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>
diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h
index 4265b5e..605d5db 100644
--- a/include/net/ip_vs.h
+++ b/include/net/ip_vs.h
@@ -90,6 +90,18 @@
 	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 @@
 						   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_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;