[libvirt] [PATCH] qemu: fix monitor socket reconnection

[Ryota Ozaki]

On Wed, Jul 29, 2009 at 11:49 PM, Cole Robinson<crobinso at redhat.com> wrote:
> On 07/29/2009 08:35 AM, Daniel P. Berrange wrote:
>> On Wed, Jul 29, 2009 at 12:09:44AM +0900, Ryota Ozaki wrote:
>>> Hi,
>>>
>>> This patch fixes a handling of a qemu monitor unix socket. Current code
>>> addresses 'Socket may not have shown up yet' case with catching EACCES
>>> of connect(2), however, in that case, an errno which should be catched
>>> is ENOENT, not EACCES.
>>>
>>> Thanks,
>>>   ozaki-r
>>>
>>>
>>> >From 5a4b7ee2296ca6756127c26c6bfbbe1f49ab8722 Mon Sep 17 00:00:00 2001
>>> From: Ryota Ozaki <ozaki.ryota at gmail.com>
>>> Date: Tue, 28 Jul 2009 23:48:22 +0900
>>> Subject: [PATCH] qemu: fix monitor socket reconnection
>>>
>>> ---
>>>  src/qemu_driver.c |    4 ++--
>>>  1 files changed, 2 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/src/qemu_driver.c b/src/qemu_driver.c
>>> index 52a77be..9fb8506 100644
>>> --- a/src/qemu_driver.c
>>> +++ b/src/qemu_driver.c
>>> @@ -917,8 +917,8 @@ qemudOpenMonitorUnix(virConnectPtr conn,
>>>          if (ret == 0)
>>>              break;
>>>
>>> -        if (errno == EACCES || errno == ECONNREFUSED) {
>>> -            /* EACCES       : Socket may not have shown up yet
>>> +        if (errno == ENOENT || errno == ECONNREFUSED) {
>>> +            /* ENOENT       : Socket may not have shown up yet
>>>               * ECONNREFUSED : Leftover socket hasn't been removed yet */
>>>              continue;
>>>          }
>>
>>
>> ACK, that existing code is clearly bogus
>>
>
> Hmm, I thoroughly tested this for both of those issues listed in the
> comments, and the original code seemed to do the job. But it certainly
> appears to be bogus.
>
> I'll try to reproduce the original issue and make sure this code works
> as expected.

The bug might appear depending on the underlying environment then I
describe my testing environment.

- libvirt-0.7.0-0.1.gitf055724
- qemu-kvm-0.10.5
- kernel-2.6.31-rc3

I hope this could be of help,
  ozaki-r

>
> - Cole
>
>