Re: [Qemu-devel] [PATCH] block: Remove -errno return value from bdrv_assign_node_name

[Markus Armbruster]

Kevin Wolf <address@hidden> writes:

> It takes an errp argument. That's enough for error handling.
>
> Signed-off-by: Kevin Wolf <address@hidden>
> ---
>  block.c | 21 ++++++++++-----------
>  1 file changed, 10 insertions(+), 11 deletions(-)
>
> diff --git a/block.c b/block.c
> index acb70fd..b4f3f77 100644
> --- a/block.c
> +++ b/block.c
> @@ -783,18 +783,18 @@ static int bdrv_open_flags(BlockDriverState *bs, int 
> flags)
>      return open_flags;
>  }
>  
> -static int bdrv_assign_node_name(BlockDriverState *bs,
> -                                 const char *node_name,
> -                                 Error **errp)
> +static void bdrv_assign_node_name(BlockDriverState *bs,
> +                                  const char *node_name,
> +                                  Error **errp)
>  {
>      if (!node_name) {
> -        return 0;
> +        return;
>      }
>  
>      /* empty string node name is invalid */
>      if (node_name[0] == '\0') {
>          error_setg(errp, "Empty node name");
> -        return -EINVAL;
> +        return;
>      }
>  
>      /* takes care of avoiding namespaces collisions */
> @@ -807,14 +807,12 @@ static int bdrv_assign_node_name(BlockDriverState *bs,
>      /* takes care of avoiding duplicates node names */
>      if (bdrv_find_node(node_name)) {
>          error_setg(errp, "Duplicate node name");
> -        return -EINVAL;
> +        return;
>      }
>  
>      /* copy node name into the bs and insert it into the graph list */
>      pstrcpy(bs->node_name, sizeof(bs->node_name), node_name);
>      QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs, node_list);
> -
> -    return 0;
>  }
>  
>  /*
> @@ -849,9 +847,10 @@ static int bdrv_open_common(BlockDriverState *bs, 
> BlockDriverState *file,
>      trace_bdrv_open_common(bs, filename ?: "", flags, drv->format_name);
>  
>      node_name = qdict_get_try_str(options, "node-name");
> -    ret = bdrv_assign_node_name(bs, node_name, errp);
> -    if (ret < 0) {
> -        return ret;
> +    bdrv_assign_node_name(bs, node_name, &local_err);
> +    if (error_is_set(&local_err)) {
> +        error_propagate(errp, local_err);
> +        return -EINVAL;
>      }
>      qdict_del(options, "node-name");

Please use 'if (local_err)' instead of 'if (error_is_set(&local_err))'.
See commit 84d18f0.

I don't like functions returning their only value through a pointer
rather than the function value, but I guess it's how Error wants to be
used.