3 files changed, 31 insertions, 1 deletions

diff --git a/include/net/inetpeer.h b/include/net/inetpeer.h
index d432489e7109..e15c0862a686 100644
--- a/include/net/inetpeer.h
+++ b/include/net/inetpeer.h
@@ -68,6 +68,7 @@ struct inet_peer {
 struct inet_peer_base {
         struct inet_peer __rcu  *root;
         seqlock_t               lock;
+        u32                     flush_seq;
         int                     total;
 };
 
@@ -168,6 +169,7 @@ extern void inet_putpeer(struct inet_peer *p);
 extern bool inet_peer_xrlim_allow(struct inet_peer *peer, int timeout);
 
 extern void inetpeer_invalidate_tree(struct inet_peer_base *);
+extern void inetpeer_invalidate_family(int family);
 
 /*
  * temporary check to make sure we dont access rid, ip_id_count, tcp_ts,
diff --git a/net/ipv4/inetpeer.c b/net/ipv4/inetpeer.c
index e4cba56a5349..cac02ad1425d 100644
--- a/net/ipv4/inetpeer.c
+++ b/net/ipv4/inetpeer.c
@@ -86,10 +86,36 @@ void inet_peer_base_init(struct inet_peer_base *bp)
 {
         bp->root = peer_avl_empty_rcu;
         seqlock_init(&bp->lock);
+        bp->flush_seq = ~0U;
         bp->total = 0;
 }
 EXPORT_SYMBOL_GPL(inet_peer_base_init);
 
+static atomic_t v4_seq = ATOMIC_INIT(0);
+static atomic_t v6_seq = ATOMIC_INIT(0);
+
+static atomic_t *inetpeer_seq_ptr(int family)
+{
+        return (family == AF_INET ? &v4_seq : &v6_seq);
+}
+
+static inline void flush_check(struct inet_peer_base *base, int family)
+{
+        atomic_t *fp = inetpeer_seq_ptr(family);
+
+        if (unlikely(base->flush_seq != atomic_read(fp))) {
+                inetpeer_invalidate_tree(base);
+                base->flush_seq = atomic_read(fp);
+        }
+}
+
+void inetpeer_invalidate_family(int family)
+{
+        atomic_t *fp = inetpeer_seq_ptr(family);
+
+        atomic_inc(fp);
+}
+
 #define PEER_MAXDEPTH 40 /* sufficient for about 2^27 nodes */
 
 /* Exported for sysctl_net_ipv4.  */
@@ -437,6 +463,8 @@ struct inet_peer *inet_getpeer(struct inet_peer_base *base,
         unsigned int sequence;
         int invalidated, gccnt = 0;
 
+        flush_check(base, daddr->family);
+
         /* Attempt a lockless lookup first.
          * Because of a concurrent writer, we might not find an existing entry.
          */
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 4f5834c4a667..456a9470fb54 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -935,7 +935,7 @@ static void rt_cache_invalidate(struct net *net)
 
         get_random_bytes(&shuffle, sizeof(shuffle));
         atomic_add(shuffle + 1U, &net->ipv4.rt_genid);
-        inetpeer_invalidate_tree(net->ipv4.peers);
+        inetpeer_invalidate_family(AF_INET);
 }
 
 /*