From patchwork Thu May 16 08:36:17 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 244250 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 5DB5F2C008C for ; Thu, 16 May 2013 18:43:07 +1000 (EST) Received: from localhost ([::1]:49475 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UctmD-0007JS-Hb for incoming@patchwork.ozlabs.org; Thu, 16 May 2013 04:43:05 -0400 Received: from eggs.gnu.org ([208.118.235.92]:55149) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Uctlf-00076p-EK for qemu-devel@nongnu.org; Thu, 16 May 2013 04:42:38 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Uctg5-000146-FU for qemu-devel@nongnu.org; Thu, 16 May 2013 04:37:08 -0400 Received: from mx1.redhat.com ([209.132.183.28]:10745) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Uctg5-00013p-5a for qemu-devel@nongnu.org; Thu, 16 May 2013 04:36:45 -0400 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r4G8ah3L003794 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 16 May 2013 04:36:43 -0400 Received: from localhost (ovpn-112-28.ams2.redhat.com [10.36.112.28]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id r4G8afVi003391; Thu, 16 May 2013 04:36:42 -0400 From: Stefan Hajnoczi To: Date: Thu, 16 May 2013 10:36:17 +0200 Message-Id: <1368693379-8434-7-git-send-email-stefanha@redhat.com> In-Reply-To: <1368693379-8434-1-git-send-email-stefanha@redhat.com> References: <1368693379-8434-1-git-send-email-stefanha@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: Kevin Wolf , Fam Zheng , dietmar@proxmox.com, imain@redhat.com, Stefan Hajnoczi , Paolo Bonzini , xiawenc@linux.vnet.ibm.com Subject: [Qemu-devel] [PATCH v4 6/8] blockdev: add DriveBackup transaction X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org This patch adds a transactional version of the drive-backup QMP command. It allows atomic snapshots of multiple drives along with automatic cleanup if there is a failure to start one of the backup jobs. Note that QMP events are emitted for block job completion/cancellation and the block job will be listed by query-block-jobs. @DriveBackup @device: the name of the device whose writes should be mirrored. @target: the target of the new image. If the file exists, or if it is a device, the existing file/device will be used as the new destination. If it does not exist, a new file will be created. @format: #optional the format of the new destination, default is to probe if @mode is 'existing', else the format of the source @mode: #optional whether and how QEMU should create a new image, default is 'absolute-paths'. @speed: #optional the maximum speed, in bytes per second Signed-off-by: Stefan Hajnoczi Reviewed-by: Eric Blake --- blockdev.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++ qapi-schema.json | 26 +++++++++++++++++++++++++- 2 files changed, 78 insertions(+), 1 deletion(-) diff --git a/blockdev.c b/blockdev.c index b6109da..c386bb6 100644 --- a/blockdev.c +++ b/blockdev.c @@ -926,6 +926,53 @@ static void external_snapshot_abort(BlkTransactionState *common) } } +typedef struct DriveBackupState { + BlkTransactionState common; + BlockDriverState *bs; + BlockJob *job; +} DriveBackupState; + +static void drive_backup_prepare(BlkTransactionState *common, Error **errp) +{ + DriveBackupState *state = DO_UPCAST(DriveBackupState, common, common); + DriveBackup *backup; + Error *local_err = NULL; + + assert(common->action->kind == TRANSACTION_ACTION_KIND_DRIVE_BACKUP); + backup = common->action->drive_backup; + + qmp_drive_backup(backup->device, backup->target, + backup->has_format, backup->format, + backup->has_mode, backup->mode, + backup->has_speed, backup->speed, + &local_err); + if (error_is_set(&local_err)) { + error_propagate(errp, local_err); + state->bs = NULL; + state->job = NULL; + return; + } + + state->bs = bdrv_find(backup->device); + state->job = state->bs->job; +} + +static void drive_backup_commit(BlkTransactionState *common) +{ + /* Block job has started, nothing to do here */ +} + +static void drive_backup_abort(BlkTransactionState *common) +{ + DriveBackupState *state = DO_UPCAST(DriveBackupState, common, common); + BlockDriverState *bs = state->bs; + + /* Only cancel if it's the job we started */ + if (bs && bs->job && bs->job == state->job) { + block_job_cancel_sync(bs->job); + } +} + static const BdrvActionOps actions[] = { [TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC] = { .instance_size = sizeof(ExternalSnapshotState), @@ -933,6 +980,12 @@ static const BdrvActionOps actions[] = { .commit = external_snapshot_commit, .abort = external_snapshot_abort, }, + [TRANSACTION_ACTION_KIND_DRIVE_BACKUP] = { + .instance_size = sizeof(DriveBackupState), + .prepare = drive_backup_prepare, + .commit = drive_backup_commit, + .abort = drive_backup_abort, + }, }; /* diff --git a/qapi-schema.json b/qapi-schema.json index e716522..114ae50 100644 --- a/qapi-schema.json +++ b/qapi-schema.json @@ -1609,6 +1609,29 @@ '*mode': 'NewImageMode' } } ## +# @DriveBackup +# +# @device: the name of the device whose writes should be mirrored. +# +# @target: the target of the new image. If the file exists, or if it +# is a device, the existing file/device will be used as the new +# destination. If it does not exist, a new file will be created. +# +# @format: #optional the format of the new destination, default is to +# probe if @mode is 'existing', else the format of the source +# +# @mode: #optional whether and how QEMU should create a new image, default is +# 'absolute-paths'. +# +# @speed: #optional the maximum speed, in bytes per second +# +# Since: 1.6 +## +{ 'type': 'DriveBackup', + 'data': { 'device': 'str', 'target': 'str', '*format': 'str', + '*mode': 'NewImageMode', '*speed': 'int' } } + +## # @TransactionAction # # A discriminated record of operations that can be performed with @@ -1616,7 +1639,8 @@ ## { 'union': 'TransactionAction', 'data': { - 'blockdev-snapshot-sync': 'BlockdevSnapshot' + 'blockdev-snapshot-sync': 'BlockdevSnapshot', + 'drive-backup': 'DriveBackup' } } ##