1 files changed, 13 insertions, 3 deletions

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 20c9440ab85e..0f0c1c9829a1 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1269,6 +1269,9 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_
         if (before(TCP_SKB_CB(ack_skb)->ack_seq, prior_snd_una - tp->max_window))
                 return 0;
 
+        if (!tp->packets_out)
+                goto out;
+
         /* SACK fastpath:
          * if the only SACK change is the increase of the end_seq of
          * the first block then only apply that SACK block
@@ -1515,6 +1518,8 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_
             (!tp->frto_highmark || after(tp->snd_una, tp->frto_highmark)))
                 tcp_update_reordering(sk, tp->fackets_out - reord, 0);
 
+out:
+
 #if FASTRETRANS_DEBUG > 0
         BUG_TRAP((int)tp->sacked_out >= 0);
         BUG_TRAP((int)tp->lost_out >= 0);
@@ -1669,6 +1674,9 @@ void tcp_enter_frto(struct sock *sk)
         }
         tcp_verify_left_out(tp);
 
+        /* Too bad if TCP was application limited */
+        tp->snd_cwnd = min(tp->snd_cwnd, tcp_packets_in_flight(tp) + 1);
+
         /* Earlier loss recovery underway (see RFC4138; Appendix B).
          * The last condition is necessary at least in tp->frto_counter case.
          */
@@ -1701,6 +1709,8 @@ static void tcp_enter_frto_loss(struct sock *sk, int allowed_segments, int flag)
         tcp_for_write_queue(skb, sk) {
                 if (skb == tcp_send_head(sk))
                         break;
+
+                TCP_SKB_CB(skb)->sacked &= ~TCPCB_LOST;
                 /*
                  * Count the retransmission made on RTO correctly (only when
                  * waiting for the first ACK and did not get it)...
@@ -1714,7 +1724,7 @@ static void tcp_enter_frto_loss(struct sock *sk, int allowed_segments, int flag)
                 } else {
                         if (TCP_SKB_CB(skb)->sacked & TCPCB_RETRANS)
                                 tp->undo_marker = 0;
-                        TCP_SKB_CB(skb)->sacked &= ~(TCPCB_LOST|TCPCB_SACKED_RETRANS);
+                        TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS;
                 }
 
                 /* Don't lost mark skbs that were fwd transmitted after RTO */
@@ -3103,11 +3113,11 @@ static int tcp_ack(struct sock *sk, struct sk_buff *skb, int flag)
         /* See if we can take anything off of the retransmit queue. */
         flag |= tcp_clean_rtx_queue(sk, &seq_rtt, prior_fackets);
 
+        if (tp->frto_counter)
+                frto_cwnd = tcp_process_frto(sk, flag);
         /* Guarantee sacktag reordering detection against wrap-arounds */
         if (before(tp->frto_highmark, tp->snd_una))
                 tp->frto_highmark = 0;
-        if (tp->frto_counter)
-                frto_cwnd = tcp_process_frto(sk, flag);
 
         if (tcp_ack_is_dubious(sk, flag)) {
                 /* Advance CWND, if state allows this. */