Don't let inter_node upgrade to module_node

native/src/core/module.cpp

@@ -37,7 +37,7 @@ tmpfs_node::tmpfs_node(node_entry *node) : dir_node(node, this) {
             for (dirent *entry; (entry = xreaddir(dir.get()));) {
                 if (entry->d_type == DT_DIR) {
                     // create a dummy inter_node to upgrade later
-                    emplace<inter_node>(entry->d_name, entry->d_name, "");
+                    emplace<inter_node>(entry->d_name, entry->d_name);
                 } else {
                     // Insert mirror nodes
                     emplace<mirror_node>(entry->d_name, entry);
@@ -61,7 +61,18 @@ bool dir_node::prepare() {
         set_exist(true);
     }
     for (auto it = children.begin(); it != children.end();) {
-        if (require_tmpfs_upgrade(it->second)) {
+        // We need to upgrade to tmpfs node if any child:
+        // - Target does not exist
+        // - Source or target is a symlink (since we cannot bind mount symlink)
+        bool cannot_mnt;
+        if (struct stat st{}; lstat(it->second->node_path().data(), &st) != 0) {
+            cannot_mnt = true;
+        } else {
+            it->second->set_exist(true);
+            cannot_mnt = it->second->is_lnk() || S_ISLNK(st.st_mode);
+        }
+
+        if (cannot_mnt) {
             if (_node_type > type_id<tmpfs_node>()) {
                 // Upgrade will fail, remove the unsupported child node
                 LOGW("Unable to add: %s, skipped\n", it->second->node_path().data());
@@ -71,15 +82,6 @@ bool dir_node::prepare() {
             }
             // Tell parent to upgrade self to tmpfs
             to_tmpfs = true;
-            // If child is inter_node and it does not exist, upgrade to module
-            if (auto dn = dyn_cast<inter_node>(it->second)) {
-                if (!dn->exist()) {
-                    if (auto nit = upgrade<module_node, inter_node>(it); nit != children.end()) {
-                        it = nit;
-                        goto next_node;
-                    }
-                }
-            }
         }
         if (auto dn = dyn_cast<dir_node>(it->second)) {
             if (skip_mirror) {
@@ -90,7 +92,6 @@ bool dir_node::prepare() {
                 it = upgrade<tmpfs_node>(it);
             }
         }
-next_node:
         ++it;
     }
     return to_tmpfs;
@@ -110,7 +111,7 @@ void dir_node::collect_module_files(const char *module, int dfd) {
 
         if (entry->d_type == DT_DIR) {
             if (auto it = children.find(entry->d_name); it == children.end()) {
-                dn = emplace<inter_node>(entry->d_name, entry->d_name, module);
+                dn = emplace<inter_node>(entry->d_name, entry->d_name);
             } else {
                 dn = dyn_cast<inter_node>(it->second);
             }
@@ -143,6 +144,10 @@ void node_entry::create_and_mount(const char *reason, const string &src) {
     }
 }
 
+void mirror_node::mount() {
+    create_and_mount("mirror", mirror_path());
+}
+
 void module_node::mount() {
     string src = module_mnt + module + parent()->root()->prefix + node_path();
     if (exist())
@@ -205,7 +210,7 @@ public:
 static void inject_magisk_bins(root_node *system) {
     auto bin = system->get_child<inter_node>("bin");
     if (!bin) {
-        bin = new inter_node("bin", "");
+        bin = new inter_node("bin");
         system->insert(bin);
     }
 

native/src/core/node.hpp

@@ -175,9 +175,9 @@ protected:
         return static_cast<T*>(it == children.end() ? nullptr : it->second);
     }
 
-    template<typename Func>
+    template<typename Builder>
-    iterator insert(string_view name, uint8_t type, const Func &fn) {
+    iterator insert(string_view name, uint8_t type, const Builder &builder) {
-        return insert_at(children.find(name), type, fn);
+        return insert_at(children.find(name), type, builder);
     }
 
     // Emplace insert a new node, or upgrade if the requested type has a higher rank.
@@ -216,17 +216,11 @@ protected:
         return it;
     }
 
-    template<class To, class From = node_entry, class ...Args>
+    template<class T, class ...Args>
     iterator upgrade(iterator it, Args &&...args) {
-        return insert_at(it, type_id<To>(), [&](node_entry *&ex) -> node_entry * {
+        return insert_at(it, type_id<T>(), [&](node_entry *&ex) -> node_entry * {
-            if (!ex)
+            if (!ex) return nullptr;
-                return nullptr;
+            auto node = new T(ex, std::forward<Args>(args)...);
-            if constexpr (!std::is_same_v<From, node_entry>) {
-                // Type check if type is specified
-                if (!isa<From>(ex))
-                    return nullptr;
-            }
-            auto node = new To(static_cast<From *>(ex), std::forward<Args>(args)...);
             ex = nullptr;
             return node;
         });
@@ -241,21 +235,6 @@ protected:
 private:
     // Root node lookup cache
     root_node *_root = nullptr;
-
-    // We need to upgrade to tmpfs node if any child:
-    // - Target does not exist
-    // - Source or target is a symlink (since we cannot bind mount link)
-    bool require_tmpfs_upgrade(node_entry *child) {
-        struct stat st{};
-        if (lstat(child->node_path().data(), &st) != 0) {
-            return true;
-        } else {
-            child->set_exist(true);
-            if (child->is_lnk() || S_ISLNK(st.st_mode))
-                return true;
-        }
-        return false;
-    }
 };
 
 class root_node : public dir_node {
@@ -271,10 +250,7 @@ public:
 
 class inter_node : public dir_node {
 public:
-    inter_node(const char *name, const char *module) : dir_node(name, this), module(module) {}
+    inter_node(const char *name) : dir_node(name, this) {}
-private:
-    const char *module;
-    friend class module_node;
 };
 
 class module_node : public node_entry {
@@ -286,8 +262,6 @@ public:
         consume(node);
     }
 
-    explicit module_node(inter_node *node) : module_node(node, node->module) {}
-
     void mount() override;
 private:
     const char *module;
@@ -297,9 +271,7 @@ private:
 class mirror_node : public node_entry {
 public:
     explicit mirror_node(dirent *entry) : node_entry(entry->d_name, entry->d_type, this) {}
-    void mount() override {
+    void mount() override;
-        create_and_mount("mirror", mirror_path());
-    }
 };
 
 class tmpfs_node : public dir_node {