Avoid creating superfluous namespaces on Geo secondaries during sync

ee/app/services/geo/base_sync_service.rb

@@ -201,17 +201,21 @@ module Geo
       # Remove the deleted path in case it exists, but it may not be there
       gitlab_shell.remove_repository(project.repository_storage_path, deleted_disk_path_temp)
 
-      # Make sure we have a namespace directory
-      gitlab_shell.add_namespace(project.repository_storage_path, deleted_disk_path_temp)
-
       # Make sure we have the most current state of exists?
       repository.expire_exists_cache
 
-      if repository.exists? && !gitlab_shell.mv_repository(project.repository_storage_path, repository.disk_path, deleted_disk_path_temp)
-        raise Gitlab::Shell::Error, 'Can not move original repository out of the way'
+      # Move the current canonical repository to the deleted path for reference
+      if repository.exists?
+        ensure_repository_namespace(deleted_disk_path_temp)
+
+        unless gitlab_shell.mv_repository(project.repository_storage_path, repository.disk_path, deleted_disk_path_temp)
+          raise Gitlab::Shell::Error, 'Can not move original repository out of the way'
+        end
       end
 
-      gitlab_shell.add_namespace(project.repository_storage_path, repository.disk_path)
+      # Move the temporary repository to the canonical path
+
+      ensure_repository_namespace(repository.disk_path)
 
       unless gitlab_shell.mv_repository(project.repository_storage_path, disk_path_temp, repository.disk_path)
         raise Gitlab::Shell::Error, 'Can not move temporary repository'
@@ -223,6 +227,13 @@ module Geo
       end
     end
 
+    def ensure_repository_namespace(disk_path)
+      gitlab_shell.add_namespace(
+        project.repository_storage_path,
+        File.dirname(disk_path)
+      )
+    end
+
     # To prevent the retry time from storing invalid dates in the database,
     # cap the max time to a week plus some random jitter value.
     def next_retry_time(retry_count)

ee/spec/services/geo/repository_sync_service_spec.rb

@@ -257,12 +257,12 @@ describe Geo::RepositorySyncService do
 
         expect(subject.gitlab_shell).to receive(:add_namespace).with(
           project.repository_storage_path,
-          "@failed-geo-sync/#{repository.disk_path}"
+          "@failed-geo-sync/#{File.dirname(repository.disk_path)}"
         ).and_call_original
 
         expect(subject.gitlab_shell).to receive(:add_namespace).with(
           project.repository_storage_path,
-          repository.disk_path
+          File.dirname(repository.disk_path)
         ).and_call_original
 
         expect(subject.gitlab_shell).to receive(:remove_repository).exactly(2).times.and_call_original