FAILED: patch "[PATCH] blk-cgroup: hold queue_lock when removing blkg->q_node" failed to apply to 6.1-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x c164c7bc9775be7bcc68754bb3431fce5823822e
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2023082019-brink-buddhist-4d1b@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..

Possible dependencies:

c164c7bc9775 ("blk-cgroup: hold queue_lock when removing blkg->q_node")
a06377c5d01e ("Revert "blk-cgroup: pin the gendisk in struct blkcg_gq"")
9a9c261e6b55 ("Revert "blk-cgroup: pass a gendisk to blkg_lookup"")
1231039db31c ("Revert "blk-cgroup: move the cgroup information to struct gendisk"")
dcb522014351 ("Revert "blk-cgroup: simplify blkg freeing from initialization failure paths"")
3f13ab7c80fd ("blk-cgroup: move the cgroup information to struct gendisk")
479664cee14d ("blk-cgroup: pass a gendisk to blkg_lookup")
ba91c849fa50 ("blk-rq-qos: store a gendisk instead of request_queue in struct rq_qos")
3963d84df797 ("blk-rq-qos: constify rq_qos_ops")
ce57b558604e ("blk-rq-qos: make rq_qos_add and rq_qos_del more useful")
b494f9c566ba ("blk-rq-qos: move rq_qos_add and rq_qos_del out of line")
f05837ed73d0 ("blk-cgroup: store a gendisk to throttle in struct task_struct")
84d7d462b16d ("blk-cgroup: pin the gendisk in struct blkcg_gq")
180b04d450a7 ("blk-cgroup: remove the !bdi->dev check in blkg_dev_name")
27b642b07a4a ("blk-cgroup: simplify blkg freeing from initialization failure paths")
0b6f93bdf07e ("blk-cgroup: improve error unwinding in blkg_alloc")
f1c006f1c685 ("blk-cgroup: synchronize pd_free_fn() from blkg_free_workfn() and blkcg_deactivate_policy()")
dfd6200a0954 ("blk-cgroup: support to track if policy is online")
c7241babf085 ("blk-cgroup: dropping parent refcount after pd_free_fn() is done")
e3ff8887e7db ("blk-cgroup: fix missing pd_online_fn() while activating policy")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From c164c7bc9775be7bcc68754bb3431fce5823822e Mon Sep 17 00:00:00 2001
From: Ming Lei <ming.lei@redhat.com>
Date: Thu, 17 Aug 2023 22:17:51 +0800
Subject: [PATCH] blk-cgroup: hold queue_lock when removing blkg->q_node

When blkg is removed from q->blkg_list from blkg_free_workfn(), queue_lock
has to be held, otherwise, all kinds of bugs(list corruption, hard lockup,
..) can be triggered from blkg_destroy_all().

Fixes: f1c006f1c685 ("blk-cgroup: synchronize pd_free_fn() from blkg_free_workfn() and blkcg_deactivate_policy()")
Cc: Yu Kuai <yukuai3@huawei.com>
Cc: xiaoli feng <xifeng@redhat.com>
Cc: Chunyu Hu <chuhu@redhat.com>
Cc: Mike Snitzer <snitzer@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230817141751.1128970-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index fc49be622e05..9faafcd10e17 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -136,7 +136,9 @@ static void blkg_free_workfn(struct work_struct *work)
 			blkcg_policy[i]->pd_free_fn(blkg->pd[i]);
 	if (blkg->parent)
 		blkg_put(blkg->parent);
+	spin_lock_irq(&q->queue_lock);
 	list_del_init(&blkg->q_node);
+	spin_unlock_irq(&q->queue_lock);
 	mutex_unlock(&q->blkcg_mutex);
 
 	blk_put_queue(q);