add option to get the mountmanager from the filesystem

lib/files/filesystem.php

@@ -148,13 +148,20 @@ class Filesystem {
 	 */
 	private static $loader;
 
-	public static function getLoader(){
+	public static function getLoader() {
 		if (!self::$loader) {
 			self::$loader = new Loader();
 		}
 		return self::$loader;
 	}
 
+	public static function getMountManager() {
+		if (!self::$mounts) {
+			\OC_Util::setupFS();
+		}
+		return self::$mounts;
+	}
+
 	/**
 	 * get the mountpoint of the storage object for a path
 	 * ( note: because a storage is not always mounted inside the fakeroot, the