+ if (r < 0)
+ return log_error_errno(r, "Read-Only bind mount failed: %m");
+ }
+ }
+
+ return 0;
+}
+
+static int mount_cgroup_hierarchy(const char *dest, const char *controller, const char *hierarchy, bool read_only) {
+ char *to;
+ int r;
+
+ to = strappenda(dest, "/sys/fs/cgroup/", hierarchy);
+
+ r = path_is_mount_point(to, false);
+ if (r < 0)
+ return log_error_errno(r, "Failed to determine if %s is mounted already: %m", to);
+ if (r > 0)
+ return 0;
+
+ mkdir_p(to, 0755);
+
+ if (mount("cgroup", to, "cgroup", MS_NOSUID|MS_NOEXEC|MS_NODEV|(read_only ? MS_RDONLY : 0), controller) < 0)
+ return log_error_errno(errno, "Failed to mount to %s: %m", to);
+
+ return 1;
+}
+
+static int mount_cgroup(const char *dest) {
+ _cleanup_set_free_free_ Set *controllers = NULL;
+ _cleanup_free_ char *own_cgroup_path = NULL;
+ const char *cgroup_root, *systemd_root, *systemd_own;
+ int r;
+
+ controllers = set_new(&string_hash_ops);
+ if (!controllers)
+ return log_oom();
+
+ r = cg_kernel_controllers(controllers);
+ if (r < 0)
+ return log_error_errno(r, "Failed to determine cgroup controllers: %m");
+
+ r = cg_pid_get_path(NULL, 0, &own_cgroup_path);
+ if (r < 0)
+ return log_error_errno(r, "Failed to determine our own cgroup path: %m");
+
+ cgroup_root = strappenda(dest, "/sys/fs/cgroup");
+ if (mount("tmpfs", cgroup_root, "tmpfs", MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME, "mode=755") < 0)
+ return log_error_errno(errno, "Failed to mount tmpfs to /sys/fs/cgroup: %m");
+
+ for (;;) {
+ _cleanup_free_ char *controller = NULL, *origin = NULL, *combined = NULL;
+
+ controller = set_steal_first(controllers);
+ if (!controller)
+ break;
+
+ origin = strappend("/sys/fs/cgroup/", controller);
+ if (!origin)
+ return log_oom();
+
+ r = readlink_malloc(origin, &combined);
+ if (r == -EINVAL) {
+ /* Not a symbolic link, but directly a single cgroup hierarchy */
+
+ r = mount_cgroup_hierarchy(dest, controller, controller, true);
+ if (r < 0)