[NETNS]: Consolidate kernel netlink socket destruction.

Create a specific helper for netlink kernel socket disposal. This just
let the code look better and provides a ground for proper disposal
inside a namespace.

Signed-off-by: Denis V. Lunev <[e-mail]>
Tested-by: Alexey Dobriyan <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/connector/connector.c

···
 
 	dev->cbdev = cn_queue_alloc_dev("cqueue", dev->nls);
 	if (!dev->cbdev) {
-		if (dev->nls->sk_socket)
-			sock_release(dev->nls->sk_socket);
+		netlink_kernel_release(dev->nls);
 		return -EINVAL;
 	}
 	
···
 	if (err) {
 		cn_already_initialized = 0;
 		cn_queue_free_dev(dev->cbdev);
-		if (dev->nls->sk_socket)
-			sock_release(dev->nls->sk_socket);
+		netlink_kernel_release(dev->nls);
 		return -EINVAL;
 	}
 
···
 
 	cn_del_callback(&dev->id);
 	cn_queue_free_dev(dev->cbdev);
-	if (dev->nls->sk_socket)
-		sock_release(dev->nls->sk_socket);
+	netlink_kernel_release(dev->nls);
 }
 
 subsys_initcall(cn_init);

drivers/scsi/scsi_netlink.c

···
 scsi_netlink_exit(void)
 {
 	if (scsi_nl_sock) {
-		sock_release(scsi_nl_sock->sk_socket);
+		netlink_kernel_release(scsi_nl_sock);
 		netlink_unregister_notifier(&scsi_netlink_notifier);
 	}
 

drivers/scsi/scsi_transport_iscsi.c

···
 	return 0;
 
 release_nls:
-	sock_release(nls->sk_socket);
+	netlink_kernel_release(nls);
 unregister_session_class:
 	transport_class_unregister(&iscsi_session_class);
 unregister_conn_class:
···
 static void __exit iscsi_transport_exit(void)
 {
 	destroy_workqueue(iscsi_eh_timer_workq);
-	sock_release(nls->sk_socket);
+	netlink_kernel_release(nls);
 	transport_class_unregister(&iscsi_connection_class);
 	transport_class_unregister(&iscsi_session_class);
 	transport_class_unregister(&iscsi_host_class);

fs/ecryptfs/netlink.c

···
  */
 void ecryptfs_release_netlink(void)
 {
-	if (ecryptfs_nl_sock && ecryptfs_nl_sock->sk_socket)
-		sock_release(ecryptfs_nl_sock->sk_socket);
+	netlink_kernel_release(ecryptfs_nl_sock);
 	ecryptfs_nl_sock = NULL;
 }

include/linux/netlink.h

···
 					  void (*input)(struct sk_buff *skb),
 					  struct mutex *cb_mutex,
 					  struct module *module);
+extern void netlink_kernel_release(struct sock *sk);
 extern int netlink_change_ngroups(struct sock *sk, unsigned int groups);
 extern void netlink_clear_multicast_users(struct sock *sk, unsigned int group);
 extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err);

net/bridge/netfilter/ebt_ulog.c

···
 	if (!ebtulognl)
 		ret = -ENOMEM;
 	else if ((ret = ebt_register_watcher(&ulog)))
-		sock_release(ebtulognl->sk_socket);
+		netlink_kernel_release(ebtulognl);
 
 	if (ret == 0)
 		nf_log_register(PF_BRIDGE, &ebt_ulog_logger);
···
 		}
 		spin_unlock_bh(&ub->lock);
 	}
-	sock_release(ebtulognl->sk_socket);
+	netlink_kernel_release(ebtulognl);
 }
 
 module_init(ebt_ulog_init);

net/core/rtnetlink.c

···
 		 * free.
 		 */
 		sk->sk_net = get_net(&init_net);
-		sock_release(net->rtnl->sk_socket);
+		netlink_kernel_release(net->rtnl);
 		net->rtnl = NULL;
 	}
 }

net/decnet/netfilter/dn_rtmsg.c

···
 
 	rv = nf_register_hook(&dnrmg_ops);
 	if (rv) {
-		sock_release(dnrmg->sk_socket);
+		netlink_kernel_release(dnrmg);
 	}
 
 	return rv;
···
 static void __exit dn_rtmsg_fini(void)
 {
 	nf_unregister_hook(&dnrmg_ops);
-	sock_release(dnrmg->sk_socket);
+	netlink_kernel_release(dnrmg);
 }
 
