[CRIU] Checkpointing LXC with external bind mount plugin

[Cyrill Gorcunov]

On Thu, Aug 07, 2014 at 10:07:43PM +0900, Yuto KAWAMURA wrote:
> Hi,
> 
> I'm doing little experiment of checkpointing a lxc container which has
> bind mounted pty from the host inside of it.
> As already noted somewhere, I know that the external bind mount of the
> lxc container can't be dumped without a plugin.
> I wrote a plugin handles paths which has major number UNIX98_PTY_SLAVE_MAJOR.
> After introduced this plugin, I'm not seeing an error such as
> "/dev/ttyX doesn't have a proper root mount" anymore, but still I'm
> getting an error:
> 
>   Error (tty.c:222): tty: Unexpected format on path /dev/tty1
>

Not sure about mount points, hopefully Andrew answer this part,
but for tty -- we expect pty to live on

#define PTS_FMT"/dev/pts/%d"

iirc lxc containers require special tricks for console. Take a look on

http://criu.org/LXC
https://lists.linuxcontainers.org/pipermail/lxc-devel/2013-November/006329.html

would it help?

> I think this is because the path /dev/tty1 is still mounted after the
> plugin handled it, and judged as a character device in
> dump_one_file at files.c.
> The question is, how to avoid this error? or am I understanding
> something incorrect? or should I consider to make some changes to
> criu?
> 
> I'm using the version HEAD of the criu git repository.