From: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Date: Sun, 15 Jul 2007 07:19:29 +0000 (-0700)
Subject: [TCP]: Verify the presence of RETRANS bit when leaving FRTO
X-Git-Tag: firefly_0821_release~28250^2
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=0a9f2a467d8dacaf7e97469dba99ed2d07287d80;p=firefly-linux-kernel-4.4.55.git

[TCP]: Verify the presence of RETRANS bit when leaving FRTO

For yet unknown reason, something cleared SACKED_RETRANS bit
underneath FRTO.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 69f9f1ef3ef6..4e5884ac8f29 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1398,7 +1398,9 @@ static void tcp_enter_frto_loss(struct sock *sk, int allowed_segments, int flag)
 		 * waiting for the first ACK and did not get it)...
 		 */
 		if ((tp->frto_counter == 1) && !(flag&FLAG_DATA_ACKED)) {
-			tp->retrans_out += tcp_skb_pcount(skb);
+			/* For some reason this R-bit might get cleared? */
+			if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS)
+				tp->retrans_out += tcp_skb_pcount(skb);
 			/* ...enter this if branch just for the first segment */
 			flag |= FLAG_DATA_ACKED;
 		} else {