From: Phillip Lougher <plougher@redhat.com>
Date: Thu, 05 May 2011 16:07:20 -0000
Subject: [net] netxen: limit skb frags for non tso packet
Message-id: <20110505160720.5374A44A53@plougher.csb>
Patchwork-id: 35819
O-Subject: [RHEL5.6.z PATCH] BZ#699609 netxen: limit skb frags for non tso
	packet 
Bugzilla: 699609
RH-Acked-by: Jiri Pirko <jpirko@redhat.com>
RH-Acked-by: David S. Miller <davem@redhat.com>
RH-Acked-by: Stefan Assmann <sassmann@redhat.com>

BZ#699609

This is a trivial fix-up of the following patch to allow it to be
applied to 5.6.z.

Thanks

Phillip

>From 5a5586b79bee9aa909c92d8091c9f7cb090f1912 Mon Sep 17 00:00:00 2001
From: Chad Dupuis <cdupuis@redhat.com>
Date: Tue, 19 Apr 2011 18:50:11 +0000
Subject: [PATCH] netxen: limit skb frags for non tso packet

Bugzilla
--------

Bug 672368 (https://bugzilla.redhat.com/show_bug.cgi?id=672368)

Upstream Status
---------------

net-2.6 commit id c968bdf6912cad6d0fc63d7037cc1c870604a808

Brew Build
----------

3266338

Testing
-------

This patch was test built against the 2.6.18-257.el5 kernel.  The patch was
functionally tested at QLogic.

Description
-----------

>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: [PATCH] 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>
Acked-by: Bob Picco <bpicco@redhat.com>
Acked-by: John Feeney <jfeeney@redhat.com>
Acked-by: Jiri Pirko <jpirko@redhat.com>
---
 drivers/net/netxen/netxen_nic.h      |    4 ++--
 drivers/net/netxen/netxen_nic_main.c |   17 +++++++++++++++++
 2 files changed, 19 insertions(+), 2 deletions(-)
diff --git a/drivers/net/netxen/netxen_nic.h b/drivers/net/netxen/netxen_nic.h
index f93b706..8346632 100644
--- a/drivers/net/netxen/netxen_nic.h
+++ b/drivers/net/netxen/netxen_nic.h
@@ -175,7 +175,7 @@
 
 #define	MAX_NUM_CARDS		4
 
-#define MAX_BUFFERS_PER_CMD	32
+#define NETXEN_MAX_FRAGS_PER_TX	14
 #define TX_STOP_THRESH		((MAX_SKB_FRAGS >> 2) + 4)
 #define NX_MAX_TX_TIMEOUTS	2
 
@@ -551,7 +551,7 @@ 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 5d0c042..2a3853f 100644
--- a/drivers/net/netxen/netxen_nic_main.c
+++ b/drivers/net/netxen/netxen_nic_main.c
@@ -1853,6 +1853,8 @@ 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;
@@ -1860,6 +1862,21 @@ 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;