* @stale: list of pages marked for freeing
* @pages_nr: number of z3fold pages in the pool.
* @c_handle: cache for z3fold_buddy_slots allocation
- * @zpool: zpool driver
- * @zpool_ops: zpool operations structure with an evict callback
* @compact_wq: workqueue for page layout background optimization
* @release_wq: workqueue for safe page release
* @work: work_struct for safe page release