From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757757AbXI0SiQ (ORCPT ); Thu, 27 Sep 2007 14:38:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755795AbXI0Sh7 (ORCPT ); Thu, 27 Sep 2007 14:37:59 -0400 Received: from THUNK.ORG ([69.25.196.29]:55967 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752165AbXI0Sh6 (ORCPT ); Thu, 27 Sep 2007 14:37:58 -0400 Date: Thu, 27 Sep 2007 14:37:42 -0400 From: Theodore Tso To: Greg KH Cc: Andrew Morton , Alan Cox , Jens Axboe , Arjan van de Ven , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH] fs: Correct SuS compliance for open of large file without options Message-ID: <20070927183742.GA23734@thunk.org> Mail-Followup-To: Theodore Tso , Greg KH , Andrew Morton , Alan Cox , Jens Axboe , Arjan van de Ven , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org References: <20070927142919.10b62f9b@the-village.bc.nu> <20070927070118.2bd4792e@laptopd505.fenrus.org> <20070927151921.29b19abb@the-village.bc.nu> <20070927143548.GT5243@kernel.dk> <20070927154432.302ec5a7@the-village.bc.nu> <20070927150853.GA10154@kernel.dk> <20070927161912.2f08aff6@the-village.bc.nu> <20070927155902.GA6450@thunk.org> <20070927102343.1a113ccc.akpm@linux-foundation.org> <20070927175917.GB8339@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070927175917.GB8339@kroah.com> User-Agent: Mutt/1.5.13 (2006-08-11) X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: tytso@thunk.org X-SA-Exim-Scanned: No (on thunker.thunk.org); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 27, 2007 at 10:59:17AM -0700, Greg KH wrote: > Come on now, I'm _very_ tired of this kind of discussion. Please go > read the documentation on how to _use_ sysfs from userspace in such a > way that you can properly access these data structures so that no > breakage occurs. I've read it; the question is whether every single application programmer or system shell script programmer who writes code my system depends upon has read it this document buried in the kernel sources, or whether things will break spectacularly --- one of those things that leaves me in suspense each time I update the kernel. I'm reminded of Rusty's 2003 OLS Keynote, where he points out that what's important is not making an interface easy to use, but _hard_ _to_ _misuse_. That fact that sysfs is all laid out in a directory, but for which some directories/symlinks are OK to use, and some are NOT OK to use --- is why I call the sysfs interface "an open pit". Sure, if you have the map to the minefield, a minefield is perfectly safe when you know what to avoid. But is that the best way to construct a path/interface for an application programmer to get from point A to point B? Maybe, maybe not. - Ted