Part of tests done [ci skip]

lib/gitlab/lfs/response.rb

@@ -42,7 +42,7 @@ module Gitlab
         when "upload"
           render_batch_upload(request_body)
         else
-          render_forbidden
+          render_not_found
         end
       end
 
@@ -322,9 +322,8 @@ module Gitlab
       def download_hypermedia_links(all_objects, existing_objects)
         all_objects.each do |object|
           # generate links only for existing objects
-          next unless existing_objects.include?(object['oid'])
-
-          object['_links'] = {
+          if existing_objects.include?(object['oid'])
+            object['actions'] = {
               'download' => {
                 'href' => "#{@origin_project.http_url_to_repo}/gitlab-lfs/objects/#{object['oid']}",
                 'header' => {
@@ -332,6 +331,12 @@ module Gitlab
                 }.compact
               }
             }
+          else
+            object['error'] = {
+              'code' => 404,
+              'message' => "Object does not exist on the server or you don't have permissions to access it",
+            }
+          end
         end
 
         { 'objects' => all_objects }
@@ -342,7 +347,7 @@ module Gitlab
           # generate links only for non-existing objects
           next if existing_objects.include?(object['oid'])
 
-          object['_links'] = {
+          object['actions'] = {
             'upload' => {
               'href' => "#{@origin_project.http_url_to_repo}/gitlab-lfs/objects/#{object['oid']}/#{object['size']}",
               'header' => {