reiserfs isn't really supported (for reasons like this among others).
 If you provide a patch, I'd be happy to add it (note that in addition
to the simple side of adding the labelDevice() method in fsset.py, you
also need to add support for reading the label off of a reiserfs
device in isys/isys.py)

Created attachment 102863 [details]
A patch to enable reading and writing of labels on ReiserFS

Here's a patch that (with luck) will enable support. I'm not a python
programmer, so there might be something horribly wrong with this code. :( But
hopefully this shows one way of doing it.

For example, that should be /usr/sbin/reiserfstune instead 
of /usr/bin/reiserfstune (I think) on line 45.

Using reiserfstune for reading the label is very error prone and
likely to break if reiserfstune at all adds labeling or anything of
the sort.  Hence why all of the code for other filesystems reads
directly from the disk.  reiserfs is going to need the same (and thus
research into how the label is stored in a reiserfs superblock,
finding the reiserfs superblock, etc)

Deferring based on Jeremy's comments.