Re: [Qemu-devel] [PATCH 2/3] Migration/colo.c: Fix COLO failover status error

[Zhang, Chen]

-----Original Message-----
From: Dr. David Alan Gilbert [mailto:address@hidden 
Sent: Tuesday, February 26, 2019 6:55 PM
To: Zhang, Chen <address@hidden>
Cc: Li Zhijian <address@hidden>; Zhang Chen <address@hidden>; Juan Quintela 
<address@hidden>; zhanghailiang <address@hidden>; qemu-dev <address@hidden>
Subject: Re: [PATCH 2/3] Migration/colo.c: Fix COLO failover status error

* Zhang Chen (address@hidden) wrote:
> From: Zhang Chen <address@hidden>
> 
> When finished COLO failover, the status is FAILOVER_STATUS_COMPLETED.
> The origin codes misunderstand the FAILOVER_STATUS_REQUIRE.
> 
> Signed-off-by: Zhang Chen <address@hidden>

Why do these 'case's have to only deal with COMPLETED - what stops the 
REQUIRE/ACTIVE states appearing when these routines check the status; even if 
those states only happen for a short amount of time?

Yes, other status just marked the failover processing. We can see 
colo_failover_bh(), the REQUIRE/ACTIVE only exist for a very short time.


Thanks
Zhang Chen

Dave

> ---
>  migration/colo.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/migration/colo.c b/migration/colo.c index 
> a916dc178c..a13acac192 100644
> --- a/migration/colo.c
> +++ b/migration/colo.c
> @@ -121,6 +121,7 @@ static void secondary_vm_do_failover(void)
>      }
>      /* Notify COLO incoming thread that failover work is finished */
>      qemu_sem_post(&mis->colo_incoming_sem);
> +
>      /* For Secondary VM, jump to incoming co */
>      if (mis->migration_incoming_co) {
>          qemu_coroutine_enter(mis->migration_incoming_co);
> @@ -262,7 +263,7 @@ COLOStatus *qmp_query_colo_status(Error **errp)
>      case FAILOVER_STATUS_NONE:
>          s->reason = COLO_EXIT_REASON_NONE;
>          break;
> -    case FAILOVER_STATUS_REQUIRE:
> +    case FAILOVER_STATUS_COMPLETED:
>          s->reason = COLO_EXIT_REASON_REQUEST;
>          break;
>      default:
> @@ -582,7 +583,7 @@ out:
>          qapi_event_send_colo_exit(COLO_MODE_PRIMARY,
>                                    COLO_EXIT_REASON_ERROR);
>          break;
> -    case FAILOVER_STATUS_REQUIRE:
> +    case FAILOVER_STATUS_COMPLETED:
>          qapi_event_send_colo_exit(COLO_MODE_PRIMARY,
>                                    COLO_EXIT_REASON_REQUEST);
>          break;
> @@ -854,7 +855,7 @@ out:
>          qapi_event_send_colo_exit(COLO_MODE_SECONDARY,
>                                    COLO_EXIT_REASON_ERROR);
>          break;
> -    case FAILOVER_STATUS_REQUIRE:
> +    case FAILOVER_STATUS_COMPLETED:
>          qapi_event_send_colo_exit(COLO_MODE_SECONDARY,
>                                    COLO_EXIT_REASON_REQUEST);
>          break;
> --
> 2.17.GIT
> 
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK