static int btrfs_real_readdir(struct file *filp, void *dirent,
			      filldir_t filldir)
{
	struct inode *inode = filp->f_dentry->d_inode;
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_item *item;
	struct btrfs_dir_item *di;
	struct btrfs_key key;
	struct btrfs_key found_key;
	struct btrfs_path *path;
	struct list_head ins_list;
	struct list_head del_list;
	int ret;
	struct extent_buffer *leaf;
	int slot;
	unsigned char d_type;
	int over = 0;
	u32 di_cur;
	u32 di_total;
	u32 di_len;
	int key_type = BTRFS_DIR_INDEX_KEY;
	char tmp_name[32];
	char *name_ptr;
	int name_len;
	int is_curr = 0;	/* filp->f_pos points to the current index? */

	/* FIXME, use a real flag for deciding about the key type */
	if (root->fs_info->tree_root == root)
		key_type = BTRFS_DIR_ITEM_KEY;

	/* special case for "." */
	if (filp->f_pos == 0) {
		over = filldir(dirent, ".", 1,
			       filp->f_pos, btrfs_ino(inode), DT_DIR);
		if (over)
			return 0;
		filp->f_pos = 1;
	}
	/* special case for .., just use the back ref */
	if (filp->f_pos == 1) {
		u64 pino = parent_ino(filp->f_path.dentry);
		over = filldir(dirent, "..", 2,
			       filp->f_pos, pino, DT_DIR);
		if (over)
			return 0;
		filp->f_pos = 2;
	}
	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	path->reada = 1;

	if (key_type == BTRFS_DIR_INDEX_KEY) {
		INIT_LIST_HEAD(&ins_list);
		INIT_LIST_HEAD(&del_list);
		btrfs_get_delayed_items(inode, &ins_list, &del_list);
	}

	btrfs_set_key_type(&key, key_type);
	key.offset = filp->f_pos;
	key.objectid = btrfs_ino(inode);

	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
	if (ret < 0)
		goto err;

	while (1) {
		leaf = path->nodes[0];
		slot = path->slots[0];
		if (slot >= btrfs_header_nritems(leaf)) {
			ret = btrfs_next_leaf(root, path);
			if (ret < 0)
				goto err;
			else if (ret > 0)
				break;
			continue;
		}

		item = btrfs_item_nr(leaf, slot);
		btrfs_item_key_to_cpu(leaf, &found_key, slot);

		if (found_key.objectid != key.objectid)
			break;
		if (btrfs_key_type(&found_key) != key_type)
			break;
		if (found_key.offset < filp->f_pos)
			goto next;
		if (key_type == BTRFS_DIR_INDEX_KEY &&
		    btrfs_should_delete_dir_index(&del_list,
						  found_key.offset))
			goto next;

		filp->f_pos = found_key.offset;
		is_curr = 1;

		di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
		di_cur = 0;
		di_total = btrfs_item_size(leaf, item);

		while (di_cur < di_total) {
			struct btrfs_key location;

			if (verify_dir_item(root, leaf, di))
				break;

			name_len = btrfs_dir_name_len(leaf, di);
			if (name_len <= sizeof(tmp_name)) {
				name_ptr = tmp_name;
			} else {
				name_ptr = kmalloc(name_len, GFP_NOFS);
				if (!name_ptr) {
					ret = -ENOMEM;
					goto err;
				}
			}
			read_extent_buffer(leaf, name_ptr,
					   (unsigned long)(di + 1), name_len);

			d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
			btrfs_dir_item_key_to_cpu(leaf, di, &location);


			/* is this a reference to our own snapshot? If so
			 * skip it.
			 *
			 * In contrast to old kernels, we insert the snapshot's
			 * dir item and dir index after it has been created, so
			 * we won't find a reference to our own snapshot. We
			 * still keep the following code for backward
			 * compatibility.
			 */
			if (location.type == BTRFS_ROOT_ITEM_KEY &&
			    location.objectid == root->root_key.objectid) {
				over = 0;
				goto skip;
			}
			over = filldir(dirent, name_ptr, name_len,
				       found_key.offset, location.objectid,
				       d_type);

skip:
			if (name_ptr != tmp_name)
				kfree(name_ptr);

			if (over)
				goto nopos;
			di_len = btrfs_dir_name_len(leaf, di) +
				 btrfs_dir_data_len(leaf, di) + sizeof(*di);
			di_cur += di_len;
			di = (struct btrfs_dir_item *)((char *)di + di_len);
		}
next:
		path->slots[0]++;
	}

	if (key_type == BTRFS_DIR_INDEX_KEY) {
		if (is_curr)
			filp->f_pos++;
		ret = btrfs_readdir_delayed_dir_index(filp, dirent, filldir,
						      &ins_list);
		if (ret)
			goto nopos;
	}

