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: James Chapman <[e-mail]>
Signed-off-by: Tom Parkin <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

net/l2tp/l2tp_core.c

···
 {
 	trace_free_session(session);
 	if (session->tunnel)
-		l2tp_tunnel_dec_refcount(session->tunnel);
+		l2tp_tunnel_put(session->tunnel);
 	kfree_rcu(session, rcu);
 }
 
···
 }
 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)
···
 		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;
···
 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);
···
 		spin_unlock(&clist->lock);
 		if (refcount_dec_and_test(&clist->ref_count))
 			kfree(clist);
-		l2tp_session_dec_refcount(session);
+		l2tp_session_put(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);
 
···
 
 	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;
···
 
 	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;
 
···
 	tunnel = l2tp_sk_to_tunnel(sk);
 	if (tunnel) {
 		l2tp_tunnel_delete(tunnel);
-		l2tp_tunnel_dec_refcount(tunnel);
+		l2tp_tunnel_put(tunnel);
 	}
 }
 
···
 
 	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
···
 
 	tunnel = l2tp_sk_to_tunnel(sk);
 	if (tunnel) {
-		l2tp_tunnel_dec_refcount(tunnel);
+		l2tp_tunnel_put(tunnel);
 		return -EBUSY;
 	}
 
···
 {
 	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);
 	}
 }
···
 {
 	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);
 	}
 }
···
 		(*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

···
 }
 
 /* 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

···
 {
 	/* 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++;
···
 {
 	/* 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,
···
 	 * 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

···
 
 	spriv = l2tp_session_priv(session);
 
-	l2tp_session_inc_refcount(session);
+	refcount_inc(&session->ref_count);
 
 	rtnl_lock();
 
···
 	if (rc < 0) {
 		rtnl_unlock();
 		l2tp_session_delete(session);
-		l2tp_session_dec_refcount(session);
+		l2tp_session_put(session);
 		free_netdev(dev);
 
 		return rc;
···
 
 	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

···
 		goto discard_sess;
 
 	l2tp_recv_common(session, skb, ptr, optr, 0, skb->len);
-	l2tp_session_dec_refcount(session);
+	l2tp_session_put(session);
 
 	return 0;
 
···
 	return sk_receive_skb(sk, skb, 1);
 
 discard_sess:
-	l2tp_session_dec_refcount(session);
+	l2tp_session_put(session);
 	goto discard;
 
 discard_put:
···
 	tunnel = l2tp_sk_to_tunnel(sk);
 	if (tunnel) {
 		l2tp_tunnel_delete(tunnel);
-		l2tp_tunnel_dec_refcount(tunnel);
+		l2tp_tunnel_put(tunnel);
 	}
 }
 

net/l2tp/l2tp_ip6.c

···
 		goto discard_sess;
 
 	l2tp_recv_common(session, skb, ptr, optr, 0, skb->len);
-	l2tp_session_dec_refcount(session);
+	l2tp_session_put(session);
 
 	return 0;
 
···
 	return sk_receive_skb(sk, skb, 1);
 
 discard_sess:
-	l2tp_session_dec_refcount(session);
+	l2tp_session_put(session);
 	goto discard;
 
 discard_put:
···
 	tunnel = l2tp_sk_to_tunnel(sk);
 	if (tunnel) {
 		l2tp_tunnel_delete(tunnel);
-		l2tp_tunnel_dec_refcount(tunnel);
+		l2tp_tunnel_put(tunnel);
 	}
 }
 

net/l2tp/l2tp_netlink.c

···
 		if (tunnel) {
 			session = l2tp_session_get(net, tunnel->sock, tunnel->version,
 						   tunnel_id, session_id);
-			l2tp_tunnel_dec_refcount(tunnel);
+			l2tp_tunnel_put(tunnel);
 		}
 	}
 
···
 	if (ret < 0)
 		goto out;
 
