Re: [bug report] WARNING: CPU: 109 PID: 739473 at block/blk-stat.c:218 blk_free_queue_stats+0x3c/0x80

[Ming Lei <ming.lei@redhat.com>]

On Tue, Oct 19, 2021 at 12:13:22PM +0800, Yi Zhang wrote:
> Hello
> Below WARNING was triggered with blktests block/001 on ppc64le/aarch64
> during CKI tests, pls help check it, thanks.
> 
>   Kernel repo: https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git
>             Commit: b199567fe754 - Merge branch 'for-5.16/bdev-size'
> into for-next
> 

Hello Yi,

Can you try the following patch?


diff --git a/block/genhd.c b/block/genhd.c
index 80943c123c3e..45143af78d90 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -589,16 +589,6 @@ 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");
@@ -621,6 +611,18 @@ 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);
 


-- 
Ming