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=-0.6 required=3.0 tests=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 E8DCAC433DF for ; Thu, 18 Jun 2020 06:56:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C93BF20773 for ; Thu, 18 Jun 2020 06:56:45 +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="iQ/jY6Bw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727115AbgFRG4i (ORCPT ); Thu, 18 Jun 2020 02:56:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41706 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727010AbgFRG4h (ORCPT ); Thu, 18 Jun 2020 02:56:37 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8D6ACC06174E; Wed, 17 Jun 2020 23:56:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.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=uAvmk2CwDLs4X+Ko7ajFBaGyB0rcXPF4WnH3SQrYs4k=; b=iQ/jY6BwNU0GexOcII4Y8RmC90 vslaU7EwpUIeDbH4l3fPejGtKiiupUxIiUtFiXf9OKFRfNWnG9EfupRM5LYyTyoqkQ4NaCxf+rQEx QpA0xyEbPpW6VGUiNbZPittAv+QRYNnNWsWAqedu0wTvaDrHGNzeST60Osvj66lkMXofncPReYaX4 xFEqPz0Pl/FlgUEfYqpEGhHy0/hcdSLaJ9QIprhDs1/QkI8aerds64dV+fhAfvor9e/DUmYIX86+S TJC0Ps7C1qPcTVNwNM4UX+vYpk2ktc961oLqTiOI4ve7lfCJzRLxzGLqieBv7S/MYQVFHGZpIRreL YlLoGcYw==; Received: from hch by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jloTS-00012N-So; Thu, 18 Jun 2020 06:56:34 +0000 Date: Wed, 17 Jun 2020 23:56:34 -0700 From: Christoph Hellwig To: Kanchan Joshi Cc: axboe@kernel.dk, viro@zeniv.linux.org.uk, bcrl@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-aio@kvack.org, io-uring@vger.kernel.org, linux-block@vger.kernel.org, selvakuma.s1@samsung.com, nj.shetty@samsung.com, javier.gonz@samsung.com Subject: Re: [PATCH 0/3] zone-append support in aio and io-uring Message-ID: <20200618065634.GB24943@infradead.org> References: <1592414619-5646-1-git-send-email-joshi.k@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1592414619-5646-1-git-send-email-joshi.k@samsung.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.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 Wed, Jun 17, 2020 at 10:53:36PM +0530, Kanchan Joshi wrote: > This patchset enables issuing zone-append using aio and io-uring direct-io interface. > > For aio, this introduces opcode IOCB_CMD_ZONE_APPEND. Application uses start LBA > of the zone to issue append. On completion 'res2' field is used to return > zone-relative offset. > > For io-uring, this introduces three opcodes: IORING_OP_ZONE_APPEND/APPENDV/APPENDV_FIXED. > Since io_uring does not have aio-like res2, cqe->flags are repurposed to return zone-relative offset And what exactly are the semantics supposed to be? Remember the unix file abstractions does not know about zones at all. I really don't think squeezing low-level not quite block storage protocol details into the Linux read/write path is a good idea. What could be a useful addition is a way for O_APPEND/RWF_APPEND writes to report where they actually wrote, as that comes close to Zone Append while still making sense at our usual abstraction level for file I/O.