bridge: add RCU annotation to bridge multicast table

[net-next-2.6.git] / net / bridge / br_multicast.c

diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index eb5b256ffc8801ff7e187c64ee3dde5da268f570..326e599f83fb2a8fa80b55a46819e708f7040a14 100644 (file)
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -33,6 +33,9 @@
 
 #include "br_private.h"
 
+#define mlock_dereference(X, br) \
+       rcu_dereference_protected(X, lockdep_is_held(&br->multicast_lock))
+
 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 static inline int ipv6_is_local_multicast(const struct in6_addr *addr)
 {
@@ -135,7 +138,7 @@ static struct net_bridge_mdb_entry *br_mdb_ip6_get(
 struct net_bridge_mdb_entry *br_mdb_get(struct net_bridge *br,
                                        struct sk_buff *skb)
 {
-       struct net_bridge_mdb_htable *mdb = br->mdb;
+       struct net_bridge_mdb_htable *mdb = rcu_dereference(br->mdb);
        struct br_ip ip;
 
        if (br->multicast_disabled)
@@ -235,7 +238,8 @@ static void br_multicast_group_expired(unsigned long data)
        if (mp->ports)
                goto out;
 
-       mdb = br->mdb;
+       mdb = mlock_dereference(br->mdb, br);
+
        hlist_del_rcu(&mp->hlist[mdb->ver]);
        mdb->size--;
 
@@ -249,16 +253,20 @@ out:
 static void br_multicast_del_pg(struct net_bridge *br,
                                struct net_bridge_port_group *pg)
 {
-       struct net_bridge_mdb_htable *mdb = br->mdb;
+       struct net_bridge_mdb_htable *mdb;
        struct net_bridge_mdb_entry *mp;
        struct net_bridge_port_group *p;
-       struct net_bridge_port_group **pp;
+       struct net_bridge_port_group __rcu **pp;
+
+       mdb = mlock_dereference(br->mdb, br);
 
        mp = br_mdb_ip_get(mdb, &pg->addr);
        if (WARN_ON(!mp))
                return;
 
-       for (pp = &mp->ports; (p = *pp); pp = &p->next) {
+       for (pp = &mp->ports;
+            (p = mlock_dereference(*pp, br)) != NULL;
+            pp = &p->next) {
                if (p != pg)
                        continue;
 
@@ -294,10 +302,10 @@ out:
        spin_unlock(&br->multicast_lock);
 }
 
-static int br_mdb_rehash(struct net_bridge_mdb_htable **mdbp, int max,
+static int br_mdb_rehash(struct net_bridge_mdb_htable __rcu **mdbp, int max,
                         int elasticity)
 {
-       struct net_bridge_mdb_htable *old = *mdbp;
+       struct net_bridge_mdb_htable *old = rcu_dereference_protected(*mdbp, 1);
        struct net_bridge_mdb_htable *mdb;
        int err;
 
@@ -569,7 +577,7 @@ static struct net_bridge_mdb_entry *br_multicast_get_group(
        struct net_bridge *br, struct net_bridge_port *port,
        struct br_ip *group, int hash)
 {
-       struct net_bridge_mdb_htable *mdb = br->mdb;
+       struct net_bridge_mdb_htable *mdb;
        struct net_bridge_mdb_entry *mp;
        struct hlist_node *p;
        unsigned count = 0;
@@ -577,6 +585,7 @@ static struct net_bridge_mdb_entry *br_multicast_get_group(
        int elasticity;
        int err;
 
+       mdb = rcu_dereference_protected(br->mdb, 1);
        hlist_for_each_entry(mp, p, &mdb->mhash[hash], hlist[mdb->ver]) {
                count++;
                if (unlikely(br_ip_equal(group, &mp->addr)))
@@ -642,10 +651,11 @@ static struct net_bridge_mdb_entry *br_multicast_new_group(
        struct net_bridge *br, struct net_bridge_port *port,
        struct br_ip *group)
 {
-       struct net_bridge_mdb_htable *mdb = br->mdb;
+       struct net_bridge_mdb_htable *mdb;
        struct net_bridge_mdb_entry *mp;
        int hash;
 
+       mdb = rcu_dereference_protected(br->mdb, 1);
        if (!mdb) {
                if (br_mdb_rehash(&br->mdb, BR_HASH_SIZE, 0))
                        return NULL;
@@ -660,7 +670,7 @@ static struct net_bridge_mdb_entry *br_multicast_new_group(
 
        case -EAGAIN:
 rehash:
-               mdb = br->mdb;
+               mdb = rcu_dereference_protected(br->mdb, 1);
                hash = br_ip_hash(mdb, group);
                break;
 
@@ -692,7 +702,7 @@ static int br_multicast_add_group(struct net_bridge *br,
 {
        struct net_bridge_mdb_entry *mp;
        struct net_bridge_port_group *p;
-       struct net_bridge_port_group **pp;
+       struct net_bridge_port_group __rcu **pp;
        unsigned long now = jiffies;
        int err;
 
@@ -712,7 +722,9 @@ static int br_multicast_add_group(struct net_bridge *br,
                goto out;
        }
 
-       for (pp = &mp->ports; (p = *pp); pp = &p->next) {
+       for (pp = &mp->ports;
+            (p = mlock_dereference(*pp, br)) != NULL;
+            pp = &p->next) {
                if (p->port == port)
                        goto found;
                if ((unsigned long)p->port < (unsigned long)port)
@@ -1106,7 +1118,7 @@ static int br_ip4_multicast_query(struct net_bridge *br,
        struct net_bridge_mdb_entry *mp;
        struct igmpv3_query *ih3;
        struct net_bridge_port_group *p;
-       struct net_bridge_port_group **pp;
+       struct net_bridge_port_group __rcu **pp;
        unsigned long max_delay;
        unsigned long now = jiffies;
        __be32 group;
@@ -1145,7 +1157,7 @@ static int br_ip4_multicast_query(struct net_bridge *br,
        if (!group)
                goto out;
 
