ixgbe: fix ring reallocation in ethtool

changing ring sizes in ethtool needs to be robust.  If an allocation fails the
driver must continue operation, with the previous settings.

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 47 insertions, 48 deletions

diff --git a/drivers/net/ixgbe/ixgbe_ethtool.c b/drivers/net/ixgbe/ixgbe_ethtool.c
index f18e3daaf4f5..928b97cc1700 100644
--- a/drivers/net/ixgbe/ixgbe_ethtool.c
+++ b/drivers/net/ixgbe/ixgbe_ethtool.c
@@ -654,12 +654,9 @@ static int ixgbe_set_ringparam(struct net_device *netdev,
 			       struct ethtool_ringparam *ring)
 {
 	struct ixgbe_adapter *adapter = netdev_priv(netdev);
-	struct ixgbe_tx_buffer *old_buf;
-	struct ixgbe_rx_buffer *old_rx_buf;
-	void *old_desc;
+	struct ixgbe_ring *temp_ring;
 	int i, err;
-	u32 new_rx_count, new_tx_count, old_size;
-	dma_addr_t old_dma;
+	u32 new_rx_count, new_tx_count;
 
 	if ((ring->rx_mini_pending) || (ring->rx_jumbo_pending))
 		return -EINVAL;
@@ -678,6 +675,15 @@ static int ixgbe_set_ringparam(struct net_device *netdev,
 		return 0;
 	}
 
+	if (adapter->num_tx_queues > adapter->num_rx_queues)
+		temp_ring = vmalloc(adapter->num_tx_queues *
+		                    sizeof(struct ixgbe_ring));
+	else
+		temp_ring = vmalloc(adapter->num_rx_queues *
+		                    sizeof(struct ixgbe_ring));
+	if (!temp_ring)
+		return -ENOMEM;
+
 	while (test_and_set_bit(__IXGBE_RESETTING, &adapter->state))
 		msleep(1);
 
@@ -690,66 +696,59 @@ static int ixgbe_set_ringparam(struct net_device *netdev,
 	 * to the tx and rx ring structs.
 	 */
 	if (new_tx_count != adapter->tx_ring->count) {
+		memcpy(temp_ring, adapter->tx_ring,
+		       adapter->num_tx_queues * sizeof(struct ixgbe_ring));
+
 		for (i = 0; i < adapter->num_tx_queues; i++) {
-			/* Save existing descriptor ring */
-			old_buf = adapter->tx_ring[i].tx_buffer_info;
-			old_desc = adapter->tx_ring[i].desc;
-			old_size = adapter->tx_ring[i].size;
-			old_dma = adapter->tx_ring[i].dma;
-			/* Try to allocate a new one */
-			adapter->tx_ring[i].tx_buffer_info = NULL;
-			adapter->tx_ring[i].desc = NULL;
-			adapter->tx_ring[i].count = new_tx_count;
-			err = ixgbe_setup_tx_resources(adapter,
-						       &adapter->tx_ring[i]);
+			temp_ring[i].count = new_tx_count;
+			err = ixgbe_setup_tx_resources(adapter, &temp_ring[i]);
 			if (err) {
-				/* Restore the old one so at least
-				   the adapter still works, even if
-				   we failed the request */
-				adapter->tx_ring[i].tx_buffer_info = old_buf;
-				adapter->tx_ring[i].desc = old_desc;
-				adapter->tx_ring[i].size = old_size;
-				adapter->tx_ring[i].dma = old_dma;
+				while (i) {
+					i--;
+					ixgbe_free_tx_resources(adapter, &temp_ring[i]);
+				}
 				goto err_setup;
 			}
-			/* Free the old buffer manually */
-			vfree(old_buf);
-			pci_free_consistent(adapter->pdev, old_size,
-					    old_desc, old_dma);
 		}
+
+		for (i = 0; i < adapter->num_tx_queues; i++)
+			ixgbe_free_tx_resources(adapter, &adapter->tx_ring[i]);
+
+		memcpy(adapter->tx_ring, temp_ring,
+		       adapter->num_tx_queues * sizeof(struct ixgbe_ring));
+
+		adapter->tx_ring_count = new_tx_count;
 	}
 
 	if (new_rx_count != adapter->rx_ring->count) {
-		for (i = 0; i < adapter->num_rx_queues; i++) {
+		memcpy(temp_ring, adapter->rx_ring,
+		       adapter->num_rx_queues * sizeof(struct ixgbe_ring));
 
-			old_rx_buf = adapter->rx_ring[i].rx_buffer_info;
-			old_desc = adapter->rx_ring[i].desc;
-			old_size = adapter->rx_ring[i].size;
-			old_dma = adapter->rx_ring[i].dma;
-
-			adapter->rx_ring[i].rx_buffer_info = NULL;
-			adapter->rx_ring[i].desc = NULL;
-			adapter->rx_ring[i].dma = 0;
-			adapter->rx_ring[i].count = new_rx_count;
-			err = ixgbe_setup_rx_resources(adapter,
-						       &adapter->rx_ring[i]);
+		for (i = 0; i < adapter->num_rx_queues; i++) {
+			temp_ring[i].count = new_rx_count;
+			err = ixgbe_setup_rx_resources(adapter, &temp_ring[i]);
 			if (err) {
-				adapter->rx_ring[i].rx_buffer_info = old_rx_buf;
-				adapter->rx_ring[i].desc = old_desc;
-				adapter->rx_ring[i].size = old_size;
-				adapter->rx_ring[i].dma = old_dma;
+				while (i) {
+					i--;
+					ixgbe_free_rx_resources(adapter, &temp_ring[i]);
+				}
 				goto err_setup;
 			}
-
-			vfree(old_rx_buf);
-			pci_free_consistent(adapter->pdev, old_size, old_desc,
-					    old_dma);
 		}
+
+		for (i = 0; i < adapter->num_rx_queues; i++)
+			ixgbe_free_rx_resources(adapter, &adapter->rx_ring[i]);
+
+		memcpy(adapter->rx_ring, temp_ring,
+		       adapter->num_rx_queues * sizeof(struct ixgbe_ring));
+
+		adapter->rx_ring_count = new_rx_count;
 	}
 
+	/* success! */
 	err = 0;
 err_setup:
-	if (netif_running(adapter->netdev))
+	if (netif_running(netdev))
 		ixgbe_up(adapter);
 
 	clear_bit(__IXGBE_RESETTING, &adapter->state);