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 139A2C3A59D for ; Fri, 16 Aug 2019 23:43:51 +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 CB0B72086C for ; Fri, 16 Aug 2019 23:43:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CB0B72086C 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]:33478 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1hylsr-0003bp-SB for qemu-devel@archiver.kernel.org; Fri, 16 Aug 2019 19:43:49 -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) 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] [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+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Archived-At: List-Archive: 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 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, Block= DriverState *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, er= rp)) { @@ -708,12 +708,6 @@ BlockJob *backup_job_create(const char *job_id, Bloc= kDriverState *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 f889da0b427..64d06d1f672 100644 --- a/blockdev.c +++ b/blockdev.c @@ -3567,6 +3567,28 @@ static BlockJob *do_backup_common(BackupCommon *ba= ckup, 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= 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 =3D=3D BITMAP_SYNC_MODE_NEVER && + backup->sync !=3D MIRROR_SYNC_MODE_BITMAP) { + error_setg(errp, "Bitmap sync mode '%s' has no meaningful ef= fect" + " 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 bitm= ap"); + return NULL; } =20 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 "incrementa= l". +# @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 aft= er -# the operation concludes. Must be present if sync is "bit= map". +# 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