Current extensible tier flush a chunked object when all chunks mark as dirty.
So, to make the state of object consistent, tier-flush operation is needed.
Signed-off-by: Myoungwon Oh <omwmw@sk.com>
This commit makes chunk_scrub as a chunk_pool-based operation.
chunk_scrub procedure:
1. find references in the chunk_pool
2. check whether the reference exists in a base_pool
3. fix references
Signed-off-by: Myoungwon Oh <omwmw@sk.com>
