Re: [PATCH 2/3] block: fix ioprio interface

[Bart Van Assche <bvanassche@xxxxxxx>]

On 8/2/21 2:21 AM, Damien Le Moal wrote:
> diff --git a/include/uapi/linux/ioprio.h b/include/uapi/linux/ioprio.h
> index 77b17e08b0da..27dc7fb0ba12 100644
> --- a/include/uapi/linux/ioprio.h
> +++ b/include/uapi/linux/ioprio.h
> @@ -6,10 +6,12 @@
>    * Gives us 8 prio classes with 13-bits of data for each class
>    */
>   #define IOPRIO_CLASS_SHIFT	(13)
> +#define IOPRIO_CLASS_MASK	(0x07)
>   #define IOPRIO_PRIO_MASK	((1UL << IOPRIO_CLASS_SHIFT) - 1)
>   
> -#define IOPRIO_PRIO_CLASS(mask)	((mask) >> IOPRIO_CLASS_SHIFT)
> -#define IOPRIO_PRIO_DATA(mask)	((mask) & IOPRIO_PRIO_MASK)
> +#define IOPRIO_PRIO_CLASS(val)	\
> +	(((val) >> IOPRIO_CLASS_SHIFT) & IOPRIO_CLASS_MASK)
> +#define IOPRIO_PRIO_DATA(val)	((val) & IOPRIO_PRIO_MASK)
>   #define IOPRIO_PRIO_VALUE(class, data)	(((class) << IOPRIO_CLASS_SHIFT) | data)
>   
>   /*
> @@ -23,9 +25,16 @@ enum {
>   	IOPRIO_CLASS_RT,
>   	IOPRIO_CLASS_BE,
>   	IOPRIO_CLASS_IDLE,
> +
> +	IOPRIO_CLASS_MAX,
>   };
>   
> -#define ioprio_valid(mask)	(IOPRIO_PRIO_CLASS((mask)) != IOPRIO_CLASS_NONE)
> +static inline bool ioprio_valid(unsigned short ioprio)
> +{
> +	unsigned short class = IOPRIO_PRIO_CLASS(ioprio);
> +
> +	return class > IOPRIO_CLASS_NONE && class < IOPRIO_CLASS_MAX;
> +}
>   
>   /*
>    * 8 best effort priority levels are supported

Are there any plans to use ioprio_valid() in user space applications? If 
not, should this function perhaps be defined in a kernel-only header?

Thanks,

Bart.