Re: [PATCH net-next] net: dcb: move getapptrust to separate function

[Joe Perches <joe@perches.com>]

On Fri, 2022-11-11 at 06:45 +0000, Daniel.Machon@microchip.com wrote:
> Den Thu, Nov 10, 2022 at 05:30:43PM +0100 skrev Petr Machata:
> > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> > 
> > Daniel Machon <daniel.machon@microchip.com> writes:
> > 
> > > diff --git a/net/dcb/dcbnl.c b/net/dcb/dcbnl.c
> > > index cec0632f96db..3f4d88c1ec78 100644
> > > --- a/net/dcb/dcbnl.c
> > > +++ b/net/dcb/dcbnl.c
> > > @@ -1060,11 +1060,52 @@ static int dcbnl_build_peer_app(struct net_device *netdev, struct sk_buff* skb,
> > >       return err;
> > >  }
> > > 
> > > +static int dcbnl_getapptrust(struct net_device *netdev, struct sk_buff *skb)
> > > +{
> > > +     const struct dcbnl_rtnl_ops *ops = netdev->dcbnl_ops;
> > > +     int nselectors, err;
> > > +     u8 *selectors;
> > > +
> > > +     selectors = kzalloc(IEEE_8021QAZ_APP_SEL_MAX + 1, GFP_KERNEL);
> > > +     if (!selectors)
> > > +             return -ENOMEM;
> > > +
> > > +     err = ops->dcbnl_getapptrust(netdev, selectors, &nselectors);
> > > +
> > > +     if (!err) {
> > > +             struct nlattr *apptrust;
> > > +             int i;
> > 
> > (Maybe consider moving these up to the function scope. This scope
> > business made sense in the generic function, IMHO is not as useful with
> > a focused function like this one.)
> 
> I dont mind doing that, however, this 'scope business' is just staying true
> to the rest of the dcbnl code :-) - that said, I think I agree with your
> point.
> 
> > 
> > > +
> > > +             err = -EMSGSIZE;
> > > +
> > > +             apptrust = nla_nest_start(skb, DCB_ATTR_DCB_APP_TRUST_TABLE);
> > > +             if (!apptrust)
> > > +                     goto nla_put_failure;
> > > +
> > > +             for (i = 0; i < nselectors; i++) {
> > > +                     enum ieee_attrs_app type =
> > > +                             dcbnl_app_attr_type_get(selectors[i]);
> > 
> > Doesn't checkpatch warn about this? There should be a blank line after
> > the variable declaration block. (Even if there wasn't one there in the
> > original code either.)
> 
> Nope, no warning. And I think it has something to do with the way the line
> is split.

yup.

And style trivia:

I suggest adding error types after specific errors,
reversing the test and unindenting the code too. 

Something like:

	err = ops->dcbnl_getapptrust(netdev, selectors, &nselectors);
	if (err) {
		err = 0;
		goto out;
	}

	apptrust = nla_nest_start(skb, DCB_ATTR_DCB_APP_TRUST_TABLE);
	if (!apptrust) {
		err = -EMSGSIZE;
		goto out;
	}

	for (i = 0; i < nselectors; i++) {
		enum ieee_attrs_app type = dcbnl_app_attr_type_get(selectors[i]);
		err = nla_put_u8(skb, type, selectors[i]);
		if (err) {
			nla_nest_cancel(skb, apptrust);
			goto out;
		}
	}
	nla_nest_end(skb, apptrust);

	err = 0;

out:
	kfree(selectors);
	return err;
}