RDMA/ipoib: Set rtnl_link_ops for ipoib interfaces

Report the "ipoib pkey", "mode" and "umcast" netlink attributes for every
IPoiB interface type, not just children created with 'ip link add'.

After setting the rtnl_link_ops for the parent interface, implement the
dellink() callback to block users from trying to remove it.

Fixes: 862096a ("IB/ipoib: Add more rtnl_link_ops callbacks")
Link: https://lore.kernel.org/r/20201004132948.26669-1-kamalheib1@gmail.com
Signed-off-by: Kamal Heib <kamalheib1@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/ulp/ipoib/ipoib_main.c

@@ -2477,6 +2477,8 @@ static struct net_device *ipoib_add_port(const char *format,
 	/* call event handler to ensure pkey in sync */
 	queue_work(ipoib_workqueue, &priv->flush_heavy);
 
+	ndev->rtnl_link_ops = ipoib_get_link_ops();
+
 	result = register_netdev(ndev);
 	if (result) {
 		pr_warn("%s: couldn't register ipoib port %d; error %d\n",

drivers/infiniband/ulp/ipoib/ipoib_netlink.c

@@ -144,6 +144,16 @@ static int ipoib_new_child_link(struct net *src_net, struct net_device *dev,
 	return 0;
 }
 
+static void ipoib_del_child_link(struct net_device *dev, struct list_head *head)
+{
+	struct ipoib_dev_priv *priv = ipoib_priv(dev);
+
+	if (!priv->parent)
+		return;
+
+	unregister_netdevice_queue(dev, head);
+}
+
 static size_t ipoib_get_size(const struct net_device *dev)
 {
 	return nla_total_size(2) +	/* IFLA_IPOIB_PKEY   */
@@ -158,6 +168,7 @@ static struct rtnl_link_ops ipoib_link_ops __read_mostly = {
 	.priv_size	= sizeof(struct ipoib_dev_priv),
 	.setup		= ipoib_setup_common,
 	.newlink	= ipoib_new_child_link,
+	.dellink	= ipoib_del_child_link,
 	.changelink	= ipoib_changelink,
 	.get_size	= ipoib_get_size,
 	.fill_info	= ipoib_fill_info,

drivers/infiniband/ulp/ipoib/ipoib_vlan.c

@@ -195,6 +195,8 @@ int ipoib_vlan_add(struct net_device *pdev, unsigned short pkey)
 	}
 	priv = ipoib_priv(ndev);
 
+	ndev->rtnl_link_ops = ipoib_get_link_ops();
+
 	result = __ipoib_vlan_add(ppriv, priv, pkey, IPOIB_LEGACY_CHILD);
 
 	if (result && ndev->reg_state == NETREG_UNINITIALIZED)