From patchwork Fri Jul 27 03:33:59 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fam Zheng X-Patchwork-Id: 10546603 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 29C38112B for ; Fri, 27 Jul 2018 03:35:38 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1779F2B98D for ; Fri, 27 Jul 2018 03:35:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0722C2B9EB; Fri, 27 Jul 2018 03:35:38 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id A3EBB2B98D for ; Fri, 27 Jul 2018 03:35:37 +0000 (UTC) Received: from localhost ([::1]:38933 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fitXS-0000PL-OR for patchwork-qemu-devel@patchwork.kernel.org; Thu, 26 Jul 2018 23:35:34 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57943) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fitWH-0007ME-81 for qemu-devel@nongnu.org; Thu, 26 Jul 2018 23:34:21 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fitWG-0003IR-Cw for qemu-devel@nongnu.org; Thu, 26 Jul 2018 23:34:21 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:58804 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fitWC-00039n-0I; Thu, 26 Jul 2018 23:34:16 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 5FF60402346C; Fri, 27 Jul 2018 03:34:14 +0000 (UTC) Received: from lemon.usersys.redhat.com (ovpn-12-150.pek2.redhat.com [10.72.12.150]) by smtp.corp.redhat.com (Postfix) with ESMTP id CD588111AF3C; Fri, 27 Jul 2018 03:34:09 +0000 (UTC) From: Fam Zheng To: qemu-devel@nongnu.org Date: Fri, 27 Jul 2018 11:33:59 +0800 Message-Id: <20180727033402.13513-1-famz@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Fri, 27 Jul 2018 03:34:14 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Fri, 27 Jul 2018 03:34:14 +0000 (UTC) for IP:'10.11.54.3' DOMAIN:'int-mx03.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'famz@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PATCH RFC for-3.0-rc3 0/3] qemu-img: Disable copy offloading by default X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , qemu-block@nongnu.org, stefanha@redhat.com, Max Reitz Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP Kevin pointed out that both glibc and kernel provides a slow fallback of copy_file_range which hurts thin provisioning. This is particularly true for thin LVs, because host_device driver cannot get allocation info from the volume, and copy_file_range is called on every sectors, making the dst fully allocated. NFS mount points also doesn't support SEEK_DATA well, so the allocation information is unknown to QEMU. That leaves only iscsi:// which seems to do what we want so far, but it is a smaller use case. Add an option to qemu-img convert, "-C", to enable (attempting) copy offloading explicitly. And mark it incompatible with "-S" and "-c". Fam Zheng (3): Revert "qemu-img: Document copy offloading implications with -S and -c" qemu-img: Add -C option for convert with copy offloading iotests: Add test for 'qemu-img convert -C' compatibility qemu-img-cmds.hx | 2 +- qemu-img.c | 21 +++++++++++++++++---- qemu-img.texi | 14 +++++++++----- tests/qemu-iotests/082 | 8 ++++++++ tests/qemu-iotests/082.out | 11 +++++++++++ 5 files changed, 46 insertions(+), 10 deletions(-) Reviewed-by: Kevin Wolf