usb/105361: [panic] Kernel panic during unmounting mass storage (Creative mp3 player)

[Rahul Siddharthan]

I wrote:
> However, I take back what I said about the problem being fixed by
> commenting out the clear endpoint stall thing.  It's not working any
> more -- and, moreover, the hard disk light stays on after I insert the
> USB stick.  And if I remove it, there's an instant panic.
>
> I have now reverted that change to usb_subr.c.  Now it lets me insert the
> stick and remove it, but if I do that 2-3 times (not in quick succession),
> it panics.  Below is a backtrace.

Let me reiterate that nothing is being mounted here -- the device is not even
being registered as a SCSI drive.

Digging further in the archives, I just came across a long thread on unmount
panics in freebsd-stable in July, including posts from you (Warner)
acknowledging
that it's a serious problem but saying fixing it will be horrendously difficult
because of historical assumptions at all levels in the VM/buffer-cache/etc that
"devices don't go away".

But this doesn't seem to be that problem.  I can't believe I'm the
only one seeing
it.  If you can't reproduce it, I'm happy to mail you the device in question
(which works nicely on linux and windows).

Rahul