From mboxrd@z Thu Jan  1 00:00:00 1970
From: Wen Congyang <wency@cn.fujitsu.com>
Subject: Re: [PATCH v2 2/5] remus: don't write xenstore data if
 it fails
Date: Tue, 5 Jan 2016 17:35:48 +0800
Message-ID: <568B8E74.3040109@cn.fujitsu.com>
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To: Andrew Cooper <andrew.cooper3@citrix.com>, xen devel <xen-devel@lists.xen.org>
Cc: Changlong Xie <xiecl.fnst@cn.fujitsu.com>, Wei Liu <wei.liu2@citrix.com>, Ian Campbell <ian.campbell@citrix.com>, Ian Jackson <ian.jackson@eu.citrix.com>, Shriram Rajagopalan <rshriram@cs.ubc.ca>, Yang Hongyang <hongyang.yang@easystack.cn>
List-Id: xen-devel@lists.xenproject.org

On 01/05/2016 05:27 PM, Andrew Cooper wrote:
> On 05/01/2016 02:06, Wen Congyang wrote:
> 
> "if it fails" is ambiguous.  What I think you mean is "remus: resume
> immediately if libxl__xc_domain_save_done() completes"
> 
>> 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). In such case, we
>> just need to complete the stream.
>>
>> 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)
> 
> Please put a small comment here as well.  Perhaps
> 
> "For remus, if libxl__xc_domain_save_done() completes, there was an
> error sending data to the secondary.  Resume the primary ASAP."

OK, I will update it in the next version.

Thanks
Wen Congyang

> 
> ~Andrew
> 
>> +            stream_complete(egc, stream, 0);
>> +        else
>> +            write_emulator_xenstore_record(egc, stream);
>> +    }
>>  }
>>  
>>  static void write_emulator_xenstore_record(libxl__egc *egc,
> 
> 
> 
> .
>