ipv6: fib: Don't assume only nodes hold a reference on routes

The code currently assumes that only FIB nodes can hold a reference on
routes. Therefore, after fib6_purge_rt() has run and the route is no
longer present in any intermediate nodes, it's assumed that its
reference count would be 1 - taken by the node where it's currently
stored.

However, we're going to allow users other than the FIB to take a
reference on a route, so this assumption is no longer valid and the
BUG_ON() needs to be removed.

Note that purging only takes place if the initial reference count is
different than 1. I've left that check intact, as in the majority of
systems (where routes are only referenced by the FIB), it does actually
mean the route is present in intermediate nodes.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index 719c10480c74f9e8d3af74a48f2f7ab3e01c92ce..fa27905de92eda284b180e749bffb9e7634c0c07 100644 (file)
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -837,8 +837,6 @@ static void fib6_purge_rt(struct rt6_info *rt, struct fib6_node *fn,
                        }
                        fn = fn->parent;
                }
-               /* No more references are possible at this point. */
-               BUG_ON(atomic_read(&rt->rt6i_ref) != 1);
        }
 }