1 files changed, 35 insertions, 65 deletions

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 7b7b45a19597..c41a88100fea 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -73,8 +73,12 @@ struct netlink_sock {
 	struct netlink_callback	*cb;
 	spinlock_t		cb_lock;
 	void			(*data_ready)(struct sock *sk, int bytes);
+	struct module		*module;
+	u32			flags;
 };
 
+#define NETLINK_KERNEL_SOCKET	0x1
+
 static inline struct netlink_sock *nlk_sk(struct sock *sk)
 {
 	return (struct netlink_sock *)sk;
@@ -97,7 +101,7 @@ struct netlink_table {
 	struct nl_pid_hash hash;
 	struct hlist_head mc_list;
 	unsigned int nl_nonroot;
-	struct proto_ops *p_ops;
+	struct module *module;
 };
 
 static struct netlink_table *nl_table;
@@ -338,6 +342,7 @@ static int netlink_create(struct socket *sock, int protocol)
 {
 	struct sock *sk;
 	struct netlink_sock *nlk;
+	struct module *module;
 
 	sock->state = SS_UNCONNECTED;
 
@@ -347,30 +352,36 @@ static int netlink_create(struct socket *sock, int protocol)
 	if (protocol<0 || protocol >= MAX_LINKS)
 		return -EPROTONOSUPPORT;
 
-	netlink_table_grab();
+	netlink_lock_table();
 	if (!nl_table[protocol].hash.entries) {
 #ifdef CONFIG_KMOD
 		/* We do 'best effort'.  If we find a matching module,
 		 * it is loaded.  If not, we don't return an error to
 		 * allow pure userspace<->userspace communication. -HW
 		 */
-		netlink_table_ungrab();
+		netlink_unlock_table();
 		request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol);
-		netlink_table_grab();
+		netlink_lock_table();
 #endif
 	}
-	netlink_table_ungrab();
+	module = nl_table[protocol].module;
+	if (!try_module_get(module))
+		module = NULL;
+	netlink_unlock_table();
 
-	sock->ops = nl_table[protocol].p_ops;
+	sock->ops = &netlink_ops;
 
 	sk = sk_alloc(PF_NETLINK, GFP_KERNEL, &netlink_proto, 1);
-	if (!sk)
+	if (!sk) {
+		module_put(module);
 		return -ENOMEM;
+	}
 
 	sock_init_data(sock, sk);
 
 	nlk = nlk_sk(sk);
 
+	nlk->module = module;
 	spin_lock_init(&nlk->cb_lock);
 	init_waitqueue_head(&nlk->wait);
 	sk->sk_destruct = netlink_sock_destruct;
@@ -415,22 +426,15 @@ static int netlink_release(struct socket *sock)
 		notifier_call_chain(&netlink_chain, NETLINK_URELEASE, &n);
 	}	
 
-	/* When this is a kernel socket, we need to remove the owner pointer,
-	 * since we don't know whether the module will be dying at any given
-	 * point - HW
-	 */
-	if (!nlk->pid) {
-		struct proto_ops *p_tmp;
+	if (nlk->module)
+		module_put(nlk->module);
 
+	if (nlk->flags & NETLINK_KERNEL_SOCKET) {
 		netlink_table_grab();
-		p_tmp = nl_table[sk->sk_protocol].p_ops;
-		if (p_tmp != &netlink_ops) {
-			nl_table[sk->sk_protocol].p_ops = &netlink_ops;
-			kfree(p_tmp);
-		}
+		nl_table[sk->sk_protocol].module = NULL;
 		netlink_table_ungrab();
 	}
-	
+
 	sock_put(sk);
 	return 0;
 }
@@ -1060,9 +1064,9 @@ static void netlink_data_ready(struct sock *sk, int len)
 struct sock *
 netlink_kernel_create(int unit, void (*input)(struct sock *sk, int len), struct module *module)
 {
-	struct proto_ops *p_ops;
 	struct socket *sock;
 	struct sock *sk;
+	struct netlink_sock *nlk;
 
 	if (!nl_table)
 		return NULL;
@@ -1070,64 +1074,32 @@ netlink_kernel_create(int unit, void (*input)(struct sock *sk, int len), struct
 	if (unit<0 || unit>=MAX_LINKS)
 		return NULL;
 
-	/* Do a quick check, to make us not go down to netlink_insert()
-	 * if protocol already has kernel socket.
-	 */
-	sk = netlink_lookup(unit, 0);
-	if (unlikely(sk)) {
-		sock_put(sk);
-		return NULL;
-	}
-
 	if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock))
 		return NULL;
 
-	sk = NULL;
-	if (module) {
-		/* Every registering protocol implemented in a module needs
-		 * it's own p_ops, since the socket code cannot deal with
-		 * module refcounting otherwise.  -HW
-		 */
-		p_ops = kmalloc(sizeof(*p_ops), GFP_KERNEL);
-		if (!p_ops)
-			goto out_sock_release;
-
-		memcpy(p_ops, &netlink_ops, sizeof(*p_ops));
-		p_ops->owner = module;
-	} else
-		p_ops = &netlink_ops;
-
-	netlink_table_grab();
-	nl_table[unit].p_ops = p_ops;
-	netlink_table_ungrab();
-
-	if (netlink_create(sock, unit) < 0) {
-		sk = NULL;
-		goto out_kfree_p_ops;
-	}
+	if (netlink_create(sock, unit) < 0)
+		goto out_sock_release;
 
 	sk = sock->sk;
 	sk->sk_data_ready = netlink_data_ready;
 	if (input)
 		nlk_sk(sk)->data_ready = input;
 
-	if (netlink_insert(sk, 0)) {
-		sk = NULL;
-		goto out_kfree_p_ops;
-	}
+	if (netlink_insert(sk, 0))
+		goto out_sock_release;
 
-	return sk;
+	nlk = nlk_sk(sk);
+	nlk->flags |= NETLINK_KERNEL_SOCKET;
 
-out_kfree_p_ops:
 	netlink_table_grab();
-	if (nl_table[unit].p_ops != &netlink_ops) {
-		kfree(nl_table[unit].p_ops);
-		nl_table[unit].p_ops = &netlink_ops;
-	}
+	nl_table[unit].module = module;
 	netlink_table_ungrab();
+
+	return sk;
+
 out_sock_release:
 	sock_release(sock);
-	return sk;
+	return NULL;
 }
 
 void netlink_set_nonroot(int protocol, unsigned int flags)
@@ -1490,8 +1462,6 @@ enomem:
 	for (i = 0; i < MAX_LINKS; i++) {
 		struct nl_pid_hash *hash = &nl_table[i].hash;
 
-		nl_table[i].p_ops = &netlink_ops;
-
 		hash->table = nl_pid_hash_alloc(1 * sizeof(*hash->table));
 		if (!hash->table) {
 			while (i-- > 0)