On Tue, May 17, 2016 at 10:50:01AM -0600, Eric Blake wrote:
> Option 2: An alternative solution would be to allow nbdkit to fail
> NBD_OPT_LIST with NBD_REP_ERR_UNSUP, at which point qemu client of 2.6
> should just ignore the failure and proceed on to NBD_OPT_EXPORT_NAME.
> It is the fact that it is returning NBD_REP_ACK with 0 names that is
> giving qemu grief.
I think this makes most sense. If you don't look at export names, you
effectively don't support them, and you can't be expected to send a list
of "supported" names, because *everything* is supported (or, put a
different way, nothing is).
I note that nbdkit has been patched to now send the empty name, which
is also fine as a way to fix interoperability in this particular case --
but for the general case, I think if we want to define ways for a server
to explicitly say that it doesn't support export names, returning
ERR_UNSUP to OPT_LIST seems cleaner.
(That does mean I'll have to fix nbd-client, since it currently assumes
that fixed newstyle implies support for OPT_LIST -- but that should be
an easy enough patch)
> But to date, I think ALL of the options (except NBD_OPT_EXPORT_NAME)
> _are_ optional. In fact, I'm arguing that per Option 2, we WANT
> NBD_OPT_LIST to be optional for servers that don't care about names.
Sortof. Like I said, nbd-client assumes that servers which support fixed
newstyle will also support OPT_LIST -- but that's mostly an artefact of
the fact that OPT_LIST was used as a test case for fixed newstyle, and
isn't necessarily a good enough reason to make that a required part of
the protocol.
--
< ron> I mean, the main *practical* problem with C++, is there's like a dozen
people in the world who think they really understand all of its rules,
and pretty much all of them are just lying to themselves too.
-- #debian-devel, OFTC, 2016-02-12
------------------------------------------------------------------------------
Mobile security can be enabling, not merely restricting. Employees who
bring their own devices (BYOD) to work are irked by the imposition of MDM
restrictions. Mobile Device Manager Plus allows you to control only the
apps on BYO-devices by containerizing them, leaving personal data untouched!
https://ad.doubleclick.net/ddm/clk/304595813;131938128;j
_______________________________________________
Nbd-general mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/nbd-general
