From 1fdd4b7be3655d39c3594bc215eb1df5ce225c7d Mon Sep 17 00:00:00 2001 From: Fam Zheng Date: Fri, 23 Oct 2015 11:08:11 +0800 Subject: [PATCH] block: Add "drained begin/end" for transactional backup 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 Reviewed-by: Jeff Cody Reviewed-by: Kevin Wolf Signed-off-by: Kevin Wolf --- blockdev.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/blockdev.c b/blockdev.c index e4a5eb43b8..0a7848bd66 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); } }