openvswitch: Simplify datapath locking.

Currently OVS uses combination of genl and rtnl lock to protect
datapath state.  This was done due to networking stack locking.
But this has complicated locking and there are few lock ordering
issues with new tunneling protocols.
Following patch simplifies locking by introducing new ovs mutex
and now this lock is used to protect entire ovs state.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/net/openvswitch/vport-netdev.c b/net/openvswitch/vport-netdev.c
index 2130d61c384a..40a89ae8e19f 100644
--- a/net/openvswitch/vport-netdev.c
+++ b/net/openvswitch/vport-netdev.c
@@ -100,16 +100,20 @@ static struct vport *netdev_create(const struct vport_parms *parms)
                 goto error_put;
         }
 
+        rtnl_lock();
         err = netdev_rx_handler_register(netdev_vport->dev, netdev_frame_hook,
                                          vport);
         if (err)
-                goto error_put;
+                goto error_unlock;
 
         dev_set_promiscuity(netdev_vport->dev, 1);
         netdev_vport->dev->priv_flags |= IFF_OVS_DATAPATH;
+        rtnl_unlock();
 
         return vport;
 
+error_unlock:
+        rtnl_unlock();
 error_put:
         dev_put(netdev_vport->dev);
 error_free_vport:
@@ -131,9 +135,11 @@ static void netdev_destroy(struct vport *vport)
 {
         struct netdev_vport *netdev_vport = netdev_vport_priv(vport);
 
+        rtnl_lock();
         netdev_vport->dev->priv_flags &= ~IFF_OVS_DATAPATH;
         netdev_rx_handler_unregister(netdev_vport->dev);
         dev_set_promiscuity(netdev_vport->dev, -1);
+        rtnl_unlock();
 
         call_rcu(&netdev_vport->rcu, free_port_rcu);
 }