	/* Reached end of directory/root. Bump pos past the last item. */
	if (key_type == BTRFS_DIR_INDEX_KEY)
		/*
		 * 32-bit glibc will use getdents64, but then strtol -
		 * so the last number we can serve is this.
		 */
		filp->f_pos = 0x7fffffff;
	else
		filp->f_pos++;
nopos:
	ret = 0;
err:
	if (key_type == BTRFS_DIR_INDEX_KEY)
		btrfs_put_delayed_items(&ins_list, &del_list);
	btrfs_free_path(path);
	return ret;
}
static int btrfs_real_readdir(struct file *filp, void *dirent,
			      filldir_t filldir)
{
	struct inode *inode = filp->f_dentry->d_inode;
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_item *item;
	struct btrfs_dir_item *di;
	struct btrfs_key key;
	struct btrfs_key found_key;
	struct btrfs_path *path;
	struct list_head ins_list;
	struct list_head del_list;
	int ret;
	struct extent_buffer *leaf;
	int slot;
	unsigned char d_type;
	int over = 0;
	u32 di_cur;
	u32 di_total;
	u32 di_len;
	int key_type = BTRFS_DIR_INDEX_KEY;
	char tmp_name[32];
	char *name_ptr;
	int name_len;
	int is_curr = 0;	 

	 
	if (root->fs_info->tree_root == root)
		key_type = BTRFS_DIR_ITEM_KEY;

	 
	if (filp->f_pos == 0) {
		over = filldir(dirent, ".", 1,
			       filp->f_pos, btrfs_ino(inode), DT_DIR);
		if (over)
			return 0;
		filp->f_pos = 1;
	}
	 
	if (filp->f_pos == 1) {
		u64 pino = parent_ino(filp->f_path.dentry);
		over = filldir(dirent, "..", 2,
			       filp->f_pos, pino, DT_DIR);
		if (over)
			return 0;
		filp->f_pos = 2;
	}
	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	path->reada = 1;

	if (key_type == BTRFS_DIR_INDEX_KEY) {
		INIT_LIST_HEAD(&ins_list);
		INIT_LIST_HEAD(&del_list);
		btrfs_get_delayed_items(inode, &ins_list, &del_list);
	}

	btrfs_set_key_type(&key, key_type);
	key.offset = filp->f_pos;
	key.objectid = btrfs_ino(inode);

	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
	if (ret < 0)
		goto err;

	while (1) {
		leaf = path->nodes[0];
		slot = path->slots[0];
		if (slot >= btrfs_header_nritems(leaf)) {
			ret = btrfs_next_leaf(root, path);
			if (ret < 0)
				goto err;
			else if (ret > 0)
				break;
			continue;
		}

		item = btrfs_item_nr(leaf, slot);
		btrfs_item_key_to_cpu(leaf, &found_key, slot);

		if (found_key.objectid != key.objectid)
			break;
		if (btrfs_key_type(&found_key) != key_type)
			break;
		if (found_key.offset < filp->f_pos)
			goto next;
		if (key_type == BTRFS_DIR_INDEX_KEY &&
		    btrfs_should_delete_dir_index(&del_list,
						  found_key.offset))
			goto next;

		filp->f_pos = found_key.offset;
		is_curr = 1;

		di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
		di_cur = 0;
		di_total = btrfs_item_size(leaf, item);

		while (di_cur < di_total) {
			struct btrfs_key location;

			if (verify_dir_item(root, leaf, di))
				break;

			name_len = btrfs_dir_name_len(leaf, di);
			if (name_len <= sizeof(tmp_name)) {
				name_ptr = tmp_name;
			} else {
				name_ptr = kmalloc(name_len, GFP_NOFS);
				if (!name_ptr) {
					ret = -ENOMEM;
					goto err;
				}
			}
			read_extent_buffer(leaf, name_ptr,
					   (unsigned long)(di + 1), name_len);

			d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
			btrfs_dir_item_key_to_cpu(leaf, di, &location);


			 
			if (location.type == BTRFS_ROOT_ITEM_KEY &&
			    location.objectid == root->root_key.objectid) {
				over = 0;
				goto skip;
			}
			over = filldir(dirent, name_ptr, name_len,
				       found_key.offset, location.objectid,
				       d_type);

skip:
			if (name_ptr != tmp_name)
				kfree(name_ptr);

			if (over)
				goto nopos;
			di_len = btrfs_dir_name_len(leaf, di) +
				 btrfs_dir_data_len(leaf, di) + sizeof(*di);
			di_cur += di_len;
			di = (struct btrfs_dir_item *)((char *)di + di_len);
		}
next:
		path->slots[0]++;
	}

	if (key_type == BTRFS_DIR_INDEX_KEY) {
		if (is_curr)
			filp->f_pos++;
		ret = btrfs_readdir_delayed_dir_index(filp, dirent, filldir,
						      &ins_list);
		if (ret)
			goto nopos;
	}

	 
	if (key_type == BTRFS_DIR_INDEX_KEY)
		 
		filp->f_pos = 0x7fffffff;
	else
		filp->f_pos++;
nopos:
	ret = 0;
err:
	if (key_type == BTRFS_DIR_INDEX_KEY)
		btrfs_put_delayed_items(&ins_list, &del_list);
	btrfs_free_path(path);
	return ret;
}