Re: [Qemu-devel] [PATCH 1/2] block: Allow bdrv_unref_child(bs, NULL)

[Jeff Cody <jcody@redhat.com>]

On Tue, Oct 13, 2015 at 02:17:39PM +0200, Kevin Wolf wrote:
> bdrv_unref() can be called with a NULL argument and doesn't do anything
> then. Make bdrv_unref_child() consistent with it.
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  block.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/block.c b/block.c
> index f38146e..6490040 100644
> --- a/block.c
> +++ b/block.c
> @@ -1104,12 +1104,17 @@ static void bdrv_detach_child(BdrvChild *child)
>  
>  void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child)
>  {
> -    BlockDriverState *child_bs = child->bs;
> +    BlockDriverState *child_bs;
> +
> +    if (child == NULL) {
> +        return;
> +    }
>  
>      if (child->bs->inherits_from == parent) {
>          child->bs->inherits_from = NULL;
>      }
>  
> +    child_bs = child->bs;
>      bdrv_detach_child(child);
>      bdrv_unref(child_bs);
>  }
> -- 
> 1.8.3.1
>

Reviewed-by: Jeff Cody <jcody@redhat.com>