From 01584c1e233740519d0e11aa20daa323d26bf598 Mon Sep 17 00:00:00 2001 From: Damien Le Moal Date: Thu, 8 Jun 2023 18:55:56 +0900 Subject: [PATCH] scsi: block: Improve ioprio value validity checks 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 Link: https://lore.kernel.org/r/20230608095556.124001-1-dlemoal@kernel.org Reviewed-by: Niklas Cassel Reviewed-by: Linus Walleij Signed-off-by: Martin K. Petersen --- block/ioprio.c | 1 + include/uapi/linux/ioprio.h | 50 ++++++++++++++++++++++++++++++--------------- 2 files changed, 34 insertions(+), 17 deletions(-) diff --git a/block/ioprio.c b/block/ioprio.c index f0d9e81..b5a9425 100644 --- a/block/ioprio.c +++ b/block/ioprio.c @@ -58,6 +58,7 @@ int ioprio_check_cap(int ioprio) if (level) return -EINVAL; break; + case IOPRIO_CLASS_INVALID: default: return -EINVAL; } diff --git a/include/uapi/linux/ioprio.h b/include/uapi/linux/ioprio.h index 4c4806e..99440b2 100644 --- a/include/uapi/linux/ioprio.h +++ b/include/uapi/linux/ioprio.h @@ -2,19 +2,20 @@ #ifndef _UAPI_LINUX_IOPRIO_H #define _UAPI_LINUX_IOPRIO_H +#include +#include + /* * 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_NR_CLASSES 8 +#define IOPRIO_CLASS_MASK (IOPRIO_NR_CLASSES - 1) #define IOPRIO_PRIO_MASK ((1UL << IOPRIO_CLASS_SHIFT) - 1) #define IOPRIO_PRIO_CLASS(ioprio) \ (((ioprio) >> IOPRIO_CLASS_SHIFT) & IOPRIO_CLASS_MASK) #define IOPRIO_PRIO_DATA(ioprio) ((ioprio) & IOPRIO_PRIO_MASK) -#define IOPRIO_PRIO_VALUE(class, data) \ - ((((class) & IOPRIO_CLASS_MASK) << IOPRIO_CLASS_SHIFT) | \ - ((data) & IOPRIO_PRIO_MASK)) /* * These are the io priority classes as implemented by the BFQ and mq-deadline @@ -25,10 +26,13 @@ * served when no one else is using the disk. */ enum { - IOPRIO_CLASS_NONE, - IOPRIO_CLASS_RT, - IOPRIO_CLASS_BE, - IOPRIO_CLASS_IDLE, + IOPRIO_CLASS_NONE = 0, + IOPRIO_CLASS_RT = 1, + IOPRIO_CLASS_BE = 2, + IOPRIO_CLASS_IDLE = 3, + + /* Special class to indicate an invalid ioprio value */ + IOPRIO_CLASS_INVALID = 7, }; /* @@ -74,15 +78,6 @@ enum { (((ioprio) >> IOPRIO_HINT_SHIFT) & IOPRIO_HINT_MASK) /* - * Alternate macro for IOPRIO_PRIO_VALUE() to define an I/O priority with - * a class, level and hint. - */ -#define IOPRIO_PRIO_VALUE_HINT(class, level, hint) \ - ((((class) & IOPRIO_CLASS_MASK) << IOPRIO_CLASS_SHIFT) | \ - (((hint) & IOPRIO_HINT_MASK) << IOPRIO_HINT_SHIFT) | \ - ((level) & IOPRIO_LEVEL_MASK)) - -/* * I/O hints. */ enum { @@ -107,4 +102,25 @@ enum { IOPRIO_HINT_DEV_DURATION_LIMIT_7 = 7, }; +#define IOPRIO_BAD_VALUE(val, max) ((val) < 0 || (val) >= (max)) + +/* + * Return an I/O priority value based on a class, a level and a hint. + */ +static __always_inline __u16 ioprio_value(int class, int level, int hint) +{ + if (IOPRIO_BAD_VALUE(class, IOPRIO_NR_CLASSES) || + IOPRIO_BAD_VALUE(level, IOPRIO_NR_LEVELS) || + IOPRIO_BAD_VALUE(hint, IOPRIO_NR_HINTS)) + return IOPRIO_CLASS_INVALID << IOPRIO_CLASS_SHIFT; + + return (class << IOPRIO_CLASS_SHIFT) | + (hint << IOPRIO_HINT_SHIFT) | level; +} + +#define IOPRIO_PRIO_VALUE(class, level) \ + ioprio_value(class, level, IOPRIO_HINT_NONE) +#define IOPRIO_PRIO_VALUE_HINT(class, level, hint) \ + ioprio_value(class, level, hint) + #endif /* _UAPI_LINUX_IOPRIO_H */ -- 2.7.4