[libvirt] [PATCH 3/3] qemu: avoid dead store in doPeer2PeerMigrate3

[Eric Blake]

On 08/05/2011 02:12 AM, Alex Jia wrote:
> On 08/04/2011 10:27 PM, Eric Blake wrote:
>> On 08/03/2011 11:30 PM, Alex Jia wrote:
>>> Value stored to 'ret' is never read. If Confirm3 returns -1, there's
>>> nothing
>>> more we can do, here should remove this dead assignment.
>>>
>>> * src/qemu/qemu_migration.c: kill dead assignment.
>>>
>>> Signed-off-by: Alex Jia<ajia at redhat.com>
>>> ---
>>> src/qemu/qemu_migration.c | 6 +++---
>>> 1 files changed, 3 insertions(+), 3 deletions(-)
>>
>> I'm thinking NACK as written. We should probably emit a log message if
>> confirm failed, at which point, ret would be used in the conditional
>> deciding whether to do a log message. Furthermore, libvirt.c
>> virDomainMigrateVersion3 has the same bug with a dead assignment to
>> ret; we should solve it in the same way for both implementations.
>>
> Eric, I haven't figured out a apposite error number in virterror.h,
> whether we need to define a new error number like this:
>
> VIR_ERR_MIGRATE_CONFIRM_FAILED = 75, /* a migration finished, but
> confirmation failed, there is a domain probably left in 'paused' state
> on source.*/

That's if we want to report the error back to the caller and fail the 
API.  But the migration happened - it is running on the destination, so 
I think we have to make the API return success.  Which means that we 
don't need a new VIR_ERR_* value, rather, we just need a new VIR_WARN() 
call to guarantee a log entry but nothing further.

-- 
Eric Blake   eblake at redhat.com    +1-801-349-2682
Libvirt virtualization library http://libvirt.org