RE: [PATCH] Drivers: hv: vmbus: Return -EINVAL for the sys files for unopened channels

[Dexuan Cui]

> From: Stephen Hemminger <stephen@xxxxxxxxxxxxxxxxxx>
> On Thu, 13 Dec 2018 16:35:43 +0000
> Dexuan Cui <decui@xxxxxxxxxxxxx> wrote:
> 
> > Before 98f4c651762c, we returned zeros for unopened channels.
> > With 98f4c651762c, we started to return random on-stack values.
> >
> > We'd better return -EINVAL instead.
> 
> The concept looks fine, but maybe it would be simpler to move it into
> hv_ringbuffer_get_debuginfo and have it return an error code.
> 
> Since so much of the code is repeated, I would probably make a
> macro which generates the code as well.
> 
> Something like this:

Thanks, Stephen! Now the patch has been in char-misc's char-misc-linus
branch, so IMO we may as well leave it as is (considering the code here is
unlikely to be frqeuencly changed), and we have a smaller patch this way. :-)

But, yes, I agree with you that generally we should make a common
function to avoid duplicate code.

Thanks,
-- Dexuan