[CRIU] mountinfo dump error

[Andrew Vagin]

On Fri, Jul 17, 2015 at 07:37:53PM -0700, Ross Boucher wrote:
> The issue was a bug in docker, the fix was merged in today. Now there's yet
> another new criu failure:
> 
> Error (mount.c:630): 115:./sys/fs/cgroup/hugetlb doesn't have a proper root
> mount

Docker starts to mount cgroups by default, these mounts should be added
into req.Opts.ExtMnt.

You can try to remove cgroup mounts from a container config and a
container should be dumped successfully in this case:
       {
	       Source:      "cgroup",
	       Destination: "/sys/fs/cgroup",
	       Device:      "cgroup",
	       Flags:       defaultMountFlags | syscall.MS_RDONLY,
       },