Function nhop_free

freebsd/net/route/nhop_ctl.c:648–691

}

void
nhop_free(struct nhop_object *nh)
{
	struct nh_control *ctl;
	struct nhop_priv *nh_priv = nh->nh_priv;
	struct epoch_tracker et;

	if (!refcount_release(&nh_priv->nh_refcnt))
		return;

	/*
	 * There are only 2 places, where nh_linked can be decreased:
	 *  rib destroy (nhops_destroy_rib) and this function.
	 * nh_link can never be increased.
	 *
	 * Hence, use initial value of 2 to make use of
	 *  refcount_release_if_not_last().
	 *
	 * There can be two scenarious when calling this function:
	 *
	 * 1) nh_linked value is 2. This means that either
	 *  nhops_destroy_rib() has not been called OR it is running,
	 *  but we are guaranteed that nh_control won't be freed in
	 *  this epoch. Hence, nexthop can be safely unlinked.
	 *
	 * 2) nh_linked value is 1. In that case, nhops_destroy_rib()
	 *  has been called and nhop unlink can be skipped.
	 */

	NET_EPOCH_ENTER(et);
	if (refcount_release_if_not_last(&nh_priv->nh_linked)) {
		ctl = nh_priv->nh_control;
		if (unlink_nhop(ctl, nh_priv) == NULL) {
			/* Do not try to reclaim */
			DPRINTF("Failed to unlink nexhop %p", nh_priv);
			NET_EPOCH_EXIT(et);
			return;
		}
	}
	NET_EPOCH_EXIT(et);

	epoch_call(net_epoch_preempt, destroy_nhop_epoch,
	    &nh_priv->nh_epoch_ctx);
}

void
nhop_ref_any(struct nhop_object *nh)