Export cgroup_find_parent and add testing code for it

This patch does not necessarily need to be accepted, it just provides testing
facility for new cgroup_find_parent.

Especially note the ugly dependence on ../src/tools/tools-common.c :)

Signed-off-by: Jan Safranek <jsafrane@redhat.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/include/libcgroup.h b/include/libcgroup.h
index 3d5660c..0942161 100644
--- a/include/libcgroup.h
+++ b/include/libcgroup.h
@@ -364,6 +364,18 @@ int cgroup_get_controller_end(void **handle);
  */
 int cgroup_get_subsys_mount_point(char *controller, char **mount_point);
 
+/**
+ * Find the parent of the specified directory. It returns the parent (the
+ * parent is usually name/.. unless name is a mount point.
+ *
+ * @param cgroup The cgroup.
+ * @param parent Output, name of parent's group (if the group has parent) or
+ *	NULL, if the provided cgroup is the root group and has no parent.
+ *	Caller is responsible for freeing the returned string!
+ * @return 0 on success, >0 on error.
+ */
+int cgroup_find_parent(struct cgroup *cgroup, char **parent);
+
 /* The wrappers for filling libcg structures */
 
 struct cgroup *cgroup_new_cgroup(const char *name);