[libvirt] [PATCH 1/3] storage: refresh volume before deletion

[Cole Robinson]

On 03/10/2016 04:30 AM, Ján Tomko wrote:
> On Wed, Mar 09, 2016 at 12:38:58PM -0500, Cole Robinson wrote:
>> file volume deletion, via virFileRemove, has some logic that depends
>> on uid/gid owner of the path. This info is cached in the volume XML.
>> We need to be sure we are using up to date uid/gid before attempting
>> to delete the volume, otherwise we can hit a case like this:
>>
>> - test.img created with uid=root
>> - VM starts up using test.img, owner changed to uid=qemu
>> - test.img pool is refreshed, uid=qemu is cached in the volume XML
>> - VM shuts down, volume owner changed to gid=root
>> - vol-delete test.img thinks uid=qemu, virFileRemove does setuid(qemu),
>>   fails to delete test.img since it is actually uid=root
>>
> 
> For local filesystems, root should be able to remove anything.
> For root-squashed NFS, the uid:gid will usually be nobody:nobody
> the whole time, so this refresh is unlikely to learn something new.
> 
> I think the real fix is patch 3/3 that stops doing setuid on NFS.

Hmm yeah I was forgetting some NFS details :) Thanks for correcting me. I'll
drop this patch

- Cole