Comment # 5 on bug 909418 from Ulrich Windl

(In reply to Takashi Iwai from comment #4)
Good question! If the problem still existed in 12.3 (i586), I did not realize
it, at least. I skipped 13.1, so I cannot tell, and for 13.2 I'm sure.
I think if things work correctly, the kernel should SCSI-lock the drive's try
once a filesystem is mounted, and on unmount the lock should be released. It
seems this does not happen.