anchor.diff:  link_key(StorageId, SpaceUuid) ->
       <<StorageId/binary, ":", SpaceUuid/binary>>.
   
  +%%--------------------------------------------------------------------
  +%% @private
  +%% @doc
  +%% Deletes all links for session
  +%% @end
  +%%--------------------------------------------------------------------
  +-spec delete_all_links(SessId :: id()) ->
  +    ok | {error, term()}.
  +delete_all_links(SessId) ->
  +    Result = datastore_model:fold_links(?CTX, SessId, all, fun
  +        (#link{tree_id = TreeId, name = Name, rev = Rev}, Acc) ->
  +            Links = maps:get(TreeId, Acc, []),
  +            {ok, maps:put(TreeId, [{Name, Rev} | Links], Acc)}
  +    end, #{}, #{}),
  +    case Result of
  +        {ok, Trees} ->
  +            maps:fold(fun
  +                (TreeId, Links, ok) ->
  +                    Deleted = datastore_model:delete_links(
  +                        ?CTX, SessId, TreeId, Links),
  +                    Deleted2 = lists:filter(fun
  +                        ({error, _}) -> true;
  +                        (ok) -> false
  +                    end, Deleted),
  +                    case Deleted2 of
  +                        [] -> ok;
  +                        _ -> {error, Deleted2}
  +                    end;
  +                (_, _, {error, Reason}) ->
  +                    {error, Reason}
  +            end, ok, Trees);
  +        {error, Reason} ->
  +            {error, Reason}
  +    end.
  +
   %%%===================================================================
   %%% datastore_model callbacks
   %%%===================================================================
  
positive.code: -define(CTX, #{
      model => ?MODULE,
      disc_driver => undefined,
      fold_enabled => true,
      local_links_tree_id => ?FILE_HANDLES_TREE_ID
  }).
  
  -define(FILE_HANDLES_TREE_ID, <<"storage_file_handles">>).
  
negative.code:             ok
      end,
  
      case delete_all_links(SessId) of
          true ->
              ?update_counter(?EXOMETER_NAME(active_sessions), -1),
              datastore_model:delete(?CTX, SessId);
          LinkError ->
              LinkError
      end.
  
  %%--------------------------------------------------------------------
  %% @doc
  