drivemount-applet recognizes cryptsetup volume as two mountable volumes

[Michal Frynas]

The gnome-applets' drivemount-applet shows 2 distinct icons for encrypted luks device and it's opened and mounted sub-device. The first one displays 'Encrypted with size 32GB, not mounted', whereas the second says 'Temp, mounted'.

The subject partition is a lvm logical volume named system-data (vg=system,lv=data). /dev/mapper/system-data is acctually a symlink to /dev/dm-0. Inside that partition there is encrypted luks partition created. It's name is secure-data and it points to /dev/dm-1. That partition holds ext4 filesystem, and is manually mounted in ~/Temp.

After booting up there is only 'Encrypted with size 32GB, not mounted' icon visible. When I click 'Mount Encrypted...' nothing happens. It's not mounted. When I open the luks partition manually and mount it then there appears a second icons. That one is mounted and I can open or unmount it using the popup menu of drivemount. It seems the first icon is related to the /dev/dm-0 device and it is recogized as volume (add_volume function). The second icon is related to the /dev/dm-1 and/or its symlink /dev/mapper/secure-data (see below) and I believe it is recognized as a new mount (add_mount function).

I see here two problems:
1. drivemount is not aware about the relation between these two devices. There should be implementation added that will ask cryptsetup library for the mapping lvm_device/physical_device <-> encrypted_device and on that basis one of these icons should be considered redundant.
2. drivemount is not able to properly mount cryptsetup volumes. For that particular type of volumes there should be 'mount -t crypt ...' used.

I'm not sure if the bug belongs to gnome-applets or the gdu implementation.

$ ll /dev/mapper/
...
crw------- 1 root root 10, 236 2011-09-21 18:00 control
lrwxrwxrwx 1 root root 7 2011-09-21 18:00 secure-data -> ../dm-1
lrwxrwxrwx 1 root root 7 2011-09-24 19:02 system-data -> ../dm-0

$ mount
...
/dev/mapper/secure-data on /home/testuser/Temp type ext4 (rw,commit=0,commit=0)

$ lsb_release -rd
Description: Ubuntu 11.04
Release: 11.04

$ apt-cache policy gnome-applets
gnome-applets:
  Zainstalowana: 2.32.1.1-0ubuntu5
  Kandydująca: 2.32.1.1-0ubuntu5
  Tabela wersji:
 *** 2.32.1.1-0ubuntu5 0
        500 http://pl.archive.ubuntu.com/ubuntu/ natty/main amd64 Packages
        100 /var/lib/dpkg/status