dm_btree_empty
r = dm_btree_empty(&md->writeset_tree_info, &md->writeset_tree_root);
r = dm_btree_empty(&pmd->bl_info, &dev_root);
r = dm_btree_empty(&pmd->info, &pmd->root);
r = dm_btree_empty(&pmd->details_info, &pmd->details_root);
return dm_btree_empty(&info->btree_info, root);
r = dm_btree_empty(info, &new_tree);
EXPORT_SYMBOL_GPL(dm_btree_empty);
int dm_btree_empty(struct dm_btree_info *info, dm_block_t *root);
r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root);
return dm_btree_empty(&ll->bitmap_info, &ll->bitmap_root);
r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root);