1 files changed, 14 insertions, 17 deletions

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index a906e0200ff..f97003ad0af 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1888,21 +1888,21 @@ static inline void tcp_reset_reno_sack(struct tcp_sock *tp)
 	tp->sacked_out = 0;
 }
 
-static void tcp_clear_retrans_partial(struct tcp_sock *tp)
+void tcp_clear_retrans(struct tcp_sock *tp)
 {
 	tp->retrans_out = 0;
 	tp->lost_out = 0;
-
 	tp->undo_marker = 0;
 	tp->undo_retrans = -1;
+	tp->fackets_out = 0;
+	tp->sacked_out = 0;
 }
 
-void tcp_clear_retrans(struct tcp_sock *tp)
+static inline void tcp_init_undo(struct tcp_sock *tp)
 {
-	tcp_clear_retrans_partial(tp);
-
-	tp->fackets_out = 0;
-	tp->sacked_out = 0;
+	tp->undo_marker = tp->snd_una;
+	/* Retransmission still in flight may cause DSACKs later. */
+	tp->undo_retrans = tp->retrans_out ? : -1;
 }
 
 /* Enter Loss state. If we detect SACK reneging, forget all SACK information
@@ -1925,18 +1925,18 @@ void tcp_enter_loss(struct sock *sk)
 		tp->prior_ssthresh = tcp_current_ssthresh(sk);
 		tp->snd_ssthresh = icsk->icsk_ca_ops->ssthresh(sk);
 		tcp_ca_event(sk, CA_EVENT_LOSS);
+		tcp_init_undo(tp);
 	}
 	tp->snd_cwnd	   = 1;
 	tp->snd_cwnd_cnt   = 0;
 	tp->snd_cwnd_stamp = tcp_time_stamp;
 
-	tcp_clear_retrans_partial(tp);
+	tp->retrans_out = 0;
+	tp->lost_out = 0;
 
 	if (tcp_is_reno(tp))
 		tcp_reset_reno_sack(tp);
 
-	tp->undo_marker = tp->snd_una;
-
 	skb = tcp_write_queue_head(sk);
 	is_reneg = skb && (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED);
 	if (is_reneg) {
@@ -1950,9 +1950,6 @@ void tcp_enter_loss(struct sock *sk)
 		if (skb == tcp_send_head(sk))
 			break;
 
-		if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS)
-			tp->undo_marker = 0;
-
 		TCP_SKB_CB(skb)->sacked &= (~TCPCB_TAGBITS)|TCPCB_SACKED_ACKED;
 		if (!(TCP_SKB_CB(skb)->sacked&TCPCB_SACKED_ACKED) || is_reneg) {
 			TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_ACKED;
@@ -2671,8 +2668,7 @@ static void tcp_enter_recovery(struct sock *sk, bool ece_ack)
 	NET_INC_STATS_BH(sock_net(sk), mib_idx);
 
 	tp->prior_ssthresh = 0;
-	tp->undo_marker = tp->snd_una;
-	tp->undo_retrans = tp->retrans_out ? : -1;
+	tcp_init_undo(tp);
 
 	if (inet_csk(sk)->icsk_ca_state < TCP_CA_CWR) {
 		if (!ece_ack)
@@ -2971,7 +2967,8 @@ void tcp_rearm_rto(struct sock *sk)
 		if (icsk->icsk_pending == ICSK_TIME_EARLY_RETRANS ||
 		    icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) {
 			struct sk_buff *skb = tcp_write_queue_head(sk);
-			const u32 rto_time_stamp = TCP_SKB_CB(skb)->when + rto;
+			const u32 rto_time_stamp =
+				tcp_skb_timestamp(skb) + rto;
 			s32 delta = (s32)(rto_time_stamp - tcp_time_stamp);
 			/* delta may not be positive if the socket is locked
 			 * when the retrans timer fires and is rescheduled.
@@ -5910,7 +5907,7 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
 	struct request_sock *req;
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct dst_entry *dst = NULL;
-	__u32 isn = TCP_SKB_CB(skb)->when;
+	__u32 isn = TCP_SKB_CB(skb)->tcp_tw_isn;
 	bool want_cookie = false, fastopen;
 	struct flowi fl;
 	struct tcp_fastopen_cookie foc = { .len = -1 };