@@ -230,6 +230,7 @@ unsigned int arpt_do_table(struct sk_buf
void *table_base;
const struct xt_table_info *private;
struct xt_target_param tgpar;
+ seqcount_t *seq;
if (!pskb_may_pull(skb, arp_hdr_len(skb->dev)))
return NF_DROP;
@@ -240,6 +241,7 @@ unsigned int arpt_do_table(struct sk_buf
read_lock_bh(&table->lock);
private = table->private;
table_base = (void *)private->entries[smp_processor_id()];
+ seq = per_cpu_ptr(private->seq, smp_processor_id());
e = get_entry(table_base, private->hook_entry[hook]);
back = get_entry(table_base, private->underflow[hook]);
@@ -256,7 +258,9 @@ unsigned int arpt_do_table(struct sk_buf
hdr_len = sizeof(*arp) + (2 * sizeof(struct in_addr)) +
(2 * skb->dev->addr_len);
+ write_seqcount_begin(seq);
ADD_COUNTER(e->counters, hdr_len, 1);
+ write_seqcount_end(seq);
t = arpt_get_target(e);
@@ -662,10 +666,20 @@ static int translate_table(const char *n
/* Gets counters. */
static inline int add_entry_to_counter(const struct arpt_entry *e,
+ seqcount_t *seq,
struct xt_counters total[],
unsigned int *i)
{
- ADD_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
+ struct xt_counters count;
+ unsigned int start;
+
+ /* Atomic fetch */
+ do {
+ start = read_seqcount_begin(seq);
+ count = e->counters;
+ } while (read_seqcount_retry(seq, start));
+
+ ADD_COUNTER(total[*i], count.bcnt, count.pcnt);
(*i)++;
return 0;
@@ -709,6 +723,7 @@ static void get_counters(const struct xt
ARPT_ENTRY_ITERATE(t->entries[cpu],
t->size,
add_entry_to_counter,
+ per_cpu_ptr(t->seq, cpu),
counters,
&i);
}
@@ -731,9 +746,9 @@ static inline struct xt_counters *alloc_
return ERR_PTR(-ENOMEM);
/* First, sum counters... */
- write_lock_bh(&table->lock);
+ local_bh_disable();
get_counters(private, counters);
- write_unlock_bh(&table->lock);
+ local_bh_enable();
return counters;
}
@@ -1736,8 +1751,7 @@ struct xt_table *arpt_register_table(str
{
int ret;
struct xt_table_info *newinfo;
- struct xt_table_info bootstrap
- = { 0, 0, 0, { 0 }, { 0 }, { } };
+ struct xt_table_info bootstrap = { 0 };
void *loc_cpu_entry;
struct xt_table *new_table;
@@ -327,6 +327,7 @@ ipt_do_table(struct sk_buff *skb,
struct xt_table_info *private;
struct xt_match_param mtpar;
struct xt_target_param tgpar;
+ seqcount_t *seq;
/* Initialization */
ip = ip_hdr(skb);
@@ -351,6 +352,7 @@ ipt_do_table(struct sk_buff *skb,
IP_NF_ASSERT(table->valid_hooks & (1 << hook));
private = table->private;
table_base = (void *)private->entries[smp_processor_id()];
+ seq = per_cpu_ptr(private->seq, smp_processor_id());
e = get_entry(table_base, private->hook_entry[hook]);
/* For return from builtin chain */
@@ -366,7 +368,9 @@ ipt_do_table(struct sk_buff *skb,
if (IPT_MATCH_ITERATE(e, do_match, skb, &mtpar) != 0)
goto no_match;
+ write_seqcount_begin(seq);
ADD_COUNTER(e->counters, ntohs(ip->tot_len), 1);
+ write_seqcount_end(seq);
t = ipt_get_target(e);
IP_NF_ASSERT(t->u.kernel.target);
@@ -872,10 +876,20 @@ translate_table(const char *name,
/* Gets counters. */
static inline int
add_entry_to_counter(const struct ipt_entry *e,
+ seqcount_t *seq,
struct xt_counters total[],
unsigned int *i)
{
- ADD_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
+ struct xt_counters count;
+ unsigned int start;
+
+ /* Atomic fetch */
+ do {
+ start = read_seqcount_begin(seq);
+ count = e->counters;
+ } while (read_seqcount_retry(seq, start));
+
+ ADD_COUNTER(total[*i], count.bcnt, count.pcnt);
(*i)++;
return 0;
@@ -921,6 +935,7 @@ get_counters(const struct xt_table_info
IPT_ENTRY_ITERATE(t->entries[cpu],
t->size,
add_entry_to_counter,
+ per_cpu_ptr(t->seq, cpu),
counters,
&i);
}
@@ -942,9 +957,9 @@ static struct xt_counters * alloc_counte
return ERR_PTR(-ENOMEM);
/* First, sum counters... */
- write_lock_bh(&table->lock);
+ local_bh_disable();
get_counters(private, counters);
- write_unlock_bh(&table->lock);
+ local_bh_enable();
