[TCP]: Move TSO mss calcs to tcp_current_mss()

Based upon a bug fix patch and suggestions from
Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 85518e0b4e83615e9ba0d22dbfa59bfa9da66883..0ba99de0eb90878c0407ad378539b26953a8d403 100644 (file)
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -639,25 +639,6 @@ unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu)
        tp->pmtu_cookie = pmtu;
        tp->mss_cache = tp->mss_cache_std = mss_now;
 
-       if (sk->sk_route_caps & NETIF_F_TSO) {
-               int large_mss, factor;
-
-               large_mss = 65535 - tp->af_specific->net_header_len -
-                       tp->ext_header_len - tp->ext2_header_len - tp->tcp_header_len;
-
-               if (tp->max_window && large_mss > (tp->max_window>>1))
-                       large_mss = max((tp->max_window>>1), 68U - tp->tcp_header_len);
-
-               /* Always keep large mss multiple of real mss, but
-                * do not exceed congestion window.
-                */
-               factor = large_mss / mss_now;
-               if (factor > tp->snd_cwnd)
-                       factor = tp->snd_cwnd;
-
-               tp->mss_cache = mss_now * factor;
-       }
-
        return mss_now;
 }
 
@@ -675,17 +656,41 @@ unsigned int tcp_current_mss(struct sock *sk, int large)
        struct dst_entry *dst = __sk_dst_get(sk);
        int do_large, mss_now;
 
-       do_large = (large &&
-                   (sk->sk_route_caps & NETIF_F_TSO) &&
-                   !tp->urg_mode);
-       mss_now = do_large ? tp->mss_cache : tp->mss_cache_std;
-
+       mss_now = tp->mss_cache_std;
        if (dst) {
                u32 mtu = dst_pmtu(dst);
                if (mtu != tp->pmtu_cookie ||
                    tp->ext2_header_len != dst->header_len)
                        mss_now = tcp_sync_mss(sk, mtu);
        }
+
+       do_large = (large &&
+                   (sk->sk_route_caps & NETIF_F_TSO) &&
+                   !tp->urg_mode);
+
+       if (do_large) {
+               int large_mss, factor;
+
+               large_mss = 65535 - tp->af_specific->net_header_len -
+                       tp->ext_header_len - tp->ext2_header_len -
+                       tp->tcp_header_len;
+
+               if (tp->max_window && large_mss > (tp->max_window>>1))
+                       large_mss = max((tp->max_window>>1),
+                                       68U - tp->tcp_header_len);
+
+               /* Always keep large mss multiple of real mss, but
+                * do not exceed congestion window.
+                */
+               factor = large_mss / mss_now;
+               if (factor > tp->snd_cwnd)
+                       factor = tp->snd_cwnd;
+
+               tp->mss_cache = mss_now * factor;
+
+               mss_now = tp->mss_cache;
+       }
+
        if (tp->eff_sacks)
                mss_now -= (TCPOLEN_SACK_BASE_ALIGNED +
                            (tp->eff_sacks * TCPOLEN_SACK_PERBLOCK));