tcp: use hash_32() in tcp_metrics

Fix a missing roundup_pow_of_two(), since tcpmhash_entries is not
guaranteed to be a power of two.

Uses hash_32() instead of custom hash.

tcpmhash_entries should be an unsigned int.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index d909c7f..0ffb8e3 100644 (file)
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -40,7 +40,7 @@ struct netns_ipv4 {
        struct sock             **icmp_sk;
        struct inet_peer_base   *peers;
        struct tcpm_hash_bucket *tcp_metrics_hash;
-       unsigned int            tcp_metrics_hash_mask;
+       unsigned int            tcp_metrics_hash_log;
        struct netns_frags      frags;
 #ifdef CONFIG_NETFILTER
        struct xt_table         *iptable_filter;

diff --git a/net/ipv4/tcp_metrics.c b/net/ipv4/tcp_metrics.c
index 99779ae..992f1bf 100644 (file)
--- a/net/ipv4/tcp_metrics.c
+++ b/net/ipv4/tcp_metrics.c
@@ -7,6 +7,7 @@
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/tcp.h>
+#include <linux/hash.h>
 
 #include <net/inet_connection_sock.h>
 #include <net/net_namespace.h>
@@ -228,10 +229,8 @@ static struct tcp_metrics_block *__tcp_get_metrics_req(struct request_sock *req,
                return NULL;
        }
 
-       hash ^= (hash >> 24) ^ (hash >> 16) ^ (hash >> 8);
-
        net = dev_net(dst->dev);
-       hash &= net->ipv4.tcp_metrics_hash_mask;
+       hash = hash_32(hash, net->ipv4.tcp_metrics_hash_log);
 
        for (tm = rcu_dereference(net->ipv4.tcp_metrics_hash[hash].chain); tm;
             tm = rcu_dereference(tm->tcpm_next)) {
@@ -265,10 +264,8 @@ static struct tcp_metrics_block *__tcp_get_metrics_tw(struct inet_timewait_sock
                return NULL;
        }
 
-       hash ^= (hash >> 24) ^ (hash >> 16) ^ (hash >> 8);
-
        net = twsk_net(tw);
-       hash &= net->ipv4.tcp_metrics_hash_mask;
+       hash = hash_32(hash, net->ipv4.tcp_metrics_hash_log);
 
        for (tm = rcu_dereference(net->ipv4.tcp_metrics_hash[hash].chain); tm;
             tm = rcu_dereference(tm->tcpm_next)) {
@@ -302,10 +299,8 @@ static struct tcp_metrics_block *tcp_get_metrics(struct sock *sk,
                return NULL;
        }
 
-       hash ^= (hash >> 24) ^ (hash >> 16) ^ (hash >> 8);
-
        net = dev_net(dst->dev);
-       hash &= net->ipv4.tcp_metrics_hash_mask;
+       hash = hash_32(hash, net->ipv4.tcp_metrics_hash_log);
 
        tm = __tcp_get_metrics(&addr, net, hash);
        reclaim = false;
@@ -694,7 +689,7 @@ void tcp_fastopen_cache_set(struct sock *sk, u16 mss,
        rcu_read_unlock();
 }
 
-static unsigned long tcpmhash_entries;
+static unsigned int tcpmhash_entries;
 static int __init set_tcpmhash_entries(char *str)
 {
        ssize_t ret;
@@ -702,7 +697,7 @@ static int __init set_tcpmhash_entries(char *str)
        if (!str)
                return 0;
 
-       ret = kstrtoul(str, 0, &tcpmhash_entries);
+       ret = kstrtouint(str, 0, &tcpmhash_entries);
        if (ret)
                return 0;
 
@@ -712,7 +707,8 @@ __setup("tcpmhash_entries=", set_tcpmhash_entries);
 
 static int __net_init tcp_net_metrics_init(struct net *net)
 {
-       int slots, size;
+       size_t size;
+       unsigned int slots;
 
        slots = tcpmhash_entries;
        if (!slots) {
@@ -722,14 +718,13 @@ static int __net_init tcp_net_metrics_init(struct net *net)
                        slots = 8 * 1024;
        }
 
-       size = slots * sizeof(struct tcpm_hash_bucket);
+       net->ipv4.tcp_metrics_hash_log = order_base_2(slots);
+       size = sizeof(struct tcpm_hash_bucket) << net->ipv4.tcp_metrics_hash_log;
 
        net->ipv4.tcp_metrics_hash = kzalloc(size, GFP_KERNEL);
        if (!net->ipv4.tcp_metrics_hash)
                return -ENOMEM;
 
-       net->ipv4.tcp_metrics_hash_mask = (slots - 1);
-
        return 0;
 }