btrfs_search_prev_slot
ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1);
ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1);
ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1);
return btrfs_search_prev_slot(trans, root, &key, p, 0, 1);
ret = btrfs_search_prev_slot(trans, root, &key, path, 0, 1);
ret = btrfs_search_prev_slot(trans, root, &key, path, 0, 1);
ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1);
ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1);
ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1);