Re: [Qemu-devel] [PATCH 02/20] nbd: correctly propagate errors

[Fam Zheng]

On Mon, 02/10 09:24, Paolo Bonzini wrote:
> Il 10/02/2014 08:38, Fam Zheng ha scritto:
> >>>      if (s->client.is_unix) {
> >>> -        sock = unix_socket_outgoing(qemu_opt_get(s->socket_opts, 
> >>> "path"));
> >>> +        sock = unix_connect(qemu_opt_get(s->socket_opts, "path"), errp);
> >Why not use unix_connect_opts like below?
> 
> Right!
> 
> >>>      } else {
> >>> -        sock = tcp_socket_outgoing_opts(s->socket_opts);
> >>> +        sock = inet_connect_opts(s->socket_opts, errp, NULL, NULL);
> >>>          if (sock >= 0) {
> >>>              socket_set_nodelay(sock);
> >>>          }
> >>> @@ -255,17 +251,19 @@ static int nbd_open(BlockDriverState *bs, QDict 
> >>> *options, int flags,
> >>>      BDRVNBDState *s = bs->opaque;
> >>>      char *export = NULL;
> >>>      int result, sock;
> >>> +    Error *local_err = NULL;
> >>>
> >>>      /* Pop the config into our state object. Exit if invalid. */
> >>> -    result = nbd_config(s, options, &export);
> >>> -    if (result != 0) {
> >>> -        return result;
> >>> +    nbd_config(s, options, &export, &local_err);
> >>> +    if (local_err) {
> >Isn't error_is_set() better here?
> 
> No, error_is_set(&foo) is the same as foo != NULL.
> 
> So we use error_is_set only with Error**, which really should never happen
> because you miss errors if the errp is NULL. :)
> 

Clear! Thanks for the explanation!

Fam