Re: [Qemu-devel] [PATCH 1/1] QMP: add snapshot_blkdev command

[Luiz Capitulino <lcapitulino@redhat.com>]

On Mon, 11 Jul 2011 19:50:45 +0200
Jes Sorensen <Jes.Sorensen@redhat.com> wrote:

> On 07/11/11 18:35, Luiz Capitulino wrote:
> > On Fri,  8 Jul 2011 14:00:13 +0200
> > Jes.Sorensen@redhat.com wrote:
> > 
> >> From: Jes Sorensen <Jes.Sorensen@redhat.com>
> >>
> >> Add QMP bits for snapshot_blkdev command. This is the same as
> >> snapshot_blkdev in the human monitor. The command is synchronous.
> >>
> >> In the future async commands and or a break down of the functionality
> >> into multiple commands might be added.
> >>
> >> Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
> >> ---
> >>  qmp-commands.hx |   38 ++++++++++++++++++++++++++++++++++++++
> >>  1 files changed, 38 insertions(+), 0 deletions(-)
> >>
> >> diff --git a/qmp-commands.hx b/qmp-commands.hx
> >> index 92c5c3a..eb135c1 100644
> >> --- a/qmp-commands.hx
> >> +++ b/qmp-commands.hx
> >> @@ -694,6 +694,44 @@ Example:
> >>  EQMP
> >>  
> >>      {
> >> +        .name       = "blockdev-snapshot",
> > 
> > blockdev-snapshot-sync.
> 
> argh, will fix
> 
> >> +        .args_type  = "device:B,snapshot_file:s?,format:s?",
> >> +        .params     = "device [new-image-file] [format]",
> >> +        .help       = "initiates a live snapshot\n\t\t\t"
> >> +                      "of device. If a new image file is specified, the\n\t\t\t"
> >> +                      "new image file will become the new root image.\n\t\t\t"
> >> +                      "If format is specified, the snapshot file will\n\t\t\t"
> >> +                      "be created in that format. Otherwise the\n\t\t\t"
> >> +                      "snapshot will be internal! (currently unsupported)",
> > 
> > The 'otherwise' part is a bit confusing. You document something as if it were
> > supported then you say it's not supported. I recommend to just not document it
> > instead.
> 
> Ok
> 
> >> +        .user_print = monitor_user_noop,
> >> +        .mhandler.cmd_new = do_snapshot_blkdev,
> >> +    },
> >> +
> >> +SQMP
> >> +blockdev-snapshot-sync
> >> +----------------------
> >> +
> >> +Synchronous snapshot of block device, using snapshot file as target,
> >> +if provided. 
> > 
> > In QMP only this text is used, the text in '.help' is discarded. Please,
> > move all command documentation here.
> 
> If .help isn't used, then please remove it from the struct. It is really
> pointless to keep carrying both around.

Yes, sorry for that. It will be completely dropped when we move to the QAPI
(which uses a schema file).

> 
> >> +
> >> +Arguments:
> >> +
> >> +- "device": device name to snapshot (json-string)
> >> +- "snapshot_file": name of new image file (json-string)
> >> +- "format": format of new image (json-string)
> >> +
> >> +Example:
> >> +
> >> +-> { "execute": "blockdev-snapshot", "arguments": { "device": "ide-hd0",
> >> +                                                    "snapshot_file":
> > 
> > We are trying to standardize the use of hyphen in QMP.
> 
> Sorry, but I haven't got a clue what you mean here.

The argument is called "snapshot_file" but it should be called snapshot-file.