Re: [Qemu-block] [PATCH v2] throttle: fix a qemu crash problem when calling blk_delete

[Alberto Garcia]

On Tue 24 Oct 2017 05:33:51 AM CEST, sochin jiang wrote:
> --- a/block/throttle-groups.c
> +++ b/block/throttle-groups.c
> @@ -576,7 +576,9 @@ void throttle_group_unregister_tgm(ThrottleGroupMember 
> *tgm)
>  
>      /* remove the current tgm from the list */
>      QLIST_REMOVE(tgm, round_robin);
> -    throttle_timers_destroy(&tgm->throttle_timers);
> +    if (throttle_timers_are_initialized(&tgm->throttle_timers)) {
> +        throttle_timers_destroy(&tgm->throttle_timers);
> +    }
>      qemu_mutex_unlock(&tg->lock);
>  
>      throttle_group_unref(&tg->ts);

I don't know what the rest of the people think, but I'm not completely
convinced that it's a good idea to have an active ThrottleState inside a
ThrottleGroupMember without timers.

Perhaps in blk_remove_bs() after detaching the AioContext from the BDS
we can attach the default one (what you would get with
blk_get_aio_context()).

On the other hand I think that Manos's series to remove the legacy
throttling code gets rid of BlockBackend.ThrottleGroupMember completely.

Berto