 

net/ipv4/fib_frontend.c

···
 	 * initial network namespace. So the socket will  be safe to free.
 	 */
 	net->ipv4.fibnl->sk_net = get_net(&init_net);
-	sock_release(net->ipv4.fibnl->sk_socket);
+	netlink_kernel_release(net->ipv4.fibnl);
 }
 
 static void fib_disable_ip(struct net_device *dev, int force)

net/ipv4/inet_diag.c

···
 
 static void __exit inet_diag_exit(void)
 {
-	sock_release(idiagnl->sk_socket);
+	netlink_kernel_release(idiagnl);
 	kfree(inet_diag_table);
 }
 

net/ipv4/netfilter/ip_queue.c

···
 	unregister_netdevice_notifier(&ipq_dev_notifier);
 	proc_net_remove(&init_net, IPQ_PROC_FS_NAME);
 cleanup_ipqnl:
-	sock_release(ipqnl->sk_socket);
+	netlink_kernel_release(ipqnl);
 	mutex_lock(&ipqnl_mutex);
 	mutex_unlock(&ipqnl_mutex);
 
···
 	unregister_netdevice_notifier(&ipq_dev_notifier);
 	proc_net_remove(&init_net, IPQ_PROC_FS_NAME);
 
-	sock_release(ipqnl->sk_socket);
+	netlink_kernel_release(ipqnl);
 	mutex_lock(&ipqnl_mutex);
 	mutex_unlock(&ipqnl_mutex);
 

net/ipv4/netfilter/ipt_ULOG.c

···
 
 	ret = xt_register_target(&ulog_tg_reg);
 	if (ret < 0) {
-		sock_release(nflognl->sk_socket);
+		netlink_kernel_release(nflognl);
 		return ret;
 	}
 	if (nflog)
···
 	if (nflog)
 		nf_log_unregister(&ipt_ulog_logger);
 	xt_unregister_target(&ulog_tg_reg);
-	sock_release(nflognl->sk_socket);
+	netlink_kernel_release(nflognl);
 
 	/* remove pending timers and free allocated skb's */
 	for (i = 0; i < ULOG_MAXNLGROUPS; i++) {

net/ipv6/netfilter/ip6_queue.c

···
 	proc_net_remove(&init_net, IPQ_PROC_FS_NAME);
 
 cleanup_ipqnl:
-	sock_release(ipqnl->sk_socket);
+	netlink_kernel_release(ipqnl);
 	mutex_lock(&ipqnl_mutex);
 	mutex_unlock(&ipqnl_mutex);
 
···
 	unregister_netdevice_notifier(&ipq_dev_notifier);
 	proc_net_remove(&init_net, IPQ_PROC_FS_NAME);
 
-	sock_release(ipqnl->sk_socket);
+	netlink_kernel_release(ipqnl);
 	mutex_lock(&ipqnl_mutex);
 	mutex_unlock(&ipqnl_mutex);
 

net/netfilter/nfnetlink.c

···
 static void __exit nfnetlink_exit(void)
 {
 	printk("Removing netfilter NETLINK layer.\n");
-	sock_release(nfnl->sk_socket);
+	netlink_kernel_release(nfnl);
 	return;
 }
 

net/netlink/af_netlink.c

···
 }
 EXPORT_SYMBOL(netlink_kernel_create);
 
+
+void
+netlink_kernel_release(struct sock *sk)
+{
+	if (sk == NULL || sk->sk_socket == NULL)
+		return;
+	sock_release(sk->sk_socket);
+}
+EXPORT_SYMBOL(netlink_kernel_release);
+
+
 /**
  * netlink_change_ngroups - change number of multicast groups
  *

net/xfrm/xfrm_user.c

···
 	xfrm_unregister_km(&netlink_mgr);
 	rcu_assign_pointer(xfrm_nl, NULL);
 	synchronize_rcu();
-	sock_release(nlsk->sk_socket);
+	netlink_kernel_release(nlsk);
 }
 
 module_init(xfrm_user_init);