rhashtable: Add rehash counter to bucket_table

This patch adds a rehash counter to bucket_table to indicate
the last bucket that has been rehashed.  This serves two purposes:

1. Any bucket that has been rehashed can never gain a new object.
2. If the rehash counter reaches the size of the table, the table
will forever remain empty.

This patch also downsizes bucket_table->size to an unsigned int
since we do not support sizes greater than 32 bits yet.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index 36fb091..ff4ea17 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -260,6 +260,7 @@
 	spin_lock_bh(old_bucket_lock);
 	while (!rhashtable_rehash_one(ht, old_hash))
 		;
+	old_tbl->rehash++;
 	spin_unlock_bh(old_bucket_lock);
 }
 
diff --git a/lib/test_rhashtable.c b/lib/test_rhashtable.c
index 67c7593..16974fd 100644
--- a/lib/test_rhashtable.c
+++ b/lib/test_rhashtable.c
@@ -80,7 +80,7 @@
 		rcu_cnt = cnt = 0;
 
 		if (!quiet)
-			pr_info(" [%#4x/%zu]", i, tbl->size);
+			pr_info(" [%#4x/%u]", i, tbl->size);
 
 		rht_for_each_entry_rcu(obj, pos, tbl, i, node) {
 			cnt++;