FS_UNCLEAN
if (fsflags & FS_UNCLEAN)
fsflags &= ~(FS_UNCLEAN | FS_FLAGS_UPDATED);
fs->fs_clean = (fs->fs_flags & FS_UNCLEAN) ? 0 : 1;
(fs->fs_flags & FS_UNCLEAN) == 0 ? 1 : 0;
fs->fs_flags &= ~FS_UNCLEAN;
fs->fs_flags |= FS_UNCLEAN;
fs->fs_clean = (fs->fs_flags & FS_UNCLEAN) ? 0 : 1;