204     children: BTreeMap<String, Arc<dyn IndexNode>>,  field
225             children: BTreeMap::new(),  in new_with_parent()
251         if guard.children.contains_key(name) {  in add_dir()
268         if this.children.contains_key(name) {  in add_dev()
272         this.children.insert(name.to_string(), dev);  in add_dev()
280             .children  in remove()
301         if guard.children.contains_key(_name) {  in do_create_with_data()
309             children: BTreeMap::new(),  in do_create_with_data()
333         guard.children.insert(String::from(_name), result.clone());  in do_create_with_data()
384                 return Ok(inode.children.get(name).ok_or(SystemError::ENOENT)?.clone());  in find()
410                     .children  in get_entry_name()
412                     .filter(|k| inode.children.get(*k).unwrap().metadata().unwrap().inode_id == ino)  in get_entry_name()
438         keys.append(&mut self.0.lock().children.keys().cloned().collect());  in list()