[PATCH 1/3][V2] cgroup : add clone_children control file

[Serge E. Hallyn]

Quoting Daniel Lezcano (daniel.lezcano at free.fr):
> This patch is sent as an answer to a previous thread around the ns_cgroup.
> 
> https://lists.linux-foundation.org/pipermail/containers/2009-June/018627.html
> 
> It adds a control file 'clone_children' for a cgroup.
> This control file is a boolean specifying if the child cgroup should
> be a clone of the parent cgroup or not. The default value is 'false'.
> 
> This flag makes the child cgroup to call the post_clone callback of all
> the subsystem, if it is available.
> 
> At present, the cpuset is the only one which had implemented the post_clone
> callback.
> 
> The option can be set at mount time by specifying the 'clone_children' mount
> option.
> 
> Signed-off-by: Daniel Lezcano <daniel.lezcano at free.fr>
> Signed-off-by: Serge E. Hallyn <serge.hallyn at canonical.com>
> Cc: Eric W. Biederman <ebiederm at xmission.com>
> Cc: Paul Menage <menage at google.com>

Paul and Eric, do you have any objections to this set?  Patch 2 in
particular will make it easier to use both libvirt-lxc and lxc.sf.net
containers at the same time, without having to reboot.

> Reviewed-by: Li Zefan <lizf at cn.fujitsu.com>

thanks,
-serge