Re: [Intel-gfx] [PATCH 1/5] dri: cleanup debugfs error handling

[Greg KH <gregkh@linuxfoundation.org>]

On Fri, Oct 08, 2021 at 12:40:47PM +0300, Jani Nikula wrote:
> On Fri, 08 Oct 2021, Nirmoy Das <nirmoy.das@amd.com> wrote:
> > Debugfs API returns encoded error instead of NULL.
> > This patch cleanups drm debugfs error handling to
> > properly set dri and its minor's root dentry to NULL.
> >
> > Also do not error out if dri/minor debugfs directory
> > creation fails as a debugfs error is not a fatal error.
> 
> Cc: Greg
> 
> I thought this is the opposite of what Greg's been telling everyone to
> do with debugfs.

Yes, that is not good.

You should never care about the result of a debugfs_create* call.  Just
take the result, and if it is a directory, save it off to use it for
creating a file, no need to check anything.

And then throw it away, later, when you want to remove the directory,
look it up with a call to debugfs_lookup() and pass that to
debugfs_remove() (which does so recursively).

There should never be a need to save, or check, the result of any
debugfs call.  If so, odds are it is being used incorrectly.

thanks,

greg k-h