+ r = chmod_and_chown(fs, mode, uid, gid);
+ if (r < 0)
+ return r;
+
+ /* Compatibility, Always keep values for "tasks" in sync with
+ * "cgroup.procs" */
+ r = cg_get_path(controller, path, "tasks", &procs);
+ if (r < 0)
+ return r;
+
+ return chmod_and_chown(procs, mode, uid, gid);
+}
+
+int cg_pid_get_path(const char *controller, pid_t pid, char **path) {
+ _cleanup_fclose_ FILE *f = NULL;
+ char line[LINE_MAX];
+ const char *fs;
+ size_t cs;
+
+ assert(path);
+ assert(pid >= 0);
+
+ if (controller) {
+ if (!cg_controller_is_valid(controller, true))
+ return -EINVAL;
+
+ controller = normalize_controller(controller);
+ } else
+ controller = SYSTEMD_CGROUP_CONTROLLER;
+
+ fs = procfs_file_alloca(pid, "cgroup");
+
+ f = fopen(fs, "re");
+ if (!f)
+ return errno == ENOENT ? -ESRCH : -errno;
+
+ cs = strlen(controller);
+
+ FOREACH_LINE(line, f, return -errno) {
+ char *l, *p, *e;
+ size_t k;
+ const char *word, *state;
+ bool found = false;
+
+ truncate_nl(line);
+
+ l = strchr(line, ':');
+ if (!l)
+ continue;
+
+ l++;
+ e = strchr(l, ':');
+ if (!e)
+ continue;
+
+ *e = 0;
+
+ FOREACH_WORD_SEPARATOR(word, k, l, ",", state) {
+
+ if (k == cs && memcmp(word, controller, cs) == 0) {
+ found = true;
+ break;
+ }
+
+ if (k == 5 + cs &&
+ memcmp(word, "name=", 5) == 0 &&
+ memcmp(word+5, controller, cs) == 0) {
+ found = true;
+ break;
+ }
+ }
+
+ if (!found)
+ continue;
+
+ p = strdup(e + 1);
+ if (!p)
+ return -ENOMEM;
+
+ *path = p;
+ return 0;
+ }
+
+ return -ENOENT;