关于ioctl

long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
long (*compat_ioctl) (struct file *, unsigned int, unsigned long);

旧的.
static const struct file_operations tty_fops = {
    .llseek        = no_llseek,
    .read        = tty_read,
    .write        = tty_write,
    .poll        = tty_poll,
    .ioctl        = tty_ioctl,
    .open        = tty_open,
    .release    = tty_release,
    .fasync        = tty_fasync,
};
新的.
static const struct file_operations tty_fops = {
    .llseek        = no_llseek,
    .read        = tty_read,
    .write        = tty_write,
    .poll        = tty_poll,
    .unlocked_ioctl    = tty_ioctl,
    .compat_ioctl    = tty_compat_ioctl,
    .open        = tty_open,
    .release    = tty_release,
    .fasync        = tty_fasync,
};