static void ext4_readahead(struct readahead_control *rac)
{
	struct inode *inode = rac->mapping->host;

	/* If the file has inline data, no need to do readahead. */
	if (ext4_has_inline_data(inode))
		return;

	ext4_mpage_readpages(inode, rac, NULL);
}
static void ext4_readahead(struct readahead_control *rac)
{
	struct inode *inode = rac->mapping->host;

	 
	if (ext4_has_inline_data(inode))
		return;

	ext4_mpage_readpages(inode, rac, NULL);
}