Function _if_delgroup_locked

freebsd/net/if.c:1565–1604

* Helper function to remove a group out of an interface. Expects the global * ifnet lock to be write-locked, and drops it before returning. */

 * ifnet lock to be write-locked, and drops it before returning.
 */
static void
_if_delgroup_locked(struct ifnet *ifp, struct ifg_list *ifgl,
    const char *groupname)
{
	struct ifg_member *ifgm;
	bool freeifgl;

	IFNET_WLOCK_ASSERT();

	IF_ADDR_WLOCK(ifp);
	CK_STAILQ_REMOVE(&ifp->if_groups, ifgl, ifg_list, ifgl_next);
	IF_ADDR_WUNLOCK(ifp);

	CK_STAILQ_FOREACH(ifgm, &ifgl->ifgl_group->ifg_members, ifgm_next) {
		if (ifgm->ifgm_ifp == ifp) {
			CK_STAILQ_REMOVE(&ifgl->ifgl_group->ifg_members, ifgm,
			    ifg_member, ifgm_next);
			break;
		}
	}

	if (--ifgl->ifgl_group->ifg_refcnt == 0) {
		CK_STAILQ_REMOVE(&V_ifg_head, ifgl->ifgl_group, ifg_group,
		    ifg_next);
		freeifgl = true;
	} else {
		freeifgl = false;
	}
	IFNET_WUNLOCK();

	epoch_wait_preempt(net_epoch_preempt);
	if (freeifgl) {
		EVENTHANDLER_INVOKE(group_detach_event, ifgl->ifgl_group);
		free(ifgl->ifgl_group, M_TEMP);
	}
	free(ifgm, M_TEMP);
	free(ifgl, M_TEMP);

	EVENTHANDLER_INVOKE(group_change_event, groupname);
}

/*
 * Remove a group from an interface