gfs2_block_map
error = mpage_read_folio(folio, gfs2_block_map);
mpage_readahead(rac, gfs2_block_map);
error = gfs2_block_map(inode, lblock, bh_result, 0);
rc = gfs2_block_map(jd->jd_inode, lblock, &bh, 0);
gfs2_block_map(&ip->i_inode, lblock, &bh, 0);
int gfs2_block_map(struct inode *inode, sector_t lblock,
gfs2_block_map(inode, blk, bh, 1);