[Libguestfs] [PATCH v3 12/14] nbd/client: Request extended headers during negotiation

[Vladimir Sementsov-Ogievskiy]

On 31.05.23 20:54, Eric Blake wrote:
> On Wed, May 31, 2023 at 08:39:53PM +0300, Vladimir Sementsov-Ogievskiy wrote:
>> On 15.05.23 22:53, Eric Blake wrote:
>>> All the pieces are in place for a client to finally request extended
>>> headers.  Note that we must not request extended headers when qemu-nbd
>>
>> why must not? It should gracefully report ENOTSUP? Or not?
> 
> The kernel code does not yet know how to send extended requests; once
> extended mode is negotiated, sending a simple request requires the

but how it could be negotiated if kernel doesn't support it?

I mean if we request extended headers during negotiation with kernel, the kernel will just say "unsupported option", isn't it?

Or, in other words, I understand that kernel doesn't support it, I don't understand why you note it here. Is kernel different from other NBD server implementations which doesn't support extended requests at the moment?


-- 
Best regards,
Vladimir