Commit abe7a1a7 authored by James Chapman's avatar James Chapman Committed by David S. Miller
Browse files

l2tp: improve tunnel/session refcount helpers 



l2tp_tunnel_inc_refcount and l2tp_session_inc_refcount wrap
refcount_inc. They add no value so just use the refcount APIs directly
and drop l2tp's helpers. l2tp already uses refcount_inc_not_zero
anyway.

Rename l2tp_tunnel_dec_refcount and l2tp_session_dec_refcount to
l2tp_tunnel_put and l2tp_session_put to better match their use pairing
various _get getters.

Signed-off-by: default avatarJames Chapman <jchapman@katalix.com>
Signed-off-by: default avatarTom Parkin <tparkin@katalix.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1f4c3dce

net/l2tp/l2tp_core.c

+20 −32
Original line number Diff line number Diff line
@@ -170,7 +170,7 @@ static void l2tp_session_free(struct l2tp_session *session) 
{

	trace_free_session(session);

	if (session->tunnel)

		l2tp_tunnel_dec_refcount(session->tunnel);

		l2tp_tunnel_put(session->tunnel);

	kfree_rcu(session, rcu);

}
@@ -197,31 +197,19 @@ struct l2tp_tunnel *l2tp_sk_to_tunnel(const struct sock *sk) 
}

EXPORT_SYMBOL_GPL(l2tp_sk_to_tunnel);



void l2tp_tunnel_inc_refcount(struct l2tp_tunnel *tunnel)

{

	refcount_inc(&tunnel->ref_count);

}

EXPORT_SYMBOL_GPL(l2tp_tunnel_inc_refcount);



void l2tp_tunnel_dec_refcount(struct l2tp_tunnel *tunnel)

void l2tp_tunnel_put(struct l2tp_tunnel *tunnel)

{

	if (refcount_dec_and_test(&tunnel->ref_count))

		l2tp_tunnel_free(tunnel);

}

EXPORT_SYMBOL_GPL(l2tp_tunnel_dec_refcount);

EXPORT_SYMBOL_GPL(l2tp_tunnel_put);



void l2tp_session_inc_refcount(struct l2tp_session *session)

{

	refcount_inc(&session->ref_count);

}

EXPORT_SYMBOL_GPL(l2tp_session_inc_refcount);



void l2tp_session_dec_refcount(struct l2tp_session *session)

void l2tp_session_put(struct l2tp_session *session)

{

	if (refcount_dec_and_test(&session->ref_count))

		l2tp_session_free(session);

}

EXPORT_SYMBOL_GPL(l2tp_session_dec_refcount);

EXPORT_SYMBOL_GPL(l2tp_session_put);



/* Lookup a tunnel. A new reference is held on the returned tunnel. */

struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id)
@@ -454,7 +442,7 @@ struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net, 
		if (tunnel) {

			list_for_each_entry_rcu(session, &tunnel->session_list, list) {

				if (!strcmp(session->ifname, ifname)) {

					l2tp_session_inc_refcount(session);

					refcount_inc(&session->ref_count);

					rcu_read_unlock_bh();



					return session;
@@ -471,7 +459,7 @@ EXPORT_SYMBOL_GPL(l2tp_session_get_by_ifname); 
static void l2tp_session_coll_list_add(struct l2tp_session_coll_list *clist,

				       struct l2tp_session *session)

{

	l2tp_session_inc_refcount(session);

	refcount_inc(&session->ref_count);

	WARN_ON_ONCE(session->coll_list);

	session->coll_list = clist;

	spin_lock(&clist->lock);
@@ -557,7 +545,7 @@ static void l2tp_session_collision_del(struct l2tp_net *pn, 
		spin_unlock(&clist->lock);

		if (refcount_dec_and_test(&clist->ref_count))

			kfree(clist);

		l2tp_session_dec_refcount(session);

		l2tp_session_put(session);

	}

}
@@ -606,7 +594,7 @@ int l2tp_session_register(struct l2tp_session *session, 
		goto out;

