8.x code:
- If the lock cannot be acquired immediately unlocks 'bar' vnode
and then locks both vnodes in order.
- wrong vnode type panics from cache_enter_time after calls by
ext2_lookup.
The fix merges the fixes from ufs/ufs_lookup.c.
Submitted by: Mateusz Guzik
Approved by: jhb@ (mentor)
Reviewed by: kib@
MFC after: 1 week