From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264226AbTF0KeS (ORCPT ); Fri, 27 Jun 2003 06:34:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264231AbTF0KeS (ORCPT ); Fri, 27 Jun 2003 06:34:18 -0400 Received: from ns.virtualhost.dk ([195.184.98.160]:55456 "EHLO virtualhost.dk") by vger.kernel.org with ESMTP id S264226AbTF0KeO (ORCPT ); Fri, 27 Jun 2003 06:34:14 -0400 Date: Fri, 27 Jun 2003 12:48:22 +0200 From: Jens Axboe To: Samium Gromoff Cc: linux-kernel@vger.kernel.org, sct@redhat.com, akpm@digeo.com Subject: Re: [BIO] request->flags ambiguity Message-ID: <20030627104822.GE821@suse.de> References: <20030627134756.4118617e.deepfire@ibe.miee.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030627134756.4118617e.deepfire@ibe.miee.ru> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 27 2003, Samium Gromoff wrote: > I might just be completely off base, but something struck me > lately as odd, and i`d like to hear what you folks think about > the issue. > > I`m wondering about the ambiguity of the struct request->flags > field. > > Is it ok to have a possibility of a request with conflicting > meanings attached to it? For example REQ_CMD | REQ_PM_SHUTDOWN > | REQ_SPECIAL. No of course not. > It may be, depending on the implementation, that they are not > completely conflicting, but its hard to believe that there is > zero ambiguity at all. > > If i`m not mistaken this looks as creating opportunities for > various subtle bugs. > > Shouldn`t it make more sense to separate request-type-indicator > flags into a separate unambiguous type field, which would take > one of the following values: - read/write request - sense query > - power control - special request > > And not a currently possible combination of all of them, which > seem to be the current situation. There has been talk of that before, search the archives. -- Jens Axboe