mptcp: introduce and use mptcp_try_coalesce()

Factor-out existing code, will be re-used by the
next patch.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 4f12a8c..5a2ff33 100644 (file)
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -110,6 +110,22 @@ static int __mptcp_socket_create(struct mptcp_sock *msk)
        return 0;
 }
 
+static bool mptcp_try_coalesce(struct sock *sk, struct sk_buff *to,
+                              struct sk_buff *from)
+{
+       bool fragstolen;
+       int delta;
+
+       if (MPTCP_SKB_CB(from)->offset ||
+           !skb_try_coalesce(to, from, &fragstolen, &delta))
+               return false;
+
+       kfree_skb_partial(from, fragstolen);
+       atomic_add(delta, &sk->sk_rmem_alloc);
+       sk_mem_charge(sk, delta);
+       return true;
+}
+
 static void __mptcp_move_skb(struct mptcp_sock *msk, struct sock *ssk,
                             struct sk_buff *skb,
                             unsigned int offset, size_t copy_len)
@@ -121,24 +137,15 @@ static void __mptcp_move_skb(struct mptcp_sock *msk, struct sock *ssk,
 
        skb_ext_reset(skb);
        skb_orphan(skb);
+       MPTCP_SKB_CB(skb)->offset = offset;
        msk->ack_seq += copy_len;
 
        tail = skb_peek_tail(&sk->sk_receive_queue);
-       if (offset == 0 && tail) {
-               bool fragstolen;
-               int delta;
-
-               if (skb_try_coalesce(tail, skb, &fragstolen, &delta)) {
-                       kfree_skb_partial(skb, fragstolen);
-                       atomic_add(delta, &sk->sk_rmem_alloc);
-                       sk_mem_charge(sk, delta);
-                       return;
-               }
-       }
+       if (tail && mptcp_try_coalesce(sk, tail, skb))
+               return;
 
        skb_set_owner_r(skb, sk);
        __skb_queue_tail(&sk->sk_receive_queue, skb);
-       MPTCP_SKB_CB(skb)->offset = offset;
 }
 
 static void mptcp_stop_timer(struct sock *sk)