Re: [PATCH] Release device_hotplug_lock when store_mem_state returns EINVAL

Greg KH
2013-10-11T15:54:57Z

On Fri, Oct 11, 2013 at 03:36:25PM +0900, Yasuaki Ishimatsu wrote:
> When inserting a wrong value to /sys/devices/system/memory/memoryX/state file,
> following messages are shown. And device_hotplug_lock is never released.
>
> ================================================
> [ BUG: lock held when returning to user space! ]
> 3.12.0-rc4-debug+ #3 Tainted: G W
> ------------------------------------------------
> bash/6442 is leaving the kernel with locks still held!
> 1 lock held by bash/6442:
> #0: (device_hotplug_lock){+.+.+.}, at: [<ffffffff8146cbb5>] lock_device_hotplug_sysfs+0x15/0x50
>
> This issue was introdued by commit fa2be40 (drivers: base: use standard
> device online/offline for state change).
>
> This patch releases device_hotplug_lcok when store_mem_state returns EINVAL.
>
> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
> CC: Toshi Kani <toshi.kani@hp.com>
> CC: Seth Jennings <sjenning@linux.vnet.ibm.com>
> CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Is this needed in 3.12-final, and possibly older kernel releases as well
(3.10, 3.11, etc.)? Or is it ok for 3.13?

thanks,

greg k-h