move creation of / and users 'files' from storage constructor to setupFS / mount initialization

lib/private/files/filesystem.php

@@ -343,6 +343,14 @@ class Filesystem {
 				$homeStorage['arguments']['legacy'] = true;
 			}
 			self::mount($homeStorage['class'], $homeStorage['arguments'], $user);
+
+			$home = \OC\Files\Filesystem::getStorage($user);
+			if ( $home->instanceOfStorage('\OC\Files\ObjectStore\AbstractObjectStore') ) {
+				//create the files folder in the cache when mounting the objectstore for a user
+				if ( ! $home->is_dir('files') ) {
+					$home->mkdir('files');
+				}
+			}
 		}
 		else {
 			self::mount('\OC\Files\Storage\Local', array('datadir' => $root), $user);

lib/private/files/objectstore/abstractobjectstore.php

@@ -131,17 +131,6 @@ abstract class AbstractObjectStore extends \OC\Files\Storage\Common {
 		} else {
 			$this->user = null;
 		}
-		//initialize cache with root directory in cache
-		if ( ! $this->is_dir('/') ) {
-			$this->mkdir('/');
-		}
-
-		if (isset($params['user']) && is_object($params['user'])) {
-			//create the files folder in the cache when mounting the objectstore for a user
-			if ( ! $this->is_dir('files') ) {
-				$this->mkdir('files');
-			}
-		}
 	}
 
 	public function mkdir($path) {

lib/private/util.php

@@ -110,8 +110,17 @@ class OC_Util {
 
 			$userDir = '/'.$user.'/files';
 
-			//autocreate users "home" directory for local storage only
-			if ( ! isset( $root_storage ) ) {
+			//autocreate users "home" directory
+			if ( isset( $root_storage ) ) {
+				$root = \OC\Files\Filesystem::getStorage('/');
+				if ( $root->instanceOfStorage('\OC\Files\ObjectStore\AbstractObjectStore') ) {
+					//initialize cache with root directory in cache
+					if ( ! $root->is_dir('/') ) {
+						$root->mkdir('/');
+					}
+				}
+			} else {
+				//copy skeleton for local storage only
 				$userRoot = OC_User::getHome($user);
 				$userDirectory = $userRoot . '/files';
 				if( !is_dir( $userDirectory )) {