Timeouts
I didn't try to burn a CD with ub in a while, because my new laptop comes with a built-in burner. After all the hustling with __blk_end_request, I thought the situation called for a test. This looked worrysome:
Track 01: Total bytes read/written: 548321280/548321280 (267735 sectors).
Errno: 5 (Input/output error), close track/session scsi sendcmd: cmd timeout after 5.000 (480) s
CDB: 5B 00 02 00 00 00 00 00 00 00
cmd finished after 5.000s timeout 480s
cmd finished after 5.000s timeout 480s
wodim: Cannot fixate disk.
The resulting CD was not a coaster though. A welcome surprise, but clearly I did something wrong regarding timeouts, and it needs fixing (although I'm quite sure that there's no other person on Earth who would want to burn CDs with ub).
BTW, the new cdrecord looks nice indeed. Before, I only used the one maintained by that self-centered dude with attitude... No idea who maintains this one, but it seems working ok.