I will attempt to reproduce the problem on my test box.
The traceback you have is not helpful other then to validate that it's
a problem related to dangling vnode locks. Whatever caused the problem
occured some time previously.
The null pointer dereference is a gdb issue, not an actual null pointer
(if you look at the args list for the procedure 'ap' is not NULL).
-Matt
Matthew Dillon
<dillon@backplane.com>