From b756b9ce8a81cd0d95ae691cee541a149463c8c9 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Fri, 21 Nov 2014 10:48:57 +0000 Subject: [PATCH] blockdev: update outdated qmp_transaction() comments Originally the transaction QMP command was just for taking snapshots. The command became more general when drive-backup and abort were added. It is more accurate to say the command is about performing operations on an atomic group than to say it is about snapshots. Signed-off-by: Stefan Hajnoczi Reviewed-by: Max Reitz Message-id: 1416566940-4430-2-git-send-email-stefanha@redhat.com Signed-off-by: Kevin Wolf --- blockdev.c | 16 ++++++---------- 1 file changed, 6 insertions(+), 10 deletions(-) diff --git a/blockdev.c b/blockdev.c index a52f20520d..490f698ce2 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1173,7 +1173,7 @@ out_aio_context: return NULL; } -/* New and old BlockDriverState structs for group snapshots */ +/* New and old BlockDriverState structs for atomic group operations */ typedef struct BlkTransactionState BlkTransactionState; @@ -1544,9 +1544,8 @@ static const BdrvActionOps actions[] = { }; /* - * 'Atomic' group snapshots. The snapshots are taken as a set, and if any fail - * then we do not pivot any of the devices in the group, and abandon the - * snapshots + * 'Atomic' group operations. The operations are performed as a set, and if + * any fail then we roll back all operations in the group. */ void qmp_transaction(TransactionActionList *dev_list, Error **errp) { @@ -1557,10 +1556,10 @@ void qmp_transaction(TransactionActionList *dev_list, Error **errp) QSIMPLEQ_HEAD(snap_bdrv_states, BlkTransactionState) snap_bdrv_states; QSIMPLEQ_INIT(&snap_bdrv_states); - /* drain all i/o before any snapshots */ + /* drain all i/o before any operations */ bdrv_drain_all(); - /* We don't do anything in this loop that commits us to the snapshot */ + /* We don't do anything in this loop that commits us to the operations */ while (NULL != dev_entry) { TransactionAction *dev_info = NULL; const BdrvActionOps *ops; @@ -1595,10 +1594,7 @@ void qmp_transaction(TransactionActionList *dev_list, Error **errp) goto exit; delete_and_fail: - /* - * failure, and it is all-or-none; abandon each new bs, and keep using - * the original bs for all images - */ + /* failure, and it is all-or-none; roll back all operations */ QSIMPLEQ_FOREACH(state, &snap_bdrv_states, entry) { if (state->ops->abort) { state->ops->abort(state);