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>
Cc: stable@xxxxxxxxxxxxxxx (4.13 and above)
---
drivers/hv/channel_mgmt.c | 4 ----
1 file changed, 4 deletions(-)
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 968af173c4c1..624d815745e4 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -945,14 +945,10 @@ static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr)
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);
--
2.14.1