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, 57 insertions, 25 deletions

diff --git a/net/openvswitch/dp_notify.c b/net/openvswitch/dp_notify.c
index 5558350..ef4feec 100644
--- a/net/openvswitch/dp_notify.c
+++ b/net/openvswitch/dp_notify.c
@@ -18,46 +18,78 @@
 
 #include <linux/netdevice.h>
 #include <net/genetlink.h>
+#include <net/netns/generic.h>
 
 #include "datapath.h"
 #include "vport-internal_dev.h"
 #include "vport-netdev.h"
 
+static void dp_detach_port_notify(struct vport *vport)
+{
+	struct sk_buff *notify;
+	struct datapath *dp;
+
+	dp = vport->dp;
+	notify = ovs_vport_cmd_build_info(vport, 0, 0,
+					  OVS_VPORT_CMD_DEL);
+	ovs_dp_detach_port(vport);
+	if (IS_ERR(notify)) {
+		netlink_set_err(ovs_dp_get_net(dp)->genl_sock, 0,
+				ovs_dp_vport_multicast_group.id,
+				PTR_ERR(notify));
+		return;
+	}
+
+	genlmsg_multicast_netns(ovs_dp_get_net(dp), notify, 0,
+				ovs_dp_vport_multicast_group.id,
+				GFP_KERNEL);
+}
+
+void ovs_dp_notify_wq(struct work_struct *work)
+{
+	struct ovs_net *ovs_net = container_of(work, struct ovs_net, dp_notify_work);
+	struct datapath *dp;
+
+	ovs_lock();
+	list_for_each_entry(dp, &ovs_net->dps, list_node) {
+		int i;
+
+		for (i = 0; i < DP_VPORT_HASH_BUCKETS; i++) {
+			struct vport *vport;
+			struct hlist_node *n;
+
+			hlist_for_each_entry_safe(vport, n, &dp->ports[i], dp_hash_node) {
+				struct netdev_vport *netdev_vport;
+
+				if (vport->ops->type != OVS_VPORT_TYPE_NETDEV)
+					continue;
+
+				netdev_vport = netdev_vport_priv(vport);
+				if (netdev_vport->dev->reg_state == NETREG_UNREGISTERED ||
+				    netdev_vport->dev->reg_state == NETREG_UNREGISTERING)
+					dp_detach_port_notify(vport);
+			}
+		}
+	}
+	ovs_unlock();
+}
+
 static int dp_device_event(struct notifier_block *unused, unsigned long event,
 			   void *ptr)
 {
+	struct ovs_net *ovs_net;
 	struct net_device *dev = ptr;
-	struct vport *vport;
+	struct vport *vport = NULL;
 
-	if (ovs_is_internal_dev(dev))
-		vport = ovs_internal_dev_get_vport(dev);
-	else
+	if (!ovs_is_internal_dev(dev))
 		vport = ovs_netdev_get_vport(dev);
 
 	if (!vport)
 		return NOTIFY_DONE;
 
-	switch (event) {
-	case NETDEV_UNREGISTER:
-		if (!ovs_is_internal_dev(dev)) {
-			struct sk_buff *notify;
-			struct datapath *dp = vport->dp;
-
-			notify = ovs_vport_cmd_build_info(vport, 0, 0,
-							  OVS_VPORT_CMD_DEL);
-			ovs_dp_detach_port(vport);
-			if (IS_ERR(notify)) {
-				netlink_set_err(ovs_dp_get_net(dp)->genl_sock, 0,
-						ovs_dp_vport_multicast_group.id,
-						PTR_ERR(notify));
-				break;
-			}
-
-			genlmsg_multicast_netns(ovs_dp_get_net(dp), notify, 0,
-						ovs_dp_vport_multicast_group.id,
-						GFP_KERNEL);
-		}
-		break;
+	if (event == NETDEV_UNREGISTER) {
+		ovs_net = net_generic(dev_net(dev), ovs_net_id);
+		queue_work(system_wq, &ovs_net->dp_notify_work);
 	}
 
 	return NOTIFY_DONE;