I have two two files /etc/apache2/sites-available/foo and /etc/apache2/sites-available/foo_maintenance

The rewrite rule I use in /etc/apache2/sites-available/foo is

<Directory /var/www/public_html>
        Options +FollowSymlinks
        RewriteOptions inherit
        RewriteEngine on
        #
        RewriteCond %{HTTP_HOST} ^mysite\.com [NC]
        RewriteRule ^(.*)$ http://www.mysite.com/$1 [R=301,L]
</Directory>

so that all mysite.com/* redirect to www.mysite.com

After I take my site down for maintenance, if the user is navigates to a subpage of the site like mysite.com/subdir/something.php I would like to redirect them to www.mysite.com so the index.html of the maintenance page would be displayed.

What is the rewrite rule to redirect all traffic from any subpage to www.mysite.com?