From d308ae0d299a6bb15be4efb91849582d19c23213 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Tue, 26 Oct 2021 18:12:04 +0800 Subject: block: drain queue after disk is removed from sysfs Before removing disk from sysfs, userspace still may change queue via sysfs, such as switching elevator or setting wbt latency, both may reinitialize wbt, then the warning in blk_free_queue_stats() will be triggered since rq_qos_exit() is moved to del_gendisk(). Fixes the issue by moving draining queue & tearing down after disk is removed from sysfs, at that time no one can come into queue's store()/show(). Reported-by: Yi Zhang Tested-by: Yi Zhang Fixes: 8e141f9eb803 ("block: drain file system I/O on del_gendisk") Signed-off-by: Ming Lei Link: https://lore.kernel.org/r/20211026101204.2897166-1-ming.lei@redhat.com Signed-off-by: Jens Axboe --- block/genhd.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) (limited to 'block') diff --git a/block/genhd.c b/block/genhd.c index b49858550fa6..ab12ae6e636e 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -588,16 +588,6 @@ void del_gendisk(struct gendisk *disk) * Prevent new I/O from crossing bio_queue_enter(). */ blk_queue_start_drain(q); - blk_mq_freeze_queue_wait(q); - - rq_qos_exit(q); - blk_sync_queue(q); - blk_flush_integrity(); - /* - * Allow using passthrough request again after the queue is torn down. - */ - blk_queue_flag_clear(QUEUE_FLAG_INIT_DONE, q); - __blk_mq_unfreeze_queue(q, true); if (!(disk->flags & GENHD_FL_HIDDEN)) { sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi"); @@ -620,6 +610,18 @@ void del_gendisk(struct gendisk *disk) sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk))); pm_runtime_set_memalloc_noio(disk_to_dev(disk), false); device_del(disk_to_dev(disk)); + + blk_mq_freeze_queue_wait(q); + + rq_qos_exit(q); + blk_sync_queue(q); + blk_flush_integrity(); + /* + * Allow using passthrough request again after the queue is torn down. + */ + blk_queue_flag_clear(QUEUE_FLAG_INIT_DONE, q); + __blk_mq_unfreeze_queue(q, true); + } EXPORT_SYMBOL(del_gendisk); -- cgit v1.2.3