Emacsでメジャーモードを保持したままバッファをリロード

(defun revert-buffer-no-confirm (&optional force-reverting)
  "Interactive call to revert-buffer. Ignoring the auto-save
 file and not requesting for confirmation. When the current buffer
 is modified, the command refuses to revert it, unless you specify
 the optional argument: force-reverting to true."
  (interactive "P")
  ;;(message "force-reverting value is %s" force-reverting)
  (if (or force-reverting (not (buffer-modified-p)))
      (let ((mm (with-current-buffer (current-buffer)
                  major-mode)))
        (revert-buffer :ignore-auto :noconfirm)
        (with-current-buffer (current-buffer) (funcall mm)))
    (error "The buffer has been modified")))

;; reload buffer
(global-set-key "\M-r" 'revert-buffer-no-confirm)