+ /* First, check if it already is a filesystem path */
+ if (path_startswith(path, "/sys/fs/cgroup")) {
+
+ t = strdup(path);
+ if (!t)
+ return -ENOMEM;
+
+ *result = path_kill_slashes(t);
+ return 0;
+ }
+
+ /* Otherwise, treat it as cg spec */
+ r = cg_split_spec(path, &c, &p);
+ if (r < 0)
+ return r;
+
+ return cg_get_path(c ? c : SYSTEMD_CGROUP_CONTROLLER, p ? p : "/", NULL, result);
+}
+
+int cg_get_root_path(char **path) {
+ char *p, *e;
+ int r;
+
+ assert(path);
+
+ r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 1, &p);
+ if (r < 0)
+ return r;
+
+ e = endswith(p, "/" SPECIAL_SYSTEM_SLICE);
+ if (e)
+ *e = 0;
+
+ *path = p;
+ return 0;
+}
+
+int cg_shift_path(const char *cgroup, const char *root, const char **shifted) {
+ _cleanup_free_ char *rt = NULL;
+ char *p;
+ int r;
+
+ assert(cgroup);
+ assert(shifted);
+
+ if (!root) {
+ /* If the root was specified let's use that, otherwise
+ * let's determine it from PID 1 */
+
+ r = cg_get_root_path(&rt);
+ if (r < 0)
+ return r;
+
+ root = rt;
+ }
+
+ p = path_startswith(cgroup, root);
+ if (p)
+ *shifted = p - 1;
+ else
+ *shifted = cgroup;
+
+ return 0;
+}
+
+int cg_pid_get_path_shifted(pid_t pid, const char *root, char **cgroup) {
+ _cleanup_free_ char *raw = NULL;
+ const char *c;
+ int r;
+
+ assert(pid >= 0);
+ assert(cgroup);
+
+ r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &raw);
+ if (r < 0)
+ return r;
+
+ r = cg_shift_path(raw, root, &c);
+ if (r < 0)
+ return r;
+
+ if (c == raw) {
+ *cgroup = raw;
+ raw = NULL;
+ } else {
+ char *n;
+
+ n = strdup(c);
+ if (!n)
+ return -ENOMEM;
+
+ *cgroup = n;
+ }
+
+ return 0;
+}