under -current. The actual preparation of the next track will now be
deferred until just before the first write operation. Otherwise,
opening the device with write intent will cause the execution of
commands that are illegal in `limited command set mode' (i.e., after
the write channel has been opened).
While i was at it, cleaned up the worm_open() function a bit.
Removed the volume overflow pre-check in worm_strategy(). It was
time-consuming, and rather useless in many cases anyway (with the size
being reported for just the entire volume only), so we can as well let
the actual SCSI command fail instead, where it'll properly be reported
as EIO.
Partially submitted by & discussed with: jmz
44099f9129