From b57b2d1fa53fe8563bdfc66a33b844463b9af285 Mon Sep 17 00:00:00 2001 From: Jozsef Kadlecsik Date: Sat, 13 Jun 2015 14:22:25 +0200 Subject: netfilter: ipset: Prepare the ipset core to use RCU at set level Replace rwlock_t with spinlock_t in "struct ip_set" and change the locking accordingly. Convert the comment extension into an rcu-avare object. Also, simplify the timeout routines. Signed-off-by: Jozsef Kadlecsik --- include/linux/netfilter/ipset/ip_set.h | 9 ++++-- include/linux/netfilter/ipset/ip_set_comment.h | 38 ++++++++++++++++++-------- include/linux/netfilter/ipset/ip_set_timeout.h | 25 +++++++---------- 3 files changed, 44 insertions(+), 28 deletions(-) (limited to 'include') diff --git a/include/linux/netfilter/ipset/ip_set.h b/include/linux/netfilter/ipset/ip_set.h index 5674b6ac6646..19b4969a25fe 100644 --- a/include/linux/netfilter/ipset/ip_set.h +++ b/include/linux/netfilter/ipset/ip_set.h @@ -108,8 +108,13 @@ struct ip_set_counter { atomic64_t packets; }; +struct ip_set_comment_rcu { + struct rcu_head rcu; + char str[0]; +}; + struct ip_set_comment { - char *str; + struct ip_set_comment_rcu __rcu *c; }; struct ip_set_skbinfo { @@ -226,7 +231,7 @@ struct ip_set { /* The name of the set */ char name[IPSET_MAXNAMELEN]; /* Lock protecting the set data */ - rwlock_t lock; + spinlock_t lock; /* References to the set */ u32 ref; /* The core set type */ diff --git a/include/linux/netfilter/ipset/ip_set_comment.h b/include/linux/netfilter/ipset/ip_set_comment.h index 21217ea008d7..8d0248525957 100644 --- a/include/linux/netfilter/ipset/ip_set_comment.h +++ b/include/linux/netfilter/ipset/ip_set_comment.h @@ -16,41 +16,57 @@ ip_set_comment_uget(struct nlattr *tb) return nla_data(tb); } +/* Called from uadd only, protected by the set spinlock. + * The kadt functions don't use the comment extensions in any way. + */ static inline void ip_set_init_comment(struct ip_set_comment *comment, const struct ip_set_ext *ext) { + struct ip_set_comment_rcu *c = rcu_dereference_protected(comment->c, 1); size_t len = ext->comment ? strlen(ext->comment) : 0; - if (unlikely(comment->str)) { - kfree(comment->str); - comment->str = NULL; + if (unlikely(c)) { + kfree_rcu(c, rcu); + rcu_assign_pointer(comment->c, NULL); } if (!len) return; if (unlikely(len > IPSET_MAX_COMMENT_SIZE)) len = IPSET_MAX_COMMENT_SIZE; - comment->str = kzalloc(len + 1, GFP_ATOMIC); - if (unlikely(!comment->str)) + c = kzalloc(sizeof(*c) + len + 1, GFP_ATOMIC); + if (unlikely(!c)) return; - strlcpy(comment->str, ext->comment, len + 1); + strlcpy(c->str, ext->comment, len + 1); + rcu_assign_pointer(comment->c, c); } +/* Used only when dumping a set, protected by rcu_read_lock_bh() */ static inline int ip_set_put_comment(struct sk_buff *skb, struct ip_set_comment *comment) { - if (!comment->str) + struct ip_set_comment_rcu *c = rcu_dereference_bh(comment->c); + + if (!c) return 0; - return nla_put_string(skb, IPSET_ATTR_COMMENT, comment->str); + return nla_put_string(skb, IPSET_ATTR_COMMENT, c->str); } +/* Called from uadd/udel, flush or the garbage collectors protected + * by the set spinlock. + * Called when the set is destroyed and when there can't be any user + * of the set data anymore. + */ static inline void ip_set_comment_free(struct ip_set_comment *comment) { - if (unlikely(!comment->str)) + struct ip_set_comment_rcu *c; + + c = rcu_dereference_protected(comment->c, 1); + if (unlikely(!c)) return; - kfree(comment->str); - comment->str = NULL; + kfree_rcu(c, rcu); + rcu_assign_pointer(comment->c, NULL); } #endif diff --git a/include/linux/netfilter/ipset/ip_set_timeout.h b/include/linux/netfilter/ipset/ip_set_timeout.h index 3c8842bcedaa..1d6a935c1ac5 100644 --- a/include/linux/netfilter/ipset/ip_set_timeout.h +++ b/include/linux/netfilter/ipset/ip_set_timeout.h @@ -40,31 +40,26 @@ ip_set_timeout_uget(struct nlattr *tb) } static inline bool -ip_set_timeout_test(unsigned long timeout) +ip_set_timeout_expired(unsigned long *t) { - return timeout == IPSET_ELEM_PERMANENT || - time_is_after_jiffies(timeout); -} - -static inline bool -ip_set_timeout_expired(unsigned long *timeout) -{ - return *timeout != IPSET_ELEM_PERMANENT && - time_is_before_jiffies(*timeout); + return *t != IPSET_ELEM_PERMANENT && time_is_before_jiffies(*t); } static inline void -ip_set_timeout_set(unsigned long *timeout, u32 t) +ip_set_timeout_set(unsigned long *timeout, u32 value) { - if (!t) { + unsigned long t; + + if (!value) { *timeout = IPSET_ELEM_PERMANENT; return; } - *timeout = msecs_to_jiffies(t * MSEC_PER_SEC) + jiffies; - if (*timeout == IPSET_ELEM_PERMANENT) + t = msecs_to_jiffies(value * MSEC_PER_SEC) + jiffies; + if (t == IPSET_ELEM_PERMANENT) /* Bingo! :-) */ - (*timeout)--; + t--; + *timeout = t; } static inline u32 -- cgit v1.2.3-58-ga151