[PATCH net-next 7/9] psp: add a new netdev event for dev unregister

[Wei Wang <weibunny@fb.com>]

Add a new netdev event for dev unregister and handle the removal of this
dev from psp->assoc_dev_list.

Signed-off-by: Wei Wang <weibunny@fb.com>
---
 net/psp/psp_main.c | 64 +++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 63 insertions(+), 1 deletion(-)

diff --git a/net/psp/psp_main.c b/net/psp/psp_main.c
index a836bb905f1a..f111547c9703 100644
--- a/net/psp/psp_main.c
+++ b/net/psp/psp_main.c
@@ -334,10 +334,72 @@ int psp_dev_rcv(struct sk_buff *skb, u16 dev_id, u8 generation, bool strip_icv)
 }
 EXPORT_SYMBOL(psp_dev_rcv);
 
+static void psp_dev_disassoc_one(struct psp_dev *psd, struct net_device *dev)
+{
+	struct psp_assoc_dev *entry, *tmp;
+
+	list_for_each_entry_safe(entry, tmp, &psd->assoc_dev_list, dev_list) {
+		if (entry->assoc_dev == dev) {
+			list_del(&entry->dev_list);
+			rcu_assign_pointer(entry->assoc_dev->psp_dev, NULL);
+			netdev_put(entry->assoc_dev, &entry->dev_tracker);
+			kfree(entry);
+			return;
+		}
+	}
+}
+
+static int psp_netdev_event(struct notifier_block *nb, unsigned long event,
+			    void *ptr)
+{
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+	struct psp_dev *psd;
+
+	if (event != NETDEV_UNREGISTER)
+		return NOTIFY_DONE;
+
+	rcu_read_lock();
+	psd = rcu_dereference(dev->psp_dev);
+	if (psd && psp_dev_tryget(psd)) {
+		rcu_read_unlock();
+		mutex_lock(&psd->lock);
+		psp_dev_disassoc_one(psd, dev);
+		mutex_unlock(&psd->lock);
+		psp_dev_put(psd);
+	} else {
+		rcu_read_unlock();
+	}
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block psp_netdev_notifier = {
+	.notifier_call = psp_netdev_event,
+};
+
 static int __init psp_init(void)
 {
+	int err;
+
 	mutex_init(&psp_devs_lock);
+	err = register_netdevice_notifier(&psp_netdev_notifier);
+	if (err)
+		return err;
+
+	err = genl_register_family(&psp_nl_family);
+	if (err) {
+		unregister_netdevice_notifier(&psp_netdev_notifier);
+		return err;
+	}
+
+	return 0;
+}
 
-	return genl_register_family(&psp_nl_family);
+static void __exit psp_exit(void)
+{
+	genl_unregister_family(&psp_nl_family);
+	unregister_netdevice_notifier(&psp_netdev_notifier);
 }
+
 subsys_initcall(psp_init);
+module_exit(psp_exit);
-- 
2.47.3