Commit 9cd8b6c9 authored by Yuchung Cheng's avatar Yuchung Cheng Committed by David S. Miller
Browse files

tcp: account total lost packets properly 



The retransmission refactoring patch
68698970 ("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: 68698970 ("tcp: simplify tcp_mark_skb_lost")
Reported-by: default avatarNeal Cardwell <ncardwell@google.com>
Signed-off-by: default avatarYuchung Cheng <ycheng@google.com>
Signed-off-by: default avatarNeal Cardwell <ncardwell@google.com>
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 223b32db

net/ipv4/tcp_input.c

+10 −0
Original line number Diff line number Diff line
@@ -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);

	}

}