slab_block_number_from_pbn
int result = slab_block_number_from_pbn(slab, pbn, &index);
result = slab_block_number_from_pbn(slab, updater->zpbn.pbn, &block_number);
result = slab_block_number_from_pbn(slab, pbn, &block_number);
result = slab_block_number_from_pbn(slab, pbn, &block_number);
(slab_block_number_from_pbn(depot->slabs[slab_number], pbn, &sbn) ==