diff --git a/apps/files_sharing/tests/mountprovidertest.php b/apps/files_sharing/tests/mountprovidertest.php
new file mode 100644
index 000000000000..90d9f0a8567e
--- /dev/null
+++ b/apps/files_sharing/tests/mountprovidertest.php
@@ -0,0 +1,139 @@
+<?php
+/**
+ * @author Vincent Petry <pvince81@owncloud.com>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program 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, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OCA\Files_Sharing\Tests;
+
+use OCA\Files_Sharing\MountProvider;
+use OCP\Files\Storage\IStorageFactory;
+use OCP\IConfig;
+use OCP\ILogger;
+use OCP\IUser;
+use OCP\Share\IShare;
+use OCP\Share\IManager;
+use OCP\Files\Mount\IMountPoint;
+
+/**
+ * @group DB
+ */
+class MountProviderTest extends \Test\TestCase {
+
+	/** @var MountProvider */
+	private $provider;
+
+	/** @var IConfig|\PHPUnit_Framework_MockObject_MockObject */
+	private $config;
+
+	/** @var IUser|\PHPUnit_Framework_MockObject_MockObject */
+	private $user;
+
+	/** @var IStorageFactory|\PHPUnit_Framework_MockObject_MockObject */
+	private $loader;
+
+	/** @var IManager|\PHPUnit_Framework_MockObject_MockObject */
+	private $shareManager;
+
+	/** @var ILogger | \PHPUnit_Framework_MockObject_MockObject */
+	private $logger;
+
+	public function setUp() {
+		parent::setUp();
+
+		$this->config = $this->getMock('OCP\IConfig');
+		$this->user = $this->getMock('OCP\IUser');
+		$this->loader = $this->getMock('OCP\Files\Storage\IStorageFactory');
+		$this->shareManager = $this->getMock('\OCP\Share\IManager');
+		$this->logger = $this->getMock('\OCP\ILogger');
+
+		$this->provider = new MountProvider($this->config, $this->shareManager, $this->logger);
+	}
+
+	public function testExcludeShares() {
+		/** @var IShare | \PHPUnit_Framework_MockObject_MockObject $share1 */
+		$share1 = $this->getMock('\OCP\Share\IShare');
+		$share1->expects($this->once())
+			->method('getPermissions')
+			->will($this->returnValue(0));
+
+		$share2 = $this->getMock('\OCP\Share\IShare');
+		$share2->expects($this->once())
+			->method('getPermissions')
+			->will($this->returnValue(31));
+		$share2->expects($this->any())
+			->method('getShareOwner')
+			->will($this->returnValue('user2'));
+		$share2->expects($this->any())
+			->method('getTarget')
+			->will($this->returnValue('/share2'));
+
+		$share3 = $this->getMock('\OCP\Share\IShare');
+		$share3->expects($this->once())
+			->method('getPermissions')
+			->will($this->returnValue(0));
+
+		/** @var IShare | \PHPUnit_Framework_MockObject_MockObject $share4 */
+		$share4 = $this->getMock('\OCP\Share\IShare');
+		$share4->expects($this->once())
+			->method('getPermissions')
+			->will($this->returnValue(31));
+		$share4->expects($this->any())
+			->method('getShareOwner')
+			->will($this->returnValue('user2'));
+		$share4->expects($this->any())
+			->method('getTarget')
+			->will($this->returnValue('/share4'));
+
+		$share5 = $this->getMock('\OCP\Share\IShare');
+		$share5->expects($this->once())
+			->method('getPermissions')
+			->will($this->returnValue(31));
+		$share5->expects($this->any())
+			->method('getShareOwner')
+			->will($this->returnValue('user1'));
+
+		$userShares = [$share1, $share2];
+		$groupShares = [$share3, $share4, $share5];
+
+		$this->user->expects($this->any())
+			->method('getUID')
+			->will($this->returnValue('user1'));
+
+		$this->shareManager->expects($this->at(0))
+			->method('getSharedWith')
+			->with('user1', \OCP\Share::SHARE_TYPE_USER)
+			->will($this->returnValue($userShares));
+		$this->shareManager->expects($this->at(1))
+			->method('getSharedWith')
+			->with('user1', \OCP\Share::SHARE_TYPE_GROUP, null, -1)
+			->will($this->returnValue($groupShares));
+
+		$mounts = $this->provider->getMountsForUser($this->user, $this->loader);
+
+		$this->assertCount(2, $mounts);
+		$this->assertSharedMount($share1, $mounts[0]);
+		$this->assertSharedMount($share4, $mounts[1]);
+	}
+
+	private function assertSharedMount(IShare $share, IMountPoint $mount) {
+		$this->assertInstanceOf('OCA\Files_Sharing\SharedMount', $mount);
+		$this->assertEquals($share, $mount->getShare());
+	}
+}
+
diff --git a/lib/private/files/view.php b/lib/private/files/view.php
index bf49ea2148df..0bc9ad211a85 100644
--- a/lib/private/files/view.php
+++ b/lib/private/files/view.php
@@ -1959,7 +1959,7 @@ private function unlockPath($path, $type, $lockMountPoint = false) {
 		$mount = $this->getMountForLock($absolutePath, $lockMountPoint);
 		if ($mount) {
 			$storage = $mount->getStorage();
-			if ($storage->instanceOfStorage('\OCP\Files\Storage\ILockingStorage')) {
+			if ($storage && $storage->instanceOfStorage('\OCP\Files\Storage\ILockingStorage')) {
 				$storage->releaseLock(
 					$mount->getInternalPath($absolutePath),
 					$type,
diff --git a/tests/objectstore/start-swift-ceph.sh b/tests/objectstore/start-swift-ceph.sh
index 089aab6a6487..bbf483c28970 100755
--- a/tests/objectstore/start-swift-ceph.sh
+++ b/tests/objectstore/start-swift-ceph.sh
@@ -30,6 +30,7 @@ thisFolder="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 
 # create readiness notification socket
 notify_sock=$(readlink -f "$thisFolder"/dockerContainerCeph.$EXECUTOR_NUMBER.swift.sock)
+rm -f "$notify_sock" # in case an unfinished test left one behind
 mkfifo "$notify_sock"
 
 port=5034
@@ -67,7 +68,13 @@ if [[ $ready != 'READY=1' ]]; then
     docker logs $container
     exit 1
 fi
-sleep 1
+if ! "$thisFolder"/wait-for-connection ${host} 80 600; then
+    echo "[ERROR] Waited 600 seconds, no response" >&2
+    docker logs $container
+    exit 1
+fi
+echo "Waiting another 15 seconds"
+sleep 15
 
 cat > $thisFolder/swift.config.php <<DELIM
 <?php
@@ -101,5 +108,7 @@ if [ -n "$DEBUG" ]; then
     cat $thisFolder/swift.config.php
     echo "### contents of $thisFolder/dockerContainerCeph.$EXECUTOR_NUMBER.swift"
     cat $thisFolder/dockerContainerCeph.$EXECUTOR_NUMBER.swift
+    echo "### docker logs"
+    docker logs $container
     echo "############## DEBUG info end ###########"
 fi
diff --git a/tests/objectstore/wait-for-connection b/tests/objectstore/wait-for-connection
new file mode 100755
index 000000000000..2c480fb733e6
--- /dev/null
+++ b/tests/objectstore/wait-for-connection
@@ -0,0 +1,45 @@
+#!/usr/bin/php
+<?php
+
+$timeout = 60;
+
+switch ($argc) {
+case 4:
+	$timeout = (float)$argv[3];
+case 3:
+	$host = $argv[1];
+	$port = (int)$argv[2];
+	break;
+default:
+	fwrite(STDERR, 'Usage: '.$argv[0].' host port [timeout]'."\n");
+	exit(2);
+}
+
+if ($timeout < 0) {
+	fwrite(STDERR, 'Timeout must be greater than zero'."\n");
+	exit(2);
+}
+if ($port < 1) {
+	fwrite(STDERR, 'Port must be an integer greater than zero'."\n");
+	exit(2);
+}
+
+$socketTimeout = (float)ini_get('default_socket_timeout');
+if ($socketTimeout > $timeout) {
+	$socketTimeout = $timeout;
+}
+
+$stopTime = time() + $timeout;
+do {
+	$sock = @fsockopen($host, $port, $errno, $errstr, $socketTimeout);
+	if ($sock !== false) {
+		fclose($sock);
+		fwrite(STDOUT, "\n");
+		exit(0);
+	}
+	sleep(1);
+	fwrite(STDOUT, '.');
+} while (time() < $stopTime);
+
+fwrite(STDOUT, "\n");
+exit(1);