Re: [Qemu-devel] [PATCH V2 2/3] block: Use bdrv_get_backing_file_ancestors_count()

[Kevin Wolf <kwolf@redhat.com>]

Am 25.07.2012 10:11, schrieb benoit.canet@gmail.com:
> From: Benoît Canet <benoit@irqsave.net>
> 
> Use the dedicated counting function in qmp_query_block in order to
> propagate the backing file count to HMP.
> 
> Signed-off-by: Benoit Canet <benoit@irqsave.net>
> ---
>  block.c          |    2 ++
>  qapi-schema.json |    9 ++++++---
>  2 files changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/block.c b/block.c
> index 03e0860..4aa3ea9 100644
> --- a/block.c
> +++ b/block.c
> @@ -2448,6 +2448,8 @@ BlockInfoList *qmp_query_block(Error **errp)
>              if (bs->backing_file[0]) {
>                  info->value->inserted->has_backing_file = true;
>                  info->value->inserted->backing_file = g_strdup(bs->backing_file);
> +                info->value->inserted->backing_file_ancestors_count =
> +                    bdrv_get_backing_file_ancestors_count(bs);
>              }
>  
>              if (bs->io_limits_enabled) {
> diff --git a/qapi-schema.json b/qapi-schema.json
> index a92adb1..eb72c16 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -398,6 +398,8 @@
>  #
>  # @backing_file: #optional the name of the backing file (for copy-on-write)
>  #
> +# @backing_file_ancestors_count: #optional the count of ancestors backing files (for copy-on-write)
> +#

Why is it optional? Would it be omitted rather than set to 0 if there
are no backing files?

Could also use a "(since: 1.2)" note.

Kevin