2 files changed, 30 insertions, 13 deletions

diff --git a/include/net/dst.h b/include/net/dst.h
index 002500e631f5..c5c318a628f8 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -128,6 +128,18 @@ static inline u32 dst_mtu(const struct dst_entry *dst)
         return mtu;
 }
 
+/* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */
+static inline unsigned long dst_metric_rtt(const struct dst_entry *dst, int metric)
+{
+        return msecs_to_jiffies(dst_metric(dst, metric));
+}
+
+static inline void set_dst_metric_rtt(struct dst_entry *dst, int metric,
+                                      unsigned long rtt)
+{
+        dst->metrics[metric-1] = jiffies_to_msecs(rtt);
+}
+
 static inline u32
 dst_allfrag(const struct dst_entry *dst)
 {
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index fac49a6e1611..88810bc01370 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -602,7 +602,7 @@ static u32 tcp_rto_min(struct sock *sk)
         u32 rto_min = TCP_RTO_MIN;
 
         if (dst && dst_metric_locked(dst, RTAX_RTO_MIN))
-                rto_min = dst_metric(dst, RTAX_RTO_MIN);
+                rto_min = dst_metric_rtt(dst, RTAX_RTO_MIN);
         return rto_min;
 }
 
@@ -729,6 +729,7 @@ void tcp_update_metrics(struct sock *sk)
         if (dst && (dst->flags & DST_HOST)) {
                 const struct inet_connection_sock *icsk = inet_csk(sk);
                 int m;
+                unsigned long rtt;
 
                 if (icsk->icsk_backoff || !tp->srtt) {
                         /* This session failed to estimate rtt. Why?
@@ -740,7 +741,8 @@ void tcp_update_metrics(struct sock *sk)
                         return;
                 }
 
-                m = dst_metric(dst, RTAX_RTT) - tp->srtt;
+                rtt = dst_metric_rtt(dst, RTAX_RTT);
+                m = rtt - tp->srtt;
 
                 /* If newly calculated rtt larger than stored one,
                  * store new one. Otherwise, use EWMA. Remember,
@@ -748,12 +750,13 @@ void tcp_update_metrics(struct sock *sk)
                  */
                 if (!(dst_metric_locked(dst, RTAX_RTT))) {
                         if (m <= 0)
-                                dst->metrics[RTAX_RTT - 1] = tp->srtt;
+                                set_dst_metric_rtt(dst, RTAX_RTT, tp->srtt);
                         else
-                                dst->metrics[RTAX_RTT - 1] -= (m >> 3);
+                                set_dst_metric_rtt(dst, RTAX_RTT, rtt - (m >> 3));
                 }
 
                 if (!(dst_metric_locked(dst, RTAX_RTTVAR))) {
+                        unsigned long var;
                         if (m < 0)
                                 m = -m;
 
@@ -762,11 +765,13 @@ void tcp_update_metrics(struct sock *sk)
                         if (m < tp->mdev)
                                 m = tp->mdev;
 
-                        if (m >= dst_metric(dst, RTAX_RTTVAR))
-                                dst->metrics[RTAX_RTTVAR - 1] = m;
+                        var = dst_metric_rtt(dst, RTAX_RTTVAR);
+                        if (m >= var)
+                                var = m;
                         else
-                                dst->metrics[RTAX_RTTVAR-1] -=
-                                        (dst_metric(dst, RTAX_RTTVAR) - m)>>2;
+                                var -= (var - m) >> 2;
+
+                        set_dst_metric_rtt(dst, RTAX_RTTVAR, var);
                 }
 
                 if (tp->snd_ssthresh >= 0xFFFF) {
@@ -897,7 +902,7 @@ static void tcp_init_metrics(struct sock *sk)
         if (dst_metric(dst, RTAX_RTT) == 0)
                 goto reset;
 
-        if (!tp->srtt && dst_metric(dst, RTAX_RTT) < (TCP_TIMEOUT_INIT << 3))
+        if (!tp->srtt && dst_metric_rtt(dst, RTAX_RTT) < (TCP_TIMEOUT_INIT << 3))
                 goto reset;
 
         /* Initial rtt is determined from SYN,SYN-ACK.
@@ -914,12 +919,12 @@ static void tcp_init_metrics(struct sock *sk)
          * to low value, and then abruptly stops to do it and starts to delay
          * ACKs, wait for troubles.
          */
-        if (dst_metric(dst, RTAX_RTT) > tp->srtt) {
-                tp->srtt = dst_metric(dst, RTAX_RTT);
+        if (dst_metric_rtt(dst, RTAX_RTT) > tp->srtt) {
+                tp->srtt = dst_metric_rtt(dst, RTAX_RTT);
                 tp->rtt_seq = tp->snd_nxt;
         }
-        if (dst_metric(dst, RTAX_RTTVAR) > tp->mdev) {
-                tp->mdev = dst_metric(dst, RTAX_RTTVAR);
+        if (dst_metric_rtt(dst, RTAX_RTTVAR) > tp->mdev) {
+                tp->mdev = dst_metric_rtt(dst, RTAX_RTTVAR);
                 tp->mdev_max = tp->rttvar = max(tp->mdev, tcp_rto_min(sk));
         }
         tcp_set_rto(sk);