netfilter: Replace call_rcu_bh(), rcu_barrier_bh(), and synchronize_rcu_bh()

Now that call_rcu()'s callback is not invoked until after bh-disable
regions of code have completed (in addition to explicitly marked
RCU read-side critical sections), call_rcu() can be used in place
of call_rcu_bh().  Similarly, rcu_barrier() can be used in place of
rcu_barrier_bh() and synchronize_rcu() in place of synchronize_rcu_bh().
This commit therefore makes these changes.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/ipv4/netfilter/ipt_CLUSTERIP.c

@@ -94,7 +94,7 @@ static inline void
 clusterip_config_put(struct clusterip_config *c)
 {
 	if (refcount_dec_and_test(&c->refcount))
-		call_rcu_bh(&c->rcu, clusterip_config_rcu_free);
+		call_rcu(&c->rcu, clusterip_config_rcu_free);
 }
 
 /* decrease the count of entries using/referencing this config.  If last
@@ -876,8 +876,8 @@ static void __exit clusterip_tg_exit(void)
 	xt_unregister_target(&clusterip_tg_reg);
 	unregister_pernet_subsys(&clusterip_net_ops);
 
-	/* Wait for completion of call_rcu_bh()'s (clusterip_config_rcu_free) */
-	rcu_barrier_bh();
+	/* Wait for completion of call_rcu()'s (clusterip_config_rcu_free) */
+	rcu_barrier();
 }
 
 module_init(clusterip_tg_init);

net/netfilter/ipset/ip_set_hash_gen.h

@@ -67,7 +67,7 @@ tune_ahash_max(u8 curr, u32 multi)
 
 /* A hash bucket */
 struct hbucket {
-	struct rcu_head rcu;	/* for call_rcu_bh */
+	struct rcu_head rcu;	/* for call_rcu */
 	/* Which positions are used in the array */
 	DECLARE_BITMAP(used, AHASH_MAX_TUNED);
 	u8 size;		/* size of the array */
@@ -664,7 +664,7 @@ mtype_resize(struct ip_set *set, bool retried)
 	spin_unlock_bh(&set->lock);
 
 	/* Give time to other readers of the set */
-	synchronize_rcu_bh();
+	synchronize_rcu();
 
 	pr_debug("set %s resized from %u (%p) to %u (%p)\n", set->name,
 		 orig->htable_bits, orig, t->htable_bits, t);

net/netfilter/nfnetlink_log.c

@@ -148,7 +148,7 @@ static void
 instance_put(struct nfulnl_instance *inst)
 {
 	if (inst && refcount_dec_and_test(&inst->use))
-		call_rcu_bh(&inst->rcu, nfulnl_instance_free_rcu);
+		call_rcu(&inst->rcu, nfulnl_instance_free_rcu);
 }
 
 static void nfulnl_timer(struct timer_list *t);

net/netfilter/xt_hashlimit.c

@@ -260,7 +260,7 @@ static inline void
 dsthash_free(struct xt_hashlimit_htable *ht, struct dsthash_ent *ent)
 {
 	hlist_del_rcu(&ent->node);
-	call_rcu_bh(&ent->rcu, dsthash_free_rcu);
+	call_rcu(&ent->rcu, dsthash_free_rcu);
 	ht->count--;
 }
 static void htable_gc(struct work_struct *work);
@@ -1329,7 +1329,7 @@ static void __exit hashlimit_mt_exit(void)
 	xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg));
 	unregister_pernet_subsys(&hashlimit_net_ops);
 
-	rcu_barrier_bh();
+	rcu_barrier();
 	kmem_cache_destroy(hashlimit_cachep);
 }