inet: Add family scope inetpeer flushes.

This implementation can deal with having many inetpeer roots, which is
a necessary prerequisite for per-FIB table rooted peer tables.

Each family (AF_INET, AF_INET6) has a sequence number which we bump
when we get a family invalidation request.

Each peer lookup cheaply checks whether the flush sequence of the
root we are using is out of date, and if so flushes it and updates
the sequence number.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/net/inetpeer.h b/include/net/inetpeer.h
index d432489e7109..e15c0862a686 100644
--- a/include/net/inetpeer.h
+++ b/include/net/inetpeer.h
@@ -68,6 +68,7 @@ struct inet_peer {
 struct inet_peer_base {
         struct inet_peer __rcu  *root;
         seqlock_t               lock;
+        u32                     flush_seq;
         int                     total;
 };
 
@@ -168,6 +169,7 @@ extern void inet_putpeer(struct inet_peer *p);
 extern bool inet_peer_xrlim_allow(struct inet_peer *peer, int timeout);
 
 extern void inetpeer_invalidate_tree(struct inet_peer_base *);
+extern void inetpeer_invalidate_family(int family);
 
 /*
  * temporary check to make sure we dont access rid, ip_id_count, tcp_ts,