datapath: rhel: Move RHEL OVS hook registration to netdev_rx_handler_…

…register() backport Moves the registration of the RHEL specific OVS hook to the compat backport of netdev_rx_handler_register(). This moves the hook unregistration from the RCU callback to the netdev_destroy() callback directly. This is purely cosmetic though, the RHEL hook is only used if the IFF_OVS_DATAPATH flag is present which was removed under RTNL protection before the RCU callback. Signed-off-by: Thomas Graf <[email protected]> Signed-off-by: Jesse Gross <[email protected]>
yqnt418 · Jul 9, 2013 · 3e35fe3 · 3e35fe3
1 parent 752378e
commit 3e35fe3
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Showing 3 changed files with 24 additions and 21 deletions.
diff --git a/datapath/linux/compat/include/linux/netdevice.h b/datapath/linux/compat/include/linux/netdevice.h
@@ -20,6 +20,11 @@ struct net;
 #define to_net_dev(class) container_of(class, struct net_device, NETDEV_DEV_MEMBER)
 #endif
 
+#ifdef HAVE_RHEL_OVS_HOOK
+extern struct sk_buff *(*openvswitch_handle_frame_hook)(struct sk_buff *skb);
+extern int nr_bridges;
+#endif
+
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,26)
 static inline
 struct net *dev_net(const struct net_device *dev)
@@ -84,19 +89,33 @@ extern int skb_checksum_help(struct sk_buff *skb, int);
 extern int skb_checksum_help(struct sk_buff *skb);
 #endif
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,36)
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,36) || \
+    defined HAVE_RHEL_OVS_HOOK
 static inline int netdev_rx_handler_register(struct net_device *dev,
 					     void *rx_handler,
 					     void *rx_handler_data)
 {
+#ifdef HAVE_RHEL_OVS_HOOK
+	rcu_assign_pointer(dev->ax25_ptr, rx_handler_data);
+	nr_bridges++;
+	rcu_assign_pointer(openvswitch_handle_frame_hook, rx_handler_data);
+#else
 	if (dev->br_port)
 		return -EBUSY;
 	rcu_assign_pointer(dev->br_port, rx_handler_data);
+#endif
 	return 0;
 }
 static inline void netdev_rx_handler_unregister(struct net_device *dev)
 {
+#ifdef HAVE_RHEL_OVS_HOOK
+	rcu_assign_pointer(dev->ax25_ptr, NULL);
+
+	if (--nr_bridges <= 0)
+		rcu_assign_pointer(openvswitch_handle_frame_hook, NULL);
+#else
 	rcu_assign_pointer(dev->br_port, NULL);
+#endif
 }
 #endif
 

diff --git a/datapath/linux/compat/netdevice.c b/datapath/linux/compat/netdevice.c
@@ -1,6 +1,10 @@
 #include <linux/netdevice.h>
 #include <linux/if_vlan.h>
 
+#ifdef HAVE_RHEL_OVS_HOOK
+int nr_bridges = 0;
+#endif
+
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,38)
 #ifndef HAVE_CAN_CHECKSUM_PROTOCOL
 static bool can_checksum_protocol(unsigned long features, __be16 protocol)

diff --git a/datapath/vport-netdev.c b/datapath/vport-netdev.c
@@ -45,12 +45,6 @@ MODULE_PARM_DESC(vlan_tso, "Enable TSO for VLAN packets");
 #define vlan_tso true
 #endif
 
-#ifdef HAVE_RHEL_OVS_HOOK
-static atomic_t nr_bridges = ATOMIC_INIT(0);
-
-extern struct sk_buff *(*openvswitch_handle_frame_hook)(struct sk_buff *skb);
-#endif
-
 static void netdev_port_receive(struct vport *vport, struct sk_buff *skb);
 
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,39)
@@ -171,16 +165,10 @@ static struct vport *netdev_create(const struct vport_parms *parms)
 	}
 
 	rtnl_lock();
-#ifdef HAVE_RHEL_OVS_HOOK
-	rcu_assign_pointer(netdev_vport->dev->ax25_ptr, vport);
-	atomic_inc(&nr_bridges);
-	rcu_assign_pointer(openvswitch_handle_frame_hook, netdev_frame_hook);
-#else
 	err = netdev_rx_handler_register(netdev_vport->dev, netdev_frame_hook,
 					 vport);
 	if (err)
 		goto error_unlock;
-#endif
 
 	dev_set_promiscuity(netdev_vport->dev, 1);
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,24)
@@ -192,9 +180,7 @@ static struct vport *netdev_create(const struct vport_parms *parms)
 	netdev_init();
 	return vport;
 
-#ifndef HAVE_RHEL_OVS_HOOK
 error_unlock:
-#endif
 	rtnl_unlock();
 error_put:
 	dev_put(netdev_vport->dev);
@@ -209,12 +195,6 @@ static void free_port_rcu(struct rcu_head *rcu)
 	struct netdev_vport *netdev_vport = container_of(rcu,
 					struct netdev_vport, rcu);
 
-#ifdef HAVE_RHEL_OVS_HOOK
-	rcu_assign_pointer(netdev_vport->dev->ax25_ptr, NULL);
-
-	if (atomic_dec_and_test(&nr_bridges))
-		rcu_assign_pointer(openvswitch_handle_frame_hook, NULL);
-#endif
 	dev_put(netdev_vport->dev);
 	ovs_vport_free(vport_from_priv(netdev_vport));
 }