Alexander Kabaev d11c07ba56 Handle a race condition where NULLFS vnode can be cleaned while threads
can still be asleep waiting for lowervp lock.

Tested by:	kkenn
Discussed with: ssouhlal, jeffr
2005-09-15 19:21:26 +00:00
..
2005-09-15 10:28:19 +00:00