Rake task for storage rollback

lib/tasks/gitlab/storage.rake

@@ -45,6 +45,51 @@ namespace :gitlab do
       puts ' Done!'
     end
 
+    desc 'GitLab | Storage | Rollback existing projects to Legacy Storage'
+    task rollback_to_legacy: :environment do
+      if Gitlab::Database.read_only?
+        warn 'This task requires database write access. Exiting.'
+
+        next
+      end
+
+      storage_migrator = Gitlab::HashedStorage::Migrator.new
+      helper = Gitlab::HashedStorage::RakeHelper
+
+      if helper.range_single_item?
+        project = Project.with_storage_feature(:repository).find_by(id: helper.range_from)
+
+        unless project
+          warn "There are no projects that can be rolledback with ID=#{helper.range_from}"
+
+          next
+        end
+
+        puts "Enqueueing storage rollback of #{project.full_path} (ID=#{project.id})..."
+        storage_migrator.rollback(project)
+
+        next
+      end
+
+      hashed_projects_count = Project.with_storage_feature(:repository).count
+
+      if hashed_projects_count == 0
+        warn 'There are no projects that can have storage rolledback. Nothing to do!'
+
+        next
+      end
+
+      print "Enqueuing rollback of #{hashed_projects_count} projects in batches of #{helper.batch_size}"
+
+      helper.project_id_batches do |start, finish|
+        storage_migrator.bulk_schedule(start: start, finish: finish, operation: :rollback)
+
+        print '.'
+      end
+
+      puts ' Done!'
+    end
+
     desc 'Gitlab | Storage | Summary of existing projects using Legacy Storage'
     task legacy_projects: :environment do
       helper = Gitlab::HashedStorage::RakeHelper