return counters;
}
@@ -2064,8 +2079,7 @@ struct xt_table *ipt_register_table(stru
{
int ret;
struct xt_table_info *newinfo;
- struct xt_table_info bootstrap
- = { 0, 0, 0, { 0 }, { 0 }, { } };
+ struct xt_table_info bootstrap = { 0 };
void *loc_cpu_entry;
struct xt_table *new_table;
@@ -357,6 +357,7 @@ ip6t_do_table(struct sk_buff *skb,
struct xt_table_info *private;
struct xt_match_param mtpar;
struct xt_target_param tgpar;
+ seqcount_t *seq;
/* Initialization */
indev = in ? in->name : nulldevname;
@@ -377,6 +378,7 @@ ip6t_do_table(struct sk_buff *skb,
IP_NF_ASSERT(table->valid_hooks & (1 << hook));
private = table->private;
table_base = (void *)private->entries[smp_processor_id()];
+ seq = per_cpu_ptr(private->seq, smp_processor_id());
e = get_entry(table_base, private->hook_entry[hook]);
/* For return from builtin chain */
@@ -392,9 +394,11 @@ ip6t_do_table(struct sk_buff *skb,
if (IP6T_MATCH_ITERATE(e, do_match, skb, &mtpar) != 0)
goto no_match;
+ write_seqcount_begin(seq);
ADD_COUNTER(e->counters,
ntohs(ipv6_hdr(skb)->payload_len) +
sizeof(struct ipv6hdr), 1);
+ write_seqcount_end(seq);
t = ip6t_get_target(e);
IP_NF_ASSERT(t->u.kernel.target);
@@ -901,11 +905,21 @@ translate_table(const char *name,
/* Gets counters. */
static inline int
add_entry_to_counter(const struct ip6t_entry *e,
+ seqcount_t *seq,
struct xt_counters total[],
unsigned int *i)
{
- ADD_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
+ struct xt_counters count;
+ unsigned int start;
+
+ /* Atomic fetch */
+ do {
+ start = read_seqcount_begin(seq);
+ count = e->counters;
+ } while (read_seqcount_retry(seq, start));
+
+ ADD_COUNTER(total[*i], count.bcnt, count.pcnt);
(*i)++;
return 0;
}
@@ -948,10 +962,11 @@ get_counters(const struct xt_table_info
continue;
i = 0;
IP6T_ENTRY_ITERATE(t->entries[cpu],
- t->size,
- add_entry_to_counter,
- counters,
- &i);
+ t->size,
+ add_entry_to_counter,
+ per_cpu_ptr(t->seq, cpu),
+ counters,
+ &i);
}
}
@@ -971,9 +986,9 @@ static struct xt_counters *alloc_counter
return ERR_PTR(-ENOMEM);
/* First, sum counters... */
- write_lock_bh(&table->lock);
+ local_bh_disable();
get_counters(private, counters);
- write_unlock_bh(&table->lock);
+ local_bh_enable();
return counters;
}
@@ -2094,8 +2109,7 @@ struct xt_table *ip6t_register_table(str
{
int ret;
struct xt_table_info *newinfo;
- struct xt_table_info bootstrap
- = { 0, 0, 0, { 0 }, { 0 }, { } };
+ struct xt_table_info bootstrap = { 0 };
void *loc_cpu_entry;
struct xt_table *new_table;
@@ -591,8 +591,18 @@ struct xt_table_info *xt_alloc_table_inf
return NULL;
newinfo->size = size;
+ newinfo->seq = alloc_percpu(seqcount_t);
+ if (!newinfo->seq) {
+ kfree(newinfo);
+ return NULL;
+ }
+
for_each_possible_cpu(cpu) {
+ seqcount_t *cnt = per_cpu_ptr(newinfo->seq, cpu);
+
+ seqcount_init(cnt);
+
if (size <= PAGE_SIZE)
newinfo->entries[cpu] = kmalloc_node(size,
GFP_KERNEL,
@@ -621,6 +631,7 @@ void xt_free_table_info(struct xt_table_
else
vfree(info->entries[cpu]);
}
+ free_percpu(info->seq);
kfree(info);
}
EXPORT_SYMBOL(xt_free_table_info);
@@ -383,6 +383,9 @@ struct xt_table_info
unsigned int hook_entry[NF_INET_NUMHOOKS];
unsigned int underflow[NF_INET_NUMHOOKS];
+ /* Secret compartment */
+ seqcount_t *seq;
+
/* ipt_entry tables: one per CPU */
/* Note : this field MUST be the last one, see XT_TABLE_INFO_SZ */
char *entries[1];
Change how synchronization is done on the iptables counters. Use seqcount wrapper instead of depending on reader/writer lock. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> --- include/linux/netfilter/x_tables.h | 3 +++ net/ipv4/netfilter/arp_tables.c | 24 +++++++++++++++++++----- net/ipv4/netfilter/ip_tables.c | 24 +++++++++++++++++++----- net/ipv6/netfilter/ip6_tables.c | 32 +++++++++++++++++++++++--------- net/netfilter/x_tables.c | 11 +++++++++++ 5 files changed, 75 insertions(+), 19 deletions(-) 4