block: Add BlockJobTxn support to backup_run

Allow a BlockJobTxn to be passed into backup_run, which
will allow the job to join a transactional group if present.

Propagate this new parameter outward into new QMP helper
functions in blockdev.c to allow transaction commands to
pass forward their BlockJobTxn object in a forthcoming patch.

[split up from a patch originally by Stefan and Fam. --js]
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>

Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 1446765200-3054-12-git-send-email-jsnow@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/include/block/block_int.h b/include/block/block_int.h
index 695393e6e6..4012e36437 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -669,6 +669,7 @@ void mirror_start(BlockDriverState *bs, BlockDriverState *target,
  * @on_target_error: The action to take upon error writing to the target.
  * @cb: Completion function for the job.
  * @opaque: Opaque pointer value passed to @cb.
+ * @txn: Transaction that this job is part of (may be NULL).
  *
  * Start a backup operation on @bs.  Clusters in @bs are written to @target
  * until the job is cancelled or manually completed.
@@ -679,7 +680,7 @@ void backup_start(BlockDriverState *bs, BlockDriverState *target,
                   BlockdevOnError on_source_error,
                   BlockdevOnError on_target_error,
                   BlockCompletionFunc *cb, void *opaque,
-                  Error **errp);
+                  BlockJobTxn *txn, Error **errp);
 
 void blk_set_bs(BlockBackend *blk, BlockDriverState *bs);