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>

1 files changed, 3 insertions, 2 deletions

diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c
index 74544bc6fdec..2949ca474ede 100644
--- a/net/decnet/dn_route.c
+++ b/net/decnet/dn_route.c
@@ -1841,10 +1841,11 @@ void __init dn_route_init(void)
         proc_net_fops_create(&init_net, "decnet_cache", S_IRUGO, &dn_rt_cache_seq_fops);
 
 #ifdef CONFIG_DECNET_ROUTER
-        rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute, dn_fib_dump);
+        rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute,
+                      dn_fib_dump, NULL);
 #else
         rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute,
-                      dn_cache_dump);
+                      dn_cache_dump, NULL);
 #endif
 }