[RFC] qemu_migration: Fix virConnectOpenAuth error code

[Michal Prívozník]

On 1/6/22 13:42, Ani Sinha wrote:
> 
> 
> On Thu, 6 Jan 2022, Michal Prívozník wrote:
> 
>> On 1/6/22 02:33, Raphael Norwitz wrote:
>>> Today if virConnectOpenAuth fails, qemuMigrationSrcPerformPeer2Peer()
>>> returns VIR_ERR_OPERATION_FAILED. This change switches that error code
>>> to VIR_ERR_NO_CONNECT, which is more accurate.
>>>
>>> This should help libvirt consumers more intellegently retry migrations
>>> on intermittent connection failures.
>>>
>>> CC: Bhuvnesh Jain <bhuvnesh.jain at nutanix.com>
>>> Suggested-by: John Levon <john.levon at nutanix.com>
>>> Signed-off-by: Raphael Norwitz <raphael.norwitz at nutanix.com>
>>> ---
>>>  src/qemu/qemu_migration.c | 2 +-
>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
>>> index b9d7d582f5..f7ced209a4 100644
>>> --- a/src/qemu/qemu_migration.c
>>> +++ b/src/qemu/qemu_migration.c
>>> @@ -5145,7 +5145,7 @@ qemuMigrationSrcPerformPeer2Peer(virQEMUDriver *driver,
>>>          goto cleanup;
>>>
>>>      if (dconn == NULL) {
>>> -        virReportError(VIR_ERR_OPERATION_FAILED,
>>> +        virReportError(VIR_ERR_NO_CONNECT,
>>>                         _("Failed to connect to remote libvirt URI %s: %s"),
>>>                         dconnuri, virGetLastErrorMessage());
>>>          return -1;
>>
>> I'm not exactly sure why we need this virReportError() in the first
>> place. Basically, we are just overwriting a more accurate error with
>> this generic one. Doesn't removing this virReportError() fix the problem?
> 
> Not all failure scenarios in virConnectOpenInternal() are
> caught with a virReportError(). Hence, we do need this.

Well, then the problem is in virConnectOpenInternal(). Either it should
report error in all cases or none, because then the caller would have to
check if error was reported or not.

Michal