diff --git a/lib/filesystem.php b/lib/filesystem.php
index b6909f5acd..dc678fba74 100644
--- a/lib/filesystem.php
+++ b/lib/filesystem.php
@@ -248,6 +248,14 @@ class OC_Filesystem{
 		return self::$defaultInstance->getRoot();
 	}
 
+	/**
+	 * clear all mounts and storage backends
+	 */
+	public static function clearMounts(){
+		self::$mounts=array();
+		self::$storages=array();
+	}
+
 	/**
 	* mount an OC_Filestorage in our virtual filesystem
 	* @param OC_Filestorage storage
diff --git a/tests/lib/filestorage/local.php b/tests/lib/filestorage/local.php
index 0a2d46c5eb..692f05f9fc 100644
--- a/tests/lib/filestorage/local.php
+++ b/tests/lib/filestorage/local.php
@@ -26,10 +26,7 @@ class Test_Filestorage_Local extends Test_FileStorage {
 	 */
 	private $tmpDir;
 	public function setUp(){
-		$this->tmpDir=get_temp_dir().'/filestoragelocal';
-		if(!file_exists($this->tmpDir)){
-			mkdir($this->tmpDir);
-		}
+		$this->tmpDir=OC_Helper::tmpFolder();
 		$this->instance=new OC_Filestorage_Local(array('datadir'=>$this->tmpDir));
 	}
 
diff --git a/tests/lib/filesystem.php b/tests/lib/filesystem.php
new file mode 100644
index 0000000000..3e28d8c06e
--- /dev/null
+++ b/tests/lib/filesystem.php
@@ -0,0 +1,64 @@
+<?php
+/**
+* ownCloud
+*
+* @author Robin Appelman
+* @copyright 2012 Robin Appelman icewind@owncloud.com
+*
+* This library is free software; you can redistribute it and/or
+* modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
+* License as published by the Free Software Foundation; either
+* version 3 of the License, or any later version.
+*
+* This library is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+* GNU AFFERO GENERAL PUBLIC LICENSE for more details.
+*
+* You should have received a copy of the GNU Affero General Public
+* License along with this library.  If not, see <http://www.gnu.org/licenses/>.
+*
+*/
+
+class Test_Filesystem extends UnitTestCase{
+	/**
+	 * @var array tmpDirs
+	 */
+	private $tmpDirs;
+
+	/**
+	 * @return array
+	 */
+	private function getStorageData(){
+		$dir=OC_Helper::tmpFolder();
+		$this->tmpDirs[]=$dir;
+		return array('datadir'=>$dir);
+	}
+
+	public function tearDown(){
+		foreach($this->tmpDirs as $dir){
+			OC_Helper::rmdirr($dir);
+		}
+	}
+	
+	public function setUp(){
+		OC_Filesystem::clearMounts();
+	}
+
+	public function testMount(){
+		OC_Filesystem::mount('OC_Filestorage_Local',self::getStorageData(),'/');
+		$this->assertEqual('/',OC_Filesystem::getMountPoint('/'));
+		$this->assertEqual('/',OC_Filesystem::getMountPoint('/some/folder'));
+		$this->assertEqual('',OC_Filesystem::getInternalPath('/'));
+		$this->assertEqual('some/folder',OC_Filesystem::getInternalPath('/some/folder'));
+
+		OC_Filesystem::mount('OC_Filestorage_Local',self::getStorageData(),'/some');
+		$this->assertEqual('/',OC_Filesystem::getMountPoint('/'));
+		$this->assertEqual('/some/',OC_Filesystem::getMountPoint('/some/folder'));
+		$this->assertEqual('/some/',OC_Filesystem::getMountPoint('/some/'));
+		$this->assertEqual('/',OC_Filesystem::getMountPoint('/some'));
+		$this->assertEqual('folder',OC_Filesystem::getInternalPath('/some/folder'));
+	}
+}
+
+?>
\ No newline at end of file