Re: [Libguestfs] [libnbd PATCH v2 11/13] api: Add nbd_aio_opt_list

On Fri, Aug 14, 2020 at 05:00:30PM -0500, Eric Blake wrote: This is fine assuming we're certain that NBD_OPT_LIST / NBD_REP_SERVER (in the protocol) cannot be extended with more fields. Otherwise I'd suggesting adding some kind id/cookie here which the caller could use to get "further information", but would be useless at the moment. NBD_OPT_LIST is documented as returning NBD_REP_SERVER replies, and not anything else. The NBD protocol documentation tries to give wiggle room for NBD_REP_SERVER but is also clear that the extra field is a description field for user display, and I guess we're all using it for that now. It seems therefore that NBD_OPT_LIST cannot be extended, and so another option would have to be introduced in future, in which case we would support that option either by needing to extend this API or by a new API (aio_list2 or something). On balance therefore, this seems fine. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-top is 'top' for virtual machines. Tiny program with many powerful monitoring features, net stats, disk stats, logging, etc. http://people.redhat.com/~rjones/virt-top