Re: [Qemu-devel] [PATCH 1/2] block/mirror: Make cancel always cancel pre-READY

[Eric Blake]

On 05/01/2018 05:05 PM, Max Reitz wrote:
> Commit b76e4458b1eb3c32e9824fe6aa51f67d2b251748 made the mirror block
> job respect block-job-cancel's @force flag: With that flag set, it would
> now always really cancel, even post-READY.
>
> Unfortunately, it had a side effect: Without that flag set, it would now
> never cancel, not even before READY.  Considering that is an
> incompatible change and not noted anywhere in the commit or the
> description of block-job-cancel's @force parameter, this seems
> unintentional and we should revert to the previous behavior, which is to
> immediately cancel the job when block-job-cancel is called before source
> and target are in sync (i.e. before the READY event).
>
> Cc: address@hidden

Actually adding that in cc on this reply.

> Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1572856
> Reported-by: Yanan Fu <address@hidden>
> Signed-off-by: Max Reitz <address@hidden>
> ---
>   block/mirror.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)

Reviewed-by: Eric Blake <address@hidden>

> diff --git a/block/mirror.c b/block/mirror.c
> index 7bfad6e844..003f957b12 100644
> --- a/block/mirror.c
> +++ b/block/mirror.c
> @@ -874,7 +874,9 @@ static void coroutine_fn mirror_run(void *opaque)
>           }
>           trace_mirror_before_sleep(s, cnt, s->synced, delay_ns);
>           block_job_sleep_ns(&s->common, delay_ns);
> -        if (block_job_is_cancelled(&s->common) && s->common.force) {
> +        if (block_job_is_cancelled(&s->common) &&
> +            (!s->synced || s->common.force))
> +        {
>               break;
>           }
>           s->last_pause_ns = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);

--
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org