Re: [Qemu-block] [PATCH] commit: Add NULL check for overlay_bs

[Peter Maydell]

On 10 July 2017 at 12:45, Kevin Wolf <address@hidden> wrote:
> I can't see how overlay_bs could become NULL with the current code, but
> other code in this function already checks it and we can make Coverity
> happy with this check, so let's add it.
>
> Signed-off-by: Kevin Wolf <address@hidden>
> ---
>  block/commit.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/block/commit.c b/block/commit.c
> index 774a8a5..50e7950 100644
> --- a/block/commit.c
> +++ b/block/commit.c
> @@ -90,7 +90,9 @@ static void commit_complete(BlockJob *job, void *opaque)
>
>      /* Make sure overlay_bs and top stay around until bdrv_set_backing_hd() 
> */
>      bdrv_ref(top);
> -    bdrv_ref(overlay_bs);
> +    if (overlay_bs) {
> +        bdrv_ref(overlay_bs);
> +    }
>
>      /* Remove base node parent that still uses BLK_PERM_WRITE/RESIZE before
>       * the normal backing chain can be restored. */
> --
> 1.8.3.1

Commit 19ebd13ed45ad5d5f2 which added the bdrv_ref() call
was cc qemu-stable; should we cc this fix too, or are you
happy that it's definitely not actually triggerable in stable?

thanks
-- PMM