[systemd-devel] Is there a reason to forcefully create /etc/mtab?

[Ivan Shapovalov]

On Sunday 06 July 2014 at 13:13:55, Mike Gilbert wrote:	
> On Sun, Jul 6, 2014 at 1:08 PM, Ivan Shapovalov <intelfx100 at gmail.com> wrote:
> > On Sunday 06 July 2014 at 13:01:22, Leonid Isaev wrote:
> >> Hi,
> >>
> >>       I have a read-only / filesystem and /etc/mtab points to
> >> /proc/self/mounts as it should.
> >>       So, in systemd-215 tmpfile.d fails to create a symbolic link /etc/mtab
> >> because /usr/lib/tmpfiles.d/etc.conf contains is a line "L+ /etc/mtab - - - -
> >> ../proc/self/mounts".
> >>       Is this intentional? Besides failing on ro /, it is also confusing
> >> because /etc/mtab can be supplied by a package (in archlinux, the 'filesystem'
> >> package), so why tmpfiles instead of including this symlink with systemd?
> >>       The same question applies to the entire etc.conf: why does tmpfiles
> >> touch /etc at all, especially if /etc is already properly set up?
> >>
> >> Thanks,
> >>
> >
> > L+ (as well as any other "+" directives) only force-overwrite files if this is
> > needed, e. g. if a symlink points to the wrong desination.
> >
> 
> Right.
> 
> I think the path matching is a little naive; Using a simple string
> comparison, "/proc/self/mounts" != "../proc/self/mounts" even though
> both paths refer to the same object.

No, they aren't referring to the same object. This makes a difference
when you mount a "foreign" system image for maintainance.

-- 
Ivan Shapovalov / intelfx /
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