This I my case:

I have a Slackware 13.37 x86_64 installed on my computer running a partial install.

I have two backup external drives, and each one has a single LUKS encrypted Ext4 filesystem. I am able to decrypt and mount this filesystems from Thunar file manager with no problems.

My question is: how can I tell Thunar (or the daemon that is managing the mounting) to use a particular set of options for the mounting? How do I tell Thunar to mount ext4 with data=journaled by default (just an example)?

If someone could point me to the proper documentation, it would be very helpful.

I haven't tried this, but I think the settings you need are in /etc/xfce/xdg/xfce4/mount.rc. You'll have to copy that file to ~/.config/xfce4/mount.rc and make your changes there.

Hope that helps.

Thank you for your interest.

Your suggestion, however, has resulted in a failure. Neither editing /etc/xfce/xdg/xfce4/mount.rc, nor ~/.config/xfce4/mount.rc, have caused the desired behaviour. I have even exported $XDG_CONFIG_HOME to ensure that mount.rc was found. It might be because I am not running a full Xfce desktop, but a Fluxbox environment. Or maybe I have not the proper HAL policies set.

I think I am goint to pass along the Thunar solution and create some udev rules with a simple script to mount the devices as needed. I will post the results of my tweakings here if I arrive somewhere.

Further suggestions are welcome, of course.