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From:   Arnd Bergmann <arnd@arndb.de>
Date:   Fri, 22 Mar 2019 17:55:11 +0100
Message-ID: <CAK8P3a2mZ-zyAMrR2zesAUoLO0BiDcmr6VnJzuJb=PFSHj4PWg@mail.gmail.com>
Subject: Re: [PATCH] rbd: avoid clang -Wuninitialized warning
To:     Ilya Dryomov <idryomov@gmail.com>
Cc:     Sage Weil <sage@redhat.com>, Alex Elder <elder@kernel.org>,
        Jens Axboe <axboe@kernel.dk>,
        clang-built-linux@googlegroups.com,
        Nick Desaulniers <ndesaulniers@google.com>,
        Nathan Chancellor <natechancellor@gmail.com>,
        Jason Dillaman <dillaman@redhat.com>,
        Ceph Development <ceph-devel@vger.kernel.org>,
        linux-block <linux-block@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>
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On Fri, Mar 22, 2019 at 5:33 PM Ilya Dryomov <idryomov@gmail.com> wrote:
>
> On Fri, Mar 22, 2019 at 3:36 PM Arnd Bergmann <arnd@arndb.de> wrote:
> >
> > diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
> > index 4ba967d65cf9..cbcc3baf3807 100644
> > --- a/drivers/block/rbd.c
> > +++ b/drivers/block/rbd.c
> > @@ -2399,7 +2399,7 @@ static int rbd_obj_read_from_parent(struct rbd_obj_request *obj_req)
> >                                                       &obj_req->bvec_pos);
> >                         break;
> >                 default:
> > -                       rbd_assert(0);
> > +                       BUG();
> >                 }
> >         } else {
> >                 ret = rbd_img_fill_from_bvecs(child_img_req,
>
> Hi Arnd,
>
> You did a couple of these last year in commit c6244b3b2377 ("rbd: avoid
> Wreturn-type warnings").

Ah, I had completely forgotten about that. Different bug and different
compiler, but same solution ;-)

>  Let's change all of those default cases to BUG
> in one go.  Do you want to do that or should I?

I've prepared another patch now and sent it out, please
apply it on top. I'd like this one-line patch to stay separate though
since it captures the warning message and may need to
be backported to stable kernels later.

      Arnd