From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:35909)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <xiecl.fnst@cn.fujitsu.com>) id 1ad7oo-0000u5-LS
	for qemu-devel@nongnu.org; Mon, 07 Mar 2016 21:56:19 -0500
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <xiecl.fnst@cn.fujitsu.com>) id 1ad7on-0001Kk-RC
	for qemu-devel@nongnu.org; Mon, 07 Mar 2016 21:56:18 -0500
Message-ID: <56DE3FAE.6000305@cn.fujitsu.com>
Date: Tue, 8 Mar 2016 10:57:50 +0800
From: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
MIME-Version: 1.0
References: <1455615450-15138-1-git-send-email-xiecl.fnst@cn.fujitsu.com>
	<1455615450-15138-3-git-send-email-xiecl.fnst@cn.fujitsu.com>
	<56DB21B7.7050104@redhat.com> <56DDA5FF.2050900@redhat.com>
	<56DDA630.4000409@redhat.com>
In-Reply-To: <56DDA630.4000409@redhat.com>
Content-Type: text/plain; charset="utf-8"; format=flowed
Content-Transfer-Encoding: 7bit
Subject: Re: [Qemu-devel] [PATCH v10 2/3] quorum: implement bdrv_add_child()
	and bdrv_del_child()
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Max Reitz <mreitz@redhat.com>, Eric Blake <eblake@redhat.com>, qemu devel <qemu-devel@nongnu.org>, Alberto Garcia <berto@igalia.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>, Markus Armbruster <armbru@redhat.com>, "Dr. David Alan Gilbert" <dgilbert@redhat.com>, Gonglei <arei.gonglei@huawei.com>, zhanghailiang <zhang.zhanghailiang@huawei.com>

On 03/08/2016 12:02 AM, Max Reitz wrote:
> On 07.03.2016 17:02, Eric Blake wrote:
>> On 03/05/2016 11:13 AM, Max Reitz wrote:
>>
>>>> +    index = atoi(child->name + 9);
>>>
>>> Optional: Assert absence of an error:
>>>
>>
>> Indeed, atoi() is worthless, because it cannot do error detection.
>>
>>> unsigned long index;
>>> char *endptr;
>>>
>>> index = strtoul(child->name + 9, &endptr, 10);
>>> assert(index >= 0 && !*endptr);
>>
>> Still incorrect; you aren't handling errno properly for detecting all
>> errors.  Even better is to use qemu_strtoul(), which already handles
>> proper error detection.
>
> Yeah, I keep forgetting that it returns ULONG_MAX on range error...

Yes, we should limit the range to INT_MAX. How do you like the following 
codes, i just steal it from xen_host_pci_get_value().

int rc;
const char *endptr;
unsigned long value;

assert(!strncmp(child->name, "children.", 9));
rc = qemu_strtoul(child->name + 9, &endptr, 10, &value);
if (!rc) {
     assert(value <= INT_MAX);
     index = value;
} else {
     error_setg_errno(errp, -rc, "Failed to parse value '%s'",
                      child->name + 9);
     return;
}

Thanks
	-Xie

>
> Max
>