[CRIU] implementing some kind of --leave-frozen option for c/r in CRIU

[Tycho Andersen]

On Mon, May 16, 2016 at 05:38:05PM +0300, Batalov Eugene wrote:
> >
> > What I'm not sure about is how this works with
> > --leave-running; doesn't it already delete these rules? If not, how is
> > the network actually unlocked?
> 
> 
> cr-dump.c: (opts.final_state == TASK_ALIVE if --leave-running is passed to
> criu)
> 1597     if (ret || post_dump_ret || opts.final_state == TASK_ALIVE) {
> 1598         network_unlock();
> 1599         delete_link_remaps();
> 1600     }
> 
> The only problem is that this 2 function calls are executed after dump and
> during restore.
> And this calls expect already initialized big c/r state. It's the problem
> that I've described in the previous email.
> 
> Also there is a pecularity in criu gc that can be important for you. You
> need to specify path to image
> files dir for criu gc because criu gc uses data from images to find the
> right iptable rules and link remaps.
> So a part of dump should be stored on node you migrate from.

I looked at this too, and using the images is a nice way to work
around the fact that network_unlock() requires a lot of state. That
will be fine for me.

> Tycho, do you have any urgency in criu gc feature arrival?

It would be nice to have in the June CRIU release if possible. Is
there some way I can help you guys with the implementation?

Tycho