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path: root/include/uapi/linux/ioprio.h
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2023-08-15block: uapi: Fix compilation errors using ioprio.h with C++Damien Le Moal
The use of the "class" argument name in the ioprio_value() inline function in include/uapi/linux/ioprio.h confuses C++ compilers resulting in compilation errors such as: /usr/include/linux/ioprio.h:110:43: error: expected primary-expression before ‘int’ 110 | static __always_inline __u16 ioprio_value(int class, int level, int hint) | ^~~ for user C++ programs including linux/ioprio.h. Avoid these errors by renaming the arguments of the ioprio_value() function to prioclass, priolevel and priohint. For consistency, the arguments of the IOPRIO_PRIO_VALUE() and IOPRIO_PRIO_VALUE_HINT() macros are also renamed in the same manner. Reported-by: Igor Pylypiv <ipylypiv@google.com> Fixes: 01584c1e2337 ("scsi: block: Improve ioprio value validity checks") Signed-off-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Tested-by: Igor Pylypiv <ipylypiv@google.com> Link: https://lore.kernel.org/r/20230814215833.259286-1-dlemoal@kernel.org Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-16scsi: block: Improve ioprio value validity checksDamien Le Moal
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@kernel.org> Link: https://lore.kernel.org/r/20230608095556.124001-1-dlemoal@kernel.org Reviewed-by: Niklas Cassel <niklas.cassel@wdc.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2023-05-22scsi: block: Introduce ioprio hintsDamien Le Moal
I/O priorities currently only use 6-bits of the 16-bits ioprio value: the 3-upper bits are used to define up to 8 priority classes (4 of which are valid) and the 3 lower bits of the value are used to define a priority level for the real-time and best-effort class. The remaining 10-bits between the I/O priority class and level are unused, and in fact, cannot be used by the user as doing so would either result in the value being completely ignored, or in an error returned by ioprio_check_cap(). Use these 10-bits of an ioprio value to allow a user to specify I/O hints. An I/O hint is defined as a 10-bitsvalue, allowing up to 1023 different hints to be specified, with the value 0 being reserved as the "no hint" case. An I/O hint can apply to any I/O that specifies a valid priority class other than NONE, regardless of the I/O priority level specified. To do so, the macros IOPRIO_PRIO_HINT() and IOPRIO_PRIO_VALUE_HINT() are introduced in include/uapi/linux/ioprio.h to respectively allow a user to get and set a hint in an ioprio value. To support the ATA and SCSI command duration limits feature, 7 hints are defined: IOPRIO_HINT_DEV_DURATION_LIMIT_1 to IOPRIO_HINT_DEV_DURATION_LIMIT_7, allowing a user to specify which command duration limit descriptor should be applied to the commands serving an I/O. Specifying these hints has for now no effect whatsoever if the target block devices do not support the command duration limits feature. However, in the future, block I/O schedulers can be modified to optimize I/O issuing order based on these hints, even for devices that do not support the command duration limits feature. Given that the 7 duration limits hints defined have no effect on any block layer component, the actual definition of the duration limits implied by these hints remains at the device level. Signed-off-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com> Link: https://lore.kernel.org/r/20230511011356.227789-3-nks@flawful.org Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2023-05-22scsi: block: ioprio: Clean up interface definitionDamien Le Moal
The I/O priority user interface defines the 16-bits ioprio values as the combination of the upper 3-bits for an I/O priority class and the lower 13-bits as priority data. However, the kernel only uses the lower 3-bits of the priority data to define priority levels for the RT and BE priority classes. The data part of an ioprio value is completely ignored for the IDLE and NONE classes. This is enforced by checks done in ioprio_check_cap(), which is called for all paths that allow defining an I/O priority for I/Os: the per-context ioprio_set() system call, aio interface and io_uring interface. Clarify this fact in the uapi ioprio.h header file and introduce the IOPRIO_PRIO_LEVEL_MASK and IOPRIO_PRIO_LEVEL() macros for users to define and get priority levels in an ioprio value. The coarser macro IOPRIO_PRIO_DATA() is retained for backward compatibility with old applications already using it. There is no functional change introduced with this. In-kernel users of the IOPRIO_PRIO_DATA() macro which are explicitly handling I/O priority data as a priority level are modified to use the new IOPRIO_PRIO_LEVEL() macro without any functional change. Since f2fs is the only user of this macro not explicitly using that value as a priority level, it is left unchanged. Signed-off-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com> Link: https://lore.kernel.org/r/20230511011356.227789-2-nks@flawful.org Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-08-18block: fix default IO priority handlingDamien Le Moal
