion on whether users should be > > using a regular mtab or a symlink to /proc/self/mountinfo? > > - disadvantage is that some userspace utils (e.g. df(1) are not able > to de-duplicate list of mounted filesystem (bind mounts)) > > + advantage is that there is only one list of mounted filesystems > with always valid mount options (on systems with mtab is not problem > to have 'rw' in mtab for read-only NFS, etc.), no problems with > namespaces, not writable files in /etc, no mtab lock, etc. > > The symlink is required for systemd. Thanks for the info. Looks like there are more advantages than disadvantages. Without wishing to stray too far off-topic, do you know if the Coreutils folks are aware of/looking at the 'df' issue? Matt.