Re: [Qemu-devel] [PATCH 06/10] blockdev: make BlockJobTxn available to qmp 'transaction'

[John Snow <jsnow@redhat.com>]

On 06/25/2015 08:12 AM, Stefan Hajnoczi wrote:
> Provide a BlockJobTxn to actions executed in a qmp 'transaction'
> command.  This allows actions to make their block jobs either complete
> as a group or fail/cancel together.
> 
> The next patch adds the first user.
> 
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
>  blockdev.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/blockdev.c b/blockdev.c
> index c572950..453f3ec 100644
> --- a/blockdev.c
> +++ b/blockdev.c
> @@ -1279,6 +1279,7 @@ typedef struct BlkActionOps {
>  struct BlkActionState {
>      TransactionAction *action;
>      const BlkActionOps *ops;
> +    BlockJobTxn *block_job_txn;
>      QSIMPLEQ_ENTRY(BlkActionState) entry;
>  };
>  
> @@ -1883,12 +1884,15 @@ static const BlkActionOps actions[] = {
>  void qmp_transaction(TransactionActionList *dev_list, Error **errp)
>  {
>      TransactionActionList *dev_entry = dev_list;
> +    BlockJobTxn *block_job_txn;
>      BlkActionState *state, *next;
>      Error *local_err = NULL;
>  
>      QSIMPLEQ_HEAD(snap_bdrv_states, BlkActionState) snap_bdrv_states;
>      QSIMPLEQ_INIT(&snap_bdrv_states);
>  
> +    block_job_txn = block_job_txn_new();
> +
>      /* drain all i/o before any operations */
>      bdrv_drain_all();
>  
> @@ -1908,6 +1912,7 @@ void qmp_transaction(TransactionActionList *dev_list, Error **errp)
>          state = g_malloc0(ops->instance_size);
>          state->ops = ops;
>          state->action = dev_info;
> +        state->block_job_txn = block_job_txn;
>          QSIMPLEQ_INSERT_TAIL(&snap_bdrv_states, state, entry);
>  
>          state->ops->prepare(state, &local_err);
> @@ -1917,6 +1922,8 @@ void qmp_transaction(TransactionActionList *dev_list, Error **errp)
>          }
>      }
>  
> +    block_job_txn_begin(block_job_txn);
> +
>      QSIMPLEQ_FOREACH(state, &snap_bdrv_states, entry) {
>          if (state->ops->commit) {
>              state->ops->commit(state);
> @@ -1927,6 +1934,8 @@ void qmp_transaction(TransactionActionList *dev_list, Error **errp)
>      goto exit;
>  
>  delete_and_fail:
> +    block_job_txn_begin(block_job_txn);
> +
>      /* failure, and it is all-or-none; roll back all operations */
>      QSIMPLEQ_FOREACH(state, &snap_bdrv_states, entry) {
>          if (state->ops->abort) {
> 

Reviewed-by: John Snow <jsnow@redhat.com>