From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jakub Kicinski Subject: Re: [PATCH net-next] netdevsim: correctly check return value of debugfs_create_dir Date: Thu, 7 Dec 2017 17:12:06 -0800 Message-ID: <20171207171206.183f69a9@cakuba.netronome.com> References: <20171208005250.2972-1-bhole_prashant_q7@lab.ntt.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: "David S . Miller" , netdev@vger.kernel.org To: Prashant Bhole Return-path: Received: from mail-qt0-f196.google.com ([209.85.216.196]:35518 "EHLO mail-qt0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750993AbdLHBMK (ORCPT ); Thu, 7 Dec 2017 20:12:10 -0500 Received: by mail-qt0-f196.google.com with SMTP id u10so22518423qtg.2 for ; Thu, 07 Dec 2017 17:12:10 -0800 (PST) In-Reply-To: <20171208005250.2972-1-bhole_prashant_q7@lab.ntt.co.jp> Sender: netdev-owner@vger.kernel.org List-ID: On Fri, 8 Dec 2017 09:52:50 +0900, Prashant Bhole wrote: > Return value is now checked with IS_ERROR_OR_NULL because > debugfs_create_dir doesn't return error value. It either returns > NULL or a valid pointer. > > Signed-off-by: Prashant Bhole > --- > drivers/net/netdevsim/netdev.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/net/netdevsim/netdev.c b/drivers/net/netdevsim/netdev.c > index eb8c679fca9f..88d8ee2c89da 100644 > --- a/drivers/net/netdevsim/netdev.c > +++ b/drivers/net/netdevsim/netdev.c > @@ -469,7 +469,7 @@ static int __init nsim_module_init(void) > int err; > > nsim_ddir = debugfs_create_dir(DRV_NAME, NULL); > - if (IS_ERR(nsim_ddir)) > + if (IS_ERR_OR_NULL(nsim_ddir)) > return PTR_ERR(nsim_ddir); PTR_ERR() will not be good in case of NULL, no? But it's anyone's guess what the correct error code would then be... the EEXIST from start_creating() I was after is dropped in debugfs_create_dir(), as you previously pointed out. Maybe just drop this error handling here and in nsim_bpf_create_prog(). Let's consistently ignore all DebugFS errors. Sorry about going back and forth on this a little bit. > err = bus_register(&nsim_bus);