From f9ea81e82519f44071b3dd617de98f0d6d6cca0a Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Mon, 24 Jun 2013 17:13:16 +0200 Subject: [PATCH] blockdev: allow BdrvActionOps->commit() to be NULL Some QMP 'transaction' types don't need to do anything on .commit(). Make .commit() optional just like .abort(). The "drive-backup" action will take advantage of this, it only needs to cancel the block job on .abort(). Other block job actions will probably follow the same pattern, so allow .commit() to be NULL. Suggested-by: Eric Blake Reviewed-by: Eric Blake Reviewed-by: Kevin Wolf Signed-off-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- blockdev.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/blockdev.c b/blockdev.c index 5312e6065f..0cf80810f5 100644 --- a/blockdev.c +++ b/blockdev.c @@ -789,7 +789,7 @@ typedef struct BdrvActionOps { size_t instance_size; /* Prepare the work, must NOT be NULL. */ void (*prepare)(BlkTransactionState *common, Error **errp); - /* Commit the changes, must NOT be NULL. */ + /* Commit the changes, can be NULL. */ void (*commit)(BlkTransactionState *common); /* Abort the changes on fail, can be NULL. */ void (*abort)(BlkTransactionState *common); @@ -969,7 +969,9 @@ void qmp_transaction(TransactionActionList *dev_list, Error **errp) } QSIMPLEQ_FOREACH(state, &snap_bdrv_states, entry) { - state->ops->commit(state); + if (state->ops->commit) { + state->ops->commit(state); + } } /* success */ -- 2.11.0