__CFTYPE_ONLY_ON_DFL
if ((cft->flags & __CFTYPE_ONLY_ON_DFL) && !cgroup_on_dfl(cgrp))
cft->flags &= ~(__CFTYPE_ONLY_ON_DFL | __CFTYPE_NOT_ON_DFL |
cft->flags |= __CFTYPE_ONLY_ON_DFL;