Re: [Qemu-block] [PATCH for-2.9-rc5 v3] block: Drain BH in bdrv_drained_begin

[Paolo Bonzini]

On 18/04/2017 12:39, Fam Zheng wrote:
> +    QLIST_FOREACH_SAFE(child, &bs->children, next, tmp) {
> +        BlockDriverState *bs = child->bs;
> +        assert(bs->refcnt > 0);
> +        bdrv_ref(bs);
> +        waited |= bdrv_drain_recurse(bs);
> +        bdrv_unref(bs);
>      }

I think this accesses global state that is not protected by the
AioContext lock?

Paolo