hyperv: Fix the error processing in netvsc_send()

[ Upstream commit d953ca4ddf71aa91a4596b2ff7ff1598f6ad4708 ]

The existing code frees the skb in EAGAIN case, in which the skb will be
retried from upper layer and used again.
Also, the existing code doesn't free send buffer slot in error case, because
there is no completion message for unsent packets.
This patch fixes these problems.

(Please also include this patch for stable trees. Thanks!)

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 7d76c9523395e5b5137784189d902d9cb1ecaed5..63d7a642733d708287834f8885d4ba4cdcd3839e 100644 (file)
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -716,7 +716,7 @@ int netvsc_send(struct hv_device *device,
        u64 req_id;
        unsigned int section_index = NETVSC_INVALID_INDEX;
        u32 msg_size = 0;
-       struct sk_buff *skb;
+       struct sk_buff *skb = NULL;
        u16 q_idx = packet->q_idx;
 
 
@@ -743,8 +743,6 @@ int netvsc_send(struct hv_device *device,
                                                           packet);
                        skb = (struct sk_buff *)
                              (unsigned long)packet->send_completion_tid;
-                       if (skb)
-                               dev_kfree_skb_any(skb);
                        packet->page_buf_cnt = 0;
                }
        }
@@ -807,6 +805,13 @@ int netvsc_send(struct hv_device *device,
                           packet, ret);
        }
 
+       if (ret != 0) {
+               if (section_index != NETVSC_INVALID_INDEX)
+                       netvsc_free_send_slot(net_device, section_index);
+       } else if (skb) {
+               dev_kfree_skb_any(skb);
+       }
+
        return ret;
 }