diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 813f2049b85d..7d843c429381 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -1765,6 +1765,20 @@ static inline void tcp_reset_reno_sack(struct tcp_sock *tp) tp->left_out = tp->lost_out; } +/* RFC: This is from the original, I doubt that this is necessary at all: + * clear xmit_retrans hint if seq of this skb is beyond hint. How could we + * retransmitted past LOST markings in the first place? I'm not fully sure + * about undo and end of connection cases, which can cause R without L? + */ +static void tcp_verify_retransmit_hint(struct tcp_sock *tp, + struct sk_buff *skb) +{ + if ((tp->retransmit_skb_hint != NULL) && + before(TCP_SKB_CB(skb)->seq, + TCP_SKB_CB(tp->retransmit_skb_hint)->seq)) + tp->retransmit_skb_hint = skb; +} + /* Mark head of queue up as lost. */ static void tcp_mark_head_lost(struct sock *sk, int packets, u32 high_seq) @@ -1795,14 +1809,7 @@ static void tcp_mark_head_lost(struct sock *sk, if (!(TCP_SKB_CB(skb)->sacked&TCPCB_TAGBITS)) { TCP_SKB_CB(skb)->sacked |= TCPCB_LOST; tp->lost_out += tcp_skb_pcount(skb); - - /* clear xmit_retransmit_queue hints - * if this is beyond hint */ - if (tp->retransmit_skb_hint != NULL && - before(TCP_SKB_CB(skb)->seq, - TCP_SKB_CB(tp->retransmit_skb_hint)->seq)) - tp->retransmit_skb_hint = NULL; - + tcp_verify_retransmit_hint(tp, skb); } } tcp_sync_left_out(tp); @@ -1843,13 +1850,7 @@ static void tcp_update_scoreboard(struct sock *sk) if (!(TCP_SKB_CB(skb)->sacked&TCPCB_TAGBITS)) { TCP_SKB_CB(skb)->sacked |= TCPCB_LOST; tp->lost_out += tcp_skb_pcount(skb); - - /* clear xmit_retrans hint */ - if (tp->retransmit_skb_hint && - before(TCP_SKB_CB(skb)->seq, - TCP_SKB_CB(tp->retransmit_skb_hint)->seq)) - - tp->retransmit_skb_hint = NULL; + tcp_verify_retransmit_hint(tp, skb); } }