alias: rework device updates

Apply immediately if alias device is not claimed, otherwise defer until release

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

diff --git a/alias.c b/alias.c
index e77defff5e42836d269a10d12c284929e964a79c..e4f28e52c277b55a908d7879e3edac2b8d674772 100644 (file)
--- a/alias.c
+++ b/alias.c
@@ -25,12 +25,40 @@ struct alias_device {
        struct avl_node avl;
        struct device dev;
        struct device_user dep;
-       bool cleanup;
+       struct device_user new_dep;
+       bool update;
        char name[];
 };
 
 static const struct device_type alias_device_type;
 
+static void alias_set_device(struct alias_device *alias, struct device *dev)
+{
+       if (dev == alias->dep.dev)
+               return;
+
+       device_remove_user(&alias->new_dep);
+       if (alias->dev.active) {
+               if (dev)
+                       device_add_user(&alias->new_dep, dev);
+
+               alias->update = true;
+               return;
+       }
+
+       alias->update = false;
+       device_remove_user(&alias->dep);
+       alias->dev.hidden = !dev;
+       if (dev) {
+               strcpy(alias->dev.ifname, dev->ifname);
+               device_broadcast_event(&alias->dev, DEV_EVENT_UPDATE_IFNAME);
+               device_add_user(&alias->dep, dev);
+       } else {
+               alias->dev.ifname[0] = 0;
+               device_broadcast_event(&alias->dev, DEV_EVENT_UPDATE_IFNAME);
+       }
+}
+
 static int
 alias_device_set_state(struct device *dev, bool state)
 {
@@ -44,8 +72,9 @@ alias_device_set_state(struct device *dev, bool state)
                return device_claim(&alias->dep);
 
        device_release(&alias->dep);
-       if (alias->cleanup)
-               device_remove_user(&alias->dep);
+       if (alias->update)
+               alias_set_device(alias, alias->new_dep.dev);
+
        return 0;
 }
 
@@ -95,27 +124,6 @@ static void alias_device_free(struct device *dev)
        free(alias);
 }
 
-static void __alias_notify_device(struct alias_device *alias, struct device *dev)
-{
-       alias->cleanup = !dev;
-       if (dev) {
-               if (dev != alias->dep.dev) {
-                       device_remove_user(&alias->dep);
-                       strcpy(alias->dev.ifname, dev->ifname);
-                       device_add_user(&alias->dep, dev);
-                       alias->dev.hidden = false;
-                       device_broadcast_event(&alias->dev, DEV_EVENT_UPDATE_IFNAME);
-               }
-       }
-
-       if (!dev && alias->dep.dev && !alias->dep.dev->active) {
-               device_remove_user(&alias->dep);
-               alias->dev.hidden = true;
-               alias->dev.ifname[0] = 0;
-               device_broadcast_event(&alias->dev, DEV_EVENT_UPDATE_IFNAME);
-       }
-}
-
 static int alias_check_state(struct device *dev)
 {
        struct alias_device *alias;
@@ -128,7 +136,7 @@ static int alias_check_state(struct device *dev)
        if (iface && iface->state == IFS_UP)
                ndev = iface->l3_dev.dev;
 
-       __alias_notify_device(alias, ndev);
+       alias_set_device(alias, ndev);
 
        return 0;
 }
@@ -149,7 +157,7 @@ alias_notify_device(const char *name, struct device *dev)
 
        alias = avl_find_element(&aliases, name, alias, avl);
        if (alias)
-               __alias_notify_device(alias, dev);
+               alias_set_device(alias, dev);
 
        device_unlock();
 }