Re: [Qemu-devel] [Qemu-block] [PATCH v2 2/4] migration: Inactivate images after .save_live_complete_precopy()

[Jeff Cody <jcody@redhat.com>]

On Tue, May 30, 2017 at 05:22:51PM +0200, Kevin Wolf wrote:
> Block migration may still access the image during its
> .save_live_complete_precopy() implementation, so we should only
> inactivate the image afterwards.
> 
> Another reason for the change is that inactivating an image fails when
> there is still a non-device BlockBackend using it, which includes the
> BBs used by block migration. We want to give block migration a chance to
> release the BBs before trying to inactivate the image (this will be done
> in another patch).
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> Reviewed-by: Fam Zheng <famz@redhat.com>
> Reviewed-by: Juan Quintela <quintela@redhat.com>
> Reviewed-by: Eric Blake <eblake@redhat.com>
> ---
>  migration/migration.c | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/migration/migration.c b/migration/migration.c
> index ad29e53..77a05d1 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -1820,17 +1820,19 @@ static void migration_completion(MigrationState *s, int current_active_state,
>  
>          if (!ret) {
>              ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
> +            if (ret >= 0) {
> +                qemu_file_set_rate_limit(s->to_dst_file, INT64_MAX);
> +                qemu_savevm_state_complete_precopy(s->to_dst_file, false);
> +            }
>              /*
>               * Don't mark the image with BDRV_O_INACTIVE flag if
>               * we will go into COLO stage later.
>               */
>              if (ret >= 0 && !migrate_colo_enabled()) {
>                  ret = bdrv_inactivate_all();
> -            }
> -            if (ret >= 0) {
> -                qemu_file_set_rate_limit(s->to_dst_file, INT64_MAX);
> -                qemu_savevm_state_complete_precopy(s->to_dst_file, false);
> -                s->block_inactive = true;
> +                if (ret >= 0) {
> +                    s->block_inactive = true;
> +                }
>              }
>          }
>          qemu_mutex_unlock_iothread();
> -- 
> 1.8.3.1
> 
>

Reviewed-by: Jeff Cody <jcody@redhat.com>