w.Close()
		return errLessData
	} else if written > fileSize && fileSize >= 0 {
		w.Close()
		return errMoreData
	}

	// Only interested in flushing the size_t not mtime/atime
	if err = Fdatasync(w); err != nil {
		w.Close()
		return err
	}

	// Dealing with error returns from close() - 'man 2 close'
	//