IPVS: Allow compilation with CONFIG_SYSCTL disabled

This is a rather naieve approach to allowing PVS to compile with
CONFIG_SYSCTL disabled.  I am working on a more comprehensive patch which
will remove compilation of all sysctl-related IPVS code when CONFIG_SYSCTL
is disabled.
Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Hans Schillstrom <hans@schillstrom.com>
Tested-by: Hans Schillstrom <hans@schillstrom.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

net/netfilter/ipvs/ip_vs_ctl.c

@@ -3552,10 +3552,15 @@ int __net_init __ip_vs_control_init(struct net *net)
 	tbl[idx++].data = &ipvs->sysctl_nat_icmp_send;
 
 
+#ifdef CONFIG_SYSCTL
 	ipvs->sysctl_hdr = register_net_sysctl_table(net, net_vs_ctl_path,
 						     tbl);
-	if (ipvs->sysctl_hdr == NULL)
-		goto err_reg;
+	if (ipvs->sysctl_hdr == NULL) {
+		if (!net_eq(net, &init_net))
+			kfree(tbl);
+		goto err_dup;
+	}
+#endif
 	ip_vs_new_estimator(net, ipvs->tot_stats);
 	ipvs->sysctl_tbl = tbl;
 	/* Schedule defense work */
@@ -3563,9 +3568,6 @@ int __net_init __ip_vs_control_init(struct net *net)
 	schedule_delayed_work(&ipvs->defense_work, DEFENSE_TIMER_PERIOD);
 	return 0;
 
-err_reg:
-	if (!net_eq(net, &init_net))
-		kfree(tbl);
 err_dup:
 	free_percpu(ipvs->cpustats);
 err_alloc:
@@ -3581,7 +3583,9 @@ static void __net_exit __ip_vs_control_cleanup(struct net *net)
 	ip_vs_kill_estimator(net, ipvs->tot_stats);
 	cancel_delayed_work_sync(&ipvs->defense_work);
 	cancel_work_sync(&ipvs->defense_work.work);
+#ifdef CONFIG_SYSCTL
 	unregister_net_sysctl_table(ipvs->sysctl_hdr);
+#endif
 	proc_net_remove(net, "ip_vs_stats_percpu");
 	proc_net_remove(net, "ip_vs_stats");
 	proc_net_remove(net, "ip_vs");

net/netfilter/ipvs/ip_vs_lblc.c

@@ -554,33 +554,33 @@ static int __net_init __ip_vs_lblc_init(struct net *net)
 						sizeof(vs_vars_table),
 						GFP_KERNEL);
 		if (ipvs->lblc_ctl_table == NULL)
-			goto err_dup;
+			return -ENOMEM;
 	} else
 		ipvs->lblc_ctl_table = vs_vars_table;
 	ipvs->sysctl_lblc_expiration = 24*60*60*HZ;
 	ipvs->lblc_ctl_table[0].data = &ipvs->sysctl_lblc_expiration;
 
+#ifdef CONFIG_SYSCTL
 	ipvs->lblc_ctl_header =
 		register_net_sysctl_table(net, net_vs_ctl_path,
 					  ipvs->lblc_ctl_table);
-	if (!ipvs->lblc_ctl_header)
-		goto err_reg;
-
-	return 0;
-
-err_reg:
+	if (!ipvs->lblc_ctl_header) {
 		if (!net_eq(net, &init_net))
 			kfree(ipvs->lblc_ctl_table);
-
-err_dup:
 		return -ENOMEM;
+	}
+#endif
+
+	return 0;
 }
 
 static void __net_exit __ip_vs_lblc_exit(struct net *net)
 {
 	struct netns_ipvs *ipvs = net_ipvs(net);
 
+#ifdef CONFIG_SYSCTL
 	unregister_net_sysctl_table(ipvs->lblc_ctl_header);
+#endif
 
 	if (!net_eq(net, &init_net))
 		kfree(ipvs->lblc_ctl_table);

net/netfilter/ipvs/ip_vs_lblcr.c

@@ -754,33 +754,33 @@ static int __net_init __ip_vs_lblcr_init(struct net *net)
 						sizeof(vs_vars_table),
 						GFP_KERNEL);
 		if (ipvs->lblcr_ctl_table == NULL)
-			goto err_dup;
+			return -ENOMEM;
 	} else
 		ipvs->lblcr_ctl_table = vs_vars_table;
 	ipvs->sysctl_lblcr_expiration = 24*60*60*HZ;
 	ipvs->lblcr_ctl_table[0].data = &ipvs->sysctl_lblcr_expiration;
 
+#ifdef CONFIG_SYSCTL
 	ipvs->lblcr_ctl_header =
 		register_net_sysctl_table(net, net_vs_ctl_path,
 					  ipvs->lblcr_ctl_table);
-	if (!ipvs->lblcr_ctl_header)
-		goto err_reg;
-
-	return 0;
-
-err_reg:
+	if (!ipvs->lblcr_ctl_header) {
 		if (!net_eq(net, &init_net))
 			kfree(ipvs->lblcr_ctl_table);
-
-err_dup:
 		return -ENOMEM;
+	}
+#endif
+
+	return 0;
 }
 
 static void __net_exit __ip_vs_lblcr_exit(struct net *net)
 {
 	struct netns_ipvs *ipvs = net_ipvs(net);
 
+#ifdef CONFIG_SYSCTL
 	unregister_net_sysctl_table(ipvs->lblcr_ctl_header);
+#endif
 
 	if (!net_eq(net, &init_net))
 		kfree(ipvs->lblcr_ctl_table);