alias: use a callback for managing device presence state, track alias deps in a separate list to avoid recursion issues

3 files changed, 41 insertions, 5 deletions

diff --git a/alias.c b/alias.c
index 338ece6..07ed5fe 100644
--- a/alias.c
+++ b/alias.c
@@ -48,6 +48,24 @@ alias_device_set_state(struct device *dev, bool state)
 	return 0;
 }
 
+static void alias_device_cb(struct device_user *dep, enum device_event ev)
+{
+	struct alias_device *alias;
+	bool present = false;
+
+	alias = container_of(dep, struct alias_device, dep);
+	switch (ev) {
+	case DEV_EVENT_ADD:
+		present = true;
+	case DEV_EVENT_REMOVE:
+		device_set_present(&alias->dev, present);
+		break;
+	default:
+		device_broadcast_event(&alias->dev, ev);
+		break;
+	}
+}
+
 static struct device *
 alias_device_create(const char *name, struct blob_attr *attr)
 {
@@ -60,6 +78,8 @@ alias_device_create(const char *name, struct blob_attr *attr)
 	device_init_virtual(&alias->dev, &alias_device_type, NULL);
 	alias->avl.key = alias->name;
 	avl_insert(&aliases, &alias->avl);
+	alias->dep.alias = true;
+	alias->dep.cb = alias_device_cb;
 
 	return &alias->dev;
 }
@@ -101,8 +121,6 @@ alias_notify_device(const char *name, struct device *dev)
 		}
 	}
 
-	device_set_present(&alias->dev, !!dev);
-
 	if (!dev && alias->dep.dev && !alias->dep.dev->active) {
 		device_remove_user(&alias->dep);
 		alias->dev.hidden = true;
diff --git a/device.c b/device.c
index 34ad9ad..80881d2 100644
--- a/device.c
+++ b/device.c
@@ -180,11 +180,12 @@ static void __init dev_init(void)
 	avl_init(&devices, avl_strcmp, true, NULL);
 }
 
-void device_broadcast_event(struct device *dev, enum device_event ev)
+
+static void __device_broadcast_event(struct list_head *head, enum device_event ev)
 {
 	struct device_user *dep, *tmp;
 
-	list_for_each_entry_safe(dep, tmp, &dev->users, list) {
+	list_for_each_entry_safe(dep, tmp, head, list) {
 		if (!dep->cb)
 			continue;
 
@@ -192,6 +193,12 @@ void device_broadcast_event(struct device *dev, enum device_event ev)
 	}
 }
 
+void device_broadcast_event(struct device *dev, enum device_event ev)
+{
+	__device_broadcast_event(&dev->aliases, ev);
+	__device_broadcast_event(&dev->users, ev);
+}
+
 int device_claim(struct device_user *dep)
 {
 	struct device *dev = dep->dev;
@@ -257,6 +264,7 @@ void device_init_virtual(struct device *dev, const struct device_type *type, con
 
 	D(DEVICE, "Initialize device '%s'\n", dev->ifname);
 	INIT_LIST_HEAD(&dev->users);
+	INIT_LIST_HEAD(&dev->aliases);
 	dev->type = type;
 
 	if (!dev->set_state)
@@ -378,6 +386,8 @@ void device_set_present(struct device *dev, bool state)
 
 void device_add_user(struct device_user *dep, struct device *dev)
 {
+	struct list_head *head;
+
 	if (dep->dev)
 		device_remove_user(dep);
 
@@ -385,7 +395,13 @@ void device_add_user(struct device_user *dep, struct device *dev)
 		return;
 
 	dep->dev = dev;
-	list_add_tail(&dep->list, &dev->users);
+
+	if (dep->alias)
+		head = &dev->aliases;
+	else
+		head = &dev->users;
+	list_add_tail(&dep->list, head);
+
 	if (dep->cb && dev->present) {
 		dep->cb(dep, DEV_EVENT_ADD);
 		if (dev->active)
diff --git a/device.h b/device.h
index 88a421f..8cedfba 100644
--- a/device.h
+++ b/device.h
@@ -85,6 +85,7 @@ struct device_user {
 
 	bool claimed;
 	bool hotplug;
+	bool alias;
 
 	struct device *dev;
 	void (*cb)(struct device_user *, enum device_event);
@@ -106,6 +107,7 @@ struct device {
 
 	struct avl_node avl;
 	struct list_head users;
+	struct list_head aliases;
 
 	char ifname[IFNAMSIZ + 1];
 	int ifindex;