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Date: Fri, 3 Jun 2016 10:13:00 +0800
From: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
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Subject: Re: [Qemu-devel] [PATCH v5 1/1] Introduce "xen-load-devices-state"
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To: Eric Blake <eblake@redhat.com>, Anthony PERARD <anthony.perard@citrix.com>
Cc: qemu devel <qemu-devel@nongnu.org>, Stefano Stabellini <sstabellini@kernel.org>, Juan Quintela <quintela@redhat.com>, Amit Shah <amit.shah@redhat.com>, Markus Armbruster <armbru@redhat.com>, "Dr. David
	Alan Gilbert" <dgilbert@redhat.com>, Wen Congyang <wency@cn.fujitsu.com>, zhanghailiang <zhang.zhanghailiang@huawei.com>

On 06/03/2016 09:45 AM, Eric Blake wrote:
> On 06/02/2016 07:26 PM, Changlong Xie wrote:
>
>>>> +
>>>> +    ioc = qio_channel_file_new_path(filename, O_WRONLY | O_CREAT,
>>>> 0660, errp);
>>>
>>> This does not look right, it looks like it's going to open the file
>>> to write to it. You probably want O_RDONLY, also I don't think the
>>> O_CREAT flag is needed. (and without O_WRONLY, mode can be 0 instead of
>>> 0660.)
>>>
>>
>> Yes, as you said. We should use 0_RDONLY for open(2), so mode should be 0.
>
> Huh?  mode doesn't affect the current fd, but DOES affect the next
> person to open the file.  If you are truly creating the file, then a
> mode of 0 means you won't be able to reopen it without chmod.  And if
> you are doing O_RDONLY | O_CREAT, all you will be able to create is an
> empty file, which is a pretty boring read.  So drop the O_CREAT, and
> then you don't need a mode argument at all.
>

Yes, i just mean qio_channel_file_new_path(filename, O_RDONLY, 0, errp) 
here. Maybe my poor english make you confused :(

Thanks
	-Xie