Re: [Qemu-devel] [PATCH 1/2] blockjob: assert(cb) in the entry functions of blockjob

[Paolo Bonzini <pbonzini@redhat.com>]

On 22/06/2016 11:16, Changlong Xie wrote:
> Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
> ---
>  block/commit.c | 1 +
>  block/mirror.c | 2 ++
>  block/stream.c | 1 +
>  3 files changed, 4 insertions(+)

Why is this useful?

Paolo

> diff --git a/block/commit.c b/block/commit.c
> index 444333b..13b55c1 100644
> --- a/block/commit.c
> +++ b/block/commit.c
> @@ -223,6 +223,7 @@ void commit_start(BlockDriverState *bs, BlockDriverState *base,
>      BlockDriverState *overlay_bs;
>      Error *local_err = NULL;
>  
> +    assert(cb);
>      assert(top != bs);
>      if (top == base) {
>          error_setg(errp, "Invalid files for merge: top and base are the same");
> diff --git a/block/mirror.c b/block/mirror.c
> index a04ed9c..fa2bdab 100644
> --- a/block/mirror.c
> +++ b/block/mirror.c
> @@ -912,6 +912,7 @@ void mirror_start(BlockDriverState *bs, BlockDriverState *target,
>      bool is_none_mode;
>      BlockDriverState *base;
>  
> +    assert(cb);
>      if (mode == MIRROR_SYNC_MODE_INCREMENTAL) {
>          error_setg(errp, "Sync mode 'incremental' not supported");
>          return;
> @@ -935,6 +936,7 @@ void commit_active_start(BlockDriverState *bs, BlockDriverState *base,
>      int ret;
>      Error *local_err = NULL;
>  
> +    assert(cb);
>      orig_base_flags = bdrv_get_flags(base);
>  
>      if (bdrv_reopen(base, bs->open_flags, errp)) {
> diff --git a/block/stream.c b/block/stream.c
> index c0efbda..fc34c63 100644
> --- a/block/stream.c
> +++ b/block/stream.c
> @@ -226,6 +226,7 @@ void stream_start(BlockDriverState *bs, BlockDriverState *base,
>  {
>      StreamBlockJob *s;
>  
> +    assert(cb);
>      s = block_job_create(&stream_job_driver, bs, speed, cb, opaque, errp);
>      if (!s) {
>          return;
>