From nobody Mon Feb 9 03:29:16 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1563235339; cv=none; d=zoho.com; s=zohoarc; b=O5uubQrUmUURNJhmjh1J8O2DHZ7v54+ArRhG52WKmHemJPoc0kYN2BfC3dQ7JtPoJSIW1THG+nCqo8O59QhZqW3I4BTq+aGcUvVtVshzjFF6K0UodSuO+C3Ujt3DKx5bxMVatgXv1fJRjZDzC3FLySm0RI8sXhuuJfrRT0zRDJ8= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zoho.com; s=zohoarc; t=1563235339; h=Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To:ARC-Authentication-Results; bh=q37fCVgbHcdHmurYm6yLIfJ1hxRecJFPE+v0ag9Q3hw=; b=eOZEcp+tgsnwAA/MEhokEHI9rYMCjMuIRItkWZ58j+I1bijge4sd/VE/ZRp7qSSczTidY/vnd2gVxHkWUfCMQ9vSCxDyEoOV+ZwQEkiNWno9VQ87OFLA8zotSSOi3Yo+14ZOFGR8tBKrBCrojZoL5ferbWwODa/gLUS7KcrONsg= ARC-Authentication-Results: i=1; mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1563235339273839.8547341951335; Mon, 15 Jul 2019 17:02:19 -0700 (PDT) Received: from localhost ([::1]:44416 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hnAvB-0000y6-El for importer@patchew.org; Mon, 15 Jul 2019 20:02:17 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:44766) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hnAua-0007Yo-3l for qemu-devel@nongnu.org; Mon, 15 Jul 2019 20:01:42 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hnAuX-0007d9-6T for qemu-devel@nongnu.org; Mon, 15 Jul 2019 20:01:39 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58794) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hnAuS-0007Ya-Jd; Mon, 15 Jul 2019 20:01:32 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id DB0C436893; Tue, 16 Jul 2019 00:01:31 +0000 (UTC) Received: from probe.bos.redhat.com (dhcp-17-130.bos.redhat.com [10.18.17.130]) by smtp.corp.redhat.com (Postfix) with ESMTP id 081F26085B; Tue, 16 Jul 2019 00:01:30 +0000 (UTC) From: John Snow To: qemu-block@nongnu.org, qemu-devel@nongnu.org Date: Mon, 15 Jul 2019 20:01:16 -0400 Message-Id: <20190716000117.25219-11-jsnow@redhat.com> In-Reply-To: <20190716000117.25219-1-jsnow@redhat.com> References: <20190716000117.25219-1-jsnow@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Tue, 16 Jul 2019 00:01:31 +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 v2 10/11] block/backup: support bitmap sync modes for non-bitmap backups 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 , vsementsov@virtuozzo.com, Markus Armbruster , Max Reitz , John Snow Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" Accept bitmaps and sync policies for the other backup modes. This allows us to do things like create a bitmap synced to a full backup without a transaction, or start a resumable backup process. Some combinations don't make sense, though: - NEVER policy combined with any non-BITMAP mode doesn't do anything, because the bitmap isn't used for input or output. It's harmless, but is almost certainly never what the user wanted. - sync=3DNONE is more questionable. It can't use on-success because this job never completes with success anyway, and the resulting artifact of 'always' is suspect: because we start with a full bitmap and only copy out segments that get written to, the final output bitmap will always be ... a fully set bitmap. Maybe there's contexts in which bitmaps make sense for sync=3Dnone, but not without more severe changes to the current job, and omitting it here doesn't prevent us from adding it later. Signed-off-by: John Snow Reviewed-by: Max Reitz --- block/backup.c | 8 +------- blockdev.c | 22 ++++++++++++++++++++++ qapi/block-core.json | 6 ++++-- 3 files changed, 27 insertions(+), 9 deletions(-) diff --git a/block/backup.c b/block/backup.c index e28fd23f6a..47628aca24 100644 --- a/block/backup.c +++ b/block/backup.c @@ -686,7 +686,7 @@ BlockJob *backup_job_create(const char *job_id, BlockDr= iverState *bs, return NULL; } =20 - if (sync_mode =3D=3D MIRROR_SYNC_MODE_BITMAP) { + if (sync_bitmap) { /* If we need to write to this bitmap, check that we can: */ if (bitmap_mode !=3D BITMAP_SYNC_MODE_NEVER && bdrv_dirty_bitmap_check(sync_bitmap, BDRV_BITMAP_DEFAULT, errp= )) { @@ -697,12 +697,6 @@ BlockJob *backup_job_create(const char *job_id, BlockD= riverState *bs, if (bdrv_dirty_bitmap_create_successor(bs, sync_bitmap, errp) < 0)= { return NULL; } - } else if (sync_bitmap) { - error_setg(errp, - "a bitmap was given to backup_job_create, " - "but it received an incompatible sync_mode (%s)", - MirrorSyncMode_str(sync_mode)); - return NULL; } =20 len =3D bdrv_getlength(bs); diff --git a/blockdev.c b/blockdev.c index 3c76c85cb5..29c6c6044a 100644 --- a/blockdev.c +++ b/blockdev.c @@ -3565,6 +3565,28 @@ static BlockJob *do_backup_common(BackupCommon *back= up, if (bdrv_dirty_bitmap_check(bmap, BDRV_BITMAP_ALLOW_RO, errp)) { return NULL; } + + /* This does not produce a useful bitmap artifact: */ + if (backup->sync =3D=3D MIRROR_SYNC_MODE_NONE) { + error_setg(errp, "sync mode '%s' does not produce meaningful b= itmap" + " outputs", MirrorSyncMode_str(backup->sync)); + return NULL; + } + + /* If the bitmap isn't used for input or output, this is useless: = */ + if (backup->bitmap_mode =3D=3D BITMAP_SYNC_MODE_NEVER && + backup->sync !=3D MIRROR_SYNC_MODE_BITMAP) { + error_setg(errp, "Bitmap sync mode '%s' has no meaningful effe= ct" + " when combined with sync mode '%s'", + BitmapSyncMode_str(backup->bitmap_mode), + MirrorSyncMode_str(backup->sync)); + return NULL; + } + } + + if (!backup->has_bitmap && backup->has_bitmap_mode) { + error_setg(errp, "Cannot specify bitmap sync mode without a bitmap= "); + return NULL; } =20 if (!backup->auto_finalize) { diff --git a/qapi/block-core.json b/qapi/block-core.json index 5a578806c5..099e4f37b2 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -1352,13 +1352,15 @@ # @speed: the maximum speed, in bytes per second. The default is 0, # for unlimited. # -# @bitmap: the name of a dirty bitmap if sync is "bitmap" or "incremental". +# @bitmap: The name of a dirty bitmap to use. # Must be present if sync is "bitmap" or "incremental". +# Can be present if sync is "full" or "top". # Must not be present otherwise. # (Since 2.4 (drive-backup), 3.1 (blockdev-backup)) # # @bitmap-mode: Specifies the type of data the bitmap should contain after -# the operation concludes. Must be present if sync is "bitma= p". +# the operation concludes. +# Must be present if a bitmap was provided, # Must NOT be present otherwise. (Since 4.2) # # @compress: true to compress data, if the target format supports it. --=20 2.21.0