(I carbon-copied to Jukka, because of similar situation. See below.)

> > > After erasing a CD-RW, it is impossible to unmount it. Obviously I did
> > > not realise it was mounted at the time :) but was couldn't unmount it
> > > and was forced to reboot.
> >
> > I often use "cdplay eject" to get my mounted disks out (if I can't eject
> > using eject button).
>
> I could manually hit the eject button, but that's not really the point.

On several of my boxes, hitting the eject button does nothing when the
disk is mounted. But, yes, I understand that doesn't fix your problem.

> The device was still locked, and I was unable to use it without
> rebooting first. :(

Jukka, Did you ever figure out a solution to your problem as seen in the
port-i386 mailing list in August and September, 2001 with subject "umount
won't"?

That thread also mentioned some small fix, but I am not sure if it was
related or even used.

Grant, I wonder if it would be useful to ktrace the umount or write a
quick unmount utility simply using unmount(2) and then trying it with
MNT_FORCE and reporting the actual unmount(2) errors.

Also, NetBSD Problem Report #4854 seems to be similar or related.

   Jeremy C. Reed
   http://www.reedmedia.net/