Re: [PATCH V2 1/4] vmbus: don't acquire the mutex in vmbus_hvsock_device_unregister()

From: Greg KH
Date: Mon Sep 18 2017 - 10:00:18 EST


On Sun, Sep 17, 2017 at 08:54:16PM -0700, kys@xxxxxxxxxxxxxxxxxxxxxx wrote:
> From: Dexuan Cui <decui@xxxxxxxxxxxxx>
>
> Due to commit 54a66265d675 ("Drivers: hv: vmbus: Fix rescind handling"),
> we need this patch to resolve the below deadlock:
>
> after we get the mutex in vmbus_hvsock_device_unregister() and call
> vmbus_device_unregister() -> device_unregister() -> ... -> device_release()
> -> vmbus_device_release(), we'll get a deadlock, because
> vmbus_device_release() tries to get the same mutex.
>
> Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
> Cc: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
> Cc: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
> Cc: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>
> Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>

As every one of these patches had questions from me, please break them
up into different series, one for 4.14-final, and one for 4.15-rc1.

thanks,

greg k-h