fast_sym_links

static inline int ext2_inode_is_fast_symlink(struct inode *inode)
  {
          int ea_blocks = EXT2_I(inode)->i_file_acl ?
                  (inode->i_sb->s_blocksize >> 9) : 0;
  
          return (S_ISLNK(inode->i_mode) &&
                  inode->i_blocks - ea_blocks == 0);
  }