From mboxrd@z Thu Jan  1 00:00:00 1970
From: Wen Congyang <wency@cn.fujitsu.com>
Subject: Re: [PATCH 2/5] remus: don't write xenstore data if it
 fails
Date: Thu, 31 Dec 2015 09:00:54 +0800
Message-ID: <56847E46.1000002@cn.fujitsu.com>
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To: Andrew Cooper <andrew.cooper3@citrix.com>, xen devel <xen-devel@lists.xen.org>
Cc: Shriram Rajagopalan <rshriram@cs.ubc.ca>, Changlong Xie <xiecl.fnst@cn.fujitsu.com>, Yang Hongyang <hongyang.yang@easystack.cn>
List-Id: xen-devel@lists.xenproject.org

On 12/30/2015 06:47 PM, Andrew Cooper wrote:
> On 30/12/2015 01:39, Wen Congyang wrote:
> 
> If what fails?
> 
> Given the content of this patch in the context of the previous one, I presume you are wishing to avoid re-sending the emulator state after libxl__xc_domain_save_done() completes, but under what circumstances will this occur?

For example: if the secondary host is down, and we fail to send the data to
the secondary host. xc_domain_save() returns 0. So in the function
libxl__xc_domain_save_done(), rc is 0(the helper program exits normally),
and retval is 0(it is xc_domain_save()'s return value).

Thanks
Wen Congyang

> 
>> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
>> ---
>>   tools/libxl/libxl_stream_write.c | 8 ++++++--
>>   1 file changed, 6 insertions(+), 2 deletions(-)
>>
>> diff --git a/tools/libxl/libxl_stream_write.c b/tools/libxl/libxl_stream_write.c
>> index 80d9208..ee9c53a 100644
>> --- a/tools/libxl/libxl_stream_write.c
>> +++ b/tools/libxl/libxl_stream_write.c
>> @@ -354,8 +354,12 @@ void libxl__xc_domain_save_done(libxl__egc *egc, void *dss_void,
>>        * alive, and check_all_finished() may have torn it down around us.
>>        * If the stream is not still alive, we must not continue any work.
>>        */
>> -    if (libxl__stream_write_inuse(stream))
>> -        write_emulator_xenstore_record(egc, stream);
>> +    if (libxl__stream_write_inuse(stream)) {
>> +        if (dss->remus)
>> +            stream_complete(egc, stream, 0);
>> +        else
>> +            write_emulator_xenstore_record(egc, stream);
>> +    }
>>   }
>>     static void write_emulator_xenstore_record(libxl__egc *egc,
> 
> 
> 
> .
>