Re: [virtio-comment] Re: [PATCH v10 03/10] admin: introduce group administration commands

[Cornelia Huck <cohuck@redhat.com>]

On Mon, Feb 13 2023, Max Gurtovoy <mgurtovoy@nvidia.com> wrote:

> On 13/02/2023 10:16, Michael S. Tsirkin wrote:
>> On Mon, Feb 13, 2023 at 02:54:47AM +0200, Max Gurtovoy wrote:
>>>> For some system calls and library functions (e.g.,
>>>>          getpriority(2)), -1 is a valid return on success.  In such cases,
>>>>          a successful return can be distinguished from an error return by
>>>>          setting errno to zero before the call, and then, if the call
>>>>          returns a status that indicates that an error may have occurred,
>>>>          checking to see if errno has a nonzero value.
>>>>
>>>>
>>>>
>>>>> Description is already good enough to describe what they are.
>>>>> Can we please drop Linux wording?
>>>>
>>>> But why should we? It's where 22 comes from so this way people are not
>>>> wondering about the value, and it's somewhat helpful for Linux
>>>> developers.
>>>>
>>>
>>> I also think we should not mention Linux. I don't think it's mentioned
>>> currently in the spec and no good reason to do so now.
>> 
>> But we do: fuse, input at least both do.
>> 
>>> Also value of 22 is not mandatory for this EINVAL status code. It can be
>>> just 1 (the first number after the OK status).
>> 
>> 22 makes it a tiny bit easier for kvm. So why not.
>
> Because people comment on that in the review :) and because a 
> specification should be OS independent.
> 22 might be EINVAL in Linux but a success in MyOS is my lucky number is 22.
>
> not a big issue for me, but I prefer to have a cleaner spec than maybe 
> simplify something in a very specific OS.

Well, my take is:
- we have to pick *something*
- using EINVAL == 22 is very convenient for one of the most common (the
  most common?) implementors
- noting that we're trying to follow what Linux uses makes it clear what
  to pick for any new return codes