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tcp: account total lost packets properly

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The retransmission refactoring patch
686989700c ("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: 686989700c ("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>
This commit is contained in:
Yuchung Cheng 2020-10-01 14:05:18 -07:00 committed by David S. Miller
parent 223b32db00
commit 9cd8b6c905
1 changed files with 10 additions and 0 deletions
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10
net/ipv4/tcp_input.c
View File

@ -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);
}
}