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 887C8C2D0C3 for ; Sat, 21 Dec 2019 18:57:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 593A020665 for ; Sat, 21 Dec 2019 18:57:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="YNcJqv62" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727101AbfLUS5p (ORCPT ); Sat, 21 Dec 2019 13:57:45 -0500 Received: from userp2130.oracle.com ([156.151.31.86]:40626 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726593AbfLUS5p (ORCPT ); Sat, 21 Dec 2019 13:57:45 -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 xBLIsYgC105795; Sat, 21 Dec 2019 18:57:07 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=D2wcasH1ZhiCVNdqmYp9V03i7PEyRJEfWju3qTFe+5A=; b=YNcJqv62W9/CZb6j+sLKFv8RjQJTMAMnpPgtc8agrx8zDCLYh0M/2VSc4RD0EcBxuCkT qcx0O8gPGM/L1Ck8vp87nnMLr3OWmFEBbAaUY0FjlqvIeDuEvJJn1MRl6Iymgu2a5m+1 H2NOdQkL6IRUuxbWEkRPPOWp6vPU//khGOnt12U+Nn1XQoju7xqrY1yDrYHdl2se0ChA X0Ff9V33AFUX5vdSNnLRUpIGQ6gFop/SIbYJ8Q6VaJODL9Sn4E+ETyUSC5dfZvm3LUwr yIWfsermwHsVUUwiZJMRT3hVavh/0R+D+YtrK5B0Y5f2AMzbIKBvhy+xzSHe05WuaKbH Ww== Received: from aserp3030.oracle.com (aserp3030.oracle.com [141.146.126.71]) by userp2130.oracle.com with ESMTP id 2x1att9mv4-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sat, 21 Dec 2019 18:57:07 +0000 Received: from pps.filterd (aserp3030.oracle.com [127.0.0.1]) by aserp3030.oracle.com (8.16.0.27/8.16.0.27) with SMTP id xBLIn6jb110474; Sat, 21 Dec 2019 18:55:06 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by aserp3030.oracle.com with ESMTP id 2x19f5ku4w-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sat, 21 Dec 2019 18:55:06 +0000 Received: from abhmp0015.oracle.com (abhmp0015.oracle.com [141.146.116.21]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id xBLIssO7006659; Sat, 21 Dec 2019 18:54:56 GMT Received: from ca-mkp.ca.oracle.com (/10.159.214.123) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Sat, 21 Dec 2019 10:54:54 -0800 To: Kirill Tkhai Cc: "Martin K. Petersen" , 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> <625c9ee4-bedb-ff60-845e-2d440c4f58aa@virtuozzo.com> Date: Sat, 21 Dec 2019 13:54:50 -0500 In-Reply-To: <625c9ee4-bedb-ff60-845e-2d440c4f58aa@virtuozzo.com> (Kirill Tkhai's message of "Fri, 20 Dec 2019 14:55:09 +0300") 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=9478 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-1912210166 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9478 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-1912210167 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Kirill, > One more thing to discuss. The new REQ_NOZERO flag won't be supported > by many block devices (their number will be even less, than number of > REQ_OP_WRITE_ZEROES supporters). Will this be a good thing, in case of > we will be completing BLKDEV_ZERO_ALLOCATE bios in > __blkdev_issue_write_zeroes() before splitting? I mean introduction of > some flag in struct request_queue::limits. Completion of them with > -EOPNOTSUPP in block devices drivers looks suboptimal for me. We already have the NOFALLBACK flag to let the user make that decision. If that flag is not specified, and I receive an allocate request for a SCSI device that does not support ANCHOR, my expectation would be that I would do a regular write same. If it's a filesystem that is the recipient of the operation and not a SCSI device, how to react would depend on how the filesystem handles unwritten extents, etc. -- Martin K. Petersen Oracle Linux Engineering