Prevent git push when LFS objects are missing

2 files changed, 35 insertions, 1 deletions

diff --git a/lib/gitlab/checks/change_access.rb b/lib/gitlab/checks/change_access.rb
index b6805230348..ef92fc5a0a0 100644
--- a/lib/gitlab/checks/change_access.rb
+++ b/lib/gitlab/checks/change_access.rb
@@ -12,7 +12,8 @@ module Gitlab
         change_existing_tags: 'You are not allowed to change existing tags on this project.',
         update_protected_tag: 'Protected tags cannot be updated.',
         delete_protected_tag: 'Protected tags cannot be deleted.',
-        create_protected_tag: 'You are not allowed to create this tag as it is protected.'
+        create_protected_tag: 'You are not allowed to create this tag as it is protected.',
+        lfs_objects_missing: 'LFS objects are missing. Ensure LFS is properly set up or try a manual "git lfs push --all".'
       }.freeze
 
       attr_reader :user_access, :project, :skip_authorization, :protocol
@@ -36,6 +37,7 @@ module Gitlab
         push_checks
         branch_checks
         tag_checks
+        lfs_objects_exist_check
 
         true
       end
@@ -136,6 +138,14 @@ module Gitlab
       def matching_merge_request?
         Checks::MatchingMergeRequest.new(@newrev, @branch_name, @project).match?
       end
+
+      def lfs_objects_exist_check
+        lfs_check = Checks::LfsIntegrity.new(project, @newrev)
+
+        if lfs_check.objects_missing?
+          raise GitAccess::UnauthorizedError, ERROR_MESSAGES[:lfs_objects_missing]
+        end
+      end
     end
   end
 end
diff --git a/lib/gitlab/checks/lfs_integrity.rb b/lib/gitlab/checks/lfs_integrity.rb
new file mode 100644
index 00000000000..27a95764dc1
--- /dev/null
+++ b/lib/gitlab/checks/lfs_integrity.rb
@@ -0,0 +1,24 @@
+module Gitlab
+  module Checks
+    class LfsIntegrity
+      REV_LIST_OBJECT_LIMIT = 2_000
+
+      def initialize(project, newrev)
+        @project = project
+        @newrev = newrev
+      end
+
+      def objects_missing?
+        return false unless @newrev && @project.lfs_enabled?
+
+        new_lfs_pointers = Gitlab::Git::LfsChanges.new(@project.repository, @newrev).new_pointers(object_limit: REV_LIST_OBJECT_LIMIT)
+
+        return false unless new_lfs_pointers.present?
+
+        existing_count = @project.lfs_objects.where(oid: new_lfs_pointers.map(&:lfs_oid)).count
+
+        existing_count != new_lfs_pointers.count
+      end
+    end
+  end
+end