Re: [PATCH 3/4] nvdimm: Add IOCTL pass thru

[Jeff Moyer <jmoyer@redhat.com>]

Jerry Hoemann <jerry.hoemann@hpe.com> writes:

> @@ -633,10 +718,11 @@ static int match_dimm(struct device *dev, void *data)
>  
>  static long nvdimm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
>  {
> -	int rc = -ENXIO, read_only;
> +	int rc = -ENXIO, ro;
>  	struct nvdimm_bus *nvdimm_bus;
> +	unsigned int type = _IOC_TYPE(cmd);
>  
> -	read_only = (O_RDWR != (file->f_flags & O_ACCMODE));
> +	ro = (O_RDWR != (file->f_flags & O_ACCMODE));

I'm still reviewing the rest of this, but this is bugging me.  The
existing check for read_only looks pretty fishy to me.  O_WRONLY is a
thing (even though it's probably not a supportable mode for this ioctl).
Why not just check for O_RDONLY?

Cheers,
Jeff