1 files changed, 82 insertions, 0 deletions
diff --git a/lib/gitlab/background_migration/link_lfs_objects_projects.rb b/lib/gitlab/background_migration/link_lfs_objects_projects.rb
new file mode 100644
index 00000000000..983470c5121
--- /dev/null
+++ b/lib/gitlab/background_migration/link_lfs_objects_projects.rb
@@ -0,0 +1,82 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module BackgroundMigration
+    # Create missing LfsObjectsProject records for forks
+    class LinkLfsObjectsProjects
+      # Model specifically used for migration.
+      class LfsObjectsProject < ActiveRecord::Base
+        include EachBatch
+
+        self.table_name = 'lfs_objects_projects'
+
+        def self.linkable
+          where(
+            <<~SQL
+              lfs_objects_projects.project_id IN (
+                SELECT fork_network_members.forked_from_project_id
+                FROM fork_network_members
+                WHERE fork_network_members.forked_from_project_id IS NOT NULL
+              )
+            SQL
+          )
+        end
+      end
+
+      # Model specifically used for migration.
+      class ForkNetworkMember < ActiveRecord::Base
+        include EachBatch
+
+        self.table_name = 'fork_network_members'
+
+        def self.without_lfs_object(lfs_object_id)
+          where(
+            <<~SQL
+              fork_network_members.project_id NOT IN (
+                SELECT lop.project_id
+                FROM lfs_objects_projects lop
+                WHERE lop.lfs_object_id = #{lfs_object_id}
+              )
+            SQL
+          )
+        end
+      end
+
+      BATCH_SIZE = 1000
+
+      def perform(start_id, end_id)
+        lfs_objects_projects =
+          Gitlab::BackgroundMigration::LinkLfsObjectsProjects::LfsObjectsProject
+            .linkable
+            .where(id: start_id..end_id)
+
+        return if lfs_objects_projects.empty?
+
+        lfs_objects_projects.find_each do |lop|
+          ForkNetworkMember
+            .select("#{lop.lfs_object_id}, fork_network_members.project_id, NOW(), NOW()")
+            .without_lfs_object(lop.lfs_object_id)
+            .where(forked_from_project_id: lop.project_id)
+            .each_batch(of: BATCH_SIZE) do |batch, index|
+              execute <<~SQL
+                INSERT INTO lfs_objects_projects (lfs_object_id, project_id, created_at, updated_at)
+                #{batch.to_sql}
+              SQL
+
+              logger.info(message: "LinkLfsObjectsProjects: created missing LfsObjectsProject records for LfsObject #{lop.lfs_object_id}")
+            end
+        end
+      end
+
+      private
+
+      def execute(sql)
+        ::ActiveRecord::Base.connection.execute(sql)
+      end
+
+      def logger
+        @logger ||= Gitlab::BackgroundMigration::Logger.build
+      end
+    end
+  end
+end