Re: [PATCH V2 08/11] migration: refactor migrate_fd_connect failures

[Peter Xu]

On Fri, Jan 12, 2024 at 07:05:07AM -0800, Steve Sistare wrote:
> Move common code for the error path in migrate_fd_connect to a shared
> fail label.  No functional change.
> 
> Signed-off-by: Steve Sistare <steven.sistare@oracle.com>

Reviewed-by: Peter Xu <peterx@redhat.com>

One nitpick below:

> ---
>  migration/migration.c | 22 +++++++++++-----------
>  1 file changed, 11 insertions(+), 11 deletions(-)
> 
> diff --git a/migration/migration.c b/migration/migration.c
> index e9914aa..c828ba7 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -3549,6 +3549,7 @@ void migrate_fd_connect(MigrationState *s, Error 
> *error_in)
>      Error *local_err = NULL;
>      uint64_t rate_limit;
>      bool resume = s->state == MIGRATION_STATUS_POSTCOPY_PAUSED;
> +    int expect_state = s->state;

IMHO we can drop this.

>  
>      /*
>       * If there's a previous error, free it and prepare for another one.
> @@ -3603,11 +3604,7 @@ void migrate_fd_connect(MigrationState *s, Error 
> *error_in)
>      if (migrate_postcopy_ram() || migrate_return_path()) {
>          if (open_return_path_on_source(s)) {
>              error_setg(&local_err, "Unable to open return-path for 
> postcopy");
> -            migrate_set_state(&s->state, s->state, MIGRATION_STATUS_FAILED);
> -            migrate_set_error(s, local_err);
> -            error_report_err(local_err);
> -            migrate_fd_cleanup(s);
> -            return;
> +            goto fail;
>          }
>      }
>  
> @@ -3629,12 +3626,8 @@ void migrate_fd_connect(MigrationState *s, Error 
> *error_in)
>      }
>  
>      if (multifd_save_setup(&local_err) != 0) {
> -        migrate_set_error(s, local_err);
> -        error_report_err(local_err);
> -        migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
> -                          MIGRATION_STATUS_FAILED);
> -        migrate_fd_cleanup(s);
> -        return;
> +        expect_state = MIGRATION_STATUS_SETUP;

Then drop this.

> +        goto fail;
>      }
>  
>      if (migrate_background_snapshot()) {
> @@ -3645,6 +3638,13 @@ void migrate_fd_connect(MigrationState *s, Error 
> *error_in)
>                  migration_thread, s, QEMU_THREAD_JOINABLE);
>      }
>      s->migration_thread_running = true;
> +    return;
> +
> +fail:
> +    migrate_set_error(s, local_err);
> +    migrate_set_state(&s->state, expect_state, MIGRATION_STATUS_FAILED);

Then constantly use s->state.

> +    error_report_err(local_err);
> +    migrate_fd_cleanup(s);
>  }
>  
>  static void migration_class_init(ObjectClass *klass, void *data)
> -- 
> 1.8.3.1
> 

-- 
Peter Xu