EXT4_MAX_BLOCKS
map.m_len = len_lblk = EXT4_MAX_BLOCKS(len, offset, blkbits);
EXT4_MAX_BLOCKS(len, offset, inode->i_blkbits), ret);
max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits);
max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits);
map.m_len = EXT4_MAX_BLOCKS(len, pos, blkbits);