1 files changed, 24 insertions, 3 deletions

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index f030435e0eb4..f893e90061eb 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -555,6 +555,16 @@ static void tcp_event_data_recv(struct sock *sk, struct sk_buff *skb)
                 tcp_grow_window(sk, skb);
 }
 
+static u32 tcp_rto_min(struct sock *sk)
+{
+        struct dst_entry *dst = __sk_dst_get(sk);
+        u32 rto_min = TCP_RTO_MIN;
+
+        if (dst && dst_metric_locked(dst, RTAX_RTO_MIN))
+                rto_min = dst->metrics[RTAX_RTO_MIN-1];
+        return rto_min;
+}
+
 /* Called to compute a smoothed rtt estimate. The data fed to this
  * routine either comes from timestamps, or from segments that were
  * known _not_ to have been retransmitted [see Karn/Partridge
@@ -616,13 +626,13 @@ static void tcp_rtt_estimator(struct sock *sk, const __u32 mrtt)
                         if (tp->mdev_max < tp->rttvar)
                                 tp->rttvar -= (tp->rttvar-tp->mdev_max)>>2;
                         tp->rtt_seq = tp->snd_nxt;
-                        tp->mdev_max = TCP_RTO_MIN;
+                        tp->mdev_max = tcp_rto_min(sk);
                 }
         } else {
                 /* no previous measure. */
                 tp->srtt = m<<3;        /* take the measured time to be rtt */
                 tp->mdev = m<<1;        /* make sure rto = 3*rtt */
-                tp->mdev_max = tp->rttvar = max(tp->mdev, TCP_RTO_MIN);
+                tp->mdev_max = tp->rttvar = max(tp->mdev, tcp_rto_min(sk));
                 tp->rtt_seq = tp->snd_nxt;
         }
 }
@@ -755,7 +765,15 @@ void tcp_update_metrics(struct sock *sk)
         }
 }
 
-/* Numbers are taken from RFC2414.  */
+/* Numbers are taken from RFC3390.
+ *
+ * John Heffner states:
+ *
+ *      The RFC specifies a window of no more than 4380 bytes
+ *      unless 2*MSS > 4380.  Reading the pseudocode in the RFC
+ *      is a bit misleading because they use a clamp at 4380 bytes
+ *      rather than use a multiplier in the relevant range.
+ */
 __u32 tcp_init_cwnd(struct tcp_sock *tp, struct dst_entry *dst)
 {
         __u32 cwnd = (dst ? dst_metric(dst, RTAX_INITCWND) : 0);
@@ -2402,6 +2420,9 @@ static int tcp_tso_acked(struct sock *sk, struct sk_buff *skb,
                         __u32 dval = min(tp->fackets_out, packets_acked);
                         tp->fackets_out -= dval;
                 }
+                /* hint's skb might be NULL but we don't need to care */
+                tp->fastpath_cnt_hint -= min_t(u32, packets_acked,
+                                               tp->fastpath_cnt_hint);
                 tp->packets_out -= packets_acked;
 
                 BUG_ON(tcp_skb_pcount(skb) == 0);