Re: [Qemu-devel] [PATCH v4 04/11] nbd: Improve server handling of bogus commands

[Paolo Bonzini]

On 12/05/2016 00:39, Eric Blake wrote:
> - If we report an error to NBD_CMD_READ, we are not writing out
> any data payload; but the protocol says that a client can expect
> to read the payload no matter what (and must instead ignore it),
> which means the client will start reading our next replies as
> its data payload. Fix by disconnecting (an alternative fix of
> sending bogus payload would be trickier to implement).

This is an error in the spec.  The Linux driver doesn't expect to read
the payload here, and neither does block/nbd-client.c.

Paolo