[systemd-devel] [PATCH 3/4] shutdown: don't do final unmounting when inside the container and running without CAP_SYS_ADMIN

[Lennart Poettering]

On Tue, 07.10.14 14:17, Michal Sekletar (msekleta at redhat.com) wrote:

> On Thu, Oct 02, 2014 at 12:04:02PM +0200, Lennart Poettering wrote:
> > On Thu, 02.10.14 09:57, Michal Sekletar (msekleta at redhat.com) wrote:
> > 
> > >  #define FINALIZE_ATTEMPTS 50
> > >  
> > > @@ -207,7 +208,11 @@ int main(int argc, char *argv[]) {
> > >  
> > >          in_container = detect_container(NULL) > 0;
> > >  
> > > -        need_umount = true;
> > > +        if (in_container && !have_effective_cap(CAP_SYS_ADMIN))
> > > +                need_umount = false;
> > > +        else
> > > +                need_umount = true;
> > > +
> > >          need_swapoff = !in_container;
> > >          need_loop_detach = !in_container;
> > >          need_dm_detach = !in_container;
> > 
> > Hmm, I think we should just do "need_umount = !in_container", like we
> > do for the other things like loopback detaching, dm detaching or
> > swapoff. After all, if we run in a container we run in a mount
> > namespace anyway, so unmounting things is done by the kernel
> > implicitly if the namespace dies. At least in theory this means we can
> > simply skip the unmounting in all containers, but I must admit that I
> > am not entirely clear on this one, so this needs to be tested in the
> > common container managers really, I figure...
> 
> Do you mind if I push just need_umount = !in_container then?

Well, yes.

I'd be thankful if you'd test this a bit first, so that this doesn't
break anything. Testing nspawn and on bare-metal should be enough.

Lennart

-- 
Lennart Poettering, Red Hat