Re: [Xen-devel] PATCH: Fix name uniqueness check

[Jim Fehlig <jfehlig@xxxxxxxxxx>]

Daniel P. Berrange wrote:
> On Thu, Sep 27, 2007 at 11:16:27AM -0600, Jim Fehlig wrote:
>   
>> Daniel P. Berrange wrote:
>>     
>>> Changeset  15124:f5459c358575 altered check_name() in XendDomainInfo so that
>>> it compares domain IDs instead of UUIDs. This breaks a number of things
>>>
>>>  - You can no longer use 'xm new' to define a persistent config file for
>>>    a running guest. This breaks the key OS provisioning scenario where
>>>    you boot a kenrel+initrd for the installer, and at the same time define
>>>    a permanent config with pygrub.
>>>
>>>  - It lets you define multiple inactive guests with different UUIDs, but  
>>>    the same name because all inactive guests have a domid of None. So you
>>>    can now end up with multiple guests with same name, which is contrary
>>>    to the goal implied by the patch which was name uniqueness.
>>>
>>> It is unclear from the original commit logs just what scenario it was trying
>>> to protect against, but the original checking of uniqueness based on UUID 
>>> was correct & is what was used in previous releases XenD.
>>>   
>>>       
>> Yes, I was not sure what this patch was attempting to fix either.  There
>> was some discussion about the patch in this thread
>>
>> http://lists.xensource.com/archives/html/xen-devel/2007-05/msg00887.html
>>     
>
> Ok, so if I follow that correctly, the crux of the issue is that it was 
> possible to start 2 unmanaged domains with same name and same uuid. So
> I think we can probably address that by checking for UUID, and the only
> if both are running, also check for domid match. So really a combo of
> both the original & current code.
>   

Unstable, but not 3.1.1, also has

  http://xenbits2.xensource.com/xen-unstable.hg?rev/207582c8d88b

I did a little testing on a 3.1-based system that includes the above c/s
and your reversion of c/s 15124.  No problems noticed testing create,
new, reboot, save, restore.  Did not test migration or hvm guests.  So
perhaps reverting 15124 is fine for unstable but not sure about 3.1.1
*without* c/s 15642.

Regards,
Jim


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