Re: [Qemu-devel] [PATCH 04/13] block: Freeze the backing chain for the duration of the stream job

[Kevin Wolf]

Am 17.01.2019 um 16:33 hat Alberto Garcia geschrieben:
> Signed-off-by: Alberto Garcia <address@hidden>
> ---
>  block/stream.c | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
> 
> diff --git a/block/stream.c b/block/stream.c
> index 7a49ac0992..39a2e10892 100644
> --- a/block/stream.c
> +++ b/block/stream.c
> @@ -54,6 +54,14 @@ static int coroutine_fn stream_populate(BlockBackend *blk,
>      return blk_co_preadv(blk, offset, qiov.size, &qiov, 
> BDRV_REQ_COPY_ON_READ);
>  }
>  
> +static void stream_abort(Job *job)
> +{
> +    StreamBlockJob *s = container_of(job, StreamBlockJob, common.job);
> +    BlockJob *bjob = &s->common;
> +
> +    bdrv_unfreeze_backing_chain(blk_bs(bjob->blk), s->base);
> +}

Like in commit, you can get a double unfreeze here if .abort is called
after .prepare returned an error.

Kevin