static struct mountpoint *unhash_mnt(struct mount *mnt)
{
	struct mountpoint *mp;
	mnt->mnt_parent = mnt;
	mnt->mnt_mountpoint = mnt->mnt.mnt_root;
	list_del_init(&mnt->mnt_child);
	hlist_del_init_rcu(&mnt->mnt_hash);
	hlist_del_init(&mnt->mnt_mp_list);
	mp = mnt->mnt_mp;
	mnt->mnt_mp = NULL;
	return mp;
}
static struct mountpoint *unhash_mnt(struct mount *mnt)
{
	struct mountpoint *mp;
	mnt->mnt_parent = mnt;
	mnt->mnt_mountpoint = mnt->mnt.mnt_root;
	list_del_init(&mnt->mnt_child);
	hlist_del_init_rcu(&mnt->mnt_hash);
	hlist_del_init(&mnt->mnt_mp_list);
	mp = mnt->mnt_mp;
	mnt->mnt_mp = NULL;
	return mp;
}