-	l2tp_tunnel_inc_refcount(tunnel);
+	refcount_inc(&tunnel->ref_count);
 	ret = l2tp_tunnel_register(tunnel, net, &cfg);
 	if (ret < 0) {
 		kfree(tunnel);
···
 	}
 	ret = l2tp_tunnel_notify(&l2tp_nl_family, info, tunnel,
 				 L2TP_CMD_TUNNEL_CREATE);
-	l2tp_tunnel_dec_refcount(tunnel);
+	l2tp_tunnel_put(tunnel);
 
 out:
 	return ret;
···
 
 	l2tp_tunnel_delete(tunnel);
 
-	l2tp_tunnel_dec_refcount(tunnel);
+	l2tp_tunnel_put(tunnel);
 
 out:
 	return ret;
···
 	ret = l2tp_tunnel_notify(&l2tp_nl_family, info,
 				 tunnel, L2TP_CMD_TUNNEL_MODIFY);
 
-	l2tp_tunnel_dec_refcount(tunnel);
+	l2tp_tunnel_put(tunnel);
 
 out:
 	return ret;
···
 	if (ret < 0)
 		goto err_nlmsg_tunnel;
 
-	l2tp_tunnel_dec_refcount(tunnel);
+	l2tp_tunnel_put(tunnel);
 
 	return genlmsg_unicast(net, msg, info->snd_portid);
 
 err_nlmsg_tunnel:
-	l2tp_tunnel_dec_refcount(tunnel);
+	l2tp_tunnel_put(tunnel);
 err_nlmsg:
 	nlmsg_free(msg);
 err:
···
 		if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).portid,
 					cb->nlh->nlmsg_seq, NLM_F_MULTI,
 					tunnel, L2TP_CMD_TUNNEL_GET) < 0) {
-			l2tp_tunnel_dec_refcount(tunnel);
+			l2tp_tunnel_put(tunnel);
 			goto out;
 		}
-		l2tp_tunnel_dec_refcount(tunnel);
+		l2tp_tunnel_put(tunnel);
 
 		key++;
 	}
···
 		if (session) {
 			ret = l2tp_session_notify(&l2tp_nl_family, info, session,
 						  L2TP_CMD_SESSION_CREATE);
-			l2tp_session_dec_refcount(session);
+			l2tp_session_put(session);
 		}
 	}
 
 out_tunnel:
-	l2tp_tunnel_dec_refcount(tunnel);
+	l2tp_tunnel_put(tunnel);
 out:
 	return ret;
 }
···
 		if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete)
 			l2tp_nl_cmd_ops[pw_type]->session_delete(session);
 
-	l2tp_session_dec_refcount(session);
+	l2tp_session_put(session);
 
 out:
 	return ret;
···
 	ret = l2tp_session_notify(&l2tp_nl_family, info,
 				  session, L2TP_CMD_SESSION_MODIFY);
 
-	l2tp_session_dec_refcount(session);
+	l2tp_session_put(session);
 
 out:
 	return ret;
···
 
 	ret = genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
 
-	l2tp_session_dec_refcount(session);
+	l2tp_session_put(session);
 
 	return ret;
 
 err_ref_msg:
 	nlmsg_free(msg);
 err_ref:
-	l2tp_session_dec_refcount(session);
+	l2tp_session_put(session);
 err:
 	return ret;
 }
···
 						tunnel->tunnel_id, &skey);
 		if (!session) {
 			tkey++;
-			l2tp_tunnel_dec_refcount(tunnel);
+			l2tp_tunnel_put(tunnel);
 			tunnel = NULL;
 			skey = 0;
 			continue;
···
 		if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).portid,
 					 cb->nlh->nlmsg_seq, NLM_F_MULTI,
 					 session, L2TP_CMD_SESSION_GET) < 0) {
-			l2tp_session_dec_refcount(session);
-			l2tp_tunnel_dec_refcount(tunnel);
+			l2tp_session_put(session);
+			l2tp_tunnel_put(tunnel);
 			break;
 		}
-		l2tp_session_dec_refcount(session);
+		l2tp_session_put(session);
 
 		skey++;
 	}

net/l2tp/l2tp_ppp.c

···
 	l2tp_xmit_skb(session, skb);
 	local_bh_enable();
 
-	l2tp_session_dec_refcount(session);
+	l2tp_session_put(session);
 
 	return total_len;
 
 error_put_sess:
-	l2tp_session_dec_refcount(session);
+	l2tp_session_put(session);
 error:
 	return error;
 }
···
 	l2tp_xmit_skb(session, skb);
 	local_bh_enable();
 
