[PATCH 1/1] cgroup mount: ignore nsroot=

[Tycho Andersen]

On Wed, Mar 30, 2016 at 06:19:32PM +0000, Serge Hallyn wrote:
> (I realize it's probably too late for anything but SRU at this point.  The
> motivator for this is criu live migration, where it is needed for container
> restart (not checkpoint afaik))

And worth noting that we have a patch in the distro for CRIU to work
around this, so it's not super urgent, tagging along with the next
major SRU would be fine.

Tycho

> our mountinfo output now shows 'nsroot='.  If userspace like
> criu copy/pastes mount options from there into a new mount
> command, we should ignore it.
> 
> Signed-off-by: Serge Hallyn <serge.hallyn at ubuntu.com>
> Tested-by: Tycho Andersen <tycho.andersen at canonical.com>
> ---
>  kernel/cgroup.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/kernel/cgroup.c b/kernel/cgroup.c
> index ef0c25d..69fb112 100644
> --- a/kernel/cgroup.c
> +++ b/kernel/cgroup.c
> @@ -1680,6 +1680,10 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
>  			opts->none = true;
>  			continue;
>  		}
> +		if (!strncmp(token, "nsroot=", 7)) {
> +			/* ignore nsroot= copied from mountinfo */
> +			continue;
> +		}
>  		if (!strcmp(token, "all")) {
>  			/* Mutually exclusive option 'all' + subsystem name */
>  			if (one_ss)
> -- 
> 2.7.0
>