sfc: Fix synchronisation of efx_mtd_{probe,rename,remove}

Currently efx_mtd_rename() can race with the probe() and remove()
functions.

Move probe() before device registration and remove() after
unregistration.  Move initialisation/update of all names based on the
netdev name into a new function and call it under the RTNL immediately
after registration.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 18 insertions, 15 deletions

diff --git a/drivers/net/sfc/efx.c b/drivers/net/sfc/efx.c
index 8f832bf1e4d2..086629c0fe57 100644
--- a/drivers/net/sfc/efx.c
+++ b/drivers/net/sfc/efx.c
@@ -1517,18 +1517,21 @@ static const struct net_device_ops efx_netdev_ops = {
 #endif
 };
 
+static void efx_update_name(struct efx_nic *efx)
+{
+        strcpy(efx->name, efx->net_dev->name);
+        efx_mtd_rename(efx);
+        efx_set_channel_names(efx);
+}
+
 static int efx_netdev_event(struct notifier_block *this,
                             unsigned long event, void *ptr)
 {
         struct net_device *net_dev = ptr;
 
-        if (net_dev->netdev_ops == &efx_netdev_ops && event == NETDEV_CHANGENAME) {
-                struct efx_nic *efx = netdev_priv(net_dev);
-
-                strcpy(efx->name, net_dev->name);
-                efx_mtd_rename(efx);
-                efx_set_channel_names(efx);
-        }
+        if (net_dev->netdev_ops == &efx_netdev_ops &&
+            event == NETDEV_CHANGENAME)
+                efx_update_name(netdev_priv(net_dev));
 
         return NOTIFY_DONE;
 }
@@ -1568,8 +1571,10 @@ static int efx_register_netdev(struct efx_nic *efx)
                 EFX_ERR(efx, "could not register net dev\n");
                 return rc;
         }
-        strcpy(efx->name, net_dev->name);
-        efx_set_channel_names(efx);
+
+        rtnl_lock();
+        efx_update_name(efx);
+        rtnl_unlock();
 
         rc = device_create_file(&efx->pci_dev->dev, &dev_attr_phy_type);
         if (rc) {
@@ -1978,8 +1983,6 @@ static void efx_pci_remove(struct pci_dev *pci_dev)
         if (!efx)
                 return;
 
-        efx_mtd_remove(efx);
-
         /* Mark the NIC as fini, then stop the interface */
         rtnl_lock();
         efx->state = STATE_FINI;
@@ -1993,6 +1996,8 @@ static void efx_pci_remove(struct pci_dev *pci_dev)
 
         efx_unregister_netdev(efx);
 
+        efx_mtd_remove(efx);
+
         /* Wait for any scheduled resets to complete. No more will be
          * scheduled from this point because efx_stop_all() has been
          * called, we are no longer registered with driverlink, and
@@ -2146,17 +2151,15 @@ static int __devinit efx_pci_probe(struct pci_dev *pci_dev,
         /* Switch to the running state before we expose the device to
          * the OS.  This is to ensure that the initial gathering of
          * MAC stats succeeds. */
-        rtnl_lock();
         efx->state = STATE_RUNNING;
-        rtnl_unlock();
+
+        efx_mtd_probe(efx); /* allowed to fail */
 
         rc = efx_register_netdev(efx);
         if (rc)
                 goto fail5;
 
         EFX_LOG(efx, "initialisation successful\n");
-
-        efx_mtd_probe(efx); /* allowed to fail */
         return 0;
 
  fail5: