[pve-devel] [PATCH container] fix #2820: block adding new volume with same id if it's pending delete

[Fabian Grünbichler]

On July 1, 2020 2:05 pm, Thomas Lamprecht wrote:
> On 01.07.20 09:11, Fabian Grünbichler wrote:
>> - we can actually just put the new mpX into the pending queue, and 
>>   remove the entry from the pending deletion queue? (it's hotplugging 
>>   that is the problem, not queuing the pending change)
> 
> Even if we could I'm not sure I want to be able to add a new mpX as pending
> if the old is still pending its deletion. But, tbh, I did not looked at details
> so I may missing something..

well, the sequence is

- delete mp0 (queued)
- set a new mp0 (queued)

just like a general

- delete foo  (queued)
- set foo (queued)

where the set removes the queued deletion. in the case of mp, applying 
that pending change should then add the old volume ID as unused, but 
that IMHO does not change the semantics of '(queuing a) set overrides 
earlier queued delete'.

but this is broken for regular hotplug without deletion as well, setting 
mpX with a new volume ID if the slot is already used does not queue it 
as pending change, but
- mounts the new volume ID in addition to the old one
- adds the old volume ID as unused, even though it is still mounted in 
  the container

so this is broken in more ways than just what I initially found..