I NFS-mount my NetBSD source tree from an NFS server with a large
source archive, and then use a null mount to mount the NetBSD portion
of the source on /usr/src.  This works fine (modulo buffer-cache
inconsistency:)), except when I reboot.  I always get a panic with
"vnode not locked" when shutdown tries to unmount the null filesystem.

Experimenting with unmounting all but the null mount on NFS shows
that it is, indeed, this mount that's causing the panics.


This is on a pmax. Has anyone else seen, or able to reproduce, similar
behaviour on other hardware?  I intend to send-pr it, but I'd like to
establish if it's a pmax bug, or a more general problem, first.

thanks
--Jonathan