Re: [PATCH] driver core: fix shutdown races with probe/remove(v2)

[Alan Stern]

On Mon, 11 Jun 2012, Ming Lei wrote:

> @@ -1820,6 +1833,18 @@ void device_shutdown(void)
>  		list_del_init(&dev->kobj.entry);
>  		spin_unlock(&devices_kset->list_lock);
>  
> +		/* hold lock to avoid race with .probe/.release */
> +		if (dev->parent && !__try_lock(dev->parent))
> +			nonlocked = 2;
> +		else if (!__try_lock(dev))
> +			nonlocked = 1;
> +		else
> +			nonlocked = 0;
> +
> +		if (nonlocked)
> +			dev_err(dev, "can't hold %slock for shutdown\n",
> +					nonlocked == 1 ? "" : "parent ");

Even if the parent can't be locked, you should still try to lock the 
device.

Alan Stern

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