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blockdev: update outdated qmp_transaction() comments

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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 <stefanha@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 1416566940-4430-2-git-send-email-stefanha@redhat.com
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Stefan Hajnoczi 2014-11-21 10:48:57 +00:00 committed by Kevin Wolf
parent 00e047926e
commit b756b9ce8a
1 changed files with 6 additions and 10 deletions
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16
blockdev.c
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@ -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);