FS_ISCLEAN
if (sblock.fs_clean & FS_ISCLEAN) {
if (markclean && (sblock.fs_clean & FS_ISCLEAN) == 0) {
sblock.fs_clean = FS_ISCLEAN;
if (!force && !printonly && sblock->fs_clean != FS_ISCLEAN) {
sblock.fs_clean = FS_ISCLEAN;