Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752027AbXAQF6m (ORCPT ); Wed, 17 Jan 2007 00:58:42 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752030AbXAQF6m (ORCPT ); Wed, 17 Jan 2007 00:58:42 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:41857 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752027AbXAQF6l (ORCPT ); Wed, 17 Jan 2007 00:58:41 -0500 Subject: Re: O_DIRECT question From: Arjan van de Ven To: 7eggert@gmx.de Cc: Helge Hafting , Michael Tokarev , Chris Mason , Linus Torvalds , dean gaudet , Viktor , Aubrey , Hua Zhong , Hugh Dickins , linux-kernel@vger.kernel.org, hch@infradead.org, kenneth.w.chen@intel.com, akpm@osdl.org In-Reply-To: References: <7BYkO-5OV-17@gated-at.bofh.it> <7BYul-6gz-5@gated-at.bofh.it> <7C74B-2A4-23@gated-at.bofh.it> <7CaYA-mT-19@gated-at.bofh.it> <7Cpuz-64X-1@gated-at.bofh.it> <7Cz0T-4PH-17@gated-at.bofh.it> <7CBcl-86B-9@gated-at.bofh.it> <7CBvH-52-9@gated-at.bofh.it> <7DyYK-6lE-3@gated-at.bofh.it> Content-Type: text/plain Organization: Intel International BV Date: Tue, 16 Jan 2007 21:55:35 -0800 Message-Id: <1169013342.3457.60.camel@laptopd505.fenrus.org> Mime-Version: 1.0 X-Mailer: Evolution 2.8.2.1 (2.8.2.1-2.fc6) Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 985 Lines: 25 On Tue, 2007-01-16 at 21:26 +0100, Bodo Eggert wrote: > Helge Hafting wrote: > > Michael Tokarev wrote: > > >> But seriously - what about just disallowing non-O_DIRECT opens together > >> with O_DIRECT ones ? > >> > > Please do not create a new local DOS attack. > > I open some important file, say /etc/resolv.conf > > with O_DIRECT and just sit on the open handle. > > Now nobody else can open that file because > > it is "busy" with O_DIRECT ? > > Suspend O_DIRECT access while non-O_DIRECT-fds are open, fdatasync on close? .. then any user can impact the operation, performance and reliability of the database application of another user... sounds like plugging one hole by making a bigger hole ;) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/