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

["Benoît Canet" <benoit.canet@irqsave.net>]

Le Wednesday 25 Jul 2012 à 13:19:15 (+0200), Kevin Wolf a écrit :
> Am 25.07.2012 13:15, schrieb Benoît Canet:
> > Le Wednesday 25 Jul 2012 à 12:57:05 (+0200), Kevin Wolf a écrit :
> >> 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?
> > 
> > I made it optional because backing_file=something is optional.
> > So It seemed coherent to make it also optional.
> > However I'll change it if you confirm it should be changed.
> 
> The reason why the backing file naem is optional is because there is no
> valid value to use when there is no backing file. But for the count, 0
> makes perfect sense.

Should I also make is alway present in the HMP output ?

Benoît

> 
> Kevin
>