Commit b3de7559 authored Sep 24, 2010 by Yuchung Cheng Committed by David S. Miller Sep 27, 2010

tcp: fix TSO FACK loss marking in tcp_mark_head_lost



When TCP uses FACK algorithm to mark lost packets in
tcp_mark_head_lost(), if the number of packets in the (TSO) skb is
greater than the number of packets that should be marked lost, TCP
incorrectly exits the loop and marks no packets lost in the skb. This
underestimates tp->lost_out and affects the recovery/retransmission.
This patch fargments the skb and marks the correct amount of packets
lost.

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 3fd6c88e

net/ipv4/tcp_input.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -2545,7 +2545,8 @@ static void tcp_mark_head_lost(struct sock *sk, int packets)
		cnt += tcp_skb_pcount(skb);

		if (cnt > packets) {
		if (tcp_is_sack(tp) \|\| (oldcnt >= packets))
		if ((tcp_is_sack(tp) && !tcp_is_fack(tp)) \|\|
		(oldcnt >= packets))
		break;

		mss = skb_shinfo(skb)->gso_size;

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