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authorLi Nan <linan122@huawei.com>2024-04-19 17:32:57 +0800
committerJens Axboe <axboe@kernel.dk>2024-04-19 08:06:24 -0600
commit01bc4fda9ea0a6b52f12326486f07a4910666cf6 (patch)
tree7279bbb793c22123882ec2a49b94e357f3eef3e8 /block/blk-iocost.c
parent752863bddacab6b5c5164b1df8c8b2e3a175ee28 (diff)
downloadlwn-01bc4fda9ea0a6b52f12326486f07a4910666cf6.tar.gz
lwn-01bc4fda9ea0a6b52f12326486f07a4910666cf6.zip
blk-iocost: do not WARN if iocg was already offlined
In iocg_pay_debt(), warn is triggered if 'active_list' is empty, which is intended to confirm iocg is active when it has debt. However, warn can be triggered during a blkcg or disk removal, if iocg_waitq_timer_fn() is run at that time: WARNING: CPU: 0 PID: 2344971 at block/blk-iocost.c:1402 iocg_pay_debt+0x14c/0x190 Call trace: iocg_pay_debt+0x14c/0x190 iocg_kick_waitq+0x438/0x4c0 iocg_waitq_timer_fn+0xd8/0x130 __run_hrtimer+0x144/0x45c __hrtimer_run_queues+0x16c/0x244 hrtimer_interrupt+0x2cc/0x7b0 The warn in this situation is meaningless. Since this iocg is being removed, the state of the 'active_list' is irrelevant, and 'waitq_timer' is canceled after removing 'active_list' in ioc_pd_free(), which ensures iocg is freed after iocg_waitq_timer_fn() returns. Therefore, add the check if iocg was already offlined to avoid warn when removing a blkcg or disk. Signed-off-by: Li Nan <linan122@huawei.com> Reviewed-by: Yu Kuai <yukuai3@huawei.com> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20240419093257.3004211-1-linan666@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-iocost.c')
-rw-r--r--block/blk-iocost.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/block/blk-iocost.c b/block/blk-iocost.c
index baa20c85799d..690ca99dfaca 100644
--- a/block/blk-iocost.c
+++ b/block/blk-iocost.c
@@ -1439,8 +1439,11 @@ static void iocg_pay_debt(struct ioc_gq *iocg, u64 abs_vpay,
lockdep_assert_held(&iocg->ioc->lock);
lockdep_assert_held(&iocg->waitq.lock);
- /* make sure that nobody messed with @iocg */
- WARN_ON_ONCE(list_empty(&iocg->active_list));
+ /*
+ * make sure that nobody messed with @iocg. Check iocg->pd.online
+ * to avoid warn when removing blkcg or disk.
+ */
+ WARN_ON_ONCE(list_empty(&iocg->active_list) && iocg->pd.online);
WARN_ON_ONCE(iocg->inuse > 1);
iocg->abs_vdebt -= min(abs_vpay, iocg->abs_vdebt);