+static bool device_supported(Manager *m) {
+ static int read_only = -1;
+ assert(m);
+
+ /* If /sys is read-only we don't support device units, and any
+ * attempts to start one should fail immediately. */
+
+ if (read_only < 0)
+ read_only = path_is_read_only_fs("/sys");
+
+ return read_only <= 0;
+}
+