IPVS: netns, ip_vs_stats and its procfs

The statistic counter locks for every packet are now removed,
and that statistic is now per CPU, i.e. no locks needed.
However summing is made in ip_vs_est into ip_vs_stats struct
which is moved to ipvs struc.

procfs, ip_vs_stats now have a "per cpu" count and a grand total.
A new function seq_file_single_net() in ip_vs.h created for handling of
single_open_net() since it does not place net ptr in a struct, like others.

/var/lib/lxc # cat /proc/net/ip_vs_stats_percpu
       Total Incoming Outgoing         Incoming         Outgoing
CPU    Conns  Packets  Packets            Bytes            Bytes
  0        0        3        1               9D               34
  1        0        1        2               49               70
  2        0        1        2               34               76
  3        1        2        2               70               74
  ~        1        7        7              18A              18E

     Conns/s   Pkts/s   Pkts/s          Bytes/s          Bytes/s
           0        0        0                0                0

*v3
ip_vs_stats reamains as before, instead ip_vs_stats_percpu is added.
u64 seq lock added

*v4
Bug correction inbytes and outbytes as own vars..
per_cpu counter for all stats now as suggested by Julian.

[horms@verge.net.au: removed whitespace-change-only hunk]
Signed-off-by: Hans Schillstrom <hans.schillstrom@ericsson.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

include/net/ip_vs.h

@@ -90,6 +90,18 @@ static inline struct net *skb_sknet(struct sk_buff *skb)
 	return &init_net;
 #endif
 }
+/*
+ * This one needed for single_open_net since net is stored directly in
+ * private not as a struct i.e. seq_file_net cant be used.
+ */
+static inline struct net *seq_file_single_net(struct seq_file *seq)
+{
+#ifdef CONFIG_NET_NS
+	return (struct net *)seq->private;
+#else
+	return &init_net;
+#endif
+}
 
 /* Connections' size value needed by ip_vs_ctl.c */
 extern int ip_vs_conn_tab_size;
@@ -320,6 +332,23 @@ struct ip_vs_seq {
 						   before last resized pkt */
 };
 
+/*
+ * counters per cpu
+ */
+struct ip_vs_counters {
+	__u32		conns;		/* connections scheduled */
+	__u32		inpkts;		/* incoming packets */
+	__u32		outpkts;	/* outgoing packets */
+	__u64		inbytes;	/* incoming bytes */
+	__u64		outbytes;	/* outgoing bytes */
+};
+/*
+ * Stats per cpu
+ */
+struct ip_vs_cpu_stats {
+	struct ip_vs_counters   ustats;
+	struct u64_stats_sync   syncp;
+};
 
 /*
  *	IPVS statistics objects
@@ -341,12 +370,28 @@ struct ip_vs_estimator {
 };
 
 struct ip_vs_stats {
-	struct ip_vs_stats_user	ustats;         /* statistics */
+	struct ip_vs_stats_user	ustats;		/* statistics */
 	struct ip_vs_estimator	est;		/* estimator */
-
-	spinlock_t              lock;           /* spin lock */
+	struct ip_vs_cpu_stats	*cpustats;	/* per cpu counters */
+	spinlock_t		lock;		/* spin lock */
 };
 
+/*
+ * Helper Macros for per cpu
+ * ipvs->tot_stats->ustats.count
+ */
+#define IPVS_STAT_INC(ipvs, count)	\
+	__this_cpu_inc((ipvs)->ustats->count)
+
+#define IPVS_STAT_ADD(ipvs, count, value) \
+	do {\
+		write_seqcount_begin(per_cpu_ptr((ipvs)->ustats_seq, \
+				     raw_smp_processor_id())); \
+		__this_cpu_add((ipvs)->ustats->count, value); \
+		write_seqcount_end(per_cpu_ptr((ipvs)->ustats_seq, \
+				   raw_smp_processor_id())); \
+	} while (0)
+
 struct dst_entry;
 struct iphdr;
 struct ip_vs_conn;

include/net/netns/ip_vs.h

@@ -61,6 +61,10 @@ struct netns_ipvs {
 	struct list_head	sctp_apps[SCTP_APP_TAB_SIZE];
 	spinlock_t		sctp_app_lock;
 #endif
+	/* ip_vs_ctl */
+	struct ip_vs_stats		*tot_stats;  /* Statistics & est. */
+	struct ip_vs_cpu_stats __percpu *cpustats;   /* Stats per cpu */
+	seqcount_t			*ustats_seq; /* u64 read retry */
 
