From mboxrd@z Thu Jan  1 00:00:00 1970
From: Cong Wang <xiyou.wangcong@gmail.com>
Subject: Re: [Patch net-next] net_sched: fix an extack message in tcf_block_find()
Date: Fri, 28 Sep 2018 10:03:08 -0700
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References: <20180927204219.17846-1-xiyou.wangcong@gmail.com> <vbf1s9dyhub.fsf@reg-r-vrt-018-180.mtr.labs.mlnx>
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Cc: Linux Kernel Network Developers <netdev@vger.kernel.org>,
        Jiri Pirko <jiri@resnulli.us>,
        Jamal Hadi Salim <jhs@mojatatu.com>
To: Vlad Buslov <vladbu@mellanox.com>
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On Fri, Sep 28, 2018 at 4:36 AM Vlad Buslov <vladbu@mellanox.com> wrote:
>
> On Thu 27 Sep 2018 at 20:42, Cong Wang <xiyou.wangcong@gmail.com> wrote:
> > It is clearly a copy-n-paste.
> >
> > Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
> > ---
> >  net/sched/cls_api.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
> > index 3de47e99b788..8dd7f8af6d54 100644
> > --- a/net/sched/cls_api.c
> > +++ b/net/sched/cls_api.c
> > @@ -655,7 +655,7 @@ static struct tcf_block *tcf_block_find(struct net *net, struct Qdisc **q,
> >
> >               *q = qdisc_refcount_inc_nz(*q);
> >               if (!*q) {
> > -                     NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
> > +                     NL_SET_ERR_MSG(extack, "Can't increase Qdisc refcount");
> >                       err = -EINVAL;
> >                       goto errout_rcu;
> >               }
>
> Is there a benefit in exposing this info to user?

Depends on what user you mean here. For kernel developers, yes,
this is useful. For others, no.


> For all intents and purposes Qdisc is gone at that point.

I don't want to be a language lawyer, but there is a difference between
"it doesn't exist" and "it exists but being removed". The errno EINVAL
betrays what you said too, it must be ENOENT to mach "Qdisc is gone".

I don't want to waste my time on this any more. Let's just drop it.

I really don't care, do you?