+
+ $status = StatusValue::newGood();
+ $storagePaths = array_merge( $this->storagePathsRead(), $this->storagePathsChanged() );
+ foreach ( array_unique( $storagePaths ) as $storagePath ) {
+ if ( !$this->backend->isPathUsableInternal( $storagePath ) ) {
+ $status->fatal( 'backend-fail-usable', $storagePath );
+ }
+ }
+ if ( !$status->isOK() ) {
+ return $status;
+ }
+