Merge branch 'xen-netfront'

David Vrabel says:

====================
xen-netfront: more multiqueue fixes

A few more xen-netfront fixes for the multiqueue support added in
3.16-rc1.  It would be great if these could make it into 3.16 but I
suspect it's a little late for that now.

The second patch fixes a significant resource leak that prevents
guests from migrating more than a handful of times.

These have been tested by repeatedly migrating a guest over 250 times
(it would previously fail with this guest after only 8 iterations).
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 10 insertions, 64 deletions

diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index 055222bae6e4..28204bc4f369 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -1196,22 +1196,6 @@ static void xennet_release_rx_bufs(struct netfront_queue *queue)
         spin_unlock_bh(&queue->rx_lock);
 }
 
-static void xennet_uninit(struct net_device *dev)
-{
-        struct netfront_info *np = netdev_priv(dev);
-        unsigned int num_queues = dev->real_num_tx_queues;
-        struct netfront_queue *queue;
-        unsigned int i;
-
-        for (i = 0; i < num_queues; ++i) {
-                queue = &np->queues[i];
-                xennet_release_tx_bufs(queue);
-                xennet_release_rx_bufs(queue);
-                gnttab_free_grant_references(queue->gref_tx_head);
-                gnttab_free_grant_references(queue->gref_rx_head);
-        }
-}
-
 static netdev_features_t xennet_fix_features(struct net_device *dev,
         netdev_features_t features)
 {
@@ -1313,7 +1297,6 @@ static void xennet_poll_controller(struct net_device *dev)
 
 static const struct net_device_ops xennet_netdev_ops = {
         .ndo_open            = xennet_open,
-        .ndo_uninit          = xennet_uninit,
         .ndo_stop            = xennet_close,
         .ndo_start_xmit      = xennet_start_xmit,
         .ndo_change_mtu      = xennet_change_mtu,
@@ -1455,6 +1438,11 @@ static void xennet_disconnect_backend(struct netfront_info *info)
 
                 napi_synchronize(&queue->napi);
 
+                xennet_release_tx_bufs(queue);
+                xennet_release_rx_bufs(queue);
+                gnttab_free_grant_references(queue->gref_tx_head);
+                gnttab_free_grant_references(queue->gref_rx_head);
+
                 /* End access and free the pages */
                 xennet_end_access(queue->tx_ring_ref, queue->tx.sring);
                 xennet_end_access(queue->rx_ring_ref, queue->rx.sring);
@@ -1827,8 +1815,8 @@ static int xennet_create_queues(struct netfront_info *info,
 
                 ret = xennet_init_queue(queue);
                 if (ret < 0) {
-                        dev_warn(&info->netdev->dev, "only created %d queues\n",
-                                 num_queues);
+                        dev_warn(&info->netdev->dev,
+                                 "only created %d queues\n", i);
                         num_queues = i;
                         break;
                 }
@@ -2001,7 +1989,7 @@ abort_transaction_no_dev_fatal:
         info->queues = NULL;
         rtnl_lock();
         netif_set_real_num_tx_queues(info->netdev, 0);
-        rtnl_lock();
+        rtnl_unlock();
  out:
         return err;
 }
@@ -2010,10 +1998,7 @@ static int xennet_connect(struct net_device *dev)
 {
         struct netfront_info *np = netdev_priv(dev);
         unsigned int num_queues = 0;
-        int i, requeue_idx, err;
-        struct sk_buff *skb;
-        grant_ref_t ref;
-        struct xen_netif_rx_request *req;
+        int err;
         unsigned int feature_rx_copy;
         unsigned int j = 0;
         struct netfront_queue *queue = NULL;
@@ -2040,47 +2025,8 @@ static int xennet_connect(struct net_device *dev)
         netdev_update_features(dev);
         rtnl_unlock();
 
-        /* By now, the queue structures have been set up */
-        for (j = 0; j < num_queues; ++j) {
-                queue = &np->queues[j];
-
-                /* Step 1: Discard all pending TX packet fragments. */
-                spin_lock_irq(&queue->tx_lock);
-                xennet_release_tx_bufs(queue);
-                spin_unlock_irq(&queue->tx_lock);
-
-                /* Step 2: Rebuild the RX buffer freelist and the RX ring itself. */
-                spin_lock_bh(&queue->rx_lock);
-
-                for (requeue_idx = 0, i = 0; i < NET_RX_RING_SIZE; i++) {
-                        skb_frag_t *frag;
-                        const struct page *page;
-                        if (!queue->rx_skbs[i])
-                                continue;
-
-                        skb = queue->rx_skbs[requeue_idx] = xennet_get_rx_skb(queue, i);
-                        ref = queue->grant_rx_ref[requeue_idx] = xennet_get_rx_ref(queue, i);
-                        req = RING_GET_REQUEST(&queue->rx, requeue_idx);
-
-                        frag = &skb_shinfo(skb)->frags[0];
-                        page = skb_frag_page(frag);
-                        gnttab_grant_foreign_access_ref(
-                                ref, queue->info->xbdev->otherend_id,
-                                pfn_to_mfn(page_to_pfn(page)),
-                                0);
-                        req->gref = ref;
-                        req->id   = requeue_idx;
-
-                        requeue_idx++;
-                }
-
-                queue->rx.req_prod_pvt = requeue_idx;
-
-                spin_unlock_bh(&queue->rx_lock);
-        }
-
         /*
-         * Step 3: All public and private state should now be sane.  Get
+         * All public and private state should now be sane.  Get
          * ready to start sending and receiving packets and give the driver
          * domain a kick because we've probably just requeued some
          * packets.