From: Jozsef Kadlecsik <kadlec@xxxxxxxxxxxxxxxxx>
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 <kadlec@xxxxxxxxxxxxxxxxx>
---
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 ++++++--------
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 5674b6a..19b4969 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 21217ea..8d02485 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 3c8842b..1d6a935 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 87b4182..2b21a19 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;
--
1.7.10.4
--
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