[NETLINK]: Make netlink_callback->done() optional

Most netlink families make no use of the done() callback, making
it optional gets rid of all unnecessary dummy implementations.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 2 deletions

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 5ca283537bc6..f3fb7e575816 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -427,7 +427,8 @@ static int netlink_release(struct socket *sock)
 
         spin_lock(&nlk->cb_lock);
         if (nlk->cb) {
-                nlk->cb->done(nlk->cb);
+                if (nlk->cb->done)
+                        nlk->cb->done(nlk->cb);
                 netlink_destroy_callback(nlk->cb);
                 nlk->cb = NULL;
         }
@@ -1322,7 +1323,8 @@ static int netlink_dump(struct sock *sk)
         skb_queue_tail(&sk->sk_receive_queue, skb);
         sk->sk_data_ready(sk, skb->len);
 
-        cb->done(cb);
+        if (cb->done)
+                cb->done(cb);
         nlk->cb = NULL;
         spin_unlock(&nlk->cb_lock);