From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 47787C433EA for ; Fri, 10 Jul 2020 13:49:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1C5C3207DF for ; Fri, 10 Jul 2020 13:49:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="hb75Vl/q" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727914AbgGJNtm (ORCPT ); Fri, 10 Jul 2020 09:49:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37718 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727092AbgGJNtm (ORCPT ); Fri, 10 Jul 2020 09:49:42 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B68F9C08C5CE; Fri, 10 Jul 2020 06:49:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=3xDdy1lO/VESQQ+XIKtdvZXNsbdN37Eb/qTJ2DIu6ic=; b=hb75Vl/qOQRKSrCFc7dBnj8nW+ DWLgtlYO8WDorx37QoqqOFXFQdt2KKIPDcszlbj3SKdQzbQFO8s4eABPxYQVxXmoGNHlJPI/JjLj2 pglouwDIRscalO2YKgKmMXSVJ00Ui8W8dUaWRrTiYOPsOGYhWbhuitupp8fnuq5utEipxiWuWvdtv iL49fdyjs3HVLBnoyB98A1PwrUP1zDq+nApWW2D5PwI5PX8nFOlV4qfGV8gPNzzRKGWZKSmIyH8Xt T8My2DllIHM3gCGhF/MFhMt8MLPgMTUREzgUp2H3W0yA51WlMSR9Bex/9L0hZi7q8Ajc0PXBd6I1S gcL2CmOg==; Received: from hch by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jttPA-0004GD-AI; Fri, 10 Jul 2020 13:49:32 +0000 Date: Fri, 10 Jul 2020 14:49:32 +0100 From: Christoph Hellwig To: Matthew Wilcox Cc: Christoph Hellwig , Kanchan Joshi , Jens Axboe , Kanchan Joshi , viro@zeniv.linux.org.uk, bcrl@kvack.org, Damien.LeMoal@wdc.com, asml.silence@gmail.com, linux-fsdevel@vger.kernel.org, Matias Bj??rling , linux-kernel@vger.kernel.org, linux-aio@kvack.org, io-uring@vger.kernel.org, linux-block@vger.kernel.org, Selvakumar S , Nitesh Shetty , Javier Gonzalez Subject: Re: [PATCH v3 4/4] io_uring: add support for zone-append Message-ID: <20200710134932.GA16257@infradead.org> References: <20200709085501.GA64935@infradead.org> <20200709140053.GA7528@infradead.org> <2270907f-670c-5182-f4ec-9756dc645376@kernel.dk> <20200710131054.GB7491@infradead.org> <20200710134824.GK12769@casper.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200710134824.GK12769@casper.infradead.org> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Sender: io-uring-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On Fri, Jul 10, 2020 at 02:48:24PM +0100, Matthew Wilcox wrote: > If we're going to go the route of changing the CQE, how about: > > struct io_uring_cqe { > __u64 user_data; /* sqe->data submission passed back */ > - __s32 res; /* result code for this event */ > - __u32 flags; > + union { > + struct { > + __s32 res; /* result code for this event */ > + __u32 flags; > + }; > + __s64 res64; > + }; > }; > > then we don't need to change the CQE size and it just depends on the SQE > whether the CQE for it uses res+flags or res64. How do you return a status code or short write when you just have a u64 that is needed for the offset?