From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752065AbdAaM6a (ORCPT ); Tue, 31 Jan 2017 07:58:30 -0500 Received: from verein.lst.de ([213.95.11.211]:56208 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751967AbdAaM6V (ORCPT ); Tue, 31 Jan 2017 07:58:21 -0500 Date: Tue, 31 Jan 2017 13:58:14 +0100 From: Christoph Hellwig To: Greg Kroah-Hartman Cc: Marek Vasut , "linux-kernel@vger.kernel.org" , hch@lst.de, Pantelis Antoniou , Joel Becker Subject: Re: [PATCH] [RFC] fs: Possible filp_open race experiment Message-ID: <20170131125814.GB5298@lst.de> References: <20170117231600.10186-1-marex@denx.de> <16b3fb38-0dfc-2d3c-7cfd-681b15432fb7@denx.de> <20170131070511.GB5149@kroah.com> <20170131102102.GA5349@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170131102102.GA5349@kroah.com> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 31, 2017 at 11:21:02AM +0100, Greg Kroah-Hartman wrote: > > -next isn't Linus's tree, sometimes stuff sits in there for years :) > > Anyway, if this is a configfs issue, Christoph and Joel can take a look > at it. Any reason you didn't cc: Joel as well (the MAINTAINERS file is > your friend...) It's really a mismatched assumption. The configfs binary file code just chunks updates up into a buffer, which only gets flushed at ->release time. If we'd move that to ->flush the issue Marek reports would be fixed. But I don't think we want that - triggering a filp_open from the update of a _binary_ attribute for a start is wrong. And second doing this using ->fs of a random calling process is bound to cause problems. I think he is using the wrong kind of interface for the job.