Freeze with mount of a UFS volume, main-n263630-ab3e6234ab6e-dirty

From: Graham Perrin <grahamperrin_at_freebsd.org>
Date: Sun, 25 Jun 2023 20:13:31 UTC
Froze at 06:40, when I used Plasma to mount and open the volume.

Photographs: 
<https://people.freebsd.org/~grahamperrin/2023-06-25/06-40%20freeze/>. 
The freeze occurred a split-second after a click; the option to mount 
and open was replaced by the option to safely remove.

Probed not long after the event 
<https://bsd-hardware.info/?probe=e7dfbf94d0> but NB it's truly SDDM and 
Plasma (not LightDM and Budgie).

As far as I can tell: nothing useful logged, unfortunately. The freeze 
was hard (no ssh, and no shutdown in response to the power button).

No freeze with subsequent mount of the (cleaned) volume.