-	l2tp_session_dec_refcount(session);
+	l2tp_session_put(session);
 
 	return 1;
 
 abort_put_sess:
-	l2tp_session_dec_refcount(session);
+	l2tp_session_put(session);
 abort:
 	/* Free the original skb */
 	kfree_skb(skb);
···
 		sock_put(ps->__sk);
 
 		/* drop ref taken when we referenced socket via sk_user_data */
-		l2tp_session_dec_refcount(session);
+		l2tp_session_put(session);
 	}
 }
 
···
 	if (session) {
 		l2tp_session_delete(session);
 		/* drop ref taken by pppol2tp_sock_to_session */
-		l2tp_session_dec_refcount(session);
+		l2tp_session_put(session);
 	}
 
 	release_sock(sk);
···
 			if (error < 0)
 				return ERR_PTR(error);
 
-			l2tp_tunnel_inc_refcount(tunnel);
+			refcount_inc(&tunnel->ref_count);
 			error = l2tp_tunnel_register(tunnel, net, &tcfg);
 			if (error < 0) {
 				kfree(tunnel);
···
 
 		/* Error if socket is not prepped */
 		if (!tunnel->sock) {
-			l2tp_tunnel_dec_refcount(tunnel);
+			l2tp_tunnel_put(tunnel);
 			return ERR_PTR(-ENOENT);
 		}
 	}
···
 
 		pppol2tp_session_init(session);
 		ps = l2tp_session_priv(session);
-		l2tp_session_inc_refcount(session);
+		refcount_inc(&session->ref_count);
 
 		mutex_lock(&ps->sk_lock);
 		error = l2tp_session_register(session, tunnel);
 		if (error < 0) {
 			mutex_unlock(&ps->sk_lock);
-			l2tp_session_dec_refcount(session);
+			l2tp_session_put(session);
 			goto end;
 		}
 
···
 			l2tp_tunnel_delete(tunnel);
 	}
 	if (drop_refcnt)
-		l2tp_session_dec_refcount(session);
-	l2tp_tunnel_dec_refcount(tunnel);
+		l2tp_session_put(session);
+	l2tp_tunnel_put(tunnel);
 	release_sock(sk);
 
 	return error;
···
 	return 0;
 
 err_sess:
-	l2tp_session_dec_refcount(session);
+	l2tp_session_put(session);
 err:
 	return error;
 }
···
 
 	error = len;
 
-	l2tp_session_dec_refcount(session);
+	l2tp_session_put(session);
 end:
 	return error;
 }
···
 		return -EBADR;
 
 	if (session->pwtype != L2TP_PWTYPE_PPP) {
-		l2tp_session_dec_refcount(session);
+		l2tp_session_put(session);
 		return -EBADR;
 	}
 
 	pppol2tp_copy_stats(stats, &session->stats);
-	l2tp_session_dec_refcount(session);
+	l2tp_session_put(session);
 
 	return 0;
 }
···
 		err = pppol2tp_session_setsockopt(sk, session, optname, val);
 	}
 
-	l2tp_session_dec_refcount(session);
+	l2tp_session_put(session);
 end:
 	return err;
 }
···
 	err = 0;
 
 end_put_sess:
-	l2tp_session_dec_refcount(session);
+	l2tp_session_put(session);
 end:
 	return err;
 }
···
 {
 	/* Drop reference taken during previous invocation */
 	if (pd->tunnel)
-		l2tp_tunnel_dec_refcount(pd->tunnel);
+		l2tp_tunnel_put(pd->tunnel);
 
 	for (;;) {
 		pd->tunnel = l2tp_tunnel_get_next(net, &pd->tkey);
···
 		if (!pd->tunnel || pd->tunnel->version == 2)
 			return;
 
-		l2tp_tunnel_dec_refcount(pd->tunnel);
+		l2tp_tunnel_put(pd->tunnel);
 	}
 }
 
···
 {
 	/* 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(net, pd->tunnel->sock,
 					    pd->tunnel->version,
···
 	 * or pppol2tp_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;
 	}
 }