tcp: fix stretch ACK bugs in BIC

Changes BIC to properly handle stretch ACKs in additive
increase mode by passing in the count of ACKed packets
to tcp_cong_avoid_ai().

Signed-off-by: Pengcheng Yang <yangpc@wangsu.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/tcp_bic.c b/net/ipv4/tcp_bic.c
index 645cc30..f5f588b 100644 (file)
--- a/net/ipv4/tcp_bic.c
+++ b/net/ipv4/tcp_bic.c
@@ -145,12 +145,13 @@ static void bictcp_cong_avoid(struct sock *sk, u32 ack, u32 acked)
        if (!tcp_is_cwnd_limited(sk))
                return;
 
-       if (tcp_in_slow_start(tp))
-               tcp_slow_start(tp, acked);
-       else {
-               bictcp_update(ca, tp->snd_cwnd);
-               tcp_cong_avoid_ai(tp, ca->cnt, 1);
+       if (tcp_in_slow_start(tp)) {
+               acked = tcp_slow_start(tp, acked);
+               if (!acked)
+                       return;
        }
+       bictcp_update(ca, tp->snd_cwnd);
+       tcp_cong_avoid_ai(tp, ca->cnt, acked);
 }
 
 /*