Re: [Qemu-devel] [PATCH v4 2/6] blockjob: Introduce block_job_complete_sync()

[Fam Zheng]

On Sat, 04/12 20:57, Max Reitz wrote:
> Implement block_job_complete_sync() by doing the exact same thing as
> block_job_cancel_sync() does, only with calling block_job_complete()
> instead of block_job_cancel().
> 
> Signed-off-by: Max Reitz <address@hidden>
> ---
>  blockjob.c               | 24 ++++++++++++++++++++++--
>  include/block/blockjob.h | 15 +++++++++++++++
>  2 files changed, 37 insertions(+), 2 deletions(-)
> 
> diff --git a/blockjob.c b/blockjob.c
> index b3ce14c..d12f3ea 100644
> --- a/blockjob.c
> +++ b/blockjob.c
> @@ -165,7 +165,9 @@ static void block_job_cancel_cb(void *opaque, int ret)
>      data->cb(data->opaque, ret);
>  }
>  
> -int block_job_cancel_sync(BlockJob *job)
> +static int block_job_finish_sync(BlockJob *job,
> +                                 void (*finish)(BlockJob *, Error **errp),
> +                                 Error **errp)
>  {
>      struct BlockCancelData data;
>      BlockDriverState *bs = job->bs;
> @@ -181,13 +183,31 @@ int block_job_cancel_sync(BlockJob *job)
>      data.ret = -EINPROGRESS;
>      job->cb = block_job_cancel_cb;
>      job->opaque = &data;
> -    block_job_cancel(job);
> +    finish(job, errp);
>      while (data.ret == -EINPROGRESS) {
>          qemu_aio_wait();
>      }
>      return (data.cancelled && data.ret == 0) ? -ECANCELED : data.ret;
>  }
>  
> +/* A wrapper around block_job_cancel() taking an Error ** parameter so it 
> may be
> + * used with block_job_finish_sync() without the need for (rather nasty)
> + * function pointer casts there. */

Why not just change the prototype of block_job_cancel to have this error
pointer?

Thanks,
Fam

> +static void block_job_cancel_err(BlockJob *job, Error **errp)
> +{
> +    block_job_cancel(job);
> +}
> +
> +int block_job_cancel_sync(BlockJob *job)
> +{
> +    return block_job_finish_sync(job, &block_job_cancel_err, NULL);
> +}
> +
> +int block_job_complete_sync(BlockJob *job, Error **errp)
> +{
> +    return block_job_finish_sync(job, &block_job_complete, errp);
> +}
> +
>  void block_job_sleep_ns(BlockJob *job, QEMUClockType type, int64_t ns)
>  {
>      assert(job->busy);
> diff --git a/include/block/blockjob.h b/include/block/blockjob.h
> index d76de62..626ea42 100644
> --- a/include/block/blockjob.h
> +++ b/include/block/blockjob.h
> @@ -253,6 +253,21 @@ bool block_job_is_paused(BlockJob *job);
>  int block_job_cancel_sync(BlockJob *job);
>  
>  /**
> + * block_job_complete_sync:
> + * @job: The job to be completed.
> + * @errp: Error object which may be set by block_job_complete(); this is not
> + *        necessarily set on every error, the job return value has to be
> + *        checked as well.
> + *
> + * Synchronously complete the job.  The completion callback is called before 
> the
> + * function returns, unless it is NULL (which is permissible when using this
> + * function).
> + *
> + * Returns the return value from the job.
> + */
> +int block_job_complete_sync(BlockJob *job, Error **errp);
> +
> +/**
>   * block_job_iostatus_reset:
>   * @job: The job whose I/O status should be reset.
>   *
> -- 
> 1.9.2
>