-       mp = br_mdb_ip4_get(br->mdb, group);
+       mp = br_mdb_ip4_get(mlock_dereference(br->mdb, br), group);
        if (!mp)
                goto out;
 
@@ -1157,7 +1169,9 @@ static int br_ip4_multicast_query(struct net_bridge *br,
             try_to_del_timer_sync(&mp->timer) >= 0))
                mod_timer(&mp->timer, now + max_delay);
 
-       for (pp = &mp->ports; (p = *pp); pp = &p->next) {
+       for (pp = &mp->ports;
+            (p = mlock_dereference(*pp, br)) != NULL;
+            pp = &p->next) {
                if (timer_pending(&p->timer) ?
                    time_after(p->timer.expires, now + max_delay) :
                    try_to_del_timer_sync(&p->timer) >= 0)
@@ -1178,7 +1192,8 @@ static int br_ip6_multicast_query(struct net_bridge *br,
        struct mld_msg *mld = (struct mld_msg *) icmp6_hdr(skb);
        struct net_bridge_mdb_entry *mp;
        struct mld2_query *mld2q;
-       struct net_bridge_port_group *p, **pp;
+       struct net_bridge_port_group *p;
+       struct net_bridge_port_group __rcu **pp;
        unsigned long max_delay;
        unsigned long now = jiffies;
        struct in6_addr *group = NULL;
@@ -1214,7 +1229,7 @@ static int br_ip6_multicast_query(struct net_bridge *br,
        if (!group)
                goto out;
 
-       mp = br_mdb_ip6_get(br->mdb, group);
+       mp = br_mdb_ip6_get(mlock_dereference(br->mdb, br), group);
        if (!mp)
                goto out;
 
@@ -1225,7 +1240,9 @@ static int br_ip6_multicast_query(struct net_bridge *br,
             try_to_del_timer_sync(&mp->timer) >= 0))
                mod_timer(&mp->timer, now + max_delay);
 
-       for (pp = &mp->ports; (p = *pp); pp = &p->next) {
+       for (pp = &mp->ports;
+            (p = mlock_dereference(*pp, br)) != NULL;
+            pp = &p->next) {
                if (timer_pending(&p->timer) ?
                    time_after(p->timer.expires, now + max_delay) :
                    try_to_del_timer_sync(&p->timer) >= 0)
@@ -1254,7 +1271,7 @@ static void br_multicast_leave_group(struct net_bridge *br,
            timer_pending(&br->multicast_querier_timer))
                goto out;
 
-       mdb = br->mdb;
+       mdb = mlock_dereference(br->mdb, br);
        mp = br_mdb_ip_get(mdb, group);
        if (!mp)
                goto out;
@@ -1277,7 +1294,9 @@ static void br_multicast_leave_group(struct net_bridge *br,
                goto out;
        }
 
-       for (p = mp->ports; p; p = p->next) {
+       for (p = mlock_dereference(mp->ports, br);
+            p != NULL;
+            p = mlock_dereference(p->next, br)) {
                if (p->port != port)
                        continue;
 
@@ -1625,7 +1644,7 @@ void br_multicast_stop(struct net_bridge *br)
        del_timer_sync(&br->multicast_query_timer);
 
        spin_lock_bh(&br->multicast_lock);
-       mdb = br->mdb;
+       mdb = mlock_dereference(br->mdb, br);
        if (!mdb)
                goto out;
 
@@ -1729,6 +1748,7 @@ int br_multicast_toggle(struct net_bridge *br, unsigned long val)
 {
        struct net_bridge_port *port;
        int err = 0;
+       struct net_bridge_mdb_htable *mdb;
 
        spin_lock(&br->multicast_lock);
        if (br->multicast_disabled == !val)
@@ -1741,15 +1761,16 @@ int br_multicast_toggle(struct net_bridge *br, unsigned long val)
        if (!netif_running(br->dev))
                goto unlock;
 
-       if (br->mdb) {
-               if (br->mdb->old) {
+       mdb = mlock_dereference(br->mdb, br);
+       if (mdb) {
+               if (mdb->old) {
                        err = -EEXIST;
 rollback:
                        br->multicast_disabled = !!val;
                        goto unlock;
                }
 
-               err = br_mdb_rehash(&br->mdb, br->mdb->max,
+               err = br_mdb_rehash(&br->mdb, mdb->max,
                                    br->hash_elasticity);
                if (err)
                        goto rollback;
@@ -1774,6 +1795,7 @@ int br_multicast_set_hash_max(struct net_bridge *br, unsigned long val)
 {
        int err = -ENOENT;
        u32 old;
+       struct net_bridge_mdb_htable *mdb;
 
        spin_lock(&br->multicast_lock);
        if (!netif_running(br->dev))
@@ -1782,7 +1804,9 @@ int br_multicast_set_hash_max(struct net_bridge *br, unsigned long val)
        err = -EINVAL;
        if (!is_power_of_2(val))
                goto unlock;
-       if (br->mdb && val < br->mdb->size)
+
+       mdb = mlock_dereference(br->mdb, br);
+       if (mdb && val < mdb->size)
                goto unlock;
 
        err = 0;
@@ -1790,8 +1814,8 @@ int br_multicast_set_hash_max(struct net_bridge *br, unsigned long val)
        old = br->hash_max;
        br->hash_max = val;
 
-       if (br->mdb) {
-               if (br->mdb->old) {
+       if (mdb) {
+               if (mdb->old) {
                        err = -EEXIST;
 rollback:
                        br->hash_max = old;