From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755664Ab3BSMrV (ORCPT ); Tue, 19 Feb 2013 07:47:21 -0500 Received: from mx1.redhat.com ([209.132.183.28]:25784 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751812Ab3BSMrS (ORCPT ); Tue, 19 Feb 2013 07:47:18 -0500 Date: Tue, 19 Feb 2013 09:46:40 -0300 From: Mauro Carvalho Chehab To: Borislav Petkov Cc: balbi@ti.com, Greg KH , Linux Kernel Mailing List , Steven Rostedt , Frederic Weisbecker , Ingo Molnar , JBottomley@parallels.com, linux-scsi@vger.kernel.org, davem@davemloft.net, netdev@vger.kernel.org, Doug Thompson , linux-edac@vger.kernel.org, rjw@sisk.pl, linux-pm@vger.kernel.org Subject: Re: SYSFS "errors" Message-ID: <20130219094640.2abf1a66@redhat.com> In-Reply-To: <20130219123502.GD26623@pd.tnic> References: <20130218184742.5a4c3c06@redhat.com> <20130218215434.GB16794@kroah.com> <20130218221306.GA21493@pd.tnic> <20130218222618.GA21818@kroah.com> <20130218224405.GB21493@pd.tnic> <20130219070310.2cadad7a@redhat.com> <20130219101121.GJ23197@arwen.pp.htv.fi> <20130219081149.46972f56@redhat.com> <20130219114345.GA26623@pd.tnic> <20130219091610.2b746a30@redhat.com> <20130219123502.GD26623@pd.tnic> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Tue, 19 Feb 2013 13:35:02 +0100 Borislav Petkov escreveu: > On Tue, Feb 19, 2013 at 09:16:10AM -0300, Mauro Carvalho Chehab wrote: > > I'm not sure if is there a way to pass fs permissions to something similar > > to device_create_file(). > > struct device_attribute.attr.mode? I.e., second arg. Ah, now I see what you're meaning. That would require to dynamically create a per-mci DEVICE_ATTR(). > > On both cases, an error will happen at open: > > - if file doesn't exist (this approach), it will return -ENOENT; > > - if file is opened with wrong permissions, open will return -EPERM. > > > > However, if the file is not created, readdir() won't show the file. > > Right, and in that case userspace which *assumes* it is always created - > like it is now - will fail when accessing it. > > If simply you adjust the attributes accordingly but *always* create the > file and it has the correct permissions, everyone is happy. Right? No, on both cases, open() will return an error (-ENOENT against -EPERM). If userspace doesn't check if open() failed, I can't see why changing the open return error code would help. -- Cheers, Mauro