How to mount a LUKS partiotion with Nautilus with option discard?

[Joerg Desch <news@jdesch.de>]

I'm using a separate LUKS encrypted partition on my SSD, which I only
mount after login. Since there is now way to to this with crypttab/fstab,
I have to use Nautilus to do this.

I'm running a regular Debian Wheezy.

After clicking on the (unmounted) LUKS partition, the system asks for the 
LUKS passphrase and than for the admin password. Now the partition is 
mounted as expected. The only problem is the missing 'discard' option, so 
I can't use fstrim with this partition.

Does anyone knows some tricks how to add discard support?

This is the current output of mount:

/dev/mapper/udisks-luks-uuid-... on /media/PRIVAT_C type ext4 
(rw,nosuid,nodev,relatime,user_xattr,barrier=1,data=ordered,uhelper=udisks)