[CRIU] Sync TODO-s for mount.c work

[Tycho Andersen]

On Wed, Apr 22, 2015 at 07:00:03PM +0200, Oleg Nesterov wrote:
> On 04/22, Pavel Emelyanov wrote:.
> >.
> > On 04/22/2015 06:35 PM, Oleg Nesterov wrote:.
> > > On 04/22, Tycho Andersen wrote:.
> > >>.
> > >> In this case you have to use --ext-mount-map KEY:VAL as in the good.
> > >> old days before --ext-mount-map auto..
> > >.
> > > I _suspected_ this ;) Thanks..
> > >.
> > > OK, before I dive into the sources, could you please tell me what.
> > > should I pass as KEY:VAL pair? (I didn't read this code yet and I.
> > > am not sure if I can understand it, at least quickly)..
> >.
> > The --ext-mount-map works like this..
> >.
> > On dump you say $mountpoint:$id pair and criu saves $id into image.
> > file for mountpoint named $mountpoint..
> >.
> > On restore you say $id:$root and criu would bind mount host's $root.
> > into the mountpoint with id $id..
> 
> Ooh, thanks.
> 
> I actually tried this some time ago and it didn't work, so I decided
> I misread that code after the qick look. Apparently I did something
> wrong. Because now this works! Although I need to recheck.
> 
> Thanks.
> 
> Now it is not clear to me why "--ext-mount-map auto" can't do this...

It can, it just gets confused as in your other unshare example. I'm
not sure we can distinguish the cases from userspace right now (or at
least, I haven't found a way).

Tycho

> Oleg.
>