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[23.128.96.18]) by mx.google.com with ESMTP id dm17si16548714edb.312.2020.06.26.02.01.20; Fri, 26 Jun 2020 02:01:45 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=fail header.i=@infradead.org header.s=casper.20170209 header.b=ec0yT0jW; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726062AbgFZI7L (ORCPT + 99 others); Fri, 26 Jun 2020 04:59:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48948 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725905AbgFZI7L (ORCPT ); Fri, 26 Jun 2020 04:59:11 -0400 Received: from casper.infradead.org (unknown [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 22962C08C5C1; Fri, 26 Jun 2020 01:59:11 -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=gW+E1Jv1j6enHoS9ci8iskFSPJ2rZo4CjUglSeffP7o=; b=ec0yT0jWfXYNE/yB3dPz5baX8B 7smSzXLFiuj9f0Ed4NKLekPpMe3/SiPIJja5Dct7nl3HgWRYIQXNMnHS6dpZPVOyL5xaG5iCqF9X0 CL3mCgMIilh6uQny45ec0cTru4ix75kp0Y/VoGHgARCzk12v4eRECmaoJuAJIQD0/Tp7bJ32ekvrI YWqtMrFLoHgzk6rGoKlqFr+ht7kheor1fGdeZ/YN27RadZ0oDsErMMl00SvVyR2aEjChHMyYZlnWR luo7btYT2RvswiLQ98qswiHpUXLJnF3hTV3xX9fg/ehbnNMRGmQTlrVE/fJQfHzp9COF8QB+Vrtm2 FLx1RVYg==; Received: from hch by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jokC6-0007l8-Fb; Fri, 26 Jun 2020 08:58:46 +0000 Date: Fri, 26 Jun 2020 09:58:46 +0100 From: Christoph Hellwig To: Kanchan Joshi Cc: axboe@kernel.dk, viro@zeniv.linux.org.uk, bcrl@kvack.org, asml.silence@gmail.com, Damien.LeMoal@wdc.com, hch@infradead.org, linux-fsdevel@vger.kernel.org, mb@lightnvm.io, 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, Arnav Dawn Subject: Re: [PATCH v2 1/2] fs,block: Introduce RWF_ZONE_APPEND and handling in direct IO path Message-ID: <20200626085846.GA24962@infradead.org> References: <1593105349-19270-1-git-send-email-joshi.k@samsung.com> <1593105349-19270-2-git-send-email-joshi.k@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1593105349-19270-2-git-send-email-joshi.k@samsung.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org To restate my previous NAK: A low-level protocol detail like RWF_ZONE_APPEND has absolutely no business being exposed in the Linux file system interface. And as mentioned before I think the idea of returning the actual position written for O_APPEND writes totally makes sense, and actually is generalizable to all files. Together with zonefs that gives you a perfect interface for zone append. On Thu, Jun 25, 2020 at 10:45:48PM +0530, Kanchan Joshi wrote: > Introduce RWF_ZONE_APPEND flag to represent zone-append. And no one but us select few even know what zone append is, nevermind what the detailed semantics are. If you add a userspace API you need to very clearly document the semantics inluding errors and corner cases.