Add recursive cgroup_delete_cgroup_ext.

Changelog:
- add braces to cgroup_delete_cgroup_ext to improve readability
- use enum instead of macro to define flags

The new function allows to recursively delete whole tree of groups. There is
new infrastructure created around (cg_delete_cgroup_controller_recursive).

It has inconsistent behavior when root group removal is requested - it removes
all children (if requested), but does not remove the root itself and returns
success value. This allows simple rewrite of cgclear functions to use this
function.

Original cgroup_delete_cgroup now leads to cgroup_delete_cgroup_ext.

Signed-off-by: Jan Safranek <jsafrane@redhat.com>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>

1 files changed, 30 insertions, 0 deletions

diff --git a/include/libcgroup.h b/include/libcgroup.h
index 3d5660c..d3fad97 100644
--- a/include/libcgroup.h
+++ b/include/libcgroup.h
@@ -114,6 +114,21 @@ enum cgroup_daemon_type {
 	CGROUP_DAEMON_UNCHANGE_CHILDREN = 0x1,
 };
 
+/**
+ * Flags for cgroup_delete_cgroup_ext
+ */
+enum cgroup_delete_flag {
+	/**
+	 * Ignore errors caused by migration of tasks to parent group.
+	 */
+	CGFLAG_DELETE_IGNORE_MIGRATION = 1,
+
+	/**
+	 * Recursively delete all child groups.
+	 */
+	CGFLAG_DELETE_RECURSIVE	= 2,
+};
+
 struct cgroup_file_info {
 	enum cgroup_file_type type;
 	const char *path;
@@ -155,6 +170,21 @@ int cgroup_create_cgroup_from_parent(struct cgroup *cgroup, int ignore_ownership
 int cgroup_copy_cgroup(struct cgroup *dst, struct cgroup *src);
 
 /**
+ * Delete control group.
+ * All tasks are automatically moved to parent group.
+ * If CGFLAG_DELETE_IGNORE_MIGRATION flag is used, the errors that occurred
+ * during the task movement are ignored.
+ * CGFLAG_DELETE_RECURSIVE flag specifies that all subgroups should be removed
+ * too. If root group is being removed with this flag specified, all subgroups
+ * are removed but the root group itself is left undeleted.
+ *
+ * @param cgroup Group to delete.
+ * @param flags  Combination of CGFLAG_DELETE_* flags, which indicate what and
+ *	how to delete.
+ */
+int cgroup_delete_cgroup_ext(struct cgroup *cgroup, int flags);
+
+/**
  * Changes the cgroup of a program based on the rules in the config file.
  * If a rule exists for the given UID, GID or PROCESS NAME, then the given
  * PID is placed into the correct group.  By default, this function parses