rht_bucket
rht_for_each_from(pos, rht_ptr(rht_bucket(tbl, hash), tbl, hash), \
rht_ptr(rht_bucket(tbl, hash), tbl, hash), \
for (pos = rht_ptr(rht_bucket(tbl, hash), tbl, hash), \
pos = rht_ptr_rcu(rht_bucket(tbl, hash)); \
rht_ptr_rcu(rht_bucket(tbl, hash)), \
bkt = rht_bucket(tbl, hash);
for (pos = rht_ptr_exclusive(rht_bucket(tbl, i)),