Re: Moving a backing device between 2 cachesets

[Gabriel de Perthuis <g2p.code@gmail.com>]

>> After flushing, detaching does two things:
>> - the backing device gets flagged as detached
>> - the backing device is removed from the cache set's metadata
>> (stored as uuid_entry in a special bucket; the entry is flagged
>> with a bogus uuid but not reused).  The offset in that uuids
>> array constitutes an id, local to the cache set, that is not
>> reused after detaching.
>>
>> The second step invalidates the backing device's id in the cache set,
>> and indirectly invalidates all buckets that referenced it (through
>> bkey->inode in the bucket key).
> 
> I understand that we are safe, then. Right ? 

tl;dr: after looking at the code, I expect you'll be fine

That's what I expected anyway (iirc these non-reusable ids appear
somewhere, maybe logs), I just spent a little more time checking.

> Thanks for your clarifications