Messages in this thread Patch in this message | | | From | Tao Su <> | Subject | [PATCH v2] block: Skip destroyed blkg when restart in blkg_destroy_all() | Date | Fri, 28 Apr 2023 12:51:49 +0800 |
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Kernel hang in blkg_destroy_all() when total blkg greater than BLKG_DESTROY_BATCH_SIZE, because of not removing destroyed blkg in blkg_list. So the size of blkg_list is same after destroying a batch of blkg, and the infinite 'restart' occurs.
Since blkg should stay on the queue list until blkg_free_workfn(), skip destroyed blkg when restart a new round, which will solve this kernel hang issue and satisfy the previous will to restart.
Reported-by: Xiangfei Ma <xiangfeix.ma@intel.com> Tested-by: Xiangfei Ma <xiangfeix.ma@intel.com> Tested-by: Farrah Chen <farrah.chen@intel.com> Signed-off-by: Yu Kuai <yukuai1@huaweicloud.com> Signed-off-by: Tao Su <tao1.su@linux.intel.com> --- v2: - change 'directly remove destroyed blkg' to 'skip destroyed blkg'
v1: - https://lore.kernel.org/all/20230425075911.839539-1-tao1.su@linux.intel.com/
block/blk-cgroup.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index bd50b55bdb61..75bad5d60c9f 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -528,6 +528,9 @@ static void blkg_destroy_all(struct gendisk *disk) list_for_each_entry_safe(blkg, n, &q->blkg_list, q_node) { struct blkcg *blkcg = blkg->blkcg; + if (hlist_unhashed(&blkg->blkcg_node)) + continue; + spin_lock(&blkcg->lock); blkg_destroy(blkg); spin_unlock(&blkcg->lock); -- 2.34.1
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