tree 28a8ae71b2939267deba0807bcbbed28e77470c0
parent 29b4817d4018df78086157ea3a55c1d9424a7cfc
author Andrey Vagin <avagin@openvz.org> 1473148033 -0700
committer Eric W. Biederman <ebiederm@xmission.com> 1474592379 -0500

kernel: add a helper to get an owning user namespace for a namespace

Return -EPERM if an owning user namespace is outside of a process
current user namespace.

v2: In a first version ns_get_owner returned ENOENT for init_user_ns.
    This special cases was removed from this version. There is nothing
    outside of init_user_ns, so we can return EPERM.
v3: rename ns->get_owner() to ns->owner(). get_* usually means that it
grabs a reference.

Acked-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>