dtfs_dirgetbyname
struct dtfs_dirent * dtfs_dirgetbyname(struct dtfs_file *,
dfd = dtfs_dirgetbyname(DTFS_PTOF(pn_parent), fname, fnlen);
dfd_src = dtfs_dirgetbyname(DTFS_PTOF(pn_sdir),
dfd = dtfs_dirgetbyname(df, pcn->pcn_name, pcn->pcn_namelen);