name cache up into nfs_lookup() instead of nfs_open(). Continue this
trend by flushing the attribute cache for leaf nodes in nfs_lookup() during
an open() if we do a LOOKUP RPC. For NFSv3 this should generally be a NOP
as the attributes are flushed before fetching the post-op attributes from
the LOOKUP RPC which most (all?) NFSv3 servers provide, so the post-op
attributes should populate the cache.
Now all NFS open() calls will always clear the cached attributes during the
nfs_lookup() prior to nfs_open() in the !NMODIFIED case to provide CTOC.
As a result, we can remove the conditional flushing of the attribute
cache from nfs_open().
Reviewed by: rmacklem, bde
MFC after: 2 weeks
72ccfc240b