Re: [Qemu-devel] [PATCH v6 4/4] hmp: add monitor command to add/remove a child

From: Alberto Garcia <berto@igalia.com>
To: Wen Congyang <wency@cn.fujitsu.com>,
	qemu devel <qemu-devel@nongnu.org>,
	Eric Blake <eblake@redhat.com>,
	Markus Armbruster <armbru@redhat.com>,
	Kevin Wolf <kwolf@redhat.com>,
	Stefan Hajnoczi <stefanha@redhat.com>
Cc: qemu block <qemu-block@nongnu.org>,
	Jiang Yunhong <yunhong.jiang@intel.com>,
	Dong Eddie <eddie.dong@intel.com>,
	"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
	Luiz Capitulino <lcapitulino@redhat.com>,
	Gonglei <arei.gonglei@huawei.com>,
	Yang Hongyang <yanghy@cn.fujitsu.com>,
	zhanghailiang <zhang.zhanghailiang@huawei.com>
Subject: Re: [Qemu-devel] [PATCH v6 4/4] hmp: add monitor command to add/remove a child
Date: Mon, 09 Nov 2015 15:54:46 +0100	[thread overview]
Message-ID: <w51y4e7w7d5.fsf@maestria.local.igalia.com> (raw)
In-Reply-To: <1444985866-12969-5-git-send-email-wency@cn.fujitsu.com>

On Fri 16 Oct 2015 10:57:46 AM CEST, Wen Congyang wrote:

> +        .name       = "blockdev_change",
> +        .args_type  = "op:s,parent:B,child:B?,node:?",
> +        .params     = "operation parent [child] [node]",
  [...]
> +    /*
> +     * FIXME: we must specify the parameter child, otherwise,
> +     * we can't specify the parameter node.
> +     */
> +    if (op == CHANGE_OPERATION_ADD) {
> +        has_child = false;
> +    }

So if you want to perform the 'add' operation you must pass both 'child'
and 'node' but the former will be discarded.

I don't think you really need to do this for the HMP interface, but it's
anyway one more good reason to merge 'child' and 'node'.

Berto