net: Explicitly initialize u64_stats_sync structures for lockdep

In order to enable lockdep on seqcount/seqlock structures, we
must explicitly initialize any locks.

The u64_stats_sync structure, uses a seqcount, and thus we need
to introduce a u64_stats_init() function and use it to initialize
the structure.

This unfortunately adds a lot of fairly trivial initialization code
to a number of drivers. But the benefit of ensuring correctness makes
this worth while.

Because these changes are required for lockdep to be enabled, and the
changes are quite trivial, I've not yet split this patch out into 30-some
separate patches, as I figured it would be better to get the various
maintainers thoughts on how to best merge this change along with
the seqcount lockdep enablement.

Feedback would be appreciated!

Signed-off-by: John Stultz <john.stultz@linaro.org>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: James Morris <jmorris@namei.org>
Cc: Jesse Gross <jesse@nicira.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Mirko Lindner <mlindner@marvell.com>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Roger Luethi <rl@hellgate.ch>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Simon Horman <horms@verge.net.au>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Wensong Zhang <wensong@linux-vs.org>
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/1381186321-4906-2-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

12 files changed, 137 insertions, 5 deletions

diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c
index 09bf1c38805b..4deff3ed1da1 100644
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -558,7 +558,7 @@ static const struct net_device_ops vlan_netdev_ops;
 static int vlan_dev_init(struct net_device *dev)
 {
         struct net_device *real_dev = vlan_dev_priv(dev)->real_dev;
-        int subclass = 0;
+        int subclass = 0, i;
 
         netif_carrier_off(dev);
 
@@ -612,6 +612,13 @@ static int vlan_dev_init(struct net_device *dev)
         if (!vlan_dev_priv(dev)->vlan_pcpu_stats)
                 return -ENOMEM;
 
+        for_each_possible_cpu(i) {
+                struct vlan_pcpu_stats *vlan_stat;
+                vlan_stat = per_cpu_ptr(vlan_dev_priv(dev)->vlan_pcpu_stats, i);
+                u64_stats_init(&vlan_stat->syncp);
+        }
+
+
         return 0;
 }
 
diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c
index ca04163635da..7893d641775b 100644
--- a/net/bridge/br_device.c
+++ b/net/bridge/br_device.c
@@ -88,11 +88,18 @@ out:
 static int br_dev_init(struct net_device *dev)
 {
         struct net_bridge *br = netdev_priv(dev);
+        int i;
 
         br->stats = alloc_percpu(struct br_cpu_netstats);
         if (!br->stats)
                 return -ENOMEM;
 
+        for_each_possible_cpu(i) {
+                struct br_cpu_netstats *br_dev_stats;
+                br_dev_stats = per_cpu_ptr(br->stats, i);
+                u64_stats_init(&br_dev_stats->syncp);
+        }
+
         return 0;
 }
 
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index cfeb85cff4f0..5f4617e377b8 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1518,6 +1518,7 @@ int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align)
         ptr[0] = __alloc_percpu(mibsize, align);
         if (!ptr[0])
                 return -ENOMEM;
+
 #if SNMP_ARRAY_SZ == 2
         ptr[1] = __alloc_percpu(mibsize, align);
         if (!ptr[1]) {
@@ -1561,6 +1562,8 @@ static const struct net_protocol icmp_protocol = {
 
 static __net_init int ipv4_mib_init_net(struct net *net)
 {
+        int i;
+
         if (snmp_mib_init((void __percpu **)net->mib.tcp_statistics,
                           sizeof(struct tcp_mib),
                           __alignof__(struct tcp_mib)) < 0)
@@ -1569,6 +1572,17 @@ static __net_init int ipv4_mib_init_net(struct net *net)
                           sizeof(struct ipstats_mib),
                           __alignof__(struct ipstats_mib)) < 0)
                 goto err_ip_mib;
+
+        for_each_possible_cpu(i) {
+                struct ipstats_mib *af_inet_stats;
+                af_inet_stats = per_cpu_ptr(net->mib.ip_statistics[0], i);
+                u64_stats_init(&af_inet_stats->syncp);
+#if SNMP_ARRAY_SZ == 2
+                af_inet_stats = per_cpu_ptr(net->mib.ip_statistics[1], i);
+                u64_stats_init(&af_inet_stats->syncp);
+#endif
+        }
+
         if (snmp_mib_init((void __percpu **)net->mib.net_statistics,
                           sizeof(struct linux_mib),
                           __alignof__(struct linux_mib)) < 0)
diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index 63a6d6d6b875..caf01176a5e4 100644
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -976,13 +976,19 @@ int ip_tunnel_init(struct net_device *dev)
 {
         struct ip_tunnel *tunnel = netdev_priv(dev);
         struct iphdr *iph = &tunnel->parms.iph;
-        int err;
+        int i, err;
 
