rtnetlink: Compute and store minimum ifinfo dump size

The message size allocated for rtnl ifinfo dumps was limited to
a single page.  This is not enough for additional interface info
available with devices that support SR-IOV and caused a bug in
which VF info would not be displayed if more than approximately
40 VFs were created per interface.

Implement a new function pointer for the rtnl_register service that will
calculate the amount of data required for the ifinfo dump and allocate
enough data to satisfy the request.

Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/net/phonet/pn_netlink.c b/net/phonet/pn_netlink.c
index 438accb..d61f676 100644
--- a/net/phonet/pn_netlink.c
+++ b/net/phonet/pn_netlink.c
@@ -289,15 +289,16 @@
 
 int __init phonet_netlink_register(void)
 {
-	int err = __rtnl_register(PF_PHONET, RTM_NEWADDR, addr_doit, NULL);
+	int err = __rtnl_register(PF_PHONET, RTM_NEWADDR, addr_doit,
+				  NULL, NULL);
 	if (err)
 		return err;
 
 	/* Further __rtnl_register() cannot fail */
-	__rtnl_register(PF_PHONET, RTM_DELADDR, addr_doit, NULL);
-	__rtnl_register(PF_PHONET, RTM_GETADDR, NULL, getaddr_dumpit);
-	__rtnl_register(PF_PHONET, RTM_NEWROUTE, route_doit, NULL);
-	__rtnl_register(PF_PHONET, RTM_DELROUTE, route_doit, NULL);
-	__rtnl_register(PF_PHONET, RTM_GETROUTE, NULL, route_dumpit);
+	__rtnl_register(PF_PHONET, RTM_DELADDR, addr_doit, NULL, NULL);
+	__rtnl_register(PF_PHONET, RTM_GETADDR, NULL, getaddr_dumpit, NULL);
+	__rtnl_register(PF_PHONET, RTM_NEWROUTE, route_doit, NULL, NULL);
+	__rtnl_register(PF_PHONET, RTM_DELROUTE, route_doit, NULL, NULL);
+	__rtnl_register(PF_PHONET, RTM_GETROUTE, NULL, route_dumpit, NULL);
 	return 0;
 }