Re: [Qemu-devel] [patch] introduce MIG_STATE_CANCELLING state

[Paolo Bonzini <pbonzini@redhat.com>]

Il 07/11/2013 12:01, Zhanghaoyu (A) ha scritto:
> Introduce MIG_STATE_CANCELLING state to avoid starting a new migration task while the previous one still exist.
> 
> Signed-off-by: Zeng Junliang <zengjunliang@huawei.com>
> Signed-off-by: Zhang Haoyu <haoyu.zhang@huawei.com>
> ---
>  migration.c |   26 ++++++++++++++++----------
>  1 files changed, 16 insertions(+), 10 deletions(-)
> 
> diff --git a/migration.c b/migration.c
> index fd73b97..af8a09c 100644
> --- a/migration.c
> +++ b/migration.c
> @@ -40,6 +40,7 @@ enum {
>      MIG_STATE_ERROR = -1,
>      MIG_STATE_NONE,
>      MIG_STATE_SETUP,
> +    MIG_STATE_CANCELLING,
>      MIG_STATE_CANCELLED,
>      MIG_STATE_ACTIVE,
>      MIG_STATE_COMPLETED,
> @@ -196,6 +197,7 @@ MigrationInfo *qmp_query_migrate(Error **errp)
>          info->has_total_time = false;
>          break;
>      case MIG_STATE_ACTIVE:
> +    case MIG_STATE_CANCELLING:
>          info->has_status = true;
>          info->status = g_strdup("active");
>          info->has_total_time = true;
> @@ -282,6 +284,13 @@ void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params,
>  
>  /* shared migration helpers */
>  
> +static void migrate_set_state(MigrationState *s, int old_state, int new_state)
> +{
> +    if (atomic_cmpxchg(&s->state, old_state, new_state) == new_state) {
> +        trace_migrate_set_state(new_state);
> +    }
> +}
> +
>  static void migrate_fd_cleanup(void *opaque)
>  {
>      MigrationState *s = opaque;
> @@ -303,18 +312,14 @@ static void migrate_fd_cleanup(void *opaque)
>  
>      if (s->state != MIG_STATE_COMPLETED) {
>          qemu_savevm_state_cancel();
> +        if (s->state == MIG_STATE_CANCELLING) {
> +            migrate_set_state(s, MIG_STATE_CANCELLING, MIG_STATE_CANCELLED);
> +        }
>      }
>  
>      notifier_list_notify(&migration_state_notifiers, s);
>  }
>  
> -static void migrate_set_state(MigrationState *s, int old_state, int new_state)
> -{
> -    if (atomic_cmpxchg(&s->state, old_state, new_state) == new_state) {
> -        trace_migrate_set_state(new_state);
> -    }
> -}
> -
>  void migrate_fd_error(MigrationState *s)
>  {
>      DPRINTF("setting error state\n");
> @@ -334,8 +339,8 @@ static void migrate_fd_cancel(MigrationState *s)
>          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);
> +        migrate_set_state(s, old_state, MIG_STATE_CANCELLING);
> +    } while (s->state != MIG_STATE_CANCELLING);
>  }
>  
>  void add_migration_state_change_notifier(Notifier *notify)
> @@ -412,7 +417,8 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk,
>      params.blk = has_blk && blk;
>      params.shared = has_inc && inc;
>  
> -    if (s->state == MIG_STATE_ACTIVE || s->state == MIG_STATE_SETUP) {
> +    if (s->state == MIG_STATE_ACTIVE || s->state == MIG_STATE_SETUP ||
> +        s->state == MIG_STATE_CANCELLING) {
>          error_set(errp, QERR_MIGRATION_ACTIVE);
>          return;
>      }
> 

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