         dev->destructor = ip_tunnel_dev_free;
         dev->tstats = alloc_percpu(struct pcpu_tstats);
         if (!dev->tstats)
                 return -ENOMEM;
 
+        for_each_possible_cpu(i) {
+                struct pcpu_tstats *ipt_stats;
+                ipt_stats = per_cpu_ptr(dev->tstats, i);
+                u64_stats_init(&ipt_stats->syncp);
+        }
+
         err = gro_cells_init(&tunnel->gro_cells, dev);
         if (err) {
                 free_percpu(dev->tstats);
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index cd3fb301da38..d62d589bb622 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -281,10 +281,24 @@ static void addrconf_mod_dad_timer(struct inet6_ifaddr *ifp,
 
 static int snmp6_alloc_dev(struct inet6_dev *idev)
 {
+        int i;
+
         if (snmp_mib_init((void __percpu **)idev->stats.ipv6,
                           sizeof(struct ipstats_mib),
                           __alignof__(struct ipstats_mib)) < 0)
                 goto err_ip;
+
+        for_each_possible_cpu(i) {
+                struct ipstats_mib *addrconf_stats;
+                addrconf_stats = per_cpu_ptr(idev->stats.ipv6[0], i);
+                u64_stats_init(&addrconf_stats->syncp);
+#if SNMP_ARRAY_SZ == 2
+                addrconf_stats = per_cpu_ptr(idev->stats.ipv6[1], i);
+                u64_stats_init(&addrconf_stats->syncp);
+#endif
+        }
+
+
         idev->stats.icmpv6dev = kzalloc(sizeof(struct icmpv6_mib_device),
                                         GFP_KERNEL);
         if (!idev->stats.icmpv6dev)
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index 7c96100b021e..a8f8559b3dce 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -719,6 +719,8 @@ static void ipv6_packet_cleanup(void)
 
 static int __net_init ipv6_init_mibs(struct net *net)
 {
+        int i;
+
         if (snmp_mib_init((void __percpu **)net->mib.udp_stats_in6,
                           sizeof(struct udp_mib),
                           __alignof__(struct udp_mib)) < 0)
@@ -731,6 +733,18 @@ static int __net_init ipv6_init_mibs(struct net *net)
                           sizeof(struct ipstats_mib),
                           __alignof__(struct ipstats_mib)) < 0)
                 goto err_ip_mib;
+
+        for_each_possible_cpu(i) {
+                struct ipstats_mib *af_inet6_stats;
+                af_inet6_stats = per_cpu_ptr(net->mib.ipv6_statistics[0], i);
+                u64_stats_init(&af_inet6_stats->syncp);
+#if SNMP_ARRAY_SZ == 2
+                af_inet6_stats = per_cpu_ptr(net->mib.ipv6_statistics[1], i);
+                u64_stats_init(&af_inet6_stats->syncp);
+#endif
+        }
+
+
         if (snmp_mib_init((void __percpu **)net->mib.icmpv6_statistics,
                           sizeof(struct icmpv6_mib),
                           __alignof__(struct icmpv6_mib)) < 0)
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index bf4a9a084de5..8acb28621f9c 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -1252,6 +1252,7 @@ static void ip6gre_tunnel_setup(struct net_device *dev)
 static int ip6gre_tunnel_init(struct net_device *dev)
 {
         struct ip6_tnl *tunnel;
+        int i;
 
         tunnel = netdev_priv(dev);
 
@@ -1269,6 +1270,13 @@ static int ip6gre_tunnel_init(struct net_device *dev)
         if (!dev->tstats)
                 return -ENOMEM;
 
