kernel/linux.git/block/ioprio.c, branch v6.19.11

block: remove test of incorrect io priority level

2025-05-08T15:04:12+00:00

Ever since commit eca2040972b4("scsi: block: ioprio: Clean up interface definition"), the macro IOPRIO_PRIO_LEVEL() will mask the level value to something between 0 and 7 so necessarily, level will always be lower than IOPRIO_NR_LEVELS(8). Remove this obsolete check. Reported-by: Kexin Wei Cc: Damien Le Moal Signed-off-by: Aaron Lu Reviewed-by: Damien Le Moal Link: https://lore.kernel.org/r/20250508083018.GA769554@bytedance Signed-off-by: Jens Axboe

block: move __get_task_ioprio() into header file

2024-01-08T19:27:39+00:00

We call this once per IO, which can be millions of times per second. Since nobody really uses io priorities, or at least it isn't very common, this is all wasted time and can amount to as much as 3% of the total kernel time. Reviewed-by: Bart Van Assche Signed-off-by: Jens Axboe

scsi: block: Improve ioprio value validity checks

2023-06-16T16:04:30+00:00

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

scsi: block: ioprio: Clean up interface definition

2023-05-22T21:05:18+00:00

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 Reviewed-by: Hannes Reinecke Reviewed-by: Christoph Hellwig Signed-off-by: Niklas Cassel Link: https://lore.kernel.org/r/20230511011356.227789-2-nks@flawful.org Signed-off-by: Martin K. Petersen

block: Fix handling of tasks without ioprio in ioprio_get(2)

2022-06-27T12:29:12+00:00

ioprio_get(2) can be asked to return the best IO priority from several tasks (IOPRIO_WHO_PGRP, IOPRIO_WHO_USER). Currently the call treats tasks without set IO priority as having priority IOPRIO_CLASS_BE/IOPRIO_BE_NORM however this does not really reflect the IO priority the task will get (which depends on task's nice value). Fix the code to use the real IO priority task's IO will use. We have to modify code for ioprio_get(IOPRIO_WHO_PROCESS) to keep returning IOPRIO_CLASS_NONE priority for tasks without set IO priority as a special case to maintain userspace visible API. Reviewed-by: Damien Le Moal Tested-by: Damien Le Moal Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20220623074840.5960-5-jack@suse.cz Signed-off-by: Jens Axboe

block: Make ioprio_best() static

2022-06-27T12:29:12+00:00

Nobody outside of block/ioprio.c uses it. Reviewed-by: Damien Le Moal Tested-by: Damien Le Moal Signed-off-by: Jan Kara Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20220623074840.5960-4-jack@suse.cz Signed-off-by: Jens Axboe

block: Generalize get_current_ioprio() for any task

2022-06-27T12:29:12+00:00

get_current_ioprio() operates only on current task. We will need the same functionality for other tasks as well. Generalize get_current_ioprio() for that and also move the bulk out of the header file because it is large enough. Reviewed-by: Damien Le Moal Tested-by: Damien Le Moal Signed-off-by: Jan Kara Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20220623074840.5960-3-jack@suse.cz Signed-off-by: Jens Axboe

block: fix default IO priority handling again

2022-06-27T12:29:12+00:00

Commit e70344c05995 ("block: fix default IO priority handling") introduced an inconsistency in get_current_ioprio() that tasks without IO context return IOPRIO_DEFAULT priority while tasks with freshly allocated IO context will return 0 (IOPRIO_CLASS_NONE/0) IO priority. Tasks without IO context used to be rare before 5a9d041ba2f6 ("block: move io_context creation into where it's needed") but after this commit they became common because now only BFQ IO scheduler setups task's IO context. Similar inconsistency is there for get_task_ioprio() so this inconsistency is now exposed to userspace and userspace will see different IO priority for tasks operating on devices with BFQ compared to devices without BFQ. Furthemore the changes done by commit e70344c05995 change the behavior when no IO priority is set for BFQ IO scheduler which is also documented in ioprio_set(2) manpage: "If no I/O scheduler has been set for a thread, then by default the I/O priority will follow the CPU nice value (setpriority(2)). In Linux kernels before version 2.6.24, once an I/O priority had been set using ioprio_set(), there was no way to reset the I/O scheduling behavior to the default. Since Linux 2.6.24, specifying ioprio as 0 can be used to reset to the default I/O scheduling behavior." So make sure we default to IOPRIO_CLASS_NONE as used to be the case before commit e70344c05995. Also cleanup alloc_io_context() to explicitely set this IO priority for the allocated IO context to avoid future surprises. Note that we tweak ioprio_best() to maintain ioprio_get(2) behavior and make this commit easily backportable. CC: stable@vger.kernel.org Fixes: e70344c05995 ("block: fix default IO priority handling") Reviewed-by: Damien Le Moal Tested-by: Damien Le Moal Signed-off-by: Jan Kara Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20220623074840.5960-1-jack@suse.cz Signed-off-by: Jens Axboe

Merge tag 'for-5.17/block-2022-01-11' of git://git.kernel.dk/linux-block

2022-01-12T18:26:52+00:00

Pull block updates from Jens Axboe: - Unify where the struct request handling code is located in the blk-mq code (Christoph) - Header cleanups (Christoph) - Clean up the io_context handling code (Christoph, me) - Get rid of ->rq_disk in struct request (Christoph) - Error handling fix for add_disk() (Christoph) - request allocation cleanusp (Christoph) - Documentation updates (Eric, Matthew) - Remove trivial crypto unregister helper (Eric) - Reduce shared tag overhead (John) - Reduce poll_stats memory overhead (me) - Known indirect function call for dio (me) - Use atomic references for struct request (me) - Support request list issue for block and NVMe (me) - Improve queue dispatch pinning (Ming) - Improve the direct list issue code (Keith) - BFQ improvements (Jan) - Direct completion helper and use it in mmc block (Sebastian) - Use raw spinlock for the blktrace code (Wander) - fsync error handling fix (Ye) - Various fixes and cleanups (Lukas, Randy, Yang, Tetsuo, Ming, me) * tag 'for-5.17/block-2022-01-11' of git://git.kernel.dk/linux-block: (132 commits) MAINTAINERS: add entries for block layer documentation docs: block: remove queue-sysfs.rst docs: sysfs-block: document virt_boundary_mask docs: sysfs-block: document stable_writes docs: sysfs-block: fill in missing documentation from queue-sysfs.rst docs: sysfs-block: add contact for nomerges docs: sysfs-block: sort alphabetically docs: sysfs-block: move to stable directory block: don't protect submit_bio_checks by q_usage_counter block: fix old-style declaration nvme-pci: fix queue_rqs list splitting block: introduce rq_list_move block: introduce rq_list_for_each_safe macro block: move rq_list macros to blk-mq.h block: drop needless assignment in set_task_ioprio() block: remove unnecessary trailing '\' bio.h: fix kernel-doc warnings block: check minor range in device_add_disk() block: use "unsigned long" for blk_validate_block_size(). block: fix error unwinding in device_add_disk ...

block: move set_task_ioprio to blk-ioc.c

2021-12-16T17:59:01+00:00

Keep set_task_ioprio with the other low-level code that accesses the io_context structure. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20211209063131.18537-8-hch@lst.de Signed-off-by: Jens Axboe