From patchwork Fri Aug 16 23:13:13 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Snow X-Patchwork-Id: 1148528 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com 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 ozlabs.org (Postfix) with ESMTPS id 469Kd50QZwz9s7T for ; Sat, 17 Aug 2019 09:43:04 +1000 (AEST) Received: from localhost ([::1]:33460 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1hyls6-0001x3-01 for incoming@patchwork.ozlabs.org; Fri, 16 Aug 2019 19:43:02 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:47238) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1hylQ4-00078e-9g for qemu-devel@nongnu.org; Fri, 16 Aug 2019 19:14:05 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hylQ2-0006OK-Nw for qemu-devel@nongnu.org; Fri, 16 Aug 2019 19:14:04 -0400 Received: from mx1.redhat.com ([209.132.183.28]:38642) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hylPz-0006Jq-7c; Fri, 16 Aug 2019 19:13:59 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 73FE8796FF; Fri, 16 Aug 2019 23:13:51 +0000 (UTC) Received: from probe.bos.redhat.com (dhcp-17-187.bos.redhat.com [10.18.17.187]) by smtp.corp.redhat.com (Postfix) with ESMTP id C15A119C6A; Fri, 16 Aug 2019 23:13:50 +0000 (UTC) From: John Snow To: qemu-devel@nongnu.org Date: Fri, 16 Aug 2019 19:13:13 -0400 Message-Id: <20190816231318.8650-32-jsnow@redhat.com> In-Reply-To: <20190816231318.8650-1-jsnow@redhat.com> References: <20190816231318.8650-1-jsnow@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Fri, 16 Aug 2019 23:13:51 +0000 (UTC) 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] [PULL 31/36] 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: peter.maydell@linaro.org, jsnow@redhat.com, qemu-stable@nongnu.org, qemu-block@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" 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=NONE 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=none, 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 Message-id: 20190716000117.25219-11-jsnow@redhat.com Signed-off-by: John Snow --- 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 9e1382ec5c6..a9be07258c1 100644 --- a/block/backup.c +++ b/block/backup.c @@ -697,7 +697,7 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs, return NULL; } - if (sync_mode == MIRROR_SYNC_MODE_BITMAP) { + if (sync_bitmap) { /* If we need to write to this bitmap, check that we can: */ if (bitmap_mode != BITMAP_SYNC_MODE_NEVER && bdrv_dirty_bitmap_check(sync_bitmap, BDRV_BITMAP_DEFAULT, errp)) { @@ -708,12 +708,6 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *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; } len = bdrv_getlength(bs); diff --git a/blockdev.c b/blockdev.c index f889da0b427..64d06d1f672 100644 --- a/blockdev.c +++ b/blockdev.c @@ -3567,6 +3567,28 @@ static BlockJob *do_backup_common(BackupCommon *backup, if (bdrv_dirty_bitmap_check(bmap, BDRV_BITMAP_ALLOW_RO, errp)) { return NULL; } + + /* This does not produce a useful bitmap artifact: */ + if (backup->sync == MIRROR_SYNC_MODE_NONE) { + error_setg(errp, "sync mode '%s' does not produce meaningful bitmap" + " outputs", MirrorSyncMode_str(backup->sync)); + return NULL; + } + + /* If the bitmap isn't used for input or output, this is useless: */ + if (backup->bitmap_mode == BITMAP_SYNC_MODE_NEVER && + backup->sync != MIRROR_SYNC_MODE_BITMAP) { + error_setg(errp, "Bitmap sync mode '%s' has no meaningful effect" + " 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; } if (!backup->auto_finalize) { diff --git a/qapi/block-core.json b/qapi/block-core.json index 8344fbe2030..d72cf5f354b 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 "bitmap". +# 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.