On Thu, Jun 8, 2023 at 11:55 AM Damien Le Moal <dlemoal@xxxxxxxxxx> wrote:
> The introduction of the macro IOPRIO_PRIO_LEVEL() in commit
> eca2040972b4 ("scsi: block: ioprio: Clean up interface definition")
> results in an iopriority level to always be masked using the macro
> IOPRIO_LEVEL_MASK, and thus to the kernel always seeing an acceptable
> value for an I/O priority level when checked in ioprio_check_cap().
> Before this patch, this function would return an error for some (but not
> all) invalid values for a level valid range of [0..7].
>
> Restore and improve the detection of invalid priority levels by
> introducing the inline function ioprio_value() to check an ioprio class,
> level and hint value before combining these fields into a single value
> to be used with ioprio_set() or AIOs. If an invalid value for the class,
> level or hint of an ioprio is detected, ioprio_value() returns an ioprio
> using the class IOPRIO_CLASS_INVALID, indicating an invalid value and
> causing ioprio_check_cap() to return -EINVAL.
>
> Fixes: 6c913257226a ("scsi: block: Introduce ioprio hints")
> Fixes: eca2040972b4 ("scsi: block: ioprio: Clean up interface definition")
> Signed-off-by: Damien Le Moal <dlemoal@xxxxxxxxxx>
This makes it easier to get things right.
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Yours,
Linus Walleij
