Re: 2.6.19-rc3-git7: scsi_device_unbusy: inconsistent lock state

[Mark Lord <liml@rtr.ca>]

Jens Axboe wrote:
> I looked over them, and cfq_cic_link() should use _irqsave() instead of
> _irq() if called without __GFP_WAIT set. That doesn't happen in the
> normal io path though, so I'm not sure that is it.
> 
> So if the bug is using spin_lock_irq() with interrupts already disabled,
> iirc that would trigger a different warning...
..

This seems 100% reproduceable here, so if there's any specific instrumentation
that might be useful, just let me know.  Meanwhile I'll try Jen's patch (below).

-ml

> 
> diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
> index 4bae64e..da9bddf 100644
> --- a/block/cfq-iosched.c
> +++ b/block/cfq-iosched.c
> @@ -1355,6 +1355,7 @@ cfq_cic_link(struct cfq_data *cfqd, stru
>  	struct rb_node **p;
>  	struct rb_node *parent;
>  	struct cfq_io_context *__cic;
> +	unsigned long flags;
>  	void *k;
>  
>  	cic->ioc = ioc;
> @@ -1384,9 +1385,9 @@ restart:
>  	rb_link_node(&cic->rb_node, parent, p);
>  	rb_insert_color(&cic->rb_node, &ioc->cic_root);
>  
> -	spin_lock_irq(cfqd->queue->queue_lock);
> +	spin_lock_irqsave(cfqd->queue->queue_lock, flags);
>  	list_add(&cic->queue_list, &cfqd->cic_list);
> -	spin_unlock_irq(cfqd->queue->queue_lock);
> +	spin_unlock_irqrestore(cfqd->queue->queue_lock, flags);
>  }