	}



	l2tp_tunnel_inc_refcount(tunnel);

	refcount_inc(&tunnel->ref_count);

	WRITE_ONCE(session->tunnel, tunnel);

	list_add_rcu(&session->list, &tunnel->session_list);
@@ -1089,7 +1077,7 @@ int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb) 


	if (!session || !session->recv_skb) {

		if (session)

			l2tp_session_dec_refcount(session);

			l2tp_session_put(session);



		/* Not found? Pass to userspace to deal with */

		goto pass;
@@ -1103,12 +1091,12 @@ int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb) 


	if (version == L2TP_HDR_VER_3 &&

	    l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr)) {

		l2tp_session_dec_refcount(session);

		l2tp_session_put(session);

		goto invalid;

	}



	l2tp_recv_common(session, skb, ptr, optr, hdrflags, length);

	l2tp_session_dec_refcount(session);

	l2tp_session_put(session);



	return 0;
@@ -1408,7 +1396,7 @@ static void l2tp_udp_encap_destroy(struct sock *sk) 
	tunnel = l2tp_sk_to_tunnel(sk);

	if (tunnel) {

		l2tp_tunnel_delete(tunnel);

		l2tp_tunnel_dec_refcount(tunnel);

		l2tp_tunnel_put(tunnel);

	}

}
@@ -1443,10 +1431,10 @@ static void l2tp_tunnel_del_work(struct work_struct *work) 


	l2tp_tunnel_remove(tunnel->l2tp_net, tunnel);

	/* drop initial ref */

	l2tp_tunnel_dec_refcount(tunnel);

	l2tp_tunnel_put(tunnel);



	/* drop workqueue ref */

	l2tp_tunnel_dec_refcount(tunnel);

	l2tp_tunnel_put(tunnel);

}



/* Create a socket for the tunnel, if one isn't set up by
@@ -1634,7 +1622,7 @@ static int l2tp_validate_socket(const struct sock *sk, const struct net *net, 


	tunnel = l2tp_sk_to_tunnel(sk);

	if (tunnel) {

		l2tp_tunnel_dec_refcount(tunnel);

		l2tp_tunnel_put(tunnel);

		return -EBUSY;

	}
@@ -1726,7 +1714,7 @@ void l2tp_tunnel_delete(struct l2tp_tunnel *tunnel) 
{

	if (!test_and_set_bit(0, &tunnel->dead)) {

		trace_delete_tunnel(tunnel);

		l2tp_tunnel_inc_refcount(tunnel);

		refcount_inc(&tunnel->ref_count);

		queue_work(l2tp_wq, &tunnel->del_work);

	}

}
@@ -1736,7 +1724,7 @@ void l2tp_session_delete(struct l2tp_session *session) 
{

	if (!test_and_set_bit(0, &session->dead)) {

		trace_delete_session(session);

		l2tp_session_inc_refcount(session);

		refcount_inc(&session->ref_count);

		queue_work(l2tp_wq, &session->del_work);

	}

}
@@ -1754,10 +1742,10 @@ static void l2tp_session_del_work(struct work_struct *work) 
		(*session->session_close)(session);



	/* drop initial ref */

	l2tp_session_dec_refcount(session);

	l2tp_session_put(session);



	/* drop workqueue ref */

	l2tp_session_dec_refcount(session);

	l2tp_session_put(session);

}



/* We come here whenever a session's send_seq, cookie_len or

net/l2tp/l2tp_core.h

+2 −4
Original line number Diff line number Diff line
@@ -209,10 +209,8 @@ static inline void *l2tp_session_priv(struct l2tp_session *session) 
}



/* Tunnel and session refcounts */

void l2tp_tunnel_inc_refcount(struct l2tp_tunnel *tunnel);

void l2tp_tunnel_dec_refcount(struct l2tp_tunnel *tunnel);

void l2tp_session_inc_refcount(struct l2tp_session *session);

void l2tp_session_dec_refcount(struct l2tp_session *session);

void l2tp_tunnel_put(struct l2tp_tunnel *tunnel);

void l2tp_session_put(struct l2tp_session *session);



/* Tunnel and session lookup.

