[TCP]: SACK fastpath did override adjusted fackets_out

Do same adjustment to SACK fastpath counters provided that
they're valid.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 0 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 53232dd6fb4..20aea1595c4 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -699,6 +699,14 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned int mss
                         tp->fackets_out -= diff;
                         if ((int)tp->fackets_out < 0)
                                 tp->fackets_out = 0;
+                        /* SACK fastpath might overwrite it unless dealt with */
+                        if (tp->fastpath_skb_hint != NULL &&
+                            after(TCP_SKB_CB(tp->fastpath_skb_hint)->seq,
+                                  TCP_SKB_CB(skb)->seq)) {
+                                tp->fastpath_cnt_hint -= diff;
+                                if ((int)tp->fastpath_cnt_hint < 0)
+                                        tp->fastpath_cnt_hint = 0;
+                        }
                 }
         }