This is a readonly filesystem right now

def write(self, path, data, offset, fh):  # pragma: no cover
        """
        This is a readonly filesystem right now
        """
        # print("write {}".format(path))
        with self.attr_lock:
            base = self.attr[path][BASE_KEY]
            staged = self.attr[path][STAGED_KEY]
            if not staged.closed:
                base.st_size += len(data)
                staged.write(data)
        return len(data)