diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index d6edb98fd526b6471c34dd197d8c429a5c9ffb9f..b54d9d37b636a79b26de0f0ee36e9f6024ba453e 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -1842,9 +1842,16 @@ static void tcp_enter_frto_loss(struct sock *sk, int allowed_segments, int flag) TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS; } - /* Don't lost mark skbs that were fwd transmitted after RTO */ - if (!(TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED) && - !after(TCP_SKB_CB(skb)->end_seq, tp->frto_highmark)) { + /* Marking forward transmissions that were made after RTO lost + * can cause unnecessary retransmissions in some scenarios, + * SACK blocks will mitigate that in some but not in all cases. + * We used to not mark them but it was causing break-ups with + * receivers that do only in-order receival. + * + * TODO: we could detect presence of such receiver and select + * different behavior per flow. + */ + if (!(TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)) { TCP_SKB_CB(skb)->sacked |= TCPCB_LOST; tp->lost_out += tcp_skb_pcount(skb); } @@ -1860,7 +1867,7 @@ static void tcp_enter_frto_loss(struct sock *sk, int allowed_segments, int flag) tp->reordering = min_t(unsigned int, tp->reordering, sysctl_tcp_reordering); tcp_set_ca_state(sk, TCP_CA_Loss); - tp->high_seq = tp->frto_highmark; + tp->high_seq = tp->snd_nxt; TCP_ECN_queue_cwr(tp); tcp_clear_retrans_hints_partial(tp);