From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43955) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZMKRd-0007c3-CN for qemu-devel@nongnu.org; Mon, 03 Aug 2015 14:26:42 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZMKRW-0000uD-88 for qemu-devel@nongnu.org; Mon, 03 Aug 2015 14:26:41 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33680) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZMKRW-0000tj-0K for qemu-devel@nongnu.org; Mon, 03 Aug 2015 14:26:34 -0400 References: <1438238370-16212-1-git-send-email-famz@redhat.com> <1438238370-16212-12-git-send-email-famz@redhat.com> From: Max Reitz Message-ID: <55BFB255.1090202@redhat.com> Date: Mon, 3 Aug 2015 20:26:29 +0200 MIME-Version: 1.0 In-Reply-To: <1438238370-16212-12-git-send-email-famz@redhat.com> Content-Type: text/plain; charset=iso-8859-15; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v4 11/14] block/backup: support block job transactions List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Fam Zheng , qemu-devel@nongnu.org Cc: Kevin Wolf , Jeff Cody , vsementsov@parallels.com, stefanha@redhat.com, John Snow On 30.07.2015 08:39, Fam Zheng wrote: > From: Stefan Hajnoczi > > Join the transaction when the 'transactional-cancel' QMP argument is > true. > > This ensures that the sync bitmap is not thrown away if another block > job in the transaction is cancelled or fails. This is critical so > incremental backup with multiple disks can be retried in case of > cancellation/failure. > > Signed-off-by: Stefan Hajnoczi > Signed-off-by: Fam Zheng > --- > block/backup.c | 25 ++++++-- > blockdev.c | 141 +++++++++++++++++++++++++++++++++++++--------- > hmp.c | 2 +- > include/block/block_int.h | 3 +- > qapi/block-core.json | 14 ++++- > 5 files changed, 148 insertions(+), 37 deletions(-) [...] > diff --git a/blockdev.c b/blockdev.c > index aba9d78..3e8b8b6 100644 > --- a/blockdev.c > +++ b/blockdev.c [...] > @@ -2770,6 +2830,31 @@ out: > aio_context_release(aio_context); > } > > +void qmp_blockdev_backup(const char *device, const char *target, > + enum MirrorSyncMode sync, > + bool has_speed, int64_t speed, > + bool has_on_source_error, > + BlockdevOnError on_source_error, > + bool has_on_target_error, > + BlockdevOnError on_target_error, > + bool has_transactional_cancel, > + bool transactional_cancel, > + Error **errp) > +{ > + if (has_transactional_cancel && transactional_cancel) { > + error_setg(errp, "Transactional cancel can only be used in the " > + "'transaction' command"); > + return; > + } > + > + do_blockdev_backup(device, target, sync, has_speed, speed, > + has_on_source_error, on_source_error, > + has_on_target_error, on_target_error, > + NULL, errp); > +} > + > +#define DEFAULT_MIRROR_BUF_SIZE (10 << 20) Why? > + > void qmp_drive_mirror(const char *device, const char *target, > bool has_format, const char *format, > bool has_node_name, const char *node_name, [...] > diff --git a/qapi/block-core.json b/qapi/block-core.json > index 7b2efb8..d4674ed 100644 > --- a/qapi/block-core.json > +++ b/qapi/block-core.json > @@ -736,6 +736,10 @@ > # default 'report' (no limitations, since this applies to > # a different block device than @device). > # > +# @transactional-cancel: #optional whether failure or cancellation of other > +# block jobs with @transactional-cancel true causes the > +# whole group to cancel. (Since 2.5) > +# Maybe it's worth adding "[of other block jobs] in the same transaction", and maybe even noting that this therefore only works with backup block jobs started as part of a transaction (although that should be clear then). Max