From c968bdf6912cad6d0fc63d7037cc1c870604a808 Mon Sep 17 00:00:00 2001
From: amit salecha <amit.salecha@qlogic.com>
Date: Mon, 11 Apr 2011 02:10:22 +0000
Subject: 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>
---
 drivers/net/netxen/netxen_nic_main.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

(limited to 'drivers/net/netxen/netxen_nic_main.c')

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;
 
-- 
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