user/sven/linux.git/include/uapi/linux/ioprio.h, branch v5.15.16

block: fix default IO priority handling

2021-08-18T13:23:15Z

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 Link: https://lore.kernel.org/r/20210811033702.368488-7-damien.lemoal@wdc.com [axboe: drop unnecessary lightnvm change] Signed-off-by: Jens Axboe

block: Introduce IOPRIO_NR_LEVELS

2021-08-18T13:21:12Z

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 Link: https://lore.kernel.org/r/20210811033702.368488-6-damien.lemoal@wdc.com Signed-off-by: Jens Axboe

block: fix IOPRIO_PRIO_CLASS() and IOPRIO_PRIO_VALUE() macros

2021-08-18T13:21:12Z

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 Link: https://lore.kernel.org/r/20210811033702.368488-5-damien.lemoal@wdc.com Signed-off-by: Jens Axboe

block: change ioprio_valid() to an inline function

2021-08-18T13:21:11Z

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 Link: https://lore.kernel.org/r/20210811033702.368488-4-damien.lemoal@wdc.com Signed-off-by: Jens Axboe

block: improve ioprio class description comment

2021-08-18T13:21:11Z

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 Link: https://lore.kernel.org/r/20210811033702.368488-3-damien.lemoal@wdc.com Signed-off-by: Jens Axboe

ioprio: move user space relevant ioprio bits to UAPI includes

2021-08-02T19:37:27Z

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 Cc: Greg Kroah-Hartman Cc: Jens Axboe Cc: linux-block@vger.kernel.org Signed-off-by: Oliver Hartkopp Link: https://lore.kernel.org/r/20210714195655.181943-1-socketcan@hartkopp.net Signed-off-by: Jens Axboe