Re: blk_mq_register_disk: kobject (00000000009f2dd8): tried to init an initialized object, something is seriously wrong.

[Ming Lei]

On Mon, Sep 21, 2015 at 7:43 PM, Meelis Roos <mroos@xxxxxxxx> wrote:
>
>
> Yes, sorry - I applied the last chunk by hand because it was mangled by
> the web UI, and added ti to a wrong struct.
>
> Now I tested it on top of 4.3.0-rc1. COmpiles, rebooted fine 6 times,
> but now it hangs again, seems to be the same message:
>
> [  107.143910] kobject (00000000009f2dd8): tried to init an initialized object, something is seriously wrong.

Looks a bit odd since blk_mq_register_disk is run only once per device,
could you apply the attached debug patch and post the boot log when the
warning is triggered?

Thanks,
diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c
index 279c5d6..d09c511 100644
--- a/block/blk-mq-sysfs.c
+++ b/block/blk-mq-sysfs.c
@@ -403,13 +403,20 @@ static void blk_mq_sysfs_init(struct request_queue *q)
 	struct blk_mq_ctx *ctx;
 	int i;
 
+	printk("%s: init mq_kobj %p\n", __func__, &q->mq_kobj);
 	kobject_init(&q->mq_kobj, &blk_mq_ktype);
 
-	queue_for_each_hw_ctx(q, hctx, i)
+	queue_for_each_hw_ctx(q, hctx, i) {
+		printk("%s: init hctx_kobj %p %d\n", __func__,
+				&hctx->kobj, i);
 		kobject_init(&hctx->kobj, &blk_mq_hw_ktype);
+	}
 
-	queue_for_each_ctx(q, ctx, i)
+	queue_for_each_ctx(q, ctx, i) {
+		printk("%s: init ctx_kobj %p %d\n", __func__,
+				&ctx->kobj, i);
 		kobject_init(&ctx->kobj, &blk_mq_ctx_ktype);
+	}
 }
 
 /* see blk_register_queue() */