good question, and i don't have the answer. BUT, i can tell you how much data i have lost doing exactly what you are doing. it seems that cd-rw's are extremely unstable (i've used every brand out there with several different burners). besides, given how cheap and stable a cdr is, why not just use a cdr then pitch them when they are out dated?
a quick google search with the terms "DirectCD; linux" yielded this link...
http://sourceforge.net/projects/linux-udf this is exactly what you are wanting.
--cheers
