hammer_btree_unlock_children
void hammer_btree_unlock_children(hammer_mount_t hmp,
hammer_btree_unlock_children(cursor->trans->hmp, &lockroot, NULL);
hammer_btree_unlock_children(hmp, parent, lcache);
hammer_btree_unlock_children(hmp, item, lcache);
hammer_btree_unlock_children(cursor->trans->hmp, &lockroot, lcache);
hammer_btree_unlock_children(cursor->trans->hmp, &lockroot, NULL);