Re: [Qemu-devel] [PATCH V10 11/17] qmp: add ImageInfo in BlockDeviceInfo used by query-block

[Kevin Wolf]

Am 29.03.2013 um 03:35 hat Wenchao Xia geschrieben:
> 于 2013-3-28 17:54, Kevin Wolf 写道:
> >Am 22.03.2013 um 15:19 hat Wenchao Xia geschrieben:
> >>   Now image info will be retrieved as an embbed json object inside
> >>BlockDeviceInfo, backing chain info and all related internal snapshot
> >>info can be got in the enhanced recursive structure of ImageInfo.
> >>
> >>Signed-off-by: Wenchao Xia <xiaw...@linux.vnet.ibm.com>
> >>---
> >>  block/qapi.c         |   39 ++++++++++++++++++++++++++--
> >>  include/block/qapi.h |    4 ++-
> >>  qapi-schema.json     |    5 +++-
> >>  qmp-commands.hx      |   67 
> >> +++++++++++++++++++++++++++++++++++++++++++++++++-
> >>  4 files changed, 109 insertions(+), 6 deletions(-)
> >>
> >>diff --git a/block/qapi.c b/block/qapi.c
> >>index df73f5b..9051947 100644
> >>--- a/block/qapi.c
> >>+++ b/block/qapi.c
> >>@@ -200,9 +200,15 @@ int bdrv_query_image_info(BlockDriverState *bs,
> >>      return 0;
> >>  }
> >>
> >>-BlockInfo *bdrv_query_info(BlockDriverState *bs)
> >>+/* return 0 on success, and @p_info will be set only on success. */
> >>+int bdrv_query_info(BlockDriverState *bs,
> >>+                    BlockInfo **p_info,
> >>+                    Error **errp)
> >>  {
> >>      BlockInfo *info = g_malloc0(sizeof(*info));
> >>+    BlockDriverState *bs0;
> >>+    ImageInfo **p_image_info;
> >>+    int ret = 0;
> >
> >ret is never changed, so this function always returns 0. I would suggest
> >to drop ret and make the function return type void.
> >
>   My bad, I forgot to set its value, the interface is intend to return
> negative error number and errp both on fail.

Why do you need two separate error reporting mechanisms? Shouldn't only
errp be enough?

Kevin