Re: [PATCH 1/2] uio: add ioctl to uio

[Greg KH]

On Thu, Feb 17, 2022 at 10:29:21AM +0800, Guixin Liu wrote:
> In TCMU, if backstore holds its own userspace buffer, for read cmd, the
> data needs to be copied from userspace buffer to tcmu data area first,
> and then needs to be copied from tcmu data area to scsi sgl pages again.
> 
> To solve this problem, add ioctl to uio to let userspace backstore can
> copy data between scsi sgl pages and its own buffer directly.
> 
> Reviewed-by: Xiaoguang Wang <xiaoguang.wang@xxxxxxxxxxxxxxxxx>
> Signed-off-by: Guixin Liu <kanie@xxxxxxxxxxxxxxxxx>
> ---
>  drivers/uio/uio.c          | 22 ++++++++++++++++++++++
>  include/linux/uio_driver.h |  1 +

No, sorry, thie uio driver will not be adding ioctls to them.  If you
need an ioctl, then you should not be using the UIO api but rather use a
custom character driver instead.

thanks,

greg k-h