diff options
| -rw-r--r-- | net/ipv4/netfilter/ipt_CLUSTERIP.c | 48 |
1 files changed, 29 insertions, 19 deletions
diff --git a/net/ipv4/netfilter/ipt_CLUSTERIP.c b/net/ipv4/netfilter/ipt_CLUSTERIP.c index f91c94b9a790..64d0875f5192 100644 --- a/net/ipv4/netfilter/ipt_CLUSTERIP.c +++ b/net/ipv4/netfilter/ipt_CLUSTERIP.c @@ -53,12 +53,13 @@ struct clusterip_config { #endif enum clusterip_hashmode hash_mode; /* which hashing mode */ u_int32_t hash_initval; /* hash initialization */ + struct rcu_head rcu; }; static LIST_HEAD(clusterip_configs); /* clusterip_lock protects the clusterip_configs list */ -static DEFINE_RWLOCK(clusterip_lock); +static DEFINE_SPINLOCK(clusterip_lock); #ifdef CONFIG_PROC_FS static const struct file_operations clusterip_proc_fops; @@ -71,11 +72,17 @@ clusterip_config_get(struct clusterip_config *c) atomic_inc(&c->refcount); } + +static void clusterip_config_rcu_free(struct rcu_head *head) +{ + kfree(container_of(head, struct clusterip_config, rcu)); +} + static inline void clusterip_config_put(struct clusterip_config *c) { if (atomic_dec_and_test(&c->refcount)) - kfree(c); + call_rcu_bh(&c->rcu, clusterip_config_rcu_free); } /* decrease the count of entries using/referencing this config. If last @@ -84,10 +91,11 @@ clusterip_config_put(struct clusterip_config *c) static inline void clusterip_config_entry_put(struct clusterip_config *c) { - write_lock_bh(&clusterip_lock); - if (atomic_dec_and_test(&c->entries)) { - list_del(&c->list); - write_unlock_bh(&clusterip_lock); + local_bh_disable(); + if (atomic_dec_and_lock(&c->entries, &clusterip_lock)) { + list_del_rcu(&c->list); + spin_unlock(&clusterip_lock); + local_bh_enable(); dev_mc_del(c->dev, c->clustermac); dev_put(c->dev); @@ -100,7 +108,7 @@ clusterip_config_entry_put(struct clusterip_config *c) #endif return; } - write_unlock_bh(&clusterip_lock); + local_bh_enable(); } static struct clusterip_config * @@ -108,7 +116,7 @@ __clusterip_config_find(__be32 clusterip) { struct clusterip_config *c; - list_for_each_entry(c, &clusterip_configs, list) { + list_for_each_entry_rcu(c, &clusterip_configs, list) { if (c->clusterip == clusterip) return c; } @@ -121,16 +129,15 @@ clusterip_config_find_get(__be32 clusterip, int entry) { struct clusterip_config *c; - read_lock_bh(&clusterip_lock); + rcu_read_lock_bh(); c = __clusterip_config_find(clusterip); - if (!c) { - read_unlock_bh(&clusterip_lock); - return NULL; + if (c) { + if (unlikely(!atomic_inc_not_zero(&c->refcount))) + c = NULL; + else if (entry) + atomic_inc(&c->entries); } - atomic_inc(&c->refcount); - if (entry) - atomic_inc(&c->entries); - read_unlock_bh(&clusterip_lock); + rcu_read_unlock_bh(); return c; } @@ -181,9 +188,9 @@ clusterip_config_init(const struct ipt_clusterip_tgt_info *i, __be32 ip, } #endif - write_lock_bh(&clusterip_lock); - list_add(&c->list, &clusterip_configs); - write_unlock_bh(&clusterip_lock); + spin_lock_bh(&clusterip_lock); + list_add_rcu(&c->list, &clusterip_configs); + spin_unlock_bh(&clusterip_lock); return c; } @@ -733,6 +740,9 @@ static void __exit clusterip_tg_exit(void) #endif nf_unregister_hook(&cip_arp_ops); xt_unregister_target(&clusterip_tg_reg); + + /* Wait for completion of call_rcu_bh()'s (clusterip_config_rcu_free) */ + rcu_barrier_bh(); } module_init(clusterip_tg_init); |