On Mon, Jun 26, 2017 at 03:30:55PM +0100, Stefan Hajnoczi wrote:
>> +    bs->file = bdrv_open_child(NULL, options, "file",
>> +                                    bs, &child_file, false, &local_err);
>> +
>> +    if (local_err) {
>> +        error_propagate(errp, local_err);
>> +        return -EINVAL;
>> +    }
>> +
>> +    qdict_flatten(options);
>> +    return throttle_configure_tgm(bs, tgm, options, errp);
>
>Who destroys bs->file on error?

It is reaped by bdrv_open_inherit() on failure, if I'm not mistaken.
That's how other drivers handle this as well. Some (eg block/qcow2.c)
check if bs->file is NULL instead of the error pointer they pass, so
this is not not very consistent.