cgroups: get controllers on the unified hierarchy

src/lxc/cgroups/cgroup.h

@@ -33,6 +33,13 @@ struct lxc_conf;
 struct lxc_list;
 
 typedef enum {
+        CGROUP_LAYOUT_UNKNOWN = -1,
+        CGROUP_LAYOUT_LEGACY  =  0,
+        CGROUP_LAYOUT_HYBRID  =  1,
+        CGROUP_LAYOUT_UNIFIED =  2,
+} cgroup_layout_t;
+
+typedef enum {
 	CGFS,
 	CGMANAGER,
 	CGFSNG,

src/lxc/cgroups/cgroup_utils.c

@@ -35,12 +35,12 @@
 int get_cgroup_version(char *line)
 {
 	if (is_cgroupfs_v1(line))
-		return CGROUP_V1;
+		return CGROUP_SUPER_MAGIC;
 
 	if (is_cgroupfs_v2(line))
-		return CGROUP_V2;
+		return CGROUP2_SUPER_MAGIC;
 
-	return -1;
+	return 0;
 }
 
 bool is_cgroupfs_v1(char *line)

src/lxc/cgroups/cgroup_utils.h

@@ -28,10 +28,6 @@
 #include <stdbool.h>
 #include <stdio.h>
 
-#define CGROUP_V1 0
-#define CGROUP_V2 1
-#define LXCFS_CGROUP 2
-
 /* Retrieve the cgroup version of a given entry from /proc/<pid>/mountinfo. */
 extern int get_cgroup_version(char *line);