db_nfree
bmp->db_nfree = le64_to_cpu(dbmp_le->dn_nfree);
bmp->db_nfree -= nblocks;
bmp->db_nfree += nblocks;
dbmp_le->dn_nfree = cpu_to_le64(bmp->db_nfree);
bmp->db_nfree -= nblocks;
bmp->db_nfree += n;
actfree = bmp->db_nfree - inactfree;
avgfree = (u32)bmp->db_nfree / bmp->db_numag;
buf->f_bfree = sbi->bmap->db_nfree;
buf->f_bavail = sbi->bmap->db_nfree;
((sbi->bmap->db_nfree >> imap->im_l2nbperiext)