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, 4 insertions, 2 deletions

diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index a9dd89552f9c..fdd0188a167e 100644
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h
@@ -221,7 +221,8 @@ struct netlink_callback {
         int                     (*dump)(struct sk_buff * skb,
                                         struct netlink_callback *cb);
         int                     (*done)(struct netlink_callback *cb);
-        int                     family;
+        u16                     family;
+        u16                     min_dump_alloc;
         long                    args[6];
 };
 
@@ -259,7 +260,8 @@ __nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq, int type, int len, int flags)
 extern int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
                               const struct nlmsghdr *nlh,
                               int (*dump)(struct sk_buff *skb, struct netlink_callback*),
-                              int (*done)(struct netlink_callback*));
+                              int (*done)(struct netlink_callback*),
+                              u16 min_dump_alloc);
 
 
 #define NL_NONROOT_RECV 0x1