fib_trie: Cleanup ip_fib_net_exit code path

While fixing a recent issue I noticed that we are doing some unnecessary
work inside the loop for ip_fib_net_exit.  As such I am pulling out the
initialization to NULL for the locally stored fib_local, fib_main, and
fib_default.

In addition I am restoring the original code for flushing the table as
there is no need to split up the fib_table_flush and hlist_del work since
the code for packing the tnodes with multiple key vectors was dropped.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 22 deletions

diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 767120111d90..718b0a16ea40 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -1176,35 +1176,20 @@ static void ip_fib_net_exit(struct net *net)
 
         rtnl_lock();
 
+#ifdef CONFIG_IP_MULTIPLE_TABLES
+        RCU_INIT_POINTER(net->ipv4.fib_local, NULL);
+        RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
+        RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
+#endif
+
         for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
                 struct hlist_head *head = &net->ipv4.fib_table_hash[i];
                 struct hlist_node *tmp;
                 struct fib_table *tb;
 
-                /* this is done in two passes as flushing the table could
-                 * cause it to be reallocated in order to accommodate new
-                 * tnodes at the root as the table shrinks.
-                 */
-                hlist_for_each_entry_safe(tb, tmp, head, tb_hlist)
-                        fib_table_flush(tb);
-
                 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
-#ifdef CONFIG_IP_MULTIPLE_TABLES
-                        switch (tb->tb_id) {
-                        case RT_TABLE_LOCAL:
-                                RCU_INIT_POINTER(net->ipv4.fib_local, NULL);
-                                break;
-                        case RT_TABLE_MAIN:
-                                RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
-                                break;
-                        case RT_TABLE_DEFAULT:
-                                RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
-                                break;
-                        default:
-                                break;
-                        }
-#endif
                         hlist_del(&tb->tb_hlist);
+                        fib_table_flush(tb);
                         fib_free_table(tb);
                 }
         }