[NET]: rtnl_unlock cleanups

There is no need to process outstanding netlink user->kernel packets
during rtnl_unlock now. There is no rtnl_trylock in the rtnetlink_rcv
anymore.

Normal code path is the following:
netlink_sendmsg
   netlink_unicast
       netlink_sendskb
           skb_queue_tail
           netlink_data_ready
               rtnetlink_rcv
                   mutex_lock(&rtnl_mutex);
                   netlink_run_queue(sk, qlen, &rtnetlink_rcv_msg);
                   mutex_unlock(&rtnl_mutex);

So, it is possible, that packets can be present in the rtnl->sk_receive_queue
during rtnl_unlock, but there is no need to process them at that moment as
rtnetlink_rcv for that packet is pending.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Acked-by: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 6 deletions

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 739fbad15c6..471d2d9f8ea 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -75,8 +75,6 @@ void __rtnl_unlock(void)
 void rtnl_unlock(void)
 {
         mutex_unlock(&rtnl_mutex);
-        if (rtnl && rtnl->sk_receive_queue.qlen)
-                rtnl->sk_data_ready(rtnl, 0);
         netdev_run_todo();
 }
 
@@ -1319,11 +1317,9 @@ static void rtnetlink_rcv(struct sock *sk, int len)
         unsigned int qlen = 0;
 
         do {
-                mutex_lock(&rtnl_mutex);
+                rtnl_lock();
                 qlen = netlink_run_queue(sk, qlen, &rtnetlink_rcv_msg);
-                mutex_unlock(&rtnl_mutex);
-
-                netdev_run_todo();
+                rtnl_unlock();
         } while (qlen);
 }