Re: [PATCH] dax: fix dax_core_init error return code

[Jianyun Gao]

Hi Jonathan,

Thank you for the review!

For the goto err_fs change, I agree it's unnecessary since there's
nothing to clean up at that point. I will drop it in v2.

For the return 0 -> return rc change, I also can't think of a reason
to deliberately swallow the error. I'll keep this change and cc the
DAX maintainers for their input.

Best regards,
Jianyun

On Mon, Oct 12, 2026 at 10:28 PM Jonathan Cameron <jic23@xxxxxxxxxx> wrote:
>
> On Sun, 11 Oct 2026 21:20:17 +0800
> jianyungao89@xxxxxxxxx wrote:
>
> > From: Jianyun Gao <jianyungao89@xxxxxxxxx>
> >
> > dax_core_init() mistakenly returns 0 on error paths. Change the
> > error return to use rc so the actual error code is propagated
> > to the caller.
>
> What is the user visible impact of this failing?
>
> >
> > Fixes: 9567da0b408a ("device-dax: Introduce bus + driver model")
> > Signed-off-by: Jianyun Gao <jianyungao89@xxxxxxxxx>
> > ---
> >  drivers/dax/super.c | 5 +++--
> >  1 file changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/dax/super.c b/drivers/dax/super.c
> > index 45f84b0eb909..0f35f65363ee 100644
> > --- a/drivers/dax/super.c
> > +++ b/drivers/dax/super.c
> > @@ -723,7 +723,7 @@ static int __init dax_core_init(void)
> >
> >       rc = dax_fs_init();
> >       if (rc)
> > -             return rc;
> > +             goto err_fs;
> I don't see an advantage in this bit.  It is a fairly common preference
> to error out directly where there is nothing to do.
>
> >
> >       rc = alloc_chrdev_region(&dax_devt, 0, MINORMASK+1, "dax");
> >       if (rc)
> > @@ -738,7 +738,8 @@ static int __init dax_core_init(void)
> >       unregister_chrdev_region(dax_devt, MINORMASK+1);
> >  err_chrdev:
> >       dax_fs_exit();
> > -     return 0;
> > +err_fs:
> > +     return rc;
> I'm not sure about this one.  Will need input from the DAX
> folk on whether they were deliberately eating the error return
> here. Not that I can immediately think of a reason to do so!
>
> Jonathan
>
>
> >  }
> >
> >  static void __exit dax_core_exit(void)
>