From 78c271344b6f64ce24c845e54903e09928cf2061 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Mon, 5 May 2025 22:18:03 +0800 Subject: block: move wbt_enable_default() out of queue freezing from sched ->exit() scheduler's ->exit() is called with queue frozen and elevator lock is held, and wbt_enable_default() can't be called with queue frozen, otherwise the following lockdep warning is triggered: #6 (&q->rq_qos_mutex){+.+.}-{4:4}: #5 (&eq->sysfs_lock){+.+.}-{4:4}: #4 (&q->elevator_lock){+.+.}-{4:4}: #3 (&q->q_usage_counter(io)#3){++++}-{0:0}: #2 (fs_reclaim){+.+.}-{0:0}: #1 (&sb->s_type->i_mutex_key#3){+.+.}-{4:4}: #0 (&q->debugfs_mutex){+.+.}-{4:4}: Fix the issue by moving wbt_enable_default() out of bfq's exit(), and call it from elevator_change_done(). Meantime add disk->rqos_state_mutex for covering wbt state change, which matches the purpose more than ->elevator_lock. Reviewed-by: Hannes Reinecke Reviewed-by: Nilay Shroff Signed-off-by: Ming Lei Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20250505141805.2751237-26-ming.lei@redhat.com Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 3aa1fd637d57..94323f303b37 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -218,6 +218,8 @@ struct gendisk { * devices that do not have multiple independent access ranges. */ struct blk_independent_access_ranges *ia_ranges; + + struct mutex rqos_state_mutex; /* rqos state change mutex */ }; /** -- cgit v1.2.3