Re: [PATCH] mm/cma_debug: Check for null tmp in cma_debugfs_add_one()

From: Greg KH
Date: Thu Feb 21 2019 - 04:10:16 EST


On Thu, Feb 21, 2019 at 04:56:42PM +0800, Yue Hu wrote:
> On Thu, 21 Feb 2019 09:23:09 +0100
> Michal Hocko <mhocko@xxxxxxxxxx> wrote:
>
> > On Thu 21-02-19 12:01:30, Yue Hu wrote:
> > > From: Yue Hu <huyue2@xxxxxxxxxx>
> > >
> > > If debugfs_create_dir() failed, the following debugfs_create_file()
> > > will be meanless since it depends on non-NULL tmp dentry and it will
> > > only waste CPU resource.
> >
> > The file will be created in the debugfs root. But, more importantly.
> > Greg (CCed now) is working on removing the failure paths because he
> > believes they do not really matter for debugfs and they make code more
> > ugly. More importantly a check for NULL is not correct because you
> > get ERR_PTR after recent changes IIRC.
>
> Same check logic in cma_debugfs_init(), i'm just finding they do not stay
> the same.

I have patches to fix that up as well :)

thanks,

greg k-h