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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 6C40DC43613 for ; Thu, 20 Jun 2019 01:21:21 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 43D2621537 for ; Thu, 20 Jun 2019 01:21:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 43D2621537 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:42948 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hdllQ-00006c-GC for qemu-devel@archiver.kernel.org; Wed, 19 Jun 2019 21:21:20 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:40379) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hdle6-0001zb-1w for qemu-devel@nongnu.org; Wed, 19 Jun 2019 21:13:47 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hdlUs-0004sk-8e for qemu-devel@nongnu.org; Wed, 19 Jun 2019 21:04:15 -0400 Received: from mx1.redhat.com ([209.132.183.28]:38914) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hdlUq-0004r4-Rd; Wed, 19 Jun 2019 21:04:13 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 175B230C1CBF; Thu, 20 Jun 2019 01:04:12 +0000 (UTC) Received: from probe.bos.redhat.com (dhcp-17-164.bos.redhat.com [10.18.17.164]) by smtp.corp.redhat.com (Postfix) with ESMTP id F19CB1001E67; Thu, 20 Jun 2019 01:04:10 +0000 (UTC) From: John Snow To: qemu-devel@nongnu.org, qemu-block@nongnu.org Date: Wed, 19 Jun 2019 21:03:51 -0400 Message-Id: <20190620010356.19164-8-jsnow@redhat.com> In-Reply-To: <20190620010356.19164-1-jsnow@redhat.com> References: <20190620010356.19164-1-jsnow@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.46]); Thu, 20 Jun 2019 01:04:12 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH 07/12] block/backup: add 'always' bitmap sync policy X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Fam Zheng , vsementsov@virtuozzo.com, Wen Congyang , Xie Changlong , Markus Armbruster , Max Reitz , John Snow Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" This adds an "always" policy for bitmap synchronization. Regardless of if the job succeeds or fails, the bitmap is *always* synchronized. This mean= s that for backups that fail part-way through, the bitmap retains a record = of which sectors need to be copied out to accomplish a new backup using the old, partial result. In effect, this allows us to "resume" a failed backup; however the new ba= ckup will be from the new point in time, so it isn't a "resume" as much as it = is an "incremental retry." This can be useful in the case of extremely large backups that fail considerably through the operation and we'd like to not= waste the work that was already performed. Signed-off-by: John Snow --- qapi/block-core.json | 5 ++++- block/backup.c | 10 ++++++---- 2 files changed, 10 insertions(+), 5 deletions(-) diff --git a/qapi/block-core.json b/qapi/block-core.json index 0332dcaabc..58d267f1f5 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -1143,6 +1143,9 @@ # An enumeration of possible behaviors for the synchronization of a bitm= ap # when used for data copy operations. # +# @always: The bitmap is always synchronized with remaining blocks to co= py, +# whether or not the operation has completed successfully or no= t. +# # @conditional: The bitmap is only synchronized when the operation is su= ccessul. # This is useful for Incremental semantics. # @@ -1153,7 +1156,7 @@ # Since: 4.1 ## { 'enum': 'BitmapSyncMode', - 'data': ['conditional', 'never'] } + 'data': ['always', 'conditional', 'never'] } =20 ## # @MirrorCopyMode: diff --git a/block/backup.c b/block/backup.c index 627f724b68..beb2078696 100644 --- a/block/backup.c +++ b/block/backup.c @@ -266,15 +266,17 @@ static void backup_cleanup_sync_bitmap(BackupBlockJ= ob *job, int ret) BlockDriverState *bs =3D blk_bs(job->common.blk); =20 if (ret < 0 || job->bitmap_mode =3D=3D BITMAP_SYNC_MODE_NEVER) { - /* Failure, or we don't want to synchronize the bitmap. - * Merge the successor back into the parent, delete nothing. */ + /* Failure, or we don't want to synchronize the bitmap. */ + if (job->bitmap_mode =3D=3D BITMAP_SYNC_MODE_ALWAYS) { + bdrv_dirty_bitmap_claim(job->sync_bitmap, &job->copy_bitmap)= ; + } + /* Merge the successor back into the parent. */ bm =3D bdrv_reclaim_dirty_bitmap(bs, job->sync_bitmap, NULL); - assert(bm); } else { /* Everything is fine, delete this bitmap and install the backup= . */ bm =3D bdrv_dirty_bitmap_abdicate(bs, job->sync_bitmap, NULL); - assert(bm); } + assert(bm); } =20 static void backup_commit(Job *job) --=20 2.21.0