hotplug: switch to using avl tree for hotplug subsystems

Preparation for adding notifications for events

Signed-off-by: Felix Fietkau <[email protected]>

diff --git a/hotplug-dispatch.c b/hotplug-dispatch.c
index 47060852ea909bc2e389003d30722682bc492eda..444e0a400de1df1a4df2032ffda6d5c5196836cf 100644 (file)
--- a/hotplug-dispatch.c
+++ b/hotplug-dispatch.c
@@ -43,12 +43,12 @@ struct ubus_context *ctx;
 static char *inotify_buffer;
 static struct uloop_fd fd_inotify_read;
 
-static LIST_HEAD(subsystems);
+static AVL_TREE(subsystems, avl_strcmp, false, NULL);
 
 extern char **environ;
 
 struct hotplug_subsys {
-       struct list_head list;
+       struct avl_node node;
        struct ubus_object ubus;
 };
 
@@ -331,39 +331,56 @@ static const struct ubus_method hotplug_methods[] = {
 static struct ubus_object_type hotplug_object_type =
        UBUS_OBJECT_TYPE("hotplug", hotplug_methods);
 
-static void add_subsystem(int nlen, char *newname)
+static void add_subsystem(const char *name)
 {
-       struct hotplug_subsys *nh = calloc(1, sizeof(struct hotplug_subsys));
-       char *name;
+       struct hotplug_subsys *nh;
+       char *name_buf;
 
-       if (asprintf(&name, "%s%.*s", HOTPLUG_OBJECT_PREFIX, nlen, newname) == -1)
-               exit(ENOMEM);
+       nh = avl_find_element(&subsystems, name, nh, node);
+       if (nh)
+               return;
+
+       nh = calloc_a(sizeof(struct hotplug_subsys),
+               &name_buf, sizeof(HOTPLUG_OBJECT_PREFIX) + 1 + strlen(name));
+       if (!nh)
+               return;
+
+       nh->ubus.name = name_buf;
+       name_buf += sprintf(name_buf, "%s", HOTPLUG_OBJECT_PREFIX);
+       nh->node.key = strcpy(name_buf, name);
 
-       /* prepare and add ubus object */
-       nh->ubus.name = name;
        nh->ubus.type = &hotplug_object_type;
        nh->ubus.methods = hotplug_object_type.methods;
        nh->ubus.n_methods = hotplug_object_type.n_methods;
-       list_add(&nh->list, &subsystems);
        ubus_add_object(ctx, &nh->ubus);
+       avl_insert(&subsystems, &nh->node);
 }
 
-static void remove_subsystem(int nlen, char *name)
+static void free_subsystem(struct hotplug_subsys *h)
+{
+       ubus_remove_object(ctx, &h->ubus);
+       free(h);
+}
+
+static void remove_all_subsystems(void)
 {
        struct hotplug_subsys *n, *h;
 
        /* find match subsystem object by name or any if not given */
-       list_for_each_entry_safe(h, n, &subsystems, list) {
-               if (nlen && (strlen(h->ubus.name) != strnlen(name, nlen) + strlen(HOTPLUG_OBJECT_PREFIX)))
-                       continue;
-               if (nlen && (strncmp(name, &h->ubus.name[strlen(HOTPLUG_OBJECT_PREFIX)], nlen)))
-                       continue;
+       avl_remove_all_elements(&subsystems, h, node, n)
+               free_subsystem(h);
+}
 
-               list_del(&h->list);
-               ubus_remove_object(ctx, &h->ubus);
-               free((void*)h->ubus.name);
-               free(h);
-       }
+static void remove_subsystem(char *name)
+{
+       struct hotplug_subsys *h;
+
+       h = avl_find_element(&subsystems, name, h, node);
+       if (!h)
+               return;
+
+       avl_delete(&subsystems, &h->node);
+       free_subsystem(h);
 }
 
 static int init_subsystems(void)
@@ -384,7 +401,7 @@ static int init_subsystems(void)
                if (dirent->d_name[0] == '.')
                        continue;
 
-               add_subsystem(strlen(dirent->d_name), dirent->d_name);
+               add_subsystem(dirent->d_name);
        }
        closedir(dir);
 
@@ -422,16 +439,16 @@ static void inotify_read_handler(struct uloop_fd *u, unsigned int events)
 
                /* add/remove subsystem objects */
                if (in->mask & (IN_CREATE | IN_MOVED_TO))
-                       add_subsystem(in->len, in->name);
+                       add_subsystem(in->name);
                else if (in->mask & (IN_DELETE | IN_MOVED_FROM))
-                       remove_subsystem(in->len, in->name);
+                       remove_subsystem(in->name);
        }
 }
 
 void ubus_init_hotplug(struct ubus_context *newctx)
 {
        ctx = newctx;
-       remove_subsystem(0, NULL);
+       remove_all_subsystems();
        if (init_subsystems()) {
                printf("failed to initialize hotplug subsystems from %s\n", HOTPLUG_BASEDIR);
                return;