1 files changed, 10 insertions, 2 deletions

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 734cfc8ff76e..9550cc42de2d 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -579,6 +579,7 @@ void tcp_rcv_space_adjust(struct sock *sk)
         int time;
         int copied;
 
+        tcp_mstamp_refresh(tp);
         time = tcp_stamp_us_delta(tp->tcp_mstamp, tp->rcvq_space.time);
         if (time < (tp->rcv_rtt_est.rtt_us >> 3) || tp->rcv_rtt_est.rtt_us == 0)
                 return;
@@ -1941,6 +1942,8 @@ void tcp_enter_loss(struct sock *sk)
         if (is_reneg) {
                 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPSACKRENEGING);
                 tp->sacked_out = 0;
+                /* Mark SACK reneging until we recover from this loss event. */
+                tp->is_sack_reneg = 1;
         }
         tcp_clear_all_retrans_hints(tp);
 
@@ -2326,6 +2329,7 @@ static void tcp_undo_cwnd_reduction(struct sock *sk, bool unmark_loss)
         }
         tp->snd_cwnd_stamp = tcp_jiffies32;
         tp->undo_marker = 0;
+        tp->rack.advanced = 1; /* Force RACK to re-exam losses */
 }
 
 static inline bool tcp_may_undo(const struct tcp_sock *tp)
@@ -2364,6 +2368,7 @@ static bool tcp_try_undo_recovery(struct sock *sk)
                 return true;
         }
         tcp_set_ca_state(sk, TCP_CA_Open);
+        tp->is_sack_reneg = 0;
         return false;
 }
 
@@ -2397,8 +2402,10 @@ static bool tcp_try_undo_loss(struct sock *sk, bool frto_undo)
                         NET_INC_STATS(sock_net(sk),
                                         LINUX_MIB_TCPSPURIOUSRTOS);
                 inet_csk(sk)->icsk_retransmits = 0;
-                if (frto_undo || tcp_is_sack(tp))
+                if (frto_undo || tcp_is_sack(tp)) {
                         tcp_set_ca_state(sk, TCP_CA_Open);
+                        tp->is_sack_reneg = 0;
+                }
                 return true;
         }
         return false;
@@ -3495,6 +3502,7 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
         struct tcp_sacktag_state sack_state;
         struct rate_sample rs = { .prior_delivered = 0 };
         u32 prior_snd_una = tp->snd_una;
+        bool is_sack_reneg = tp->is_sack_reneg;
         u32 ack_seq = TCP_SKB_CB(skb)->seq;
         u32 ack = TCP_SKB_CB(skb)->ack_seq;
         bool is_dupack = false;
@@ -3611,7 +3619,7 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
 
         delivered = tp->delivered - delivered;  /* freshly ACKed or SACKed */
         lost = tp->lost - lost;                 /* freshly marked lost */
-        tcp_rate_gen(sk, delivered, lost, sack_state.rate);
+        tcp_rate_gen(sk, delivered, lost, is_sack_reneg, sack_state.rate);
         tcp_cong_control(sk, ack, delivered, flag, sack_state.rate);
         tcp_xmit_recovery(sk, rexmit);
         return 1;