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=-0.8 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 DB5FBC43603 for ; Fri, 20 Dec 2019 02:23:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AFDEC2465E for ; Fri, 20 Dec 2019 02:23:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="o5pMNgBD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727089AbfLTCXH (ORCPT ); Thu, 19 Dec 2019 21:23:07 -0500 Received: from userp2130.oracle.com ([156.151.31.86]:58666 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726963AbfLTCXH (ORCPT ); Thu, 19 Dec 2019 21:23:07 -0500 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.27/8.16.0.27) with SMTP id xBK2Ft2F010080; Fri, 20 Dec 2019 02:22:46 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-2019-08-05; bh=UJWbPBLIw8v2NtR3K7tOCA0lIPKrvRnjfNoGkJqvNLw=; b=o5pMNgBDCHodm/dDo4k5bp6zaRnszLzYsSQ6dlBmtYwhtkmGmUloMpGFYtzOWATVgkKc 2cvRtFmz+7cLmKVFuPt69Qwm4Fheg1CTuVGtiv9Hk9EcQc7ALk1PKUKjnJKSDw9JcBcU 9K5s3KfPUohCuerXob0/O/tJHDFwxn+qDkIwhA8vmatQ2UFQtbcrVm111kgd6Op98QiM 4KfJuubjS51m2LNYMgPfuCagwdwIKqGed23iSBwX7LgoKeTIsn/ThLeDgseP8IPrV3fB 61cLD202Ge8PbHEKBRXsn3BOgJ/CnTy3YoALqRdZNCHyEleu7oPathSVdRJ9CvKp6PjA cQ== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by userp2130.oracle.com with ESMTP id 2x01jae80k-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 20 Dec 2019 02:22:46 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.27/8.16.0.27) with SMTP id xBK2JN0t072948; Fri, 20 Dec 2019 02:22:46 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userp3030.oracle.com with ESMTP id 2wyxqjmt50-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 20 Dec 2019 02:22:46 +0000 Received: from abhmp0020.oracle.com (abhmp0020.oracle.com [141.146.116.26]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id xBK2MfI4026306; Fri, 20 Dec 2019 02:22:41 GMT Received: from ca-mkp.ca.oracle.com (/10.159.214.123) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 19 Dec 2019 18:22:41 -0800 To: "Darrick J. Wong" Cc: "Martin K. Petersen" , Kirill Tkhai , axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-ext4@vger.kernel.org, tytso@mit.edu, adilger.kernel@dilger.ca, 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, chaitanya.kulkarni@wdc.com, bvanassche@acm.org, dhowells@redhat.com, asml.silence@gmail.com Subject: Re: [PATCH RFC 1/3] block: Add support for REQ_OP_ASSIGN_RANGE operation From: "Martin K. Petersen" Organization: Oracle Corporation References: <157599668662.12112.10184894900037871860.stgit@localhost.localdomain> <157599696813.12112.14140818972910110796.stgit@localhost.localdomain> <3f2e341b-dea4-c5d0-8eb0-568b6ad2f17b@virtuozzo.com> <20191220015338.GB7473@magnolia> Date: Thu, 19 Dec 2019 21:22:36 -0500 In-Reply-To: <20191220015338.GB7473@magnolia> (Darrick J. Wong's message of "Thu, 19 Dec 2019 17:53:39 -0800") 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=9476 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1911140001 definitions=main-1912200014 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9476 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1911140001 definitions=main-1912200014 Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org Darrick, [Anchor] > What happens if you anchor and then try to read the results? IO > error? Depends on the device. Typically you get the same results as UNMAP. Anchoring is essentially a way to preallocate blocks on a thinly provisioned device. If you then run out of actual storage capacity you won't get a write failure writing to those LBAs. It is intended to protect block ranges that do not tolerate write failures (journals, metadata). -- Martin K. Petersen Oracle Linux Engineering