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 4EA4DC73C63 for ; Tue, 9 Jul 2019 23:59:10 +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 11ECA206C3 for ; Tue, 9 Jul 2019 23:59:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 11ECA206C3 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]:56962 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hl00p-0000lo-Ok for qemu-devel@archiver.kernel.org; Tue, 09 Jul 2019 19:59:09 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:49124) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hkzVX-0007Oa-FM for qemu-devel@nongnu.org; Tue, 09 Jul 2019 19:26:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hkzVL-0003IA-C2 for qemu-devel@nongnu.org; Tue, 09 Jul 2019 19:26:40 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51114) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hkzVB-0002rn-K3; Tue, 09 Jul 2019 19:26:27 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B36F181DFC; Tue, 9 Jul 2019 23:26:19 +0000 (UTC) Received: from probe.bos.redhat.com (dhcp-17-215.bos.redhat.com [10.18.17.215]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5C0645B80B; Tue, 9 Jul 2019 23:26:18 +0000 (UTC) From: John Snow To: qemu-block@nongnu.org, qemu-devel@nongnu.org Date: Tue, 9 Jul 2019 19:25:44 -0400 Message-Id: <20190709232550.10724-13-jsnow@redhat.com> In-Reply-To: <20190709232550.10724-1-jsnow@redhat.com> References: <20190709232550.10724-1-jsnow@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Tue, 09 Jul 2019 23:26:19 +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 v4 12/18] 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, Juan Quintela , John Snow , Xie Changlong , "Dr. David Alan Gilbert" , Max Reitz , Stefan Hajnoczi , Wen Congyang , Markus Armbruster 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 Reviewed-by: Max Reitz --- block/backup.c | 27 +++++++++++++++++++-------- qapi/block-core.json | 5 ++++- 2 files changed, 23 insertions(+), 9 deletions(-) diff --git a/block/backup.c b/block/backup.c index fb1b39c44e..acfe87b756 100644 --- a/block/backup.c +++ b/block/backup.c @@ -268,18 +268,29 @@ static void backup_cleanup_sync_bitmap(BackupBlockJ= ob *job, int ret) { BdrvDirtyBitmap *bm; BlockDriverState *bs =3D blk_bs(job->common.blk); + bool sync =3D (((ret =3D=3D 0) || (job->bitmap_mode =3D=3D BITMAP_SY= NC_MODE_ALWAYS)) \ + && (job->bitmap_mode !=3D BITMAP_SYNC_MODE_NEVER)); =20 - if (ret < 0 || job->bitmap_mode =3D=3D BITMAP_SYNC_MODE_NEVER) { + if (sync) { /* - * Failure, or we don't want to synchronize the bitmap. - * Merge the successor back into the parent, delete nothing. + * We succeeded, or we always intended to sync the bitmap. + * Delete this bitmap and install the child. */ - 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); + } else { + /* + * We failed, or we never intended to sync the bitmap anyway. + * Merge the successor back into the parent, keeping all data. + */ + bm =3D bdrv_reclaim_dirty_bitmap(bs, job->sync_bitmap, NULL); + } + + assert(bm); + + if (ret < 0 && job->bitmap_mode =3D=3D BITMAP_SYNC_MODE_ALWAYS) { + /* If we failed and synced, merge in the bits we didn't copy: */ + bdrv_dirty_bitmap_merge_internal(bm, job->copy_bitmap, + NULL, true); } } =20 diff --git a/qapi/block-core.json b/qapi/block-core.json index b1aaaaa98e..5a578806c5 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -1149,10 +1149,13 @@ # @never: The bitmap is never synchronized with the operation, and is # treated solely as a read-only manifest of blocks to copy. # +# @always: The bitmap is always synchronized with the operation, +# regardless of whether or not the operation was successful. +# # Since: 4.2 ## { 'enum': 'BitmapSyncMode', - 'data': ['on-success', 'never'] } + 'data': ['on-success', 'never', 'always'] } =20 ## # @MirrorCopyMode: --=20 2.21.0