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.

3 files changed, 37 insertions, 4 deletions

diff --git a/lib/private/setup.php b/lib/private/setup.php
index 0d5bf424b33..b1061b3a25b 100644
--- a/lib/private/setup.php
+++ b/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();
diff --git a/lib/private/updater.php b/lib/private/updater.php
index fd2d46a1fac..2ca705193cc 100644
--- a/lib/private/updater.php
+++ b/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
 		 */
diff --git a/lib/private/util.php b/lib/private/util.php
index 920161949ae..75e1711b0de 100755
--- a/lib/private/util.php
+++ b/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);
@@ -541,6 +546,25 @@ class OC_Util {
 	}
 
 	/**
+	 * 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 $errors;
+	}
+
+	/**
 	 * @return void
 	 */
 	public static function displayLoginPage($errors = array()) {