[UNIX]: Extend unix_sysctl_(un)register prototypes

Add the struct net * argument to both of them to use in
the future. Also make the register one return an error code.

It is useless right now, but will make the future patches
much simpler.
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Acked-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/net/af_unix.h

@@ -60,11 +60,11 @@ struct unix_sock {
 
 #ifdef CONFIG_SYSCTL
 extern int sysctl_unix_max_dgram_qlen;
-extern void unix_sysctl_register(void);
-extern void unix_sysctl_unregister(void);
+extern int unix_sysctl_register(struct net *net);
+extern void unix_sysctl_unregister(struct net *net);
 #else
-static inline void unix_sysctl_register(void) {}
-static inline void unix_sysctl_unregister(void) {}
+static inline int unix_sysctl_register(struct net *net) { return 0; }
+static inline void unix_sysctl_unregister(struct net *net) {}
 #endif
 #endif
 #endif

net/unix/af_unix.c

@@ -2175,7 +2175,7 @@ static int __init af_unix_init(void)
 
 	sock_register(&unix_family_ops);
 	register_pernet_subsys(&unix_net_ops);
-	unix_sysctl_register();
+	unix_sysctl_register(&init_net);
 out:
 	return rc;
 }
@@ -2183,7 +2183,7 @@ static int __init af_unix_init(void)
 static void __exit af_unix_exit(void)
 {
 	sock_unregister(PF_UNIX);
-	unix_sysctl_unregister();
+	unix_sysctl_unregister(&init_net);
 	proto_unregister(&unix_proto);
 	unregister_pernet_subsys(&unix_net_ops);
 }

net/unix/sysctl_net_unix.c

@@ -48,12 +48,13 @@ static ctl_table unix_root_table[] = {
 
 static struct ctl_table_header * unix_sysctl_header;
 
-void unix_sysctl_register(void)
+int unix_sysctl_register(struct net *net)
 {
 	unix_sysctl_header = register_sysctl_table(unix_root_table);
+	return unix_sysctl_header == NULL ? -ENOMEM : 0;
 }
 
-void unix_sysctl_unregister(void)
+void unix_sysctl_unregister(struct net *net)
 {
 	unregister_sysctl_table(unix_sysctl_header);
 }