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Date: Thu, 07 Nov 2013 10:54:28 +0100
From: Paolo Bonzini <pbonzini@redhat.com>
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Subject: Re: [Qemu-devel] [patch] avoid a bogus COMPLETED->CANCELLED
	transition
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To: "Zhanghaoyu (A)" <haoyu.zhang@huawei.com>
Cc: "Huangweidong (C)" <weidong.huang@huawei.com>, Gleb Natapov <gleb@redhat.com>, "Michael S. Tsirkin" <mst@redhat.com>, Marcelo Tosatti <mtosatti@redhat.com>, Luonengjun <luonengjun@huawei.com>, "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>, Zengjunliang <zengjunliang@huawei.com>, "Wangrui (K)" <moon.wangrui@huawei.com>

Il 07/11/2013 09:21, Zhanghaoyu (A) ha scritto:
> Avoid a bogus COMPLETED->CANCELLED transition.
> There is a period of time from the timing of setting COMPLETED state to that of migration thread exits, so during which it's problematic in COMPLETED->CANCELLED transition.
> 
> Signed-off-by: Zeng Junliang <zengjunliang@huawei.com>
> Signed-off-by: Zhang Haoyu <haoyu.zhang@huawei.com>
> ---
>  migration.c |    9 ++++++++-
>  1 files changed, 8 insertions(+), 1 deletions(-)
> 
> diff --git a/migration.c b/migration.c
> index 2b1ab20..fd73b97 100644
> --- a/migration.c
> +++ b/migration.c
> @@ -326,9 +326,16 @@ void migrate_fd_error(MigrationState *s)
>  
>  static void migrate_fd_cancel(MigrationState *s)
>  {
> +    int old_state ;
>      DPRINTF("cancelling migration\n");
>  
> -    migrate_set_state(s, s->state, MIG_STATE_CANCELLED);
> +    do {
> +        old_state = s->state;
> +        if (old_state != MIG_STATE_SETUP && old_state != MIG_STATE_ACTIVE) {
> +            break;
> +        }
> +        migrate_set_state(s, old_state, MIG_STATE_CANCELLED);
> +    } while (s->state != MIG_STATE_CANCELLED);
>  }
>  
>  void add_migration_state_change_notifier(Notifier *notify)
> 

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>