Re: [PATCH] powerpc: fix debugfs_create_dir error checking

[Immad Mir <mirimmad17@gmail.com>]

[-- Attachment #1: Type: text/plain, Size: 2068 bytes --]

> Still I think this patch is an improvement so I'll plan to merge it.

Please let me know when you commit it.

Thanks
Immad.

On Tue, May 30, 2023 at 4:17 PM Michael Ellerman <mpe@ellerman.id.au> wrote:

> Greg KH <gregkh@linuxfoundation.org> writes:
> > On Sun, May 28, 2023 at 01:16:44PM +0530, mirimmad@outlook.com wrote:
> >> From: Immad Mir <mirimmad17@gmail.com>
> >>
> >> The debugfs_create_dir returns ERR_PTR incase of an error and the
> >> correct way of checking it by using the IS_ERR inline function, and
> >> not the simple null comparision. This patch fixes this.
> >>
> >> Suggested-By: Ivan Orlov <ivan.orlov0322@gmail.com>
> >> Signed-off-by: Immad Mir <mirimmad17@gmail.com>
> >> ---
> >>  arch/powerpc/platforms/powernv/opal-xscom.c | 4 ++--
> >>  1 file changed, 2 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/arch/powerpc/platforms/powernv/opal-xscom.c
> b/arch/powerpc/platforms/powernv/opal-xscom.c
> >> index 6b4eed2ef..262cd6fac 100644
> >> --- a/arch/powerpc/platforms/powernv/opal-xscom.c
> >> +++ b/arch/powerpc/platforms/powernv/opal-xscom.c
> >> @@ -168,7 +168,7 @@ static int scom_debug_init_one(struct dentry *root,
> struct device_node *dn,
> >>      ent->path.size = strlen((char *)ent->path.data);
> >>
> >>      dir = debugfs_create_dir(ent->name, root);
> >> -    if (!dir) {
> >> +    if (IS_ERR(dir)) {
> >>              kfree(ent->path.data);
> >>              kfree(ent);
> >>              return -1;
> >
> > Why is this driver caring if debugfs is working or not at all?  It
> > should just ignore the error and keep moving forward.
>
> It's creating directories and then creating files in those directories.
> So I think it makes sense that it checks that the directory was created
> successfully. It doesn't check whether the files were created.
>
> > And -1 is not a valid error number :(
>
> It's EPERM :) - but yeah probably not really the right error in this
> case.
>
> Still I think this patch is an improvement so I'll plan to merge it.
>
> cheers
>

[-- Attachment #2: Type: text/html, Size: 3054 bytes --]