n_dirchain
TAILQ_INIT(&np->n_dirchain);
TAILQ_REMOVE(&np->n_dirchain, ndp, dc_chain);
nfs_unlinkdircache(np, TAILQ_FIRST(&np->n_dirchain));
TAILQ_INSERT_TAIL(&np->n_dirchain, ndp, dc_chain);
while ((ndp = TAILQ_FIRST(&np->n_dirchain)) != NULL) {
TAILQ_FOREACH(ndp, &np->n_dirchain, dc_chain)