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);