Revert "blk-cgroup: synchronize pd_free_fn() from blkg_free_workfn() and blkcg_deactivate_policy()"

This reverts commit 81c1188905 which is
commit f1c006f1c6 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@gmail.com>
Reported-by: Eric Biggers <ebiggers@kernel.org>
Cc: Yu Kuai <yukuai3@huawei.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Sasha Levin <sashal@kernel.org>
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@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Greg Kroah-Hartman 2023-03-11 10:34:32 +01:00
parent 8a923980a1
commit b5dae1cd0d
2 changed files with 6 additions and 30 deletions

View File

@ -87,32 +87,16 @@ static void blkg_free_workfn(struct work_struct *work)
{
struct blkcg_gq *blkg = container_of(work, struct blkcg_gq,
free_work);
struct request_queue *q = blkg->q;
int i;
/*
* pd_free_fn() can also be called from blkcg_deactivate_policy(),
* in order to make sure pd_free_fn() is called in order, the deletion
* of the list blkg->q_node is delayed to here from blkg_destroy(), and
* blkcg_mutex is used to synchronize blkg_free_workfn() and
* blkcg_deactivate_policy().
*/
if (q)
mutex_lock(&q->blkcg_mutex);
for (i = 0; i < BLKCG_MAX_POLS; i++)
if (blkg->pd[i])
blkcg_policy[i]->pd_free_fn(blkg->pd[i]);
if (blkg->parent)
blkg_put(blkg->parent);
if (q) {
list_del_init(&blkg->q_node);
mutex_unlock(&q->blkcg_mutex);
blk_put_queue(q);
}
if (blkg->q)
blk_put_queue(blkg->q);
free_percpu(blkg->iostat_cpu);
percpu_ref_exit(&blkg->refcnt);
kfree(blkg);
@ -441,14 +425,9 @@ static void blkg_destroy(struct blkcg_gq *blkg)
lockdep_assert_held(&blkg->q->queue_lock);
lockdep_assert_held(&blkcg->lock);
/*
* blkg stays on the queue list until blkg_free_workfn(), see details in
* blkg_free_workfn(), hence this function can be called from
* blkcg_destroy_blkgs() first and again from blkg_destroy_all() before
* blkg_free_workfn().
*/
if (hlist_unhashed(&blkg->blkcg_node))
return;
/* Something wrong if we are trying to remove same group twice */
WARN_ON_ONCE(list_empty(&blkg->q_node));
WARN_ON_ONCE(hlist_unhashed(&blkg->blkcg_node));
for (i = 0; i < BLKCG_MAX_POLS; i++) {
struct blkcg_policy *pol = blkcg_policy[i];
@ -460,6 +439,7 @@ static void blkg_destroy(struct blkcg_gq *blkg)
blkg->online = false;
radix_tree_delete(&blkcg->blkg_tree, blkg->q->id);
list_del_init(&blkg->q_node);
hlist_del_init_rcu(&blkg->blkcg_node);
/*
@ -1246,7 +1226,6 @@ int blkcg_init_disk(struct gendisk *disk)
int ret;
INIT_LIST_HEAD(&q->blkg_list);
mutex_init(&q->blkcg_mutex);
new_blkg = blkg_alloc(&blkcg_root, disk, GFP_KERNEL);
if (!new_blkg)
@ -1484,7 +1463,6 @@ void blkcg_deactivate_policy(struct request_queue *q,
if (queue_is_mq(q))
blk_mq_freeze_queue(q);
mutex_lock(&q->blkcg_mutex);
spin_lock_irq(&q->queue_lock);
__clear_bit(pol->plid, q->blkcg_pols);
@ -1503,7 +1481,6 @@ void blkcg_deactivate_policy(struct request_queue *q,
}
spin_unlock_irq(&q->queue_lock);
mutex_unlock(&q->blkcg_mutex);
if (queue_is_mq(q))
blk_mq_unfreeze_queue(q);

View File

@ -487,7 +487,6 @@ struct request_queue {
DECLARE_BITMAP (blkcg_pols, BLKCG_MAX_POLS);
struct blkcg_gq *root_blkg;
struct list_head blkg_list;
struct mutex blkcg_mutex;
#endif
struct queue_limits limits;