Re: [Qemu-devel] [PATCH V10 12/17] hmp: add function hmp_info_snapshots()

[Wenchao Xia]

于 2013-3-30 7:04, Eric Blake 写道:
> On 03/22/2013 08:19 AM, Wenchao Xia wrote:
> >    This function will simply call qmp interface qmp_query_snapshots()
> > added in last commit and then dump information in monitor console.
> >    To get snapshot info, Now qemu and qemu-img both call block layer
> > function bdrv_query_snapshot_info_list() in their calling path, and
> > then they just translate the qmp object got to strings in stdout or
> > monitor console.
> >
> > Signed-off-by: Wenchao Xia <address@hidden>
> > ---
> >   hmp.c |   42 ++++++++++++++++++++++++++++++++++++++++++
> >   hmp.h |    1 +
> >   2 files changed, 43 insertions(+), 0 deletions(-)
> >
> > diff --git a/hmp.c b/hmp.c
> > index b0a861c..c475d65 100644
> > --- a/hmp.c
> > +++ b/hmp.c
> > @@ -651,6 +651,48 @@ void hmp_info_tpm(Monitor *mon, const QDict *qdict)
> >       qapi_free_TPMInfoList(info_list);
> >   }
> >
> > +/* assume list is valid */
> > +static void monitor_dump_snapshotinfolist(Monitor *mon, SnapshotInfoList *list)
> > +{
> > +    SnapshotInfoList *elem;
> > +    char buf[256];
> > +
> > +    monitor_printf(mon, "%s\n", bdrv_snapshot_dump(buf, sizeof(buf), NULL));
>
> Are you sure that won't ever be truncated?  I'm pretty sure that I could
> come up with a scenario where I cause bdrv_snapshot_dump() to want to
> output more than 256 bytes of details.
  I hope not use dynamic buff for strings, how about check it as
following:

char buf[254] = 0;
monitor_printf(mon, "%s\n", bdrv_snapshot_dump(buf, sizeof(buf), NULL));
if (buf[254]) {
     monitor_printf(mon, "'string truncated'");
}
--
Best Regards

Wenchao Xia