tcp: tcp_mark_head_lost is only valid for sack-tcp (636ef28d) · Commits · 戴 / test

net/ipv4/tcp_input.c

+7 −25

Original line number	Diff line number	Diff line
		@@ -2183,8 +2183,7 @@ static bool tcp_time_to_recover(struct sock *sk, int flag)
		}

		/* Detect loss in event "A" above by marking head of queue up as lost.
		* For non-SACK(Reno) senders, the first "packets" number of segments
		* are considered lost. For RFC3517 SACK, a segment is considered lost if it
		* For RFC3517 SACK, a segment is considered lost if it
		* has at least tp->reordering SACKed seqments above it; "packets" refers to
		* the maximum SACKed segments to pass before reaching this limit.
		*/
		@@ -2192,10 +2191,9 @@ static void tcp_mark_head_lost(struct sock *sk, int packets, int mark_head)
		{
		struct tcp_sock *tp = tcp_sk(sk);
		struct sk_buff *skb;
		int cnt, oldcnt, lost;
		unsigned int mss;
		int cnt;
		/* Use SACK to deduce losses of new sequences sent during recovery */
		const u32 loss_high = tcp_is_sack(tp) ? tp->snd_nxt : tp->high_seq;
		const u32 loss_high = tp->snd_nxt;

		WARN_ON(packets > tp->packets_out);
		skb = tp->lost_skb_hint;
		@@ -2218,26 +2216,11 @@ static void tcp_mark_head_lost(struct sock *sk, int packets, int mark_head)
		if (after(TCP_SKB_CB(skb)->end_seq, loss_high))
		break;

		oldcnt = cnt;
		if (tcp_is_reno(tp) \|\|
		(TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED))
		if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)
		cnt += tcp_skb_pcount(skb);

		if (cnt > packets) {
		if (tcp_is_sack(tp) \|\|
		(TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED) \|\|
		(oldcnt >= packets))
		break;

		mss = tcp_skb_mss(skb);
		/* If needed, chop off the prefix to mark as lost. */
		lost = (packets - oldcnt) * mss;
		if (lost < skb->len &&
		tcp_fragment(sk, TCP_FRAG_IN_RTX_QUEUE, skb,
		lost, mss, GFP_ATOMIC) < 0)
		if (cnt > packets)
		break;
		cnt = packets;
		}

		tcp_skb_mark_lost(tp, skb);

		@@ -2849,8 +2832,7 @@ static void tcp_fastretrans_alert(struct sock *sk, const u32 prior_snd_una,
		if (tcp_try_undo_partial(sk, prior_snd_una))
		return;
		/* Partial ACK arrived. Force fast retransmit. */
		do_lost = tcp_is_reno(tp) \|\|
		tcp_force_fast_retransmit(sk);
		do_lost = tcp_force_fast_retransmit(sk);
		}
		if (tcp_try_undo_dsack(sk)) {
		tcp_try_keep_open(sk);

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