From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52701) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZoioS-0003Rj-Gf for qemu-devel@nongnu.org; Tue, 20 Oct 2015 22:07:37 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZoioQ-0003yj-K9 for qemu-devel@nongnu.org; Tue, 20 Oct 2015 22:07:35 -0400 From: Fam Zheng Date: Wed, 21 Oct 2015 10:06:44 +0800 Message-Id: <1445393209-26545-8-git-send-email-famz@redhat.com> In-Reply-To: <1445393209-26545-1-git-send-email-famz@redhat.com> References: <1445393209-26545-1-git-send-email-famz@redhat.com> Subject: [Qemu-devel] [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: qemu-devel@nongnu.org Cc: kwolf@redhat.com, pbonzini@redhat.com, stefanha@redhat.com, qemu-block@nongnu.org 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