> > can cache_enter() be called without dvp locked exclusively?
> 
> Yes, any "read-only" lookup in a directory will not pass LOCKPARENT
> to the filesystem lookup routine. So multiple processes may be looking
> for an entry simultaneously.

hm, right.  VOP_LOOKUP unlocks dvp before calling cache_enter.

i think VOP_LOOKUP should be changed to do cache_enter
before unlocking dvp.  otherwise, we can see stale namecaches anyway.

YAMAMOTO Takashi