From b57b2d1fa53fe8563bdfc66a33b844463b9af285 Mon Sep 17 00:00:00 2001 From: Jozsef Kadlecsik Date: Sat, 13 Jun 2015 14:22:25 +0200 Subject: [PATCH] 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 +++- .../linux/netfilter/ipset/ip_set_comment.h | 38 +++++++++++----- .../linux/netfilter/ipset/ip_set_timeout.h | 25 +++++------ net/netfilter/ipset/ip_set_core.c | 44 +++++++++---------- 4 files changed, 66 insertions(+), 50 deletions(-) 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 diff --git a/net/netfilter/ipset/ip_set_core.c b/net/netfilter/ipset/ip_set_core.c index 87b4182660ba..2b21a1983a98 100644 --- a/net/netfilter/ipset/ip_set_core.c +++ b/net/netfilter/ipset/ip_set_core.c @@ -209,15 +209,15 @@ ip_set_type_register(struct ip_set_type *type) pr_warn("ip_set type %s, family %s with revision min %u already registered!\n", type->name, family_name(type->family), type->revision_min); - ret = -EINVAL; - goto unlock; + ip_set_type_unlock(); + return -EINVAL; } list_add_rcu(&type->list, &ip_set_type_list); pr_debug("type %s, family %s, revision %u:%u registered.\n", type->name, family_name(type->family), type->revision_min, type->revision_max); -unlock: ip_set_type_unlock(); + return ret; } EXPORT_SYMBOL_GPL(ip_set_type_register); @@ -231,12 +231,12 @@ ip_set_type_unregister(struct ip_set_type *type) pr_warn("ip_set type %s, family %s with revision min %u not registered\n", type->name, family_name(type->family), type->revision_min); - goto unlock; + ip_set_type_unlock(); + return; } list_del_rcu(&type->list); pr_debug("type %s, family %s with revision min %u unregistered.\n", type->name, family_name(type->family), type->revision_min); -unlock: ip_set_type_unlock(); synchronize_rcu(); @@ -531,16 +531,16 @@ ip_set_test(ip_set_id_t index, const struct sk_buff *skb, !(opt->family == set->family || set->family == NFPROTO_UNSPEC)) return 0; - read_lock_bh(&set->lock); + rcu_read_lock_bh(); ret = set->variant->kadt(set, skb, par, IPSET_TEST, opt); - read_unlock_bh(&set->lock); + rcu_read_unlock_bh(); if (ret == -EAGAIN) { /* Type requests element to be completed */ pr_debug("element must be completed, ADD is triggered\n"); - write_lock_bh(&set->lock); + spin_lock_bh(&set->lock); set->variant->kadt(set, skb, par, IPSET_ADD, opt); - write_unlock_bh(&set->lock); + spin_unlock_bh(&set->lock); ret = 1; } else { /* --return-nomatch: invert matched element */ @@ -570,9 +570,9 @@ ip_set_add(ip_set_id_t index, const struct sk_buff *skb, !(opt->family == set->family || set->family == NFPROTO_UNSPEC)) return -IPSET_ERR_TYPE_MISMATCH; - write_lock_bh(&set->lock); + spin_lock_bh(&set->lock); ret = set->variant->kadt(set, skb, par, IPSET_ADD, opt); - write_unlock_bh(&set->lock); + spin_unlock_bh(&set->lock); return ret; } @@ -593,9 +593,9 @@ ip_set_del(ip_set_id_t index, const struct sk_buff *skb, !(opt->family == set->family || set->family == NFPROTO_UNSPEC)) return -IPSET_ERR_TYPE_MISMATCH; - write_lock_bh(&set->lock); + spin_lock_bh(&set->lock); ret = set->variant->kadt(set, skb, par, IPSET_DEL, opt); - write_unlock_bh(&set->lock); + spin_unlock_bh(&set->lock); return ret; } @@ -880,7 +880,7 @@ ip_set_create(struct sock *ctnl, struct sk_buff *skb, set = kzalloc(sizeof(struct ip_set), GFP_KERNEL); if (!set) return -ENOMEM; - rwlock_init(&set->lock); + spin_lock_init(&set->lock); strlcpy(set->name, name, IPSET_MAXNAMELEN); set->family = family; set->revision = revision; @@ -1062,9 +1062,9 @@ ip_set_flush_set(struct ip_set *set) { pr_debug("set: %s\n", set->name); - write_lock_bh(&set->lock); + spin_lock_bh(&set->lock); set->variant->flush(set); - write_unlock_bh(&set->lock); + spin_unlock_bh(&set->lock); } static int @@ -1377,9 +1377,9 @@ dump_last: set->variant->uref(set, cb, true); /* Fall through and add elements */ default: - read_lock_bh(&set->lock); + rcu_read_lock_bh(); ret = set->variant->list(set, skb, cb); - read_unlock_bh(&set->lock); + rcu_read_unlock_bh(); if (!cb->args[IPSET_CB_ARG0]) /* Set is done, proceed with next one */ goto next_set; @@ -1462,9 +1462,9 @@ call_ad(struct sock *ctnl, struct sk_buff *skb, struct ip_set *set, bool eexist = flags & IPSET_FLAG_EXIST, retried = false; do { - write_lock_bh(&set->lock); + spin_lock_bh(&set->lock); ret = set->variant->uadt(set, tb, adt, &lineno, flags, retried); - write_unlock_bh(&set->lock); + spin_unlock_bh(&set->lock); retried = true; } while (ret == -EAGAIN && set->variant->resize && @@ -1644,9 +1644,9 @@ ip_set_utest(struct sock *ctnl, struct sk_buff *skb, set->type->adt_policy)) return -IPSET_ERR_PROTOCOL; - read_lock_bh(&set->lock); + rcu_read_lock_bh(); ret = set->variant->uadt(set, tb, IPSET_TEST, NULL, 0, 0); - read_unlock_bh(&set->lock); + rcu_read_unlock_bh(); /* Userspace can't trigger element to be re-added */ if (ret == -EAGAIN) ret = 1; -- 2.30.2