ipvs: make the service replacement more robust

[mirror_ubuntu-zesty-kernel.git] / net / netfilter / ipvs / ip_vs_core.c

diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c
index 4f69e83ff836b0ec415342772055a58a52c25fc4..74fd00c272100d5271533689abf074c5f9e8c454 100644 (file)
--- a/net/netfilter/ipvs/ip_vs_core.c
+++ b/net/netfilter/ipvs/ip_vs_core.c
@@ -116,6 +116,7 @@ ip_vs_in_stats(struct ip_vs_conn *cp, struct sk_buff *skb)
 
        if (dest && (dest->flags & IP_VS_DEST_F_AVAILABLE)) {
                struct ip_vs_cpu_stats *s;
+               struct ip_vs_service *svc;
 
                s = this_cpu_ptr(dest->stats.cpustats);
                s->ustats.inpkts++;
@@ -123,11 +124,14 @@ ip_vs_in_stats(struct ip_vs_conn *cp, struct sk_buff *skb)
                s->ustats.inbytes += skb->len;
                u64_stats_update_end(&s->syncp);
 
-               s = this_cpu_ptr(dest->svc->stats.cpustats);
+               rcu_read_lock();
+               svc = rcu_dereference(dest->svc);
+               s = this_cpu_ptr(svc->stats.cpustats);
                s->ustats.inpkts++;
                u64_stats_update_begin(&s->syncp);
                s->ustats.inbytes += skb->len;
                u64_stats_update_end(&s->syncp);
+               rcu_read_unlock();
 
                s = this_cpu_ptr(ipvs->tot_stats.cpustats);
                s->ustats.inpkts++;
@@ -146,6 +150,7 @@ ip_vs_out_stats(struct ip_vs_conn *cp, struct sk_buff *skb)
 
        if (dest && (dest->flags & IP_VS_DEST_F_AVAILABLE)) {
                struct ip_vs_cpu_stats *s;
+               struct ip_vs_service *svc;
 
                s = this_cpu_ptr(dest->stats.cpustats);
                s->ustats.outpkts++;
@@ -153,11 +158,14 @@ ip_vs_out_stats(struct ip_vs_conn *cp, struct sk_buff *skb)
                s->ustats.outbytes += skb->len;
                u64_stats_update_end(&s->syncp);
 
-               s = this_cpu_ptr(dest->svc->stats.cpustats);
+               rcu_read_lock();
+               svc = rcu_dereference(dest->svc);
+               s = this_cpu_ptr(svc->stats.cpustats);
                s->ustats.outpkts++;
                u64_stats_update_begin(&s->syncp);
                s->ustats.outbytes += skb->len;
                u64_stats_update_end(&s->syncp);
+               rcu_read_unlock();
 
                s = this_cpu_ptr(ipvs->tot_stats.cpustats);
                s->ustats.outpkts++;