diff --git a/lib/redmine_dmsf/webdav/base_resource.rb b/lib/redmine_dmsf/webdav/base_resource.rb
index 764d9879..8f8ca6d8 100644
--- a/lib/redmine_dmsf/webdav/base_resource.rb
+++ b/lib/redmine_dmsf/webdav/base_resource.rb
@@ -34,6 +34,7 @@ module RedmineDmsf
         raise NotFound if Setting.plugin_redmine_dmsf['dmsf_webdav'].blank?
         @project = nil
         @public_path = "#{options[:root_uri_path]}#{path}"
+        @children = nil
         super path, request, response, options
       end
 
@@ -87,7 +88,6 @@ module RedmineDmsf
       def child_project(p)
         project_display_name = ProjectResource.create_project_name(p)
         new_path = @path
-        #new_path = +'/'
         new_path = new_path + '/' unless new_path[-1,1] == '/'
         new_path = '/' + new_path unless new_path[0,1] == '/'
         new_path += project_display_name
@@ -152,7 +152,40 @@ module RedmineDmsf
       end
 
       def path_prefix
-        @public_path.gsub(/#{Regexp.escape(path)}$/, '')
+        @public_path.gsub /#{Regexp.escape(path)}$/, ''
+      end
+
+      def load_projects(project_scope)
+        project_scope
+            .where.not(status: Project::STATUS_ARCHIVED)
+            .find_each do |p|
+          if dmsf_visible?(p) || dmsf_enabled?(p)
+            @children << child_project(p)
+          end
+        end
+      end
+
+      private
+
+      def dmsf_enabled?(prj)
+        prj.module_enabled?(:dmsf) && Project.allowed_to_condition(User.current, :view_dmsf_folders)
+      end
+
+      def dmsf_visible?(prj)
+        Rails.cache.fetch("#{prj.cache_key_with_version}/dmsf-visible", expires_in: 12.hours) do
+          dmsf_visible_recursive? prj
+        end
+      end
+
+      def dmsf_visible_recursive?(prj)
+        prj.children.each do |p|
+          if dmsf_enabled?(p)
+            return true
+          else
+            return dmsf_visible?(p)
+          end
+        end
+        false
       end
 
     end
diff --git a/lib/redmine_dmsf/webdav/dmsf_resource.rb b/lib/redmine_dmsf/webdav/dmsf_resource.rb
index 4a308e4c..6ea68bc4 100644
--- a/lib/redmine_dmsf/webdav/dmsf_resource.rb
+++ b/lib/redmine_dmsf/webdav/dmsf_resource.rb
@@ -58,10 +58,7 @@ module RedmineDmsf
             end
           elsif subproject
             # Projects
-            subproject.children.visible.select(:id, :identifier, :name).has_module(:dmsf).where(
-                Project.allowed_to_condition(User.current, :view_dmsf_folders)).find_each do |p|
-              @children << child_project(p)
-            end
+            load_projects subproject.children
             # Folders
             subproject.dmsf_folders.visible.pluck(:title).each do |title|
               @children.push child(title)
diff --git a/lib/redmine_dmsf/webdav/index_resource.rb b/lib/redmine_dmsf/webdav/index_resource.rb
index 9b26eac1..238f3874 100644
--- a/lib/redmine_dmsf/webdav/index_resource.rb
+++ b/lib/redmine_dmsf/webdav/index_resource.rb
@@ -26,19 +26,14 @@ module RedmineDmsf
 
       def initialize(path, request, response, options)
         super(path, request, response, options)
-        @projects = nil
       end
       
       def children
-        unless @projects
-          @projects = []
-          Project.visible.select(:id, :identifier, :name).has_module(:dmsf).where(
-            Project.allowed_to_condition(
-              User.current, :view_dmsf_folders)).find_each do |p|
-            @projects << child_project(p)
-          end
+        unless @children
+          @children = []
+          load_projects Project.where(parent_id: nil)
         end
-        @projects
+        @children
       end
 
       def collection?
diff --git a/lib/redmine_dmsf/webdav/project_resource.rb b/lib/redmine_dmsf/webdav/project_resource.rb
index cd3f0968..674b029b 100644
--- a/lib/redmine_dmsf/webdav/project_resource.rb
+++ b/lib/redmine_dmsf/webdav/project_resource.rb
@@ -27,7 +27,6 @@ module RedmineDmsf
 
       def initialize(path, request, response, options)
         super path, request, response, options
-        @children = nil
       end
       
       def children
@@ -35,14 +34,7 @@ module RedmineDmsf
           @children = []
           if project
             # Sub-projects
-            # project.children.select(:id, :identifier, :name).has_module(:dmsf).where(
-            #     Project.allowed_to_condition(
-            #         User.current, :view_dmsf_folders)).order('lft').pluck(:name).each do |name|
-            #   @children.push child(name)
-            project.children.visible.select(:id, :identifier, :name).has_module(:dmsf).where(
-                Project.allowed_to_condition(User.current, :view_dmsf_folders)).find_each do |p|
-                  @children << child_project(p)
-            end
+            load_projects project.children
             # Folders
             project.dmsf_folders.visible.pluck(:title).each do |title|
               @children.push child(title)