From 9cd8b6c90529344694f0d941841c08e2ee5d9a82 Mon Sep 17 00:00:00 2001
From: Yuchung Cheng <ycheng@google.com>
Date: Thu, 1 Oct 2020 14:05:18 -0700
Subject: [PATCH] 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>
---
net/ipv4/tcp_input.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index f7b3e37d2198..20f89078fa8d 100644
--- 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);
}
}
--
2.30.9