diff mbox

[v2,2/5] remus: don't write xenstore data if it fails

Message ID 1451959581-14275-3-git-send-email-wency@cn.fujitsu.com (mailing list archive)
State New, archived
Headers show

Commit Message

Wen Congyang Jan. 5, 2016, 2:06 a.m. UTC
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(-)

Comments

Andrew Cooper Jan. 5, 2016, 9:27 a.m. UTC | #1
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."

~Andrew

> +            stream_complete(egc, stream, 0);
> +        else
> +            write_emulator_xenstore_record(egc, stream);
> +    }
>  }
>  
>  static void write_emulator_xenstore_record(libxl__egc *egc,
Wen Congyang Jan. 5, 2016, 9:35 a.m. UTC | #2
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,
> 
> 
> 
> .
>
diff mbox

Patch

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,