FIF_INSERTED
if (fp->f_iflags & FIF_INSERTED)
KASSERT(wfp->f_iflags & FIF_INSERTED);
KASSERT(fp->f_iflags & FIF_INSERTED);
if ((fp->f_iflags & FIF_INSERTED) == 0) {
atomic_setbits_int(&fp->f_iflags, FIF_INSERTED);