tcp: account total lost packets properly

The retransmission refactoring patch
686989700cab ("tcp: simplify tcp_mark_skb_lost")
does not properly update the total lost packet counter which may
break the policer mode in BBR. This patch fixes it.

Fixes: 686989700cab ("tcp: simplify tcp_mark_skb_lost")
Reported-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index f7b3e37..20f8907 100644 (file)
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1020,6 +1020,14 @@ static void tcp_verify_retransmit_hint(struct tcp_sock *tp, struct sk_buff *skb)
                tp->retransmit_skb_hint = skb;
 }
 
+/* Sum the number of packets on the wire we have marked as lost, and
+ * notify the congestion control module that the given skb was marked lost.
+ */
+static void tcp_notify_skb_loss_event(struct tcp_sock *tp, const struct sk_buff *skb)
+{
+       tp->lost += tcp_skb_pcount(skb);
+}
+
 void tcp_mark_skb_lost(struct sock *sk, struct sk_buff *skb)
 {
        __u8 sacked = TCP_SKB_CB(skb)->sacked;
@@ -1036,10 +1044,12 @@ void tcp_mark_skb_lost(struct sock *sk, struct sk_buff *skb)
                        tp->retrans_out -= tcp_skb_pcount(skb);
                        NET_ADD_STATS(sock_net(sk), LINUX_MIB_TCPLOSTRETRANSMIT,
                                      tcp_skb_pcount(skb));
+                       tcp_notify_skb_loss_event(tp, skb);
                }
        } else {
                tp->lost_out += tcp_skb_pcount(skb);
                TCP_SKB_CB(skb)->sacked |= TCPCB_LOST;
+               tcp_notify_skb_loss_event(tp, skb);
        }
 }