4.13-stable review patch. If anyone has any objections, please let me know.
------------------ From: Dexuan Cui <[email protected]> commit 33c150c2ee4a65a59190a124b45d05b1abf9478e upstream. 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 <[email protected]> Cc: K. Y. Srinivasan <[email protected]> Cc: Haiyang Zhang <[email protected]> Cc: Stephen Hemminger <[email protected]> Signed-off-by: K. Y. Srinivasan <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/hv/channel_mgmt.c | 4 ---- 1 file changed, 4 deletions(-) --- a/drivers/hv/channel_mgmt.c +++ b/drivers/hv/channel_mgmt.c @@ -922,14 +922,10 @@ static void vmbus_onoffer_rescind(struct void vmbus_hvsock_device_unregister(struct vmbus_channel *channel) { - mutex_lock(&vmbus_connection.channel_mutex); - BUG_ON(!is_hvsock_channel(channel)); channel->rescind = true; vmbus_device_unregister(channel->device_obj); - - mutex_unlock(&vmbus_connection.channel_mutex); } EXPORT_SYMBOL_GPL(vmbus_hvsock_device_unregister);
