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

[Pavel Emelyanov]

On 04/22/2015 08:48 PM, Oleg Nesterov wrote:

>> We
>> could have some other option that knows how to do this, though (or
>> figure out how to detect the "same" mounts somehow and remove this
>> restriction).
> 
> To me, "remove this restriction" makes much more sense. In fact, this
> restriction looks like a bug to me.
> 
> Once again, in this particular case "auto" will wrongly treat all
> mounts (except /) as a bind mount. This just means that you can never
> use this option if the process inherits some mntpoint from parent ns.

Now I'm getting confused, sorry :(

If we unshare the mount namespace and have all the mountpoints "cloned",
why can't we use the --ext-mount-map auto option? All these cloned mounts
will either have roots accessible from new tree or not. In the former case
mountpoint will be (should be) treated as internal and "just dumped", and
in the latter case criu will scan for criu mntns for the "matching" mount
and will (should) find one.

So what's the problem then? :)

-- Pavel