Re: [Qemu-block] [PATCH v23 11/12] support replication driver in blockdev-add

[Changlong Xie]

On 07/27/2016 12:22 AM, Max Reitz wrote:
> On 26.07.2016 10:15, Changlong Xie wrote:
> > From: Wen Congyang <address@hidden>
> >
> > Signed-off-by: Wen Congyang <address@hidden>
> > Signed-off-by: Changlong Xie <address@hidden>
> > Signed-off-by: Wang WeiWei <address@hidden>
> > Signed-off-by: zhanghailiang <address@hidden>
> > Signed-off-by: Gonglei <address@hidden>
> > Reviewed-by: Eric Blake <address@hidden>
> > ---
> >   qapi/block-core.json | 22 ++++++++++++++++++++--
> >   1 file changed, 20 insertions(+), 2 deletions(-)
> >
> > diff --git a/qapi/block-core.json b/qapi/block-core.json
> > index 7258a87..48aa112 100644
> > --- a/qapi/block-core.json
> > +++ b/qapi/block-core.json
> > @@ -248,6 +248,7 @@
> >   #       2.3: 'host_floppy' deprecated
> >   #       2.5: 'host_floppy' dropped
> >   #       2.6: 'luks' added
> > +#       2.8: 'replication' added
> >   #
> >   # @backing_file: #optional the name of the backing file (for copy-on-write)
> >   #
> > @@ -1696,8 +1697,8 @@
> >     'data': [ 'archipelago', 'blkdebug', 'blkverify', 'bochs', 'cloop',
> >               'dmg', 'file', 'ftp', 'ftps', 'gluster', 'host_cdrom',
> >               'host_device', 'http', 'https', 'luks', 'null-aio', 'null-co',
> > -            'parallels', 'qcow', 'qcow2', 'qed', 'quorum', 'raw', 'tftp',
> > -            'vdi', 'vhdx', 'vmdk', 'vpc', 'vvfat' ] }
> > +            'parallels', 'qcow', 'qcow2', 'qed', 'quorum', 'raw', 
> > 'replication',
> > +            'tftp', 'vdi', 'vhdx', 'vmdk', 'vpc', 'vvfat' ] }
> >
> >   ##
> >   # @BlockdevOptionsFile
> > @@ -2160,6 +2161,22 @@
> >   { 'enum' : 'ReplicationMode', 'data' : [ 'primary', 'secondary' ] }
> >
> >   ##
> > +# @BlockdevOptionsReplication
> > +#
> > +# Driver specific block device options for replication
> > +#
> > +# @mode: the replication mode
> > +#
> > +# @top-id: the id to protect replication model chain
>
> It's hard for me to understand this sentence without reading the code
> and thus knowing what this ID is used for. I'd use the following instead:
>
> @top-id: In secondary mode, node name or device ID of the root node who
> owns the replication node chain. Ignored in primary mode.

Pretty description

> Also, since this parameter is only necessary in secondary mode and
> completely ignored in primary mode, I would probably make it an optional
> parameter.

Surely.

> Max
>
> > +#
> > +# Since: 2.8
> > +##
> > +{ 'struct': 'BlockdevOptionsReplication',
> > +  'base': 'BlockdevOptionsGenericFormat',
> > +  'data': { 'mode': 'ReplicationMode',
> > +            'top-id': 'str' } }
> > +
> > +##
> >   # @BlockdevOptions
> >   #
> >   # Options for creating a block device.  Many options are available for all
> > @@ -2224,6 +2241,7 @@
> >         'quorum':     'BlockdevOptionsQuorum',
> >         'raw':        'BlockdevOptionsGenericFormat',
> >   # TODO rbd: Wait for structured options
> > +      'replication':'BlockdevOptionsReplication',
> >   # TODO sheepdog: Wait for structured options
> >   # TODO ssh: Should take InetSocketAddress for 'host'?
> >         'tftp':       'BlockdevOptionsFile',