[RFC net-next 3/6] openvswitch: vport: remove infrastructure for separate modules

[Ilya Maximets <i.maximets@ovn.org>]

Since removal of legacy tunnel vport types only the built-in ones
remain.  So, there is no need for the extra infrastructure for dynamic
module loading.  Can be reinstated in the future if we need a new
vport type.

Note: It is technically possible that someone has an out-of-tree
module named vport-type-N that implements a different vport type.
At this time we're not aware of anyone doing that.  People running
out-of-tree modules normally just have an out-of-tree openvswitch
module as a whole.  And there are actually no supported out-of-tree
implementations of the openvswitch module known to the community.
Alternative to immediate removal would be printing out a deprecation
warning whenever a vport module is loaded, but I'm not sure if we
need it at this time.

Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
---
 net/openvswitch/vport.c | 22 ++--------------------
 net/openvswitch/vport.h |  9 +--------
 2 files changed, 3 insertions(+), 28 deletions(-)

diff --git a/net/openvswitch/vport.c b/net/openvswitch/vport.c
index 7a9caacfd6ac2..ef2fff4353c0a 100644
--- a/net/openvswitch/vport.c
+++ b/net/openvswitch/vport.c
@@ -57,7 +57,7 @@ static struct hlist_head *hash_bucket(const struct net *net, const char *name)
 	return &dev_table[hash & (VPORT_HASH_BUCKETS - 1)];
 }
 
-int __ovs_vport_ops_register(struct vport_ops *ops)
+int ovs_vport_ops_register(struct vport_ops *ops)
 {
 	int err = -EEXIST;
 	struct vport_ops *o;
@@ -73,7 +73,6 @@ int __ovs_vport_ops_register(struct vport_ops *ops)
 	ovs_unlock();
 	return err;
 }
-EXPORT_SYMBOL_GPL(__ovs_vport_ops_register);
 
 void ovs_vport_ops_unregister(struct vport_ops *ops)
 {
@@ -81,7 +80,6 @@ void ovs_vport_ops_unregister(struct vport_ops *ops)
 	list_del(&ops->list);
 	ovs_unlock();
 }
-EXPORT_SYMBOL_GPL(ovs_vport_ops_unregister);
 
 /**
  *	ovs_vport_locate - find a port that has already been created
@@ -210,12 +208,8 @@ struct vport *ovs_vport_add(const struct vport_parms *parms)
 	if (ops) {
 		struct hlist_head *bucket;
 
-		if (!try_module_get(ops->owner))
-			return ERR_PTR(-EAFNOSUPPORT);
-
 		vport = ops->create(parms);
 		if (IS_ERR(vport)) {
-			module_put(ops->owner);
 			return vport;
 		}
 
@@ -225,18 +219,7 @@ struct vport *ovs_vport_add(const struct vport_parms *parms)
 		return vport;
 	}
 
-	/* Unlock to attempt module load and return -EAGAIN if load
-	 * was successful as we need to restart the port addition
-	 * workflow.
-	 */
-	ovs_unlock();
-	request_module("vport-type-%d", parms->type);
-	ovs_lock();
-
-	if (!ovs_vport_lookup(parms))
-		return ERR_PTR(-EAFNOSUPPORT);
-	else
-		return ERR_PTR(-EAGAIN);
+	return ERR_PTR(-EAFNOSUPPORT);
 }
 
 /**
@@ -250,7 +233,6 @@ struct vport *ovs_vport_add(const struct vport_parms *parms)
 void ovs_vport_del(struct vport *vport)
 {
 	hlist_del_rcu(&vport->hash_node);
-	module_put(vport->ops->owner);
 	vport->ops->destroy(vport);
 }
 
diff --git a/net/openvswitch/vport.h b/net/openvswitch/vport.h
index 636788b59907c..930f1ccc85581 100644
--- a/net/openvswitch/vport.h
+++ b/net/openvswitch/vport.h
@@ -116,7 +116,6 @@ struct vport_parms {
  * before an RCU grace period has elapsed.
  * @send: Send a packet on the device.
  * zero for dropped packets or negative for error.
- * @owner: Module that implements this vport type.
  * @list: List entry in the global list of vport types.
  */
 struct vport_ops {
@@ -127,7 +126,6 @@ struct vport_ops {
 	void (*destroy)(struct vport *);
 
 	int (*send)(struct sk_buff *skb);
-	struct module *owner;
 	struct list_head list;
 };
 
@@ -191,12 +189,7 @@ static inline const char *ovs_vport_name(struct vport *vport)
 	return vport->dev->name;
 }
 
-int __ovs_vport_ops_register(struct vport_ops *ops);
-#define ovs_vport_ops_register(ops)		\
-	({					\
-		(ops)->owner = THIS_MODULE;	\
-		__ovs_vport_ops_register(ops);	\
-	})
+int ovs_vport_ops_register(struct vport_ops *ops);
 
 void ovs_vport_ops_unregister(struct vport_ops *ops);
 void ovs_vport_send(struct vport *vport, struct sk_buff *skb, u8 mac_proto);
-- 
2.53.0