The default IO priority is the best effort (BE) class with the normal priority level IOPRIO_NORM (4). However, get_task_ioprio() returns IOPRIO_CLASS_NONE/IOPRIO_NORM as the default priority and get_current_ioprio() returns IOPRIO_CLASS_NONE/0. Let's be consistent with the defined default and have both of these functions return the default priority IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, IOPRIO_NORM) when the user did not define another default IO priority for the task. In include/uapi/linux/ioprio.h, introduce the IOPRIO_BE_NORM macro as an alias to IOPRIO_NORM to clarify that this default level applies to the BE priotity class. In include/linux/ioprio.h, define the macro IOPRIO_DEFAULT as IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, IOPRIO_BE_NORM) and use this new macro when setting a priority to the default. Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Link: https://lore.kernel.org/r/20210811033702.368488-7-damien.lemoal@wdc.com [axboe: drop unnecessary lightnvm change] Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-18block: Introduce IOPRIO_NR_LEVELSDamien Le Moal
The BFQ scheduler and ioprio_check_cap() both assume that the RT priority class (IOPRIO_CLASS_RT) can have up to 8 different priority levels, similarly to the BE class (IOPRIO_CLASS_iBE). This is controlled using the IOPRIO_BE_NR macro , which is badly named as the number of levels also applies to the RT class. Introduce the class independent IOPRIO_NR_LEVELS macro, defined to 8, to make things clear. Keep the old IOPRIO_BE_NR macro definition as an alias for IOPRIO_NR_LEVELS. Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Link: https://lore.kernel.org/r/20210811033702.368488-6-damien.lemoal@wdc.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-18block: fix IOPRIO_PRIO_CLASS() and IOPRIO_PRIO_VALUE() macrosDamien Le Moal
The ki_ioprio field of struct kiocb is 16-bits (u16) but often handled as an int in the block layer. E.g. ioprio_check_cap() takes an int as argument. With such implicit int casting function calls, the upper 16-bits of the int argument may be left uninitialized by the compiler, resulting in invalid values for the IOPRIO_PRIO_CLASS() macro (garbage upper bits) and in an error return for functions such as ioprio_check_cap(). Fix this by masking the result of the shift by IOPRIO_CLASS_SHIFT bits in the IOPRIO_PRIO_CLASS() macro. The new macro IOPRIO_CLASS_MASK defines the 3-bits mask for the priority class. Similarly, apply the IOPRIO_PRIO_MASK mask to the data argument of the IOPRIO_PRIO_VALUE() macro to ignore the upper bits of the data value. The IOPRIO_CLASS_MASK mask is also applied to the class argument of this macro before shifting the result by IOPRIO_CLASS_SHIFT bits. While at it, also change the argument name of the IOPRIO_PRIO_CLASS() and IOPRIO_PRIO_DATA() macros from "mask" to "ioprio" to reflect the fact that a priority value should be passed rather than a mask. Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Link: https://lore.kernel.org/r/20210811033702.368488-5-damien.lemoal@wdc.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-18block: change ioprio_valid() to an inline functionDamien Le Moal
Change the ioprio_valid() macro in include/usapi/linux/ioprio.h to an inline function declared on the kernel side in include/linux/ioprio.h. Also improve checks on the class value by checking the upper bound value. Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Link: https://lore.kernel.org/r/20210811033702.368488-4-damien.lemoal@wdc.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-18block: improve ioprio class description commentDamien Le Moal
In include/usapi/linux/ioprio.h, change the ioprio class enum comment to remove the outdated reference to CFQ and mention BFQ and mq-deadline instead. Also document the high priority NCQ command use for RT class IOs directed at ATA drives that support NCQ priority. Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Link: https://lore.kernel.org/r/20210811033702.368488-3-damien.lemoal@wdc.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02ioprio: move user space relevant ioprio bits to UAPI includesOliver Hartkopp
systemd added a modified copy of include/linux/ioprio.h into its code to get the relevant content definitions for the exposed ioprio_[get|set] system calls. Move the user space relevant ioprio bits to the UAPI includes to be able to use the ioprio_[get|set] syscalls as intended. Cc: Kay Sievers <kay@vrfy.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: linux-block@vger.kernel.org Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Link: https://lore.kernel.org/r/20210714195655.181943-1-socketcan@hartkopp.net Signed-off-by: Jens Axboe <axboe@kernel.dk>