qlcnic: 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, 15 insertions, 0 deletions

diff --git a/drivers/net/qlcnic/qlcnic.h b/drivers/net/qlcnic/qlcnic.h
index dc44564ef6f9..b0dead00b2d1 100644
--- a/drivers/net/qlcnic/qlcnic.h
+++ b/drivers/net/qlcnic/qlcnic.h
@@ -99,6 +99,7 @@
 #define TX_UDPV6_PKT    0x0c
 
 /* Tx defines */
+#define QLCNIC_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 \
diff --git a/drivers/net/qlcnic/qlcnic_main.c b/drivers/net/qlcnic/qlcnic_main.c
index cd88c7e1bfa9..cb1a1ef36c0a 100644
--- a/drivers/net/qlcnic/qlcnic_main.c
+++ b/drivers/net/qlcnic/qlcnic_main.c
@@ -2099,6 +2099,7 @@ qlcnic_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
         struct cmd_desc_type0 *hwdesc, *first_desc;
         struct pci_dev *pdev;
         struct ethhdr *phdr;
+        int delta = 0;
         int i, k;
 
         u32 producer;
@@ -2118,6 +2119,19 @@ qlcnic_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 > QLCNIC_MAX_FRAGS_PER_TX) {
+
+                for (i = 0; i < (frag_count - QLCNIC_MAX_FRAGS_PER_TX); i++)
+                        delta += skb_shinfo(skb)->frags[i].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;