Re: [PATCH] call_usermodehelper hang

[Chris Wright]

* Brian King (brking@xxxxxxxxxx) wrote:
> The following patch fixes a deadlock experienced when devices are
> being added to a bus both from a user process and eventd process.
> The eventd process was hung waiting on dev->bus->subsys.rwsem which
> was held by another process, which was hung since it was calling 
> call_usermodehelper directly which was hung waiting for work scheduled
> on the eventd workqueue to complete. The patch fixes this by delaying
> the kobject_hotplug work, running it from eventd if possible. 

Couple of gratuitous formatting changes.

> -	   failure, no hotplug event is required. */
> +	 failure, no hotplug event is required. */

here

> -				  &envp[i], NUM_ENVP - i, scratch,
> -				  BUFFER_SIZE - (scratch - buffer));
> +						     &envp[i], NUM_ENVP - i, scratch,
> +						     BUFFER_SIZE - (scratch - buffer));

and here.

Overall, why does it seem to just be pushing the problem around?
Similarly, if you did your work in a child of keventd the problem would
move away.

thanks,
-chris
-- 
Linux Security Modules     http://lsm.immunix.org     http://lsm.bkbits.net
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/