[lxc-devel] lxc-start leaves temporary pivot dir behind

[Ferenc Wagner]

Daniel Lezcano <daniel.lezcano at free.fr> writes:

> Ferenc Wagner wrote:
>
>> Daniel Lezcano <daniel.lezcano at free.fr> writes:
>>   
>>> Ferenc Wagner wrote:
>>>     
>>>> Actually, I'm not sure you can fully solve this.  If rootfs is a
>>>> separate file system, this is only much ado about nothing.  If rootfs
>>>> isn't a separate filesystem, you can't automatically find a good
>>>> place and also clean it up.
>>>
>>> Maybe a single /tmp/lxc directory may be used as the mount points are
>>> private to the container. So it would be acceptable to have a single
>>> directory for N containers, no ?
>>
>> Then why not /usr/lib/lxc/pivotdir or something like that?  Such a
>> directory could belong to the lxc package and not clutter up /tmp.  As
>> you pointed out, this directory would always be empty in the outer name
>> space, so a single one would suffice.  Thus there would be no need
>> cleaning it up, either.
>
> Agree. Shall we consider $(prefix)/var/run/lxc ?

Hmm, /var/run/lxc is inconvenient, because it disappears on each reboot
if /var/run is on tmpfs.  This isn't variable data either, that's why I
recommended /usr above.

>> Now the question is: if rootfs is a separate file system (which
>> includes bind mounts), is the superfluous rbind of the original root
>> worth skipping, or should we just do it to avoid needing an extra
>> code path?
>
> Good question. IMO, skipping the rbind is ok for this case but it may
> be interesting from a coding point of view to have a single place
> identified for the rootfs (especially for mounting an image). I will
> cook a patchset to fix the rootfs location and then we can look at
> removing the superfluous rbind.

I'm testing your patchset now.  So far it seems to work as advertised.
-- 
Thanks,
Feri.