ice: Fix error with handling of bonding MTU

When a bonded interface is destroyed, .ndo_change_mtu can be called
during the tear-down process while the RTNL lock is held.  This is a
problem since the auxiliary driver linked to the LAN driver needs to be
notified of the MTU change, and this requires grabbing a device_lock on
the auxiliary_device's dev.  Currently this is being attempted in the
same execution context as the call to .ndo_change_mtu which is causing a
dead-lock.

Move the notification of the changed MTU to a separate execution context
(watchdog service task) and eliminate the "before" notification.

Fixes: 348048e724a0e ("ice: Implement iidc operations")
Signed-off-by: Dave Ertman <david.m.ertman@intel.com>
Tested-by: Jonathan Toppins <jtoppins@redhat.com>
Tested-by: Gurucharan G <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

diff --git a/drivers/net/ethernet/intel/ice/ice.h b/drivers/net/ethernet/intel/ice/ice.h
index 473b1f6..3121f9b 100644 (file)
--- a/drivers/net/ethernet/intel/ice/ice.h
+++ b/drivers/net/ethernet/intel/ice/ice.h
@@ -483,6 +483,7 @@ enum ice_pf_flags {
        ICE_FLAG_MDD_AUTO_RESET_VF,
        ICE_FLAG_LINK_LENIENT_MODE_ENA,
        ICE_FLAG_PLUG_AUX_DEV,
+       ICE_FLAG_MTU_CHANGED,
        ICE_PF_FLAGS_NBITS              /* must be last */
 };
 

diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
index f3c346e..6fc6514 100644 (file)
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -2258,6 +2258,17 @@ static void ice_service_task(struct work_struct *work)
        if (test_and_clear_bit(ICE_FLAG_PLUG_AUX_DEV, pf->flags))
                ice_plug_aux_dev(pf);
 
+       if (test_and_clear_bit(ICE_FLAG_MTU_CHANGED, pf->flags)) {
+               struct iidc_event *event;
+
+               event = kzalloc(sizeof(*event), GFP_KERNEL);
+               if (event) {
+                       set_bit(IIDC_EVENT_AFTER_MTU_CHANGE, event->type);
+                       ice_send_event_to_aux(pf, event);
+                       kfree(event);
+               }
+       }
+
        ice_clean_adminq_subtask(pf);
        ice_check_media_subtask(pf);
        ice_check_for_hang_subtask(pf);
@@ -6822,7 +6833,6 @@ static int ice_change_mtu(struct net_device *netdev, int new_mtu)
        struct ice_netdev_priv *np = netdev_priv(netdev);
        struct ice_vsi *vsi = np->vsi;
        struct ice_pf *pf = vsi->back;
-       struct iidc_event *event;
        u8 count = 0;
        int err = 0;
 
@@ -6857,14 +6867,6 @@ static int ice_change_mtu(struct net_device *netdev, int new_mtu)
                return -EBUSY;
        }
 
-       event = kzalloc(sizeof(*event), GFP_KERNEL);
-       if (!event)
-               return -ENOMEM;
-
-       set_bit(IIDC_EVENT_BEFORE_MTU_CHANGE, event->type);
-       ice_send_event_to_aux(pf, event);
-       clear_bit(IIDC_EVENT_BEFORE_MTU_CHANGE, event->type);
-
        netdev->mtu = (unsigned int)new_mtu;
 
        /* if VSI is up, bring it down and then back up */
@@ -6872,21 +6874,18 @@ static int ice_change_mtu(struct net_device *netdev, int new_mtu)
                err = ice_down(vsi);
                if (err) {
                        netdev_err(netdev, "change MTU if_down err %d\n", err);
-                       goto event_after;
+                       return err;
                }
 
                err = ice_up(vsi);
                if (err) {
                        netdev_err(netdev, "change MTU if_up err %d\n", err);
-                       goto event_after;
+                       return err;
                }
        }
 
        netdev_dbg(netdev, "changed MTU to %d\n", new_mtu);
-event_after:
-       set_bit(IIDC_EVENT_AFTER_MTU_CHANGE, event->type);
-       ice_send_event_to_aux(pf, event);
-       kfree(event);
+       set_bit(ICE_FLAG_MTU_CHANGED, pf->flags);
 
        return err;
 }