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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY 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 86379C54FCF for ; Wed, 25 Mar 2020 17:24:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5E16A20772 for ; Wed, 25 Mar 2020 17:24:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="SsLqtwNs" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727376AbgCYRYg (ORCPT ); Wed, 25 Mar 2020 13:24:36 -0400 Received: from userp2120.oracle.com ([156.151.31.85]:55392 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727320AbgCYRYg (ORCPT ); Wed, 25 Mar 2020 13:24:36 -0400 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 02PHIUu9063725; Wed, 25 Mar 2020 17:23:45 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=to : cc : subject : from : references : date : in-reply-to : message-id : mime-version : content-type; s=corp-2020-01-29; bh=BVLD2DnNfc3hv/pKnHW3xvm86ovl8foR84Cu3jjRluI=; b=SsLqtwNsiMxQfXKTjwpsTimV5kVfZurxza6rlE6nubcGWAuwfTQLsLzfoqG0Stq9ih08 JPc3GVkauUN9Cml8EKZvjx69mZwbc+VFBo0XITYoEyIu99jyzN2TJm/F2sx57xWqNmOh zf792px6wXY0CY6mrHRCF2ct3trMMgap/0VufstShpXG/ZafG3BTY0QKhfGEra51fy1s bVcRlQFVCNRwWWIGQ8CXRaRPqg/kGM6NAgfMca09okEe2kHd280CipW0AqoOSFCv+deO 6GesVjacIeNC6T/w8+zLlG+Fz5PlAFNc1I53QbM4qMrLiNxiF65nF5uiIX0kBdvOmngY gQ== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by userp2120.oracle.com with ESMTP id 3005kva3e8-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 25 Mar 2020 17:23:45 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 02PHMVh7021581; Wed, 25 Mar 2020 17:23:44 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by userp3030.oracle.com with ESMTP id 2yxw4rvfvw-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 25 Mar 2020 17:23:44 +0000 Received: from abhmp0013.oracle.com (abhmp0013.oracle.com [141.146.116.19]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 02PHNepp026829; Wed, 25 Mar 2020 17:23:40 GMT Received: from ca-mkp.ca.oracle.com (/10.159.214.123) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 25 Mar 2020 10:23:40 -0700 To: Christoph Hellwig Cc: "Darrick J. Wong" , "Martin K. Petersen" , Kirill Tkhai , axboe@kernel.dk, bob.liu@oracle.com, agk@redhat.com, snitzer@redhat.com, dm-devel@redhat.com, song@kernel.org, tytso@mit.edu, adilger.kernel@dilger.ca, Chaitanya.Kulkarni@wdc.com, ming.lei@redhat.com, osandov@fb.com, jthumshirn@suse.de, minwoo.im.dev@gmail.com, damien.lemoal@wdc.com, andrea.parri@amarulasolutions.com, hare@suse.com, tj@kernel.org, ajay.joshi@wdc.com, sagi@grimberg.me, dsterba@suse.com, bvanassche@acm.org, dhowells@redhat.com, asml.silence@gmail.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v7 0/6] block: Introduce REQ_ALLOCATE flag for REQ_OP_WRITE_ZEROES From: "Martin K. Petersen" Organization: Oracle Corporation References: <158157930219.111879.12072477040351921368.stgit@localhost.localdomain> <69c0b8a4-656f-98c4-eb55-2fd1184f5fc9@virtuozzo.com> <67d63190-c16f-cd26-6b67-641c8943dc3d@virtuozzo.com> <20200319102819.GA26418@infradead.org> <20200325162656.GJ29351@magnolia> <20200325163223.GA27156@infradead.org> Date: Wed, 25 Mar 2020 13:23:33 -0400 In-Reply-To: <20200325163223.GA27156@infradead.org> (Christoph Hellwig's message of "Wed, 25 Mar 2020 09:32:23 -0700") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1.92 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9571 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 suspectscore=0 spamscore=0 mlxlogscore=786 adultscore=0 phishscore=0 mlxscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2003250140 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9571 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 bulkscore=0 phishscore=0 suspectscore=0 impostorscore=0 spamscore=0 adultscore=0 priorityscore=1501 mlxlogscore=841 lowpriorityscore=0 mlxscore=0 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2003250139 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Christoph, > I am very much against that for the following reason: > > - the current REQ_OP_DISCARD is purely a hint, and implementations can > (and do) choose to ignore it > > - REQ_OP_WRITE_ZEROES is an actual data integrity operation with > everything that entails If you want to keep emphasis on the "integrity operation" instead of the provisioning aspect, would you expect REQ_ALLOCATE (which may or may not zero blocks) to be considered a deterministic operation or a non-deterministic one? Should this depend on whether the device guarantees zeroing when provisioning blocks or not? -- Martin K. Petersen Oracle Linux Engineering