netxen: limit skb frags for non tso packet

Machines are getting deadlock in four node cluster environment.
All nodes are accessing (find /gfs2 -depth -print|cpio -ocv > /dev/null)
200 GB storage on a GFS2 filesystem.
This result in memory fragmentation and driver receives 18 frags for
1448 byte packets.
For non tso packet, fw drops the tx request, if it has >14 frags.

Fixing it by pulling extra frags.

Cc: stable@kernel.org
Signed-off-by: Amit Kumar Salecha <amit.salecha@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 19 insertions, 2 deletions

diff --git a/drivers/net/netxen/netxen_nic.h b/drivers/net/netxen/netxen_nic.h
index d7299f1a4940..679dc8519c5b 100644
--- a/drivers/net/netxen/netxen_nic.h
+++ b/drivers/net/netxen/netxen_nic.h
@@ -174,7 +174,7 @@
 
 #define MAX_NUM_CARDS           4
 
-#define MAX_BUFFERS_PER_CMD     32
+#define NETXEN_MAX_FRAGS_PER_TX 14
 #define MAX_TSO_HEADER_DESC     2
 #define MGMT_CMD_DESC_RESV      4
 #define TX_STOP_THRESH          ((MAX_SKB_FRAGS >> 2) + MAX_TSO_HEADER_DESC \
@@ -558,7 +558,7 @@ struct netxen_recv_crb {
  */
 struct netxen_cmd_buffer {
         struct sk_buff *skb;
-        struct netxen_skb_frag frag_array[MAX_BUFFERS_PER_CMD + 1];
+        struct netxen_skb_frag frag_array[MAX_SKB_FRAGS + 1];
         u32 frag_count;
 };
 
diff --git a/drivers/net/netxen/netxen_nic_main.c b/drivers/net/netxen/netxen_nic_main.c
index 83348dc4b184..e8a4b6655999 100644
--- a/drivers/net/netxen/netxen_nic_main.c
+++ b/drivers/net/netxen/netxen_nic_main.c
@@ -1844,6 +1844,8 @@ netxen_nic_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
         struct cmd_desc_type0 *hwdesc, *first_desc;
         struct pci_dev *pdev;
         int i, k;
+        int delta = 0;
+        struct skb_frag_struct *frag;
 
         u32 producer;
         int frag_count, no_of_desc;
@@ -1851,6 +1853,21 @@ netxen_nic_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
 
         frag_count = skb_shinfo(skb)->nr_frags + 1;
 
+        /* 14 frags supported for normal packet and
+         * 32 frags supported for TSO packet
+         */
+        if (!skb_is_gso(skb) && frag_count > NETXEN_MAX_FRAGS_PER_TX) {
+
+                for (i = 0; i < (frag_count - NETXEN_MAX_FRAGS_PER_TX); i++) {
+                        frag = &skb_shinfo(skb)->frags[i];
+                        delta += frag->size;
+                }
+
+                if (!__pskb_pull_tail(skb, delta))
+                        goto drop_packet;
+
+                frag_count = 1 + skb_shinfo(skb)->nr_frags;
+        }
         /* 4 fragments per cmd des */
         no_of_desc = (frag_count + 3) >> 2;