This is a note to let you know that I've just added the patch titled Revert "blk-cgroup: dropping parent refcount after pd_free_fn() is done" to the 6.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: revert-blk-cgroup-dropping-parent-refcount-after-pd_free_fn-is-done.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From a53f77eb6c2d0b1befbcecbb70ff6f94ce6d2817 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Date: Sat, 11 Mar 2023 10:34:39 +0100 Subject: Revert "blk-cgroup: dropping parent refcount after pd_free_fn() is done" From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> This reverts commit 029f1f1efa84387474b445dac4281cf95a398db8 which is commit c7241babf0855d8a6180cd1743ff0ec34de40b4e upstream. It is reported to cause problems, as only 2 of the 3 patch series were applied to the stable branches. Reported-by: Mike Cloaked <mike.cloaked@xxxxxxxxx> Reported-by: Eric Biggers <ebiggers@xxxxxxxxxx> Cc: Yu Kuai <yukuai3@xxxxxxxxxx> Cc: Tejun Heo <tj@xxxxxxxxxx> Cc: Christoph Hellwig <hch@xxxxxx> Cc: Jens Axboe <axboe@xxxxxxxxx> Cc: Sasha Levin <sashal@xxxxxxxxxx> Link: https://bugzilla.kernel.org/show_bug.cgi?id=217174 Link: https://lore.kernel.org/r/ZAuPkCn49urWBN5P@sol.localdomain Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- block/blk-cgroup.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -93,8 +93,6 @@ static void blkg_free_workfn(struct work if (blkg->pd[i]) blkcg_policy[i]->pd_free_fn(blkg->pd[i]); - if (blkg->parent) - blkg_put(blkg->parent); if (blkg->q) blk_put_queue(blkg->q); free_percpu(blkg->iostat_cpu); @@ -129,6 +127,8 @@ static void __blkg_release(struct rcu_he /* release the blkcg and parent blkg refs this blkg has been holding */ css_put(&blkg->blkcg->css); + if (blkg->parent) + blkg_put(blkg->parent); blkg_free(blkg); } Patches currently in stable-queue which might be from gregkh@xxxxxxxxxxxxxxxxxxx are queue-6.1/revert-blk-cgroup-synchronize-pd_free_fn-from-blkg_free_workfn-and-blkcg_deactivate_policy.patch queue-6.1/revert-blk-cgroup-dropping-parent-refcount-after-pd_free_fn-is-done.patch