 	/* ip_vs_lblc */
 	int			sysctl_lblc_expiration;

net/netfilter/ipvs/ip_vs_core.c

@@ -115,21 +115,28 @@ static inline void
 ip_vs_in_stats(struct ip_vs_conn *cp, struct sk_buff *skb)
 {
 	struct ip_vs_dest *dest = cp->dest;
+	struct netns_ipvs *ipvs = net_ipvs(skb_net(skb));
+
 	if (dest && (dest->flags & IP_VS_DEST_F_AVAILABLE)) {
-		spin_lock(&dest->stats.lock);
-		dest->stats.ustats.inpkts++;
-		dest->stats.ustats.inbytes += skb->len;
-		spin_unlock(&dest->stats.lock);
-
-		spin_lock(&dest->svc->stats.lock);
-		dest->svc->stats.ustats.inpkts++;
-		dest->svc->stats.ustats.inbytes += skb->len;
-		spin_unlock(&dest->svc->stats.lock);
-
-		spin_lock(&ip_vs_stats.lock);
-		ip_vs_stats.ustats.inpkts++;
-		ip_vs_stats.ustats.inbytes += skb->len;
-		spin_unlock(&ip_vs_stats.lock);
+		struct ip_vs_cpu_stats *s;
+
+		s = this_cpu_ptr(dest->stats.cpustats);
+		s->ustats.inpkts++;
+		u64_stats_update_begin(&s->syncp);
+		s->ustats.inbytes += skb->len;
+		u64_stats_update_end(&s->syncp);
+
+		s = this_cpu_ptr(dest->svc->stats.cpustats);
+		s->ustats.inpkts++;
+		u64_stats_update_begin(&s->syncp);
+		s->ustats.inbytes += skb->len;
+		u64_stats_update_end(&s->syncp);
+
+		s = this_cpu_ptr(ipvs->cpustats);
+		s->ustats.inpkts++;
+		u64_stats_update_begin(&s->syncp);
+		s->ustats.inbytes += skb->len;
+		u64_stats_update_end(&s->syncp);
 	}
 }
 
@@ -138,39 +145,46 @@ static inline void
 ip_vs_out_stats(struct ip_vs_conn *cp, struct sk_buff *skb)
 {
 	struct ip_vs_dest *dest = cp->dest;
+	struct netns_ipvs *ipvs = net_ipvs(skb_net(skb));
+
 	if (dest && (dest->flags & IP_VS_DEST_F_AVAILABLE)) {
-		spin_lock(&dest->stats.lock);
-		dest->stats.ustats.outpkts++;
-		dest->stats.ustats.outbytes += skb->len;
-		spin_unlock(&dest->stats.lock);
-
-		spin_lock(&dest->svc->stats.lock);
-		dest->svc->stats.ustats.outpkts++;
-		dest->svc->stats.ustats.outbytes += skb->len;
-		spin_unlock(&dest->svc->stats.lock);
-
-		spin_lock(&ip_vs_stats.lock);
-		ip_vs_stats.ustats.outpkts++;
-		ip_vs_stats.ustats.outbytes += skb->len;
-		spin_unlock(&ip_vs_stats.lock);
+		struct ip_vs_cpu_stats *s;
+
+		s = this_cpu_ptr(dest->stats.cpustats);
+		s->ustats.outpkts++;
+		u64_stats_update_begin(&s->syncp);
+		s->ustats.outbytes += skb->len;
+		u64_stats_update_end(&s->syncp);
+
+		s = this_cpu_ptr(dest->svc->stats.cpustats);
+		s->ustats.outpkts++;
+		u64_stats_update_begin(&s->syncp);
+		s->ustats.outbytes += skb->len;
+		u64_stats_update_end(&s->syncp);
+
+		s = this_cpu_ptr(ipvs->cpustats);
+		s->ustats.outpkts++;
+		u64_stats_update_begin(&s->syncp);
+		s->ustats.outbytes += skb->len;
+		u64_stats_update_end(&s->syncp);
 	}
 }
 
 
 static inline void
 ip_vs_conn_stats(struct ip_vs_conn *cp, struct ip_vs_service *svc)
 {
-	spin_lock(&cp->dest->stats.lock);
-	cp->dest->stats.ustats.conns++;
-	spin_unlock(&cp->dest->stats.lock);
+	struct netns_ipvs *ipvs = net_ipvs(svc->net);
+	struct ip_vs_cpu_stats *s;
 
-	spin_lock(&svc->stats.lock);
-	svc->stats.ustats.conns++;
-	spin_unlock(&svc->stats.lock);
+	s = this_cpu_ptr(cp->dest->stats.cpustats);
+	s->ustats.conns++;
 
-	spin_lock(&ip_vs_stats.lock);
-	ip_vs_stats.ustats.conns++;
-	spin_unlock(&ip_vs_stats.lock);
+	s = this_cpu_ptr(svc->stats.cpustats);
+	s->ustats.conns++;
+
+	s = this_cpu_ptr(ipvs->cpustats);
+	s->ustats.conns++;
 }
 
 
@@ -1841,7 +1855,6 @@ static struct nf_hook_ops ip_vs_ops[] __read_mostly = {
 	},
 #endif
 };
-
 /*
  *	Initialize IP Virtual Server netns mem.
  */