//
	// Visit https://man7.org/linux/man-pages/man2/copy_file_range.2.html#ERRORS and
	// https://man7.org/linux/man-pages/man2/splice.2.html#ERRORS for details.
	if f.appendMode {
		return 0, false, nil
	}

	written, handled, err = f.copyFileRange(r)
	if handled {
		return
	}
	return f.spliceToFile(r)
}