IPVS: init and cleanup restructuring

DESCRIPTION
This patch tries to restore the initial init and cleanup
sequences that was before namspace patch.
Netns also requires action when net devices unregister
which has never been implemented. I.e this patch also
covers when a device moves into a network namespace,
and has to be released.

IMPLEMENTATION
The number of calls to register_pernet_device have been
reduced to one for the ip_vs.ko
Schedulers still have their own calls.

This patch adds a function __ip_vs_service_cleanup()
and an enable flag for the netfilter hooks.

The nf hooks will be enabled when the first service is loaded
and never disabled again, except when a namespace exit starts.

Signed-off-by: Hans Schillstrom <hans@schillstrom.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
[horms@verge.net.au: minor edit to changelog]
Signed-off-by: Simon Horman <horms@verge.net.au>

1 files changed, 101 insertions, 19 deletions

diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index ae47090bf45f..ea722810faf3 100644
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -69,6 +69,11 @@ int ip_vs_get_debug_level(void)
 }
 #endif
 
+
+/*  Protos */
+static void __ip_vs_del_service(struct ip_vs_service *svc);
+
+
 #ifdef CONFIG_IP_VS_IPV6
 /* Taken from rt6_fill_node() in net/ipv6/route.c, is there a better way? */
 static int __ip_vs_addr_is_local_v6(struct net *net,
@@ -1214,6 +1219,8 @@ ip_vs_add_service(struct net *net, struct ip_vs_service_user_kern *u,
 	write_unlock_bh(&__ip_vs_svc_lock);
 
 	*svc_p = svc;
+	/* Now there is a service - full throttle */
+	ipvs->enable = 1;
 	return 0;
 
 
@@ -1472,6 +1479,84 @@ static int ip_vs_flush(struct net *net)
 	return 0;
 }
 
+/*
+ *	Delete service by {netns} in the service table.
+ *	Called by __ip_vs_cleanup()
+ */
+void __ip_vs_service_cleanup(struct net *net)
+{
+	EnterFunction(2);
+	/* Check for "full" addressed entries */
+	mutex_lock(&__ip_vs_mutex);
+	ip_vs_flush(net);
+	mutex_unlock(&__ip_vs_mutex);
+	LeaveFunction(2);
+}
+/*
+ * Release dst hold by dst_cache
+ */
+static inline void
+__ip_vs_dev_reset(struct ip_vs_dest *dest, struct net_device *dev)
+{
+	spin_lock_bh(&dest->dst_lock);
+	if (dest->dst_cache && dest->dst_cache->dev == dev) {
+		IP_VS_DBG_BUF(3, "Reset dev:%s dest %s:%u ,dest->refcnt=%d\n",
+			      dev->name,
+			      IP_VS_DBG_ADDR(dest->af, &dest->addr),
+			      ntohs(dest->port),
+			      atomic_read(&dest->refcnt));
+		ip_vs_dst_reset(dest);
+	}
+	spin_unlock_bh(&dest->dst_lock);
+
+}
+/*
+ * Netdev event receiver
+ * Currently only NETDEV_UNREGISTER is handled, i.e. if we hold a reference to
+ * a device that is "unregister" it must be released.
+ */
+static int ip_vs_dst_event(struct notifier_block *this, unsigned long event,
+			    void *ptr)
+{
+	struct net_device *dev = ptr;
+	struct net *net = dev_net(dev);
+	struct ip_vs_service *svc;
+	struct ip_vs_dest *dest;
+	unsigned int idx;
+
+	if (event != NETDEV_UNREGISTER)
+		return NOTIFY_DONE;
+	IP_VS_DBG(3, "%s() dev=%s\n", __func__, dev->name);
+	EnterFunction(2);
+	mutex_lock(&__ip_vs_mutex);
+	for (idx = 0; idx < IP_VS_SVC_TAB_SIZE; idx++) {
+		list_for_each_entry(svc, &ip_vs_svc_table[idx], s_list) {
+			if (net_eq(svc->net, net)) {
+				list_for_each_entry(dest, &svc->destinations,
+						    n_list) {
+					__ip_vs_dev_reset(dest, dev);
+				}
+			}
+		}
+
+		list_for_each_entry(svc, &ip_vs_svc_fwm_table[idx], f_list) {
+			if (net_eq(svc->net, net)) {
+				list_for_each_entry(dest, &svc->destinations,
+						    n_list) {
+					__ip_vs_dev_reset(dest, dev);
+				}
+			}
+
+		}
+	}
+
+	list_for_each_entry(dest, &net_ipvs(net)->dest_trash, n_list) {
+		__ip_vs_dev_reset(dest, dev);
+	}
+	mutex_unlock(&__ip_vs_mutex);
+	LeaveFunction(2);
+	return NOTIFY_DONE;
+}
 
 /*
  *	Zero counters in a service or all services
@@ -3588,6 +3673,10 @@ void __net_init __ip_vs_control_cleanup_sysctl(struct net *net) { }
 
 #endif
 
+static struct notifier_block ip_vs_dst_notifier = {
+	.notifier_call = ip_vs_dst_event,
+};
+
 int __net_init __ip_vs_control_init(struct net *net)
 {
 	int idx;
@@ -3626,7 +3715,7 @@ err:
 	return -ENOMEM;
 }
 
-static void __net_exit __ip_vs_control_cleanup(struct net *net)
+void __net_exit __ip_vs_control_cleanup(struct net *net)
 {
 	struct netns_ipvs *ipvs = net_ipvs(net);
 
@@ -3639,11 +3728,6 @@ static void __net_exit __ip_vs_control_cleanup(struct net *net)
 	free_percpu(ipvs->tot_stats.cpustats);
 }
 
-static struct pernet_operations ipvs_control_ops = {
-	.init = __ip_vs_control_init,
-	.exit = __ip_vs_control_cleanup,
-};
-
 int __init ip_vs_control_init(void)
 {
 	int idx;
@@ -3657,33 +3741,32 @@ int __init ip_vs_control_init(void)
 		INIT_LIST_HEAD(&ip_vs_svc_fwm_table[idx]);
 	}
 
-	ret = register_pernet_subsys(&ipvs_control_ops);
-	if (ret) {
-		pr_err("cannot register namespace.\n");
-		goto err;
-	}
-
 	smp_wmb();	/* Do we really need it now ? */
 
 	ret = nf_register_sockopt(&ip_vs_sockopts);
 	if (ret) {
 		pr_err("cannot register sockopt.\n");
-		goto err_net;
+		goto err_sock;
 	}
 
 	ret = ip_vs_genl_register();
 	if (ret) {
 		pr_err("cannot register Generic Netlink interface.\n");
-		nf_unregister_sockopt(&ip_vs_sockopts);
-		goto err_net;
+		goto err_genl;
 	}
 
+	ret = register_netdevice_notifier(&ip_vs_dst_notifier);
+	if (ret < 0)
+		goto err_notf;
+
 	LeaveFunction(2);
 	return 0;
 
-err_net:
-	unregister_pernet_subsys(&ipvs_control_ops);
-err:
+err_notf:
+	ip_vs_genl_unregister();
+err_genl:
+	nf_unregister_sockopt(&ip_vs_sockopts);
+err_sock:
 	return ret;
 }
 
@@ -3691,7 +3774,6 @@ err:
 void ip_vs_control_cleanup(void)
 {
 	EnterFunction(2);
-	unregister_pernet_subsys(&ipvs_control_ops);
 	ip_vs_genl_unregister();
 	nf_unregister_sockopt(&ip_vs_sockopts);
 	LeaveFunction(2);