Commit e8d00590 authored by Martin KaFai Lau's avatar Martin KaFai Lau Committed by Jakub Kicinski
Browse files

net: inet: Open code inet_hash2 and inet_unhash2 



This patch folds lhash2 related functions into __inet_hash and
inet_unhash.  This will make the removal of the listening_hash
in a latter patch easier to review.

First, this patch folds inet_hash2 into __inet_hash.

For unhash, the current call sequence is like
inet_unhash() => __inet_unhash() => inet_unhash2().
The specific testing cases in __inet_unhash() are mostly related
to TCP_LISTEN sk and its caller inet_unhash() already has
the TCP_LISTEN test, so this patch folds both __inet_unhash() and
inet_unhash2() into inet_unhash().

Note that all listening_hash users also have lhash2 initialized,
so the !h->lhash2 check is no longer needed.

Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 8ea1eebb

net/ipv4/inet_hashtables.c

+33 −55
Original line number Diff line number Diff line
@@ -193,40 +193,6 @@ inet_lhash2_bucket_sk(struct inet_hashinfo *h, struct sock *sk) 
	return inet_lhash2_bucket(h, hash);

}



static void inet_hash2(struct inet_hashinfo *h, struct sock *sk)

{

	struct inet_listen_hashbucket *ilb2;



	if (!h->lhash2)

		return;



	ilb2 = inet_lhash2_bucket_sk(h, sk);



	spin_lock(&ilb2->lock);

	if (sk->sk_reuseport && sk->sk_family == AF_INET6)

		hlist_add_tail_rcu(&inet_csk(sk)->icsk_listen_portaddr_node,

				   &ilb2->head);

	else

		hlist_add_head_rcu(&inet_csk(sk)->icsk_listen_portaddr_node,

				   &ilb2->head);

	spin_unlock(&ilb2->lock);

}



static void inet_unhash2(struct inet_hashinfo *h, struct sock *sk)

{

	struct inet_listen_hashbucket *ilb2;



	if (!h->lhash2 ||

	    WARN_ON_ONCE(hlist_unhashed(&inet_csk(sk)->icsk_listen_portaddr_node)))

		return;



	ilb2 = inet_lhash2_bucket_sk(h, sk);



	spin_lock(&ilb2->lock);

	hlist_del_init_rcu(&inet_csk(sk)->icsk_listen_portaddr_node);

	spin_unlock(&ilb2->lock);

}



static inline int compute_score(struct sock *sk, struct net *net,

				const unsigned short hnum, const __be32 daddr,

				const int dif, const int sdif)
@@ -631,6 +597,7 @@ static int inet_reuseport_add_sock(struct sock *sk, 
int __inet_hash(struct sock *sk, struct sock *osk)

{

	struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;

	struct inet_listen_hashbucket *ilb2;

	struct inet_listen_hashbucket *ilb;

	int err = 0;
@@ -642,22 +609,29 @@ int __inet_hash(struct sock *sk, struct sock *osk) 
	}

	WARN_ON(!sk_unhashed(sk));

	ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];

	ilb2 = inet_lhash2_bucket_sk(hashinfo, sk);



	spin_lock(&ilb->lock);

	spin_lock(&ilb2->lock);

	if (sk->sk_reuseport) {

		err = inet_reuseport_add_sock(sk, ilb);

		if (err)

			goto unlock;

	}

	if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&

		sk->sk_family == AF_INET6)

		sk->sk_family == AF_INET6) {

		hlist_add_tail_rcu(&inet_csk(sk)->icsk_listen_portaddr_node,

				   &ilb2->head);

		__sk_nulls_add_node_tail_rcu(sk, &ilb->nulls_head);

	else

	} else {

		hlist_add_head_rcu(&inet_csk(sk)->icsk_listen_portaddr_node,

				   &ilb2->head);

		__sk_nulls_add_node_rcu(sk, &ilb->nulls_head);

	inet_hash2(hashinfo, sk);

	}

	sock_set_flag(sk, SOCK_RCU_FREE);

	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);

unlock:

	spin_unlock(&ilb2->lock);

	spin_unlock(&ilb->lock);



	return err;
@@ -675,22 +649,6 @@ int inet_hash(struct sock *sk) 
}

EXPORT_SYMBOL_GPL(inet_hash);



static void __inet_unhash(struct sock *sk, struct inet_listen_hashbucket *ilb)

{

	if (sk_unhashed(sk))

		return;



	if (rcu_access_pointer(sk->sk_reuseport_cb))

		reuseport_stop_listen_sock(sk);

	if (ilb) {

		struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;



		inet_unhash2(hashinfo, sk);

	}

	__sk_nulls_del_node_init_rcu(sk);

	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);

}



void inet_unhash(struct sock *sk)

{

	struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
@@ -699,20 +657,40 @@ void inet_unhash(struct sock *sk) 
		return;



	if (sk->sk_state == TCP_LISTEN) {

		struct inet_listen_hashbucket *ilb2;

		struct inet_listen_hashbucket *ilb;



		ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];

		ilb2 = inet_lhash2_bucket_sk(hashinfo, sk);

		/* Don't disable bottom halves while acquiring the lock to

		 * avoid circular locking dependency on PREEMPT_RT.

		 */

		spin_lock(&ilb->lock);

		__inet_unhash(sk, ilb);

		spin_lock(&ilb2->lock);

		if (sk_unhashed(sk)) {

			spin_unlock(&ilb2->lock);

			spin_unlock(&ilb->lock);

			return;

		}



		if (rcu_access_pointer(sk->sk_reuseport_cb))

			reuseport_stop_listen_sock(sk);



		hlist_del_init_rcu(&inet_csk(sk)->icsk_listen_portaddr_node);

		__sk_nulls_del_node_init_rcu(sk);

		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);

		spin_unlock(&ilb2->lock);

		spin_unlock(&ilb->lock);

	} else {

		spinlock_t *lock = inet_ehash_lockp(hashinfo, sk->sk_hash);



		spin_lock_bh(lock);

		__inet_unhash(sk, NULL);

		if (sk_unhashed(sk)) {

			spin_unlock_bh(lock);

			return;

		}

		__sk_nulls_del_node_init_rcu(sk);

		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);

		spin_unlock_bh(lock);

	}

}