net: Fix for dst_negative_advice

dst_negative_advice() should check for changed dst and reset
sk_tx_queue_mapping accordingly. Pass sock to the callers of
dst_negative_advice.

(sk_reset_txq is defined just for use by dst_negative_advice. The
only way I could find to get around this is to move dst_negative_()
from dst.h to dst.c, include sock.h in dst.c, etc)

Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/dst.h b/include/net/dst.h
index 5a900dd..720d906 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -222,11 +222,19 @@
 		neigh_confirm(dst->neighbour);
 }
 
-static inline void dst_negative_advice(struct dst_entry **dst_p)
+static inline void dst_negative_advice(struct dst_entry **dst_p,
+				       struct sock *sk)
 {
 	struct dst_entry * dst = *dst_p;
-	if (dst && dst->ops->negative_advice)
+	if (dst && dst->ops->negative_advice) {
 		*dst_p = dst->ops->negative_advice(dst);
+
+		if (dst != *dst_p) {
+			extern void sk_reset_txq(struct sock *sk);
+
+			sk_reset_txq(sk);
+		}
+	}
 }
 
 static inline void dst_link_failure(struct sk_buff *skb)