 * These functions take a reference on the instances they return, so

net/l2tp/l2tp_debugfs.c

+4 −4
Original line number Diff line number Diff line
@@ -44,7 +44,7 @@ static void l2tp_dfs_next_tunnel(struct l2tp_dfs_seq_data *pd) 
{

	/* Drop reference taken during previous invocation */

	if (pd->tunnel)

		l2tp_tunnel_dec_refcount(pd->tunnel);

		l2tp_tunnel_put(pd->tunnel);



	pd->tunnel = l2tp_tunnel_get_next(pd->net, &pd->tkey);

	pd->tkey++;
@@ -54,7 +54,7 @@ static void l2tp_dfs_next_session(struct l2tp_dfs_seq_data *pd) 
{

	/* Drop reference taken during previous invocation */

	if (pd->session)

		l2tp_session_dec_refcount(pd->session);

		l2tp_session_put(pd->session);



	pd->session = l2tp_session_get_next(pd->net, pd->tunnel->sock,

					    pd->tunnel->version,
@@ -111,11 +111,11 @@ static void l2tp_dfs_seq_stop(struct seq_file *p, void *v) 
	 * or l2tp_dfs_next_tunnel().

	 */

	if (pd->session) {

		l2tp_session_dec_refcount(pd->session);

		l2tp_session_put(pd->session);

		pd->session = NULL;

	}

	if (pd->tunnel) {

		l2tp_tunnel_dec_refcount(pd->tunnel);

		l2tp_tunnel_put(pd->tunnel);

		pd->tunnel = NULL;

	}

}

net/l2tp/l2tp_eth.c

+5 −5
Original line number Diff line number Diff line
@@ -283,7 +283,7 @@ static int l2tp_eth_create(struct net *net, struct l2tp_tunnel *tunnel, 


	spriv = l2tp_session_priv(session);



	l2tp_session_inc_refcount(session);

	refcount_inc(&session->ref_count);



	rtnl_lock();
@@ -301,7 +301,7 @@ static int l2tp_eth_create(struct net *net, struct l2tp_tunnel *tunnel, 
	if (rc < 0) {

		rtnl_unlock();

		l2tp_session_delete(session);

		l2tp_session_dec_refcount(session);

		l2tp_session_put(session);

		free_netdev(dev);



		return rc;
@@ -312,17 +312,17 @@ static int l2tp_eth_create(struct net *net, struct l2tp_tunnel *tunnel, 


	rtnl_unlock();



	l2tp_session_dec_refcount(session);

	l2tp_session_put(session);



	__module_get(THIS_MODULE);



	return 0;



err_sess_dev:

	l2tp_session_dec_refcount(session);

	l2tp_session_put(session);

	free_netdev(dev);

err_sess:

	l2tp_session_dec_refcount(session);

	l2tp_session_put(session);

err:

	return rc;

}

net/l2tp/l2tp_ip.c

+3 −3
Original line number Diff line number Diff line
@@ -167,7 +167,7 @@ static int l2tp_ip_recv(struct sk_buff *skb) 
		goto discard_sess;



	l2tp_recv_common(session, skb, ptr, optr, 0, skb->len);

	l2tp_session_dec_refcount(session);

	l2tp_session_put(session);



	return 0;
@@ -200,7 +200,7 @@ static int l2tp_ip_recv(struct sk_buff *skb) 
	return sk_receive_skb(sk, skb, 1);



discard_sess:

	l2tp_session_dec_refcount(session);

	l2tp_session_put(session);

	goto discard;



discard_put:
@@ -265,7 +265,7 @@ static void l2tp_ip_destroy_sock(struct sock *sk) 
	tunnel = l2tp_sk_to_tunnel(sk);

	if (tunnel) {

		l2tp_tunnel_delete(tunnel);

		l2tp_tunnel_dec_refcount(tunnel);

		l2tp_tunnel_put(tunnel);

	}

}