[libvirt] [PATCH for v5.3.0 10/17] security: Remember owner only for top level image

[Cole Robinson]

On 3/28/19 11:04 AM, Michal Privoznik wrote:
> Here is the problem: If all disks had XATTRs (i.e. domains using
> them were started with owner remembering turned on) then
> refcounting implemented in XATTRs would work nicely and we could
> set the whole backing chain and restore it later. But world is
> not that simple. As soon as there is one domain that was started
> with the feature turned off (or simply by older libvirt), the
> XATTR refounting does not reflect the actual number of uses by
> running domains and therefore any attempt to restore might cut
> off the old domain.
> 
> There is no simple way around this. Except artificially turning
> the feature off for the rest of the backing chain.
> 

Is there a thread discussing the issues that led to disabling this code?
I looked but couldn't find one. I could use some more context on what
case this patch fixes, and the upcoming patches. I'm having trouble
groking these comments

Thanks,
Cole