+        for_each_possible_cpu(i) {
+                struct pcpu_tstats *ip6gre_tunnel_stats;
+                ip6gre_tunnel_stats = per_cpu_ptr(dev->tstats, i);
+                u64_stats_init(&ip6gre_tunnel_stats->syncp);
+        }
+
+
         return 0;
 }
 
@@ -1449,6 +1457,7 @@ static void ip6gre_netlink_parms(struct nlattr *data[],
 static int ip6gre_tap_init(struct net_device *dev)
 {
         struct ip6_tnl *tunnel;
+        int i;
 
         tunnel = netdev_priv(dev);
 
@@ -1462,6 +1471,12 @@ static int ip6gre_tap_init(struct net_device *dev)
         if (!dev->tstats)
                 return -ENOMEM;
 
+        for_each_possible_cpu(i) {
+                struct pcpu_tstats *ip6gre_tap_stats;
+                ip6gre_tap_stats = per_cpu_ptr(dev->tstats, i);
+                u64_stats_init(&ip6gre_tap_stats->syncp);
+        }
+
         return 0;
 }
 
diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 583b77e2f69b..df1fa58528c6 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -1494,12 +1494,19 @@ static inline int
 ip6_tnl_dev_init_gen(struct net_device *dev)
 {
         struct ip6_tnl *t = netdev_priv(dev);
+        int i;
 
         t->dev = dev;
         t->net = dev_net(dev);
         dev->tstats = alloc_percpu(struct pcpu_tstats);
         if (!dev->tstats)
                 return -ENOMEM;
+
+        for_each_possible_cpu(i) {
+                struct pcpu_tstats *ip6_tnl_stats;
+                ip6_tnl_stats = per_cpu_ptr(dev->tstats, i);
+                u64_stats_init(&ip6_tnl_stats->syncp);
+        }
         return 0;
 }
 
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 19269453a8ea..365dc5473eb2 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -1310,6 +1310,7 @@ static void ipip6_tunnel_setup(struct net_device *dev)
 static int ipip6_tunnel_init(struct net_device *dev)
 {
         struct ip_tunnel *tunnel = netdev_priv(dev);
+        int i;
 
         tunnel->dev = dev;
         tunnel->net = dev_net(dev);
@@ -1322,6 +1323,12 @@ static int ipip6_tunnel_init(struct net_device *dev)
         if (!dev->tstats)
                 return -ENOMEM;
 
+        for_each_possible_cpu(i) {
+                struct pcpu_tstats *ipip6_tunnel_stats;
+                ipip6_tunnel_stats = per_cpu_ptr(dev->tstats, i);
+                u64_stats_init(&ipip6_tunnel_stats->syncp);
+        }
+
         return 0;
 }
 
@@ -1331,6 +1338,7 @@ static int __net_init ipip6_fb_tunnel_init(struct net_device *dev)
         struct iphdr *iph = &tunnel->parms.iph;
         struct net *net = dev_net(dev);
         struct sit_net *sitn = net_generic(net, sit_net_id);
+        int i;
 
         tunnel->dev = dev;
         tunnel->net = dev_net(dev);
@@ -1344,6 +1352,13 @@ static int __net_init ipip6_fb_tunnel_init(struct net_device *dev)
         dev->tstats = alloc_percpu(struct pcpu_tstats);
         if (!dev->tstats)
                 return -ENOMEM;
+
+        for_each_possible_cpu(i) {
+                struct pcpu_tstats *ipip6_fb_stats;
+                ipip6_fb_stats = per_cpu_ptr(dev->tstats, i);
+                u64_stats_init(&ipip6_fb_stats->syncp);
+        }
+
         dev_hold(dev);
         rcu_assign_pointer(sitn->tunnels_wc[0], tunnel);
         return 0;
diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index a3df9bddc4f7..3825725907f6 100644
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -842,7 +842,7 @@ ip_vs_new_dest(struct ip_vs_service *svc, struct ip_vs_dest_user_kern *udest,
                struct ip_vs_dest **dest_p)
 {
         struct ip_vs_dest *dest;
-        unsigned int atype;
+        unsigned int atype, i;
 
         EnterFunction(2);
 
@@ -869,6 +869,12 @@ ip_vs_new_dest(struct ip_vs_service *svc, struct ip_vs_dest_user_kern *udest,
         if (!dest->stats.cpustats)
                 goto err_alloc;
 
+        for_each_possible_cpu(i) {
+                struct ip_vs_cpu_stats *ip_vs_dest_stats;
+                ip_vs_dest_stats = per_cpu_ptr(dest->stats.cpustats, i);
+                u64_stats_init(&ip_vs_dest_stats->syncp);
+        }
+
         dest->af = svc->af;
         dest->protocol = svc->protocol;
         dest->vaddr = svc->addr;
@@ -1134,7 +1140,7 @@ static int
 ip_vs_add_service(struct net *net, struct ip_vs_service_user_kern *u,
                   struct ip_vs_service **svc_p)
 {
-        int ret = 0;
+        int ret = 0, i;
         struct ip_vs_scheduler *sched = NULL;
         struct ip_vs_pe *pe = NULL;
         struct ip_vs_service *svc = NULL;
@@ -1184,6 +1190,13 @@ ip_vs_add_service(struct net *net, struct ip_vs_service_user_kern *u,
                 goto out_err;
         }
 
+        for_each_possible_cpu(i) {
+                struct ip_vs_cpu_stats *ip_vs_stats;
+                ip_vs_stats = per_cpu_ptr(svc->stats.cpustats, i);
+                u64_stats_init(&ip_vs_stats->syncp);
+        }
+
+
         /* I'm the first user of the service */
         atomic_set(&svc->refcnt, 0);
 
@@ -3780,7 +3793,7 @@ static struct notifier_block ip_vs_dst_notifier = {
 
 int __net_init ip_vs_control_net_init(struct net *net)
 {
-        int idx;
+        int i, idx;
         struct netns_ipvs *ipvs = net_ipvs(net);
 
         /* Initialize rs_table */
@@ -3799,6 +3812,12 @@ int __net_init ip_vs_control_net_init(struct net *net)
         if (!ipvs->tot_stats.cpustats)
                 return -ENOMEM;
 
+        for_each_possible_cpu(i) {
+                struct ip_vs_cpu_stats *ipvs_tot_stats;
+                ipvs_tot_stats = per_cpu_ptr(ipvs->tot_stats.cpustats, i);
+                u64_stats_init(&ipvs_tot_stats->syncp);
+        }
+
         spin_lock_init(&ipvs->tot_stats.lock);
 
         proc_create("ip_vs", 0, net->proc_net, &ip_vs_info_fops);
diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index 2aa13bd7f2b2..b92553c02279 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -1698,6 +1698,12 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct genl_info *info)
                 goto err_destroy_table;
         }
 
+        for_each_possible_cpu(i) {
+                struct dp_stats_percpu *dpath_stats;
+                dpath_stats = per_cpu_ptr(dp->stats_percpu, i);
+                u64_stats_init(&dpath_stats->sync);
+        }
+
         dp->ports = kmalloc(DP_VPORT_HASH_BUCKETS * sizeof(struct hlist_head),
                         GFP_KERNEL);
         if (!dp->ports) {
diff --git a/net/openvswitch/vport.c b/net/openvswitch/vport.c
index 6f65dbe13812..d830a95f03a4 100644
--- a/net/openvswitch/vport.c
+++ b/net/openvswitch/vport.c
@@ -118,6 +118,7 @@ struct vport *ovs_vport_alloc(int priv_size, const struct vport_ops *ops,
 {
         struct vport *vport;
         size_t alloc_size;
+        int i;
 
         alloc_size = sizeof(struct vport);
         if (priv_size) {
@@ -141,6 +142,13 @@ struct vport *ovs_vport_alloc(int priv_size, const struct vport_ops *ops,
                 return ERR_PTR(-ENOMEM);
         }
 
+        for_each_possible_cpu(i) {
+                struct pcpu_tstats *vport_stats;
+                vport_stats = per_cpu_ptr(vport->percpu_stats, i);
+                u64_stats_init(&vport_stats->syncp);
+        }
+
+
         spin_lock_init(&vport->stats_lock);
 
         return vport;