kernel/linux.git/block/blk-throttle.c, branch v6.1.174

blk-throttle: fix lockdep warning of "cgroup_mutex or RCU read lock required!"

2023-12-20T16:00:21+00:00

[ Upstream commit 27b13e209ddca5979847a1b57890e0372c1edcee ] Inside blkg_for_each_descendant_pre(), both css_for_each_descendant_pre() and blkg_lookup() requires RCU read lock, and either cgroup_assert_mutex_or_rcu_locked() or rcu_read_lock_held() is called. Fix the warning by adding rcu read lock. Reported-by: Changhui Zhong Signed-off-by: Ming Lei Link: https://lore.kernel.org/r/20231117023527.3188627-2-ming.lei@redhat.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

blk-throttle: check for overflow in calculate_bytes_allowed

2023-11-02T08:35:29+00:00

commit 2dd710d476f2f1f6eaca884f625f69ef4389ed40 upstream. Inexact, we may reject some not-overflowing values incorrectly, but they'll be on the order of exabytes allowed anyways. This fixes divide error crash on x86 if bps_limit is not configured or is set too high in the rare case that jiffy_elapsed is greater than HZ. Fixes: e8368b57c006 ("blk-throttle: use calculate_io/bytes_allowed() for throtl_trim_slice()") Fixes: 8d6bbaada2e0 ("blk-throttle: prevent overflow while calculating wait time") Signed-off-by: Khazhismel Kumykov Acked-by: Tejun Heo Link: https://lore.kernel.org/r/20231020223617.2739774-1-khazhy@google.com Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

blk-throttle: consider 'carryover_ios/bytes' in throtl_trim_slice()

2023-09-19T10:28:00+00:00

[ Upstream commit eead0056648cef49d7b15c07ae612fa217083165 ] Currently, 'carryover_ios/bytes' is not handled in throtl_trim_slice(), for consequence, 'carryover_ios/bytes' will be used to throttle bio multiple times, for example: 1) set iops limit to 100, and slice start is 0, slice end is 100ms; 2) current time is 0, and 10 ios are dispatched, those io won't be throttled and io_disp is 10; 3) still at current time 0, update iops limit to 1000, carryover_ios is updated to (0 - 10) = -10; 4) in this slice(0 - 100ms), io_allowed = 100 + (-10) = 90, which means only 90 ios can be dispatched without waiting; 5) assume that io is throttled in slice(0 - 100ms), and throtl_trim_slice() update silce to (100ms - 200ms). In this case, 'carryover_ios/bytes' is not cleared and still only 90 ios can be dispatched between 100ms - 200ms. Fix this problem by updating 'carryover_ios/bytes' in throtl_trim_slice(). Fixes: a880ae93e5b5 ("blk-throttle: fix io hung due to configuration updates") Reported-by: zhuxiaohui Link: https://lore.kernel.org/all/20230812072116.42321-1-zhuxiaohui.400@bytedance.com/ Signed-off-by: Yu Kuai Acked-by: Tejun Heo Link: https://lore.kernel.org/r/20230816012708.1193747-5-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

blk-throttle: use calculate_io/bytes_allowed() for throtl_trim_slice()

2023-09-19T10:28:00+00:00

[ Upstream commit e8368b57c006dc0e02dcd8a9dc9f2060ff5476fe ] There are no functional changes, just make the code cleaner. Signed-off-by: Yu Kuai Acked-by: Tejun Heo Link: https://lore.kernel.org/r/20230816012708.1193747-4-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe Stable-dep-of: eead0056648c ("blk-throttle: consider 'carryover_ios/bytes' in throtl_trim_slice()") Signed-off-by: Sasha Levin

blk-throttle: Fix that bps of child could exceed bps limited in parent

2023-04-13T14:55:37+00:00

commit 84aca0a7e039c8735abc0f89f3f48e9006c0dfc7 upstream. Consider situation as following (on the default hierarchy): HDD | root (bps limit: 4k) | child (bps limit :8k) | fio bs=8k Rate of fio is supposed to be 4k, but result is 8k. Reason is as following: Size of single IO from fio is larger than bytes allowed in one throtl_slice in child, so IOs are always queued in child group first. When queued IOs in child are dispatched to parent group, BIO_BPS_THROTTLED is set and these IOs will not be limited by tg_within_bps_limit anymore. Fix this by only set BIO_BPS_THROTTLED when the bio traversed the entire tree. There patch has no influence on situation which is not on the default hierarchy as each group is a single root group without parent. Acked-by: Tejun Heo Signed-off-by: Kemeng Shi Link: https://lore.kernel.org/r/20221205115709.251489-3-shikemeng@huaweicloud.com Signed-off-by: Jens Axboe Cc: Khazhy Kumykov Signed-off-by: Greg Kroah-Hartman

blk-throttle: pass a gendisk to blk_throtl_cancel_bios

2022-09-27T01:17:28+00:00

Pass the gendisk to blk_throtl_cancel_bios as part of moving the blk-cgroup infrastructure to be gendisk based. Signed-off-by: Christoph Hellwig Reviewed-by: Andreas Herrmann Acked-by: Tejun Heo Link: https://lore.kernel.org/r/20220921180501.1539876-15-hch@lst.de Signed-off-by: Jens Axboe

blk-throttle: pass a gendisk to blk_throtl_register_queue

2022-09-27T01:17:27+00:00

Pass the gendisk to blk_throtl_register_queue as part of moving the blk-cgroup infrastructure to be gendisk based. Signed-off-by: Christoph Hellwig Reviewed-by: Andreas Herrmann Acked-by: Tejun Heo Link: https://lore.kernel.org/r/20220921180501.1539876-14-hch@lst.de Signed-off-by: Jens Axboe

blk-throttle: pass a gendisk to blk_throtl_init and blk_throtl_exit

2022-09-27T01:17:27+00:00

Pass the gendisk to blk_throtl_init and blk_throtl_exit as part of moving the blk-cgroup infrastructure to be gendisk based. Signed-off-by: Christoph Hellwig Reviewed-by: Andreas Herrmann Acked-by: Tejun Heo Link: https://lore.kernel.org/r/20220921180501.1539876-13-hch@lst.de Signed-off-by: Jens Axboe

blk-throttle: improve bypassing bios checkings

2022-09-24T14:59:43+00:00

"tg->has_rules" is extended to "tg->has_rules_iops/bps", thus bios that don't need to be throttled can be checked accurately. With this patch, bio will be throttled if: 1) Bio is read/write, and corresponding read/write iops limit exist. 2) If corresponding doesn't exist, corresponding bps limit exist and bio is not throttled before. Signed-off-by: Yu Kuai Acked-by: Tejun Heo Link: https://lore.kernel.org/r/20220921095309.1481289-3-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe

blk-throttle: remove THROTL_TG_HAS_IOPS_LIMIT

2022-09-24T14:59:43+00:00

Currently, "tg->has_rules" and "tg->flags & THROTL_TG_HAS_IOPS_LIMIT" both try to bypass bios that don't need to be throttled, however, they are a little redundant and both not perfect: 1) "tg->has_rules" only distinguish read and write, but not iops and bps limit. 2) "tg->flags & THROTL_TG_HAS_IOPS_LIMIT" only check if iops limit exist, read and write is not distinguished, and bps limit is not checked. tg->has_rules will extended to distinguish bps and iops in the following patch. There is no need to keep the flag. Signed-off-by: Yu Kuai Acked-by: Tejun Heo Link: https://lore.kernel.org/r/20220921095309.1481289-2-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe