[SK_BUFF]: Convert skb->tail to sk_buff_data_t

So that it is also an offset from skb->head, reduces its size from 8 to 4 bytes
on 64bit architectures, allowing us to combine the 4 bytes hole left by the
layer headers conversion, reducing struct sk_buff size to 256 bytes, i.e. 4
64byte cachelines, and since the sk_buff slab cache is SLAB_HWCACHE_ALIGN...
:-)

Many calculations that previously required that skb->{transport,network,
mac}_header be first converted to a pointer now can be done directly, being
meaningful as offsets or pointers.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 2 deletions

diff --git a/net/ipv4/ipvs/ip_vs_ftp.c b/net/ipv4/ipvs/ip_vs_ftp.c
index 25bd68967305..344ddbbdc756 100644
--- a/net/ipv4/ipvs/ip_vs_ftp.c
+++ b/net/ipv4/ipvs/ip_vs_ftp.c
@@ -162,7 +162,7 @@ static int ip_vs_ftp_out(struct ip_vs_app *app, struct ip_vs_conn *cp,
                 iph = ip_hdr(*pskb);
                 th = (struct tcphdr *)&(((char *)iph)[iph->ihl*4]);
                 data = (char *)th + (th->doff << 2);
-                data_limit = (*pskb)->tail;
+                data_limit = skb_tail_pointer(*pskb);
 
                 if (ip_vs_ftp_get_addrport(data, data_limit,
                                            SERVER_STRING,
@@ -269,7 +269,7 @@ static int ip_vs_ftp_in(struct ip_vs_app *app, struct ip_vs_conn *cp,
            the length of the header in 32-bit multiples, it is accurate
            to calculate data address by th+HLEN*4 */
         data = data_start = (char *)th + (th->doff << 2);
-        data_limit = (*pskb)->tail;
+        data_limit = skb_tail_pointer(*pskb);
 
         while (data <= data_limit - 6) {
                 if (strnicmp(data, "PASV\r\n", 6) == 0) {