From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60422) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zox46-0001Db-4D for qemu-devel@nongnu.org; Wed, 21 Oct 2015 13:20:43 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Zox45-0003o8-AC for qemu-devel@nongnu.org; Wed, 21 Oct 2015 13:20:42 -0400 Date: Wed, 21 Oct 2015 13:20:32 -0400 From: Jeff Cody Message-ID: <20151021172032.GF6466@localhost.localdomain> References: <1445393209-26545-1-git-send-email-famz@redhat.com> <1445393209-26545-8-git-send-email-famz@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1445393209-26545-8-git-send-email-famz@redhat.com> Subject: Re: [Qemu-devel] [Qemu-block] [PATCH v5 07/12] block: Add "drained begin/end" for transactional backup List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Fam Zheng Cc: kwolf@redhat.com, pbonzini@redhat.com, qemu-block@nongnu.org, qemu-devel@nongnu.org, stefanha@redhat.com On Wed, Oct 21, 2015 at 10:06:44AM +0800, Fam Zheng wrote: > This ensures the atomicity of the transaction by avoiding processing of > external requests such as those from ioeventfd. > > Move the assignment to state->bs up right after bdrv_drained_begin, so > that we can use it in the clean callback. The abort callback will still > check bs->job and state->job, so it's OK. > > Signed-off-by: Fam Zheng > --- > blockdev.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/blockdev.c b/blockdev.c > index e4a5eb4..0a7848b 100644 > --- a/blockdev.c > +++ b/blockdev.c > @@ -1684,9 +1684,16 @@ static void drive_backup_prepare(BlkTransactionState *common, Error **errp) > return; > } > > + if (!blk_is_available(blk)) { > + error_setg(errp, QERR_DEVICE_HAS_NO_MEDIUM, backup->device); > + return; > + } > + > /* AioContext is released in .clean() */ > state->aio_context = blk_get_aio_context(blk); > aio_context_acquire(state->aio_context); > + bdrv_drained_begin(blk_bs(blk)); > + state->bs = blk_bs(blk); > > qmp_drive_backup(backup->device, backup->target, > backup->has_format, backup->format, > @@ -1702,7 +1709,6 @@ static void drive_backup_prepare(BlkTransactionState *common, Error **errp) > return; > } > > - state->bs = blk_bs(blk); > state->job = state->bs->job; > } > > @@ -1722,6 +1728,7 @@ static void drive_backup_clean(BlkTransactionState *common) > DriveBackupState *state = DO_UPCAST(DriveBackupState, common, common); > > if (state->aio_context) { > + bdrv_drained_end(state->bs); > aio_context_release(state->aio_context); > } > } > -- > 2.4.3 > > Reviewed-by: Jeff Cody