/* @orig_inode: original inode structure @donor_inode: donor inode structure Acquire write lock of i_data_sem of the two inodes (orig and donor) by i_ino order.  */
static void double_down_write_data_sem(struct inode *orig_inode, struct inode *donor_inode)
/* @orig_inode: original inode structure @donor_inode: donor inode structure Acquire write lock of i_data_sem of the two inodes (orig and donor) by i_ino order.  */
static void double_down_write_data_sem(struct inode *orig_inode, struct inode *donor_inode)
{
	struct inode *first = orig_inode, *second = donor_inode;
	if (donor_inode->i_ino < orig_inode->i_ino) {
		first = donor_inode;
		second = orig_inode;
	}
	down_write(&EXT4_I(first)->i_data_sem);
	down_write_nested(&EXT4_I(second)->i_data_sem, SINGLE_DEPTH_NESTING);
}