int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
		__u64 start, __u64 len)
{
	ext4_lblk_t start_blk;
	int error = 0;

	if (ext4_has_inline_data(inode)) {
		int has_inline = 1;

		error = ext4_inline_data_fiemap(inode, fieinfo, &has_inline,
						start, len);

		if (has_inline)
			return error;
	}

	if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) {
		error = ext4_ext_precache(inode);
		if (error)
			return error;
	}

	/* fallback to generic here if not in extents fmt */
	if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
		return generic_block_fiemap(inode, fieinfo, start, len,
			ext4_get_block);

	if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS))
		return -EBADR;

	if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
		error = ext4_xattr_fiemap(inode, fieinfo);
	} else {
		ext4_lblk_t len_blks;
		__u64 last_blk;

		start_blk = start >> inode->i_sb->s_blocksize_bits;
		last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits;
		if (last_blk >= EXT_MAX_BLOCKS)
			last_blk = EXT_MAX_BLOCKS-1;
		len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1;

		/*
		 * Walk the extent tree gathering extent information
		 * and pushing extents back to the user.
		 */
		error = ext4_fill_fiemap_extents(inode, start_blk,
						 len_blks, fieinfo);
	}
	return error;
}
int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
		__u64 start, __u64 len)
{
	ext4_lblk_t start_blk;
	int error = 0;

	if (ext4_has_inline_data(inode)) {
		int has_inline = 1;

		error = ext4_inline_data_fiemap(inode, fieinfo, &has_inline,
						start, len);

		if (has_inline)
			return error;
	}

	if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) {
		error = ext4_ext_precache(inode);
		if (error)
			return error;
	}

	 
	if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
		return generic_block_fiemap(inode, fieinfo, start, len,
			ext4_get_block);

	if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS))
		return -EBADR;

	if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
		error = ext4_xattr_fiemap(inode, fieinfo);
	} else {
		ext4_lblk_t len_blks;
		__u64 last_blk;

		start_blk = start >> inode->i_sb->s_blocksize_bits;
		last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits;
		if (last_blk >= EXT_MAX_BLOCKS)
			last_blk = EXT_MAX_BLOCKS-1;
		len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1;

		 
		error = ext4_fill_fiemap_extents(inode, start_blk,
						 len_blks, fieinfo);
	}
	return error;
}