Re: [PATCH] [media] v4l2 core: return -ENOIOCTLCMD if an ioctl doesn't exist

[Sakari Ailus <sakari.ailus@iki.fi>]

Mauro Carvalho Chehab wrote:
> Currently, -EINVAL is used to return either when an IOCTL is not
> implemented, or if the ioctl was not implemented.

Hi Mauro,

Thanks for the patch.

The V4L2 core probably should return -ENOIOCTLCMD when an IOCTL isn't 
implemented, but as long as vfs_ioctl() would stay as it is, the user 
space would still get -EINVAL. Or is vfs_ioctl() about to change?

fs/ioctl.c:
----8<-----------
static long vfs_ioctl(struct file *filp, unsigned int cmd,
                       unsigned long arg)
{
         int error = -ENOTTY;

         if (!filp->f_op || !filp->f_op->unlocked_ioctl)
                 goto out;

         error = filp->f_op->unlocked_ioctl(filp, cmd, arg);
         if (error == -ENOIOCTLCMD)
                 error = -EINVAL;
  out:
         return error;
}
----8<-----------

-- 
Sakari Ailus
sakari.ailus@iki.fi