Re: [PATCH 08/17] nfp: no need to check return value of debugfs_create functions

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Tue, Aug 06, 2019 at 09:50:08AM -0700, Jakub Kicinski wrote:
> On Tue,  6 Aug 2019 18:11:19 +0200, Greg Kroah-Hartman wrote:
> > When calling debugfs functions, there is no need to ever check the
> > return value.  The function can work or not, but the code logic should
> > never do something different based on this.
> > 
> > Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
> > Cc: "David S. Miller" <davem@davemloft.net>
> > Cc: Alexei Starovoitov <ast@kernel.org>
> > Cc: Daniel Borkmann <daniel@iogearbox.net>
> > Cc: Jesper Dangaard Brouer <hawk@kernel.org>
> > Cc: John Fastabend <john.fastabend@gmail.com>
> > Cc: Edwin Peer <edwin.peer@netronome.com>
> > Cc: Yangtao Li <tiny.windzz@gmail.com>
> > Cc: Simon Horman <simon.horman@netronome.com>
> > Cc: oss-drivers@netronome.com
> > Cc: netdev@vger.kernel.org
> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> 
> Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
> 
> I take it this is the case since commit ff9fb72bc077 ("debugfs: return
> error values, not NULL")? I.e. v5.0? It'd be useful to know for backport
> purposes.

You were always safe to ignore debugfs calls before that, but in 5.0 and
then 5.2 we got a bit more "robust" with some internal debugfs logic to
make it even easier.  These can be backported to 2.6.11+ if you really
want to, no functionality should change.

But why would you want to backport them?  This really isn't a "bugfix"
for a stable kernel.  No one should ever noticed the difference except
for less memory being used.

thanks,

greg k-h