The unique ID number is completely unrelated to block number.
On an non-native UDF disk, the value could be anything, so this
case has to be supported.
I'm getting real tempted to throw together a VFS (not fs) patch
for 64-bit inode numbers. It ought to be pretty simple, and completely
compatible with the current implementation. You'd have to wait for a
filesystem (say ext3) that supports them in order to make use of the
extra elbow room.
-- Andrew E. Mileski mailto:aem@netcom.ca