From: Yu Kuai <yukuai3@xxxxxxxxxx> The problem was found in iocost orignally([1]) that ioc can be freed in ioc_pd_free(). And later we found that there are more problem in iocost([2]). After some discussion, as suggested by Tejun([3]), we decide to fix the problem that parent pd can be freed before child pd in cgroup layer first. And the problem in [1] will be fixed later if this patchset is applied. [1] https://lore.kernel.org/all/20221130132156.2836184-8-linan122@xxxxxxxxxx/ [2] https://lore.kernel.org/all/aa924294-2f54-1b53-fc6e-e4f8fa019b14@xxxxxxxxxxxxxxx/ [3] https://lore.kernel.org/all/20221227125502.541931-1-yukuai1@xxxxxxxxxxxxxxx/ Yu Kuai (3): blk-cgroup: dropping parent refcount after pd_free_fn() is done blk-cgroup: support to track if policy is online blk-cgroup: synchronize pd_free_fn() from blkg_free_workfn() and blkcg_deactivate_policy() block/blk-cgroup.c | 61 +++++++++++++++++++++++++++++++----------- block/blk-cgroup.h | 1 + include/linux/blkdev.h | 1 + 3 files changed, 48 insertions(+), 15 deletions(-) -- 2.31.1
