Added .ocdata file to check for data folder validity

In environments where the data folder is mount from another partition,
it is important to check that the data folder we see is actually the
real one. If the mount failed for some reasons, this fix will make
ownCloud temporarily unavailable instead of causing unpredictable
behavior.

lib/private/setup.php

@@ -106,6 +106,10 @@ class OC_Setup {
 			//guess what this does
 			OC_Installer::installShippedApps();
 
+			// create empty file in data dir, so we can later find
+			// out that this is indeed an ownCloud data directory
+			file_put_contents(OC_Config::getValue('datadirectory', OC::$SERVERROOT.'/data').'/.ocdata', '');
+
 			//create htaccess files for apache hosts
 			if (isset($_SERVER['SERVER_SOFTWARE']) && strstr($_SERVER['SERVER_SOFTWARE'], 'Apache')) {
 				self::createHtaccess();

lib/private/updater.php

@@ -105,6 +105,11 @@ class Updater extends BasicEmitter {
 		}
 		$this->emit('\OC\Updater', 'maintenanceStart');
 
+		// create empty file in data dir, so we can later find
+		// out that this is indeed an ownCloud data directory
+		// (in case it didn't exist before)
+		file_put_contents(\OC_Config::getValue('datadirectory', \OC::$SERVERROOT.'/data').'/.ocdata', '');
+
 		/*
 		 * START CONFIG CHANGES FOR OLDER VERSIONS
 		 */

lib/private/util.php

@@ -290,13 +290,19 @@ class OC_Util {
 	 * @return array arrays with error messages and hints
 	 */
 	public static function checkServer() {
+		$errors = array();
+		$CONFIG_DATADIRECTORY = OC_Config::getValue('datadirectory', OC::$SERVERROOT . '/data');
+
+		if (!\OC::needUpgrade() && OC_Config::getValue('installed', false)) {
+			// this check needs to be done every time
+			$errors = self::checkDataDirectoryValidity($CONFIG_DATADIRECTORY);
+		}
+
 		// Assume that if checkServer() succeeded before in this session, then all is fine.
 		if(\OC::$session->exists('checkServer_suceeded') && \OC::$session->get('checkServer_suceeded')) {
-			return array();
+			return $errors;
 		}
 
-		$errors = array();
-
 		$defaults = new \OC_Defaults();
 
 		$webServerRestart = false;
@@ -341,7 +347,6 @@ class OC_Util {
 					);
 			}
 		}
-		$CONFIG_DATADIRECTORY = OC_Config::getValue( "datadirectory", OC::$SERVERROOT."/data" );
 		// Create root dir.
 		if(!is_dir($CONFIG_DATADIRECTORY)) {
 			$success=@mkdir($CONFIG_DATADIRECTORY);
@@ -540,6 +545,25 @@ class OC_Util {
 		return $errors;
 	}
 
+	/**
+	 * Check that the data directory exists and is valid by
+	 * checking the existence of the ".ocdata" file.
+	 *
+	 * @param string $dataDirectory data directory path
+	 * @return bool true if the data directory is valid, false otherwise
+	 */
+	public static function checkDataDirectoryValidity($dataDirectory) {
+		$errors = array();
+		if (!file_exists($dataDirectory.'/.ocdata')) {
+			$errors[] = array(
+				'error' => 'Data directory (' . $dataDirectory . ') is invalid',
+				'hint' => 'Please check that the data directory contains a file' .
+					' ".ocdata" in its root.'
+			);
+		}
+		return $errors;
+	}
+
 	/**
 	 * @return void
 	 */

tests/lib/utilcheckserver.php

@@ -0,0 +1,108 @@
+<?php
+/**
+ * Copyright (c) 2014 Vincent Petry <pvince81@owncloud.com>
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ * See the COPYING-README file.
+ */
+
+/**
+ * Tests for server check functions
+ */
+class Test_Util_CheckServer extends PHPUnit_Framework_TestCase {
+
+	private $datadir;
+
+	public function setUp() {
+		$this->datadir = \OC_Config::getValue('datadirectory', \OC::$SERVERROOT . '/data');
+
+		file_put_contents($this->datadir . '/.ocdata', '');
+	}
+
+	public function tearDown() {
+		// clean up
+		@unlink($this->datadir . '/.ocdata');
+	}
+
+	/**
+	 * Test that checkServer() returns no errors in the regular case.
+	 */
+	public function testCheckServer() {
+		$result = \OC_Util::checkServer();
+		$this->assertEmpty($result);
+	}
+
+	/**
+	 * Test that checkServer() does not check the data dir validity
+	 * when the server is not installed yet (else the setup cannot
+	 * be run...)
+	 */
+	public function testCheckServerSkipDataDirValidityOnSetup() {
+		// simulate old version that didn't have it
+		unlink($this->datadir . '/.ocdata');
+
+		$session = \OC::$server->getSession();
+		$oldInstalled = \OC_Config::getValue('installed', false);
+
+		// simulate that the server isn't setup yet
+		\OC_Config::setValue('installed', false);
+
+		// even though ".ocdata" is missing, the error isn't
+		// triggered to allow setup to run
+		$result = \OC_Util::checkServer();
+		$this->assertEmpty($result);
+
+		// restore config
+		\OC_Config::setValue('installed', $oldInstalled);
+	}
+
+	/**
+	 * Test that checkServer() does not check the data dir validity
+	 * when an upgrade is required (else the upgrade cannot be
+	 * performed...)
+	 */
+	public function testCheckServerSkipDataDirValidityOnUpgrade() {
+		// simulate old version that didn't have it
+		unlink($this->datadir . '/.ocdata');
+
+		$session = \OC::$server->getSession();
+		$oldCurrentVersion = $session->get('OC_Version');
+		$oldInstallVersion = \OC_Config::getValue('version', '0.0.0');
+
+		// upgrade condition to simulate needUpgrade() === true
+		$session->set('OC_Version', array(6, 0, 0, 2));
+		\OC_Config::setValue('version', '6.0.0.1');
+
+		// even though ".ocdata" is missing, the error isn't
+		// triggered to allow for upgrade
+		$result = \OC_Util::checkServer();
+		$this->assertEmpty($result);
+
+		// restore versions
+		$session->set('OC_Version', $oldCurrentVersion);
+		\OC_Config::setValue('version', $oldInstallVersion);
+	}
+
+	/**
+	 * Test that checkDataDirectoryValidity returns no error
+	 * when ".ocdata" is present.
+	 */
+	public function testCheckDataDirValidity() {
+		$result = \OC_Util::checkDataDirectoryValidity($this->datadir);
+		$this->assertEmpty($result);
+	}
+
+	/**
+	 * Test that checkDataDirectoryValidity and checkServer 
+	 * both return an error when ".ocdata" is missing.
+	 */
+	public function testCheckDataDirValidityWhenFileMissing() {
+		unlink($this->datadir . '/.ocdata');
+		$result = \OC_Util::checkDataDirectoryValidity($this->datadir);
+		$this->assertEquals(1, count($result));
+
+		$result = \OC_Util::checkServer();
+		$this->assertEquals(1, count($result));
+	}
+
+}

tests/testcleanuplistener.php

@@ -83,6 +83,7 @@ class TestCleanupListener implements PHPUnit_Framework_TestListener {
 		$knownEntries = array(
 			'owncloud.log' => true,
 			'owncloud.db' => true,
+			'.ocdata' => true,
 			'..' => true,
 			'.' => true
 		);