RDMA/be2net: Remove open and close entry points

Devesh Sharma · dledford · commit f41647ef0653 · 2015-12-28T11:45:55.000-05:00
Recently Dough Ledford reported a deadlock happening
between ocrdma-load sequence and NetworkManager service
issueing "open" on be2net interface.

The deadlock happens when any be2net hook (e.g. open/close) is called
in parallel to insmod ocrdma.ko.

A. be2net is sending administrative open/close event to ocrdma holding
   device_list_mutex. It does this from ndo_open/ndo_stop hooks of be2net.
   So sequence of locks is rtnl_lock---&gt; device_list lock

B.  When new ocrdma roce device gets registered, infiniband stack now
    takes rtnl_lock in ib_register_device() in GID initialization routines.
    So sequence of locks in this path is device_list lock ---&gt; rtnl_lock.

This improper locking sequence causes deadlock.

In order to resolve the above deadlock condition, ocrdma intorduced a
patch to stop listening to administrative open/close events generated from
be2net driver. It now depends on link-state-change async-event generated from
CNA. This change leaves behind dead code which used to generate administrative
open/close events. This patch cleans-up all that dead code from be2net.

Reported-by: Doug Ledford &lt;dledford@redhat.com&gt;
CC: Sathya Perla &lt;sathya.perla@avagotech.com&gt;
Signed-off-by: Padmanabh Ratnakar &lt;padmanabh.ratnakar@avagotech.com&gt;
Signed-off-by: Selvin Xavier &lt;selvin.xavier@avagotech.com&gt;
Signed-off-by: Devesh Sharma &lt;devesh.sharma@avagotech.com&gt;
Signed-off-by: Doug Ledford &lt;dledford@redhat.com&gt;
diff --git a/drivers/net/ethernet/emulex/benet/be.h b/drivers/net/ethernet/emulex/benet/be.h
@@ -848,8 +848,6 @@ void be_roce_dev_remove(struct be_adapter *);
 /*
  * internal function to open-close roce device during ifup-ifdown.
  */
-void be_roce_dev_open(struct be_adapter *);
-void be_roce_dev_close(struct be_adapter *);
 void be_roce_dev_shutdown(struct be_adapter *);
 
 #endif				/* BE_H */
diff --git a/drivers/net/ethernet/emulex/benet/be_main.c b/drivers/net/ethernet/emulex/benet/be_main.c
@@ -3432,8 +3432,6 @@ static int be_close(struct net_device *netdev)
 
 	be_disable_if_filters(adapter);
 
-	be_roce_dev_close(adapter);
-
 	if (adapter->flags & BE_FLAGS_NAPI_ENABLED) {
 		for_all_evt_queues(adapter, eqo, i) {
 			napi_disable(&eqo->napi);
@@ -3601,8 +3599,6 @@ static int be_open(struct net_device *netdev)
 		be_link_status_update(adapter, link_status);
 
 	netif_tx_start_all_queues(netdev);
-	be_roce_dev_open(adapter);
-
 #ifdef CONFIG_BE2NET_VXLAN
 	if (skyhawk_chip(adapter))
 		vxlan_get_rx_port(netdev);
diff --git a/drivers/net/ethernet/emulex/benet/be_roce.c b/drivers/net/ethernet/emulex/benet/be_roce.c
@@ -116,40 +116,6 @@ void be_roce_dev_remove(struct be_adapter *adapter)
 	}
 }
 
-static void _be_roce_dev_open(struct be_adapter *adapter)
-{
-	if (ocrdma_drv && adapter->ocrdma_dev &&
-	    ocrdma_drv->state_change_handler)
-		ocrdma_drv->state_change_handler(adapter->ocrdma_dev,
-						 BE_DEV_UP);
-}
-
-void be_roce_dev_open(struct be_adapter *adapter)
-{
-	if (be_roce_supported(adapter)) {
-		mutex_lock(&be_adapter_list_lock);
-		_be_roce_dev_open(adapter);
-		mutex_unlock(&be_adapter_list_lock);
-	}
-}
-
-static void _be_roce_dev_close(struct be_adapter *adapter)
-{
-	if (ocrdma_drv && adapter->ocrdma_dev &&
-	    ocrdma_drv->state_change_handler)
-		ocrdma_drv->state_change_handler(adapter->ocrdma_dev,
-						 BE_DEV_DOWN);
-}
-
-void be_roce_dev_close(struct be_adapter *adapter)
-{
-	if (be_roce_supported(adapter)) {
-		mutex_lock(&be_adapter_list_lock);
-		_be_roce_dev_close(adapter);
-		mutex_unlock(&be_adapter_list_lock);
-	}
-}
-
 void be_roce_dev_shutdown(struct be_adapter *adapter)
 {
 	if (be_roce_supported(adapter)) {
@@ -177,8 +143,6 @@ int be_roce_register_driver(struct ocrdma_driver *drv)
 
 		_be_roce_dev_add(dev);
 		netdev = dev->netdev;
-		if (netif_running(netdev) && netif_oper_up(netdev))
-			_be_roce_dev_open(dev);
 	}
 	mutex_unlock(&be_adapter_list_lock);
 	return 0;
diff --git a/drivers/net/ethernet/emulex/benet/be_roce.h b/drivers/net/ethernet/emulex/benet/be_roce.h
@@ -60,9 +60,7 @@ struct ocrdma_driver {
 	void (*state_change_handler) (struct ocrdma_dev *, u32 new_state);
 };
 
-enum {
-	BE_DEV_UP	= 0,
-	BE_DEV_DOWN	= 1,
+enum be_roce_event {
 	BE_DEV_SHUTDOWN = 2
 };
 
