Re: [PATCH v2] migration: use "" instead of (null) for tls-authz

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Mao Zhongyi (maozhongyi@cmss.chinamobile.com) wrote:
> run:
> (qemu) info migrate_parameters
> announce-initial: 50 ms
> ...
> announce-max: 550 ms
> multifd-compression: none
> xbzrle-cache-size: 4194304
> max-postcopy-bandwidth: 0
>  tls-authz: '(null)'
> 
> Migration parameter 'tls-authz' is used to provide the QOM ID
> of a QAuthZ subclass instance that provides the access control
> check, default is NULL. But the empty string is not a valid
> object ID, so use "" instead of the default. Although it will
> fail when lookup an object with ID "", it is harmless, just
> consistent with tls_creds.

Yes, it's probably the best we can do given Dan's explanation that
we can't change tls_authz to be non-null.

> Also fixed the bad indentation on the last line.
> 
> Signed-off-by: Mao Zhongyi <maozhongyi@cmss.chinamobile.com>
> ---
>  migration/migration.c | 3 ++-
>  monitor/hmp-cmds.c    | 2 +-
>  2 files changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/migration/migration.c b/migration/migration.c
> index c1d88ace7f..b060153ef7 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -790,7 +790,8 @@ MigrationParameters *qmp_query_migrate_parameters(Error **errp)
>      params->has_tls_hostname = true;
>      params->tls_hostname = g_strdup(s->parameters.tls_hostname);
>      params->has_tls_authz = true;
> -    params->tls_authz = g_strdup(s->parameters.tls_authz);
> +    params->tls_authz = s->parameters.tls_authz ? \
> +                        g_strdup(s->parameters.tls_authz) : g_strdup("");

The \ is unneeded; this isn't a macro; it's also a little shorter to do
it as:
    params->tls_authz = g_strdup(s->parameters.tls_authz ?
                                 s->parameters.tls_authz : "");

Dave


>      params->has_max_bandwidth = true;
>      params->max_bandwidth = s->parameters.max_bandwidth;
>      params->has_downtime_limit = true;
> diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
> index 58724031ea..f8be6bbb16 100644
> --- a/monitor/hmp-cmds.c
> +++ b/monitor/hmp-cmds.c
> @@ -459,7 +459,7 @@ void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict)
>          monitor_printf(mon, "%s: %" PRIu64 "\n",
>              MigrationParameter_str(MIGRATION_PARAMETER_MAX_POSTCOPY_BANDWIDTH),
>              params->max_postcopy_bandwidth);
> -        monitor_printf(mon, " %s: '%s'\n",
> +        monitor_printf(mon, "%s: '%s'\n",
>              MigrationParameter_str(MIGRATION_PARAMETER_TLS_AUTHZ),
>              params->has_tls_authz ? params->tls_authz : "");
>      }
> -- 
> 2.17.1
> 
> 
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK