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tcp_metrics: Use a single hash table for all network namespaces.
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Now that all of the operations are safe on a single hash table
accross network namespaces, allocate a single global hash table
and update the code to use it.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Eric W. Biederman authored and David S. Miller committed Mar 13, 2015
1 parent 04f721c commit 098a697
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Showing 2 changed files with 30 additions and 38 deletions.
2 changes: 0 additions & 2 deletions include/net/netns/ipv4.h
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Original file line number Diff line number Diff line change
Expand Up @@ -54,8 +54,6 @@ struct netns_ipv4 {
struct sock *mc_autojoin_sk;

struct inet_peer_base *peers;
struct tcpm_hash_bucket *tcp_metrics_hash;
unsigned int tcp_metrics_hash_log;
struct sock * __percpu *tcp_sk;
struct netns_frags frags;
#ifdef CONFIG_NETFILTER
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66 changes: 30 additions & 36 deletions net/ipv4/tcp_metrics.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -97,6 +97,9 @@ struct tcpm_hash_bucket {
struct tcp_metrics_block __rcu *chain;
};

static struct tcpm_hash_bucket *tcp_metrics_hash __read_mostly;
static unsigned int tcp_metrics_hash_log __read_mostly;

static DEFINE_SPINLOCK(tcp_metrics_lock);

static void tcpm_suck_dst(struct tcp_metrics_block *tm,
Expand Down Expand Up @@ -177,7 +180,7 @@ static struct tcp_metrics_block *tcpm_new(struct dst_entry *dst,
if (unlikely(reclaim)) {
struct tcp_metrics_block *oldest;

oldest = rcu_dereference(net->ipv4.tcp_metrics_hash[hash].chain);
oldest = rcu_dereference(tcp_metrics_hash[hash].chain);
for (tm = rcu_dereference(oldest->tcpm_next); tm;
tm = rcu_dereference(tm->tcpm_next)) {
if (time_before(tm->tcpm_stamp, oldest->tcpm_stamp))
Expand All @@ -196,8 +199,8 @@ static struct tcp_metrics_block *tcpm_new(struct dst_entry *dst,
tcpm_suck_dst(tm, dst, true);

if (likely(!reclaim)) {
tm->tcpm_next = net->ipv4.tcp_metrics_hash[hash].chain;
rcu_assign_pointer(net->ipv4.tcp_metrics_hash[hash].chain, tm);
tm->tcpm_next = tcp_metrics_hash[hash].chain;
rcu_assign_pointer(tcp_metrics_hash[hash].chain, tm);
}

out_unlock:
Expand All @@ -221,7 +224,7 @@ static struct tcp_metrics_block *__tcp_get_metrics(const struct inetpeer_addr *s
struct tcp_metrics_block *tm;
int depth = 0;

for (tm = rcu_dereference(net->ipv4.tcp_metrics_hash[hash].chain); tm;
for (tm = rcu_dereference(tcp_metrics_hash[hash].chain); tm;
tm = rcu_dereference(tm->tcpm_next)) {
if (addr_same(&tm->tcpm_saddr, saddr) &&
addr_same(&tm->tcpm_daddr, daddr) &&
Expand Down Expand Up @@ -261,9 +264,9 @@ static struct tcp_metrics_block *__tcp_get_metrics_req(struct request_sock *req,

net = dev_net(dst->dev);
hash ^= net_hash_mix(net);
hash = hash_32(hash, net->ipv4.tcp_metrics_hash_log);
hash = hash_32(hash, tcp_metrics_hash_log);

for (tm = rcu_dereference(net->ipv4.tcp_metrics_hash[hash].chain); tm;
for (tm = rcu_dereference(tcp_metrics_hash[hash].chain); tm;
tm = rcu_dereference(tm->tcpm_next)) {
if (addr_same(&tm->tcpm_saddr, &saddr) &&
addr_same(&tm->tcpm_daddr, &daddr) &&
Expand Down Expand Up @@ -310,9 +313,9 @@ static struct tcp_metrics_block *__tcp_get_metrics_tw(struct inet_timewait_sock

net = twsk_net(tw);
hash ^= net_hash_mix(net);
hash = hash_32(hash, net->ipv4.tcp_metrics_hash_log);
hash = hash_32(hash, tcp_metrics_hash_log);

for (tm = rcu_dereference(net->ipv4.tcp_metrics_hash[hash].chain); tm;
for (tm = rcu_dereference(tcp_metrics_hash[hash].chain); tm;
tm = rcu_dereference(tm->tcpm_next)) {
if (addr_same(&tm->tcpm_saddr, &saddr) &&
addr_same(&tm->tcpm_daddr, &daddr) &&
Expand Down Expand Up @@ -360,7 +363,7 @@ static struct tcp_metrics_block *tcp_get_metrics(struct sock *sk,

net = dev_net(dst->dev);
hash ^= net_hash_mix(net);
hash = hash_32(hash, net->ipv4.tcp_metrics_hash_log);
hash = hash_32(hash, tcp_metrics_hash_log);

tm = __tcp_get_metrics(&saddr, &daddr, net, hash);
if (tm == TCP_METRICS_RECLAIM_PTR)
Expand Down Expand Up @@ -911,13 +914,13 @@ static int tcp_metrics_nl_dump(struct sk_buff *skb,
struct netlink_callback *cb)
{
struct net *net = sock_net(skb->sk);
unsigned int max_rows = 1U << net->ipv4.tcp_metrics_hash_log;
unsigned int max_rows = 1U << tcp_metrics_hash_log;
unsigned int row, s_row = cb->args[0];
int s_col = cb->args[1], col = s_col;

for (row = s_row; row < max_rows; row++, s_col = 0) {
struct tcp_metrics_block *tm;
struct tcpm_hash_bucket *hb = net->ipv4.tcp_metrics_hash + row;
struct tcpm_hash_bucket *hb = tcp_metrics_hash + row;

rcu_read_lock();
for (col = 0, tm = rcu_dereference(hb->chain); tm;
Expand Down Expand Up @@ -1010,10 +1013,10 @@ static int tcp_metrics_nl_cmd_get(struct sk_buff *skb, struct genl_info *info)
goto nla_put_failure;

hash ^= net_hash_mix(net);
hash = hash_32(hash, net->ipv4.tcp_metrics_hash_log);
hash = hash_32(hash, tcp_metrics_hash_log);
ret = -ESRCH;
rcu_read_lock();
for (tm = rcu_dereference(net->ipv4.tcp_metrics_hash[hash].chain); tm;
for (tm = rcu_dereference(tcp_metrics_hash[hash].chain); tm;
tm = rcu_dereference(tm->tcpm_next)) {
if (addr_same(&tm->tcpm_daddr, &daddr) &&
(!src || addr_same(&tm->tcpm_saddr, &saddr)) &&
Expand Down Expand Up @@ -1045,8 +1048,8 @@ static int tcp_metrics_nl_cmd_get(struct sk_buff *skb, struct genl_info *info)

static void tcp_metrics_flush_all(struct net *net)
{
unsigned int max_rows = 1U << net->ipv4.tcp_metrics_hash_log;
struct tcpm_hash_bucket *hb = net->ipv4.tcp_metrics_hash;
unsigned int max_rows = 1U << tcp_metrics_hash_log;
struct tcpm_hash_bucket *hb = tcp_metrics_hash;
struct tcp_metrics_block *tm;
unsigned int row;

Expand Down Expand Up @@ -1090,8 +1093,8 @@ static int tcp_metrics_nl_cmd_del(struct sk_buff *skb, struct genl_info *info)
src = false;

hash ^= net_hash_mix(net);
hash = hash_32(hash, net->ipv4.tcp_metrics_hash_log);
hb = net->ipv4.tcp_metrics_hash + hash;
hash = hash_32(hash, tcp_metrics_hash_log);
hb = tcp_metrics_hash + hash;
pp = &hb->chain;
spin_lock_bh(&tcp_metrics_lock);
for (tm = deref_locked_genl(*pp); tm; tm = deref_locked_genl(*pp)) {
Expand Down Expand Up @@ -1147,6 +1150,9 @@ static int __net_init tcp_net_metrics_init(struct net *net)
size_t size;
unsigned int slots;

if (!net_eq(net, &init_net))
return 0;

slots = tcpmhash_entries;
if (!slots) {
if (totalram_pages >= 128 * 1024)
Expand All @@ -1155,34 +1161,22 @@ static int __net_init tcp_net_metrics_init(struct net *net)
slots = 8 * 1024;
}

net->ipv4.tcp_metrics_hash_log = order_base_2(slots);
size = sizeof(struct tcpm_hash_bucket) << net->ipv4.tcp_metrics_hash_log;
tcp_metrics_hash_log = order_base_2(slots);
size = sizeof(struct tcpm_hash_bucket) << tcp_metrics_hash_log;

net->ipv4.tcp_metrics_hash = kzalloc(size, GFP_KERNEL | __GFP_NOWARN);
if (!net->ipv4.tcp_metrics_hash)
net->ipv4.tcp_metrics_hash = vzalloc(size);
tcp_metrics_hash = kzalloc(size, GFP_KERNEL | __GFP_NOWARN);
if (!tcp_metrics_hash)
tcp_metrics_hash = vzalloc(size);

if (!net->ipv4.tcp_metrics_hash)
if (!tcp_metrics_hash)
return -ENOMEM;

return 0;
}

static void __net_exit tcp_net_metrics_exit(struct net *net)
{
unsigned int i;

for (i = 0; i < (1U << net->ipv4.tcp_metrics_hash_log) ; i++) {
struct tcp_metrics_block *tm, *next;

tm = rcu_dereference_protected(net->ipv4.tcp_metrics_hash[i].chain, 1);
while (tm) {
next = rcu_dereference_protected(tm->tcpm_next, 1);
kfree(tm);
tm = next;
}
}
kvfree(net->ipv4.tcp_metrics_hash);
tcp_metrics_flush_all(net);
}

static __net_initdata struct pernet_operations tcp_net_metrics_ops = {
Expand Down

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