Re: [PATCH 1/1] debugfs: use IS_ERR to check for error

[Greg KH <gregkh@linuxfoundation.org>]

On Thu, Sep 02, 2021 at 02:03:12PM +0200, Christian König wrote:
> 
> 
> Am 02.09.21 um 12:38 schrieb Greg KH:
> > On Thu, Sep 02, 2021 at 12:29:17PM +0200, Nirmoy Das wrote:
> > > debugfs_create_file() returns encoded error so
> > > use IS_ERR for checking return value.
> > > 
> > > References: https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgitlab.freedesktop.org%2Fdrm%2Famd%2F-%2Fissues%2F1686&data=04%7C01%7CChristian.Koenig%40amd.com%7C82691bea64d3491fe86008d96dfddc60%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637661759378883940%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=Xs4xnihnMzNvl%2BSEEpCcWkdvMaDw1Ofvekn%2Fnvz1mM8%3D&reserved=0
> > > Signed-off-by: Nirmoy Das <nirmoy.das@amd.com>
> > > ---
> > >   fs/debugfs/inode.c | 2 +-
> > >   1 file changed, 1 insertion(+), 1 deletion(-)
> > > 
> > > diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
> > > index 8129a430d789..2f117c57160d 100644
> > > --- a/fs/debugfs/inode.c
> > > +++ b/fs/debugfs/inode.c
> > > @@ -528,7 +528,7 @@ void debugfs_create_file_size(const char *name, umode_t mode,
> > >   {
> > >   	struct dentry *de = debugfs_create_file(name, mode, parent, data, fops);
> > > -	if (de)
> > > +	if (!IS_ERR(de))
> > >   		d_inode(de)->i_size = file_size;
> > >   }
> > >   EXPORT_SYMBOL_GPL(debugfs_create_file_size);
> > > -- 
> > > 2.32.0
> > > 
> > Ah, good catch, I'll queue this up after 5.15-rc1 is out, thanks!
> 
> Thinking more about this if I'm not completely mistaken
> debugfs_create_file() returns -ENODEV when debugfs is disabled and NULL on
> any other error.

How can this function be called if debugfs is not enabled in the system
configuration?  This _is_ the debugfs core code.

thanks,

greg k-h