ext2_find_near()

Hi all, Sorry to bother. for ext2_find_near(), why we tro to find near block by tring priveous block? Why not forward? static ext2_fsblk_t ext2_find_near(struct inode *inode, Indirect *ind) {     struct ext2_inode_info *ei = EXT2_I(inode);     __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data;     __le32 *p;     ext2_fsblk_t bg_start;     ext2_fsblk_t colour;     /* Try to find previous block */     for (p = ind->p - 1; p >= start; p--)         if (*p)             return le32_to_cpu(*p);     /* No such thing, so let's try location of indirect block */     if (ind->bh)         return ind->bh->b_blocknr; Thank you!