Re: [PATCH for-6.1? v2 6/7] mirror: Check job_is_cancelled() earlier

[Vladimir Sementsov-Ogievskiy]

26.07.2021 17:46, Max Reitz wrote:
> We must check whether the job is force-cancelled early in our main loop,
> most importantly before any `continue` statement.  For example, we used
> to have `continue`s before our current checking location that are
> triggered by `mirror_flush()` failing.  So, if `mirror_flush()` kept
> failing, force-cancelling the job would not terminate it.
>
> A job being force-cancelled should be treated the same as the job having
> failed, so put the check in the same place where we check `s->ret < 0`.
>
> Buglink: https://gitlab.com/qemu-project/qemu/-/issues/462
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> ---
>   block/mirror.c | 7 +------
>   1 file changed, 1 insertion(+), 6 deletions(-)
>
> diff --git a/block/mirror.c b/block/mirror.c
> index 72e02fa34e..46d1a1e5a2 100644
> --- a/block/mirror.c
> +++ b/block/mirror.c
> @@ -993,7 +993,7 @@ static int coroutine_fn mirror_run(Job *job, Error **errp)
>               mirror_wait_for_any_operation(s, true);
>           }
>   
> -        if (s->ret < 0) {
> +        if (s->ret < 0 || job_is_cancelled(&s->common.job)) {
>               ret = s->ret;
>               goto immediate_exit;
>           }
> @@ -1078,8 +1078,6 @@ static int coroutine_fn mirror_run(Job *job, Error **errp)
>               break;
>           }
>   
> -        ret = 0;
> -

That's just a cleanup, that statement is useless pre-patch, yes?

>           if (job_is_ready(&s->common.job) && !should_complete) {
>               delay_ns = (s->in_flight == 0 &&
>                           cnt == 0 ? BLOCK_JOB_SLICE_TIME : 0);
> @@ -1087,9 +1085,6 @@ static int coroutine_fn mirror_run(Job *job, Error **errp)
>           trace_mirror_before_sleep(s, cnt, job_is_ready(&s->common.job),
>                                     delay_ns);
>           job_sleep_ns(&s->common.job, delay_ns);
> -        if (job_is_cancelled(&s->common.job)) {
> -            break;
> -        }
>           s->last_pause_ns = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
>       }
>   

Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

--
Best regards,
Vladimir