FMARK
(oflags | FSCAN) & ~(FMARK|FDEFER));
(fp->f_flag & FMARK) != 0 ||
atomic_or_uint(&fp->f_flag, FMARK);
(fp->f_flag & (FMARK | FSCAN)) != FSCAN) {
if (fp->f_flag & (FMARK | FDEFER)) {
atomic_or_uint(&fp->f_flag, FMARK);