Merge branch 'tcp-cwnd-undo-refactor'

Yuchung Cheng says:

====================
tcp cwnd undo refactor

This patch series consolidate similar cwnd undo functions
implemented by various congestion control by using existing
tcp socket state variable. The first patch fixes a corner
case in of cwnd undo in Reno and HTCP. Since the bug has
existed for many years and is very minor, we consider this
patch set more suitable for net-next as the major change
is the refactor itself.

- v1->v2
  Fix trivial compile errors
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 13 deletions

diff --git a/net/ipv4/tcp_bic.c b/net/ipv4/tcp_bic.c
index 609965f0e298..fc3614377413 100644
--- a/net/ipv4/tcp_bic.c
+++ b/net/ipv4/tcp_bic.c
@@ -49,7 +49,6 @@ MODULE_PARM_DESC(smooth_part, "log(B/(B*Smin))/log(B/(B-1))+B, # of RTT from Wma
 struct bictcp {
 	u32	cnt;		/* increase cwnd by 1 after ACKs */
 	u32	last_max_cwnd;	/* last maximum snd_cwnd */
-	u32	loss_cwnd;	/* congestion window at last loss */
 	u32	last_cwnd;	/* the last snd_cwnd */
 	u32	last_time;	/* time when updated last_cwnd */
 	u32	epoch_start;	/* beginning of an epoch */
@@ -72,7 +71,6 @@ static void bictcp_init(struct sock *sk)
 	struct bictcp *ca = inet_csk_ca(sk);
 
 	bictcp_reset(ca);
-	ca->loss_cwnd = 0;
 
 	if (initial_ssthresh)
 		tcp_sk(sk)->snd_ssthresh = initial_ssthresh;
@@ -172,22 +170,12 @@ static u32 bictcp_recalc_ssthresh(struct sock *sk)
 	else
 		ca->last_max_cwnd = tp->snd_cwnd;
 
-	ca->loss_cwnd = tp->snd_cwnd;
-
 	if (tp->snd_cwnd <= low_window)
 		return max(tp->snd_cwnd >> 1U, 2U);
 	else
 		return max((tp->snd_cwnd * beta) / BICTCP_BETA_SCALE, 2U);
 }
 
-static u32 bictcp_undo_cwnd(struct sock *sk)
-{
-	const struct tcp_sock *tp = tcp_sk(sk);
-	const struct bictcp *ca = inet_csk_ca(sk);
-
-	return max(tp->snd_cwnd, ca->loss_cwnd);
-}
-
 static void bictcp_state(struct sock *sk, u8 new_state)
 {
 	if (new_state == TCP_CA_Loss)
@@ -214,7 +202,7 @@ static struct tcp_congestion_ops bictcp __read_mostly = {
 	.ssthresh	= bictcp_recalc_ssthresh,
 	.cong_avoid	= bictcp_cong_avoid,
 	.set_state	= bictcp_state,
-	.undo_cwnd	= bictcp_undo_cwnd,
+	.undo_cwnd	= tcp_reno_undo_cwnd,
 	.pkts_acked     = bictcp_acked,
 	.owner		= THIS_MODULE,
 	.name		= "bic",