From e80516880019aa1f7c5c410276edfea9575ec89f Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 15 Nov 2010 06:38:10 +0000 Subject: [PATCH] bridge: add RCU annotation to bridge multicast table Add modern __rcu annotatations to bridge multicast table. Use newer hlist macros to avoid direct access to hlist internals. Signed-off-by: Eric Dumazet Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller --- net/bridge/br_forward.c | 4 +- net/bridge/br_multicast.c | 78 +++++++++++++++++++++++++-------------- net/bridge/br_private.h | 6 +-- 3 files changed, 56 insertions(+), 32 deletions(-) diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c index cbfe87f0f34a..2bd11ec6d166 100644 --- a/net/bridge/br_forward.c +++ b/net/bridge/br_forward.c @@ -223,7 +223,7 @@ static void br_multicast_flood(struct net_bridge_mdb_entry *mdst, struct net_bridge_port_group *p; struct hlist_node *rp; - rp = rcu_dereference(br->router_list.first); + rp = rcu_dereference(hlist_first_rcu(&br->router_list)); p = mdst ? rcu_dereference(mdst->ports) : NULL; while (p || rp) { struct net_bridge_port *port, *lport, *rport; @@ -242,7 +242,7 @@ static void br_multicast_flood(struct net_bridge_mdb_entry *mdst, if ((unsigned long)lport >= (unsigned long)port) p = rcu_dereference(p->next); if ((unsigned long)rport >= (unsigned long)port) - rp = rcu_dereference(rp->next); + rp = rcu_dereference(hlist_next_rcu(rp)); } if (!prev) diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c index eb5b256ffc88..326e599f83fb 100644 --- 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; diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h index 75c90edaf7db..b862071bf601 100644 --- a/net/bridge/br_private.h +++ b/net/bridge/br_private.h @@ -72,7 +72,7 @@ struct net_bridge_fdb_entry struct net_bridge_port_group { struct net_bridge_port *port; - struct net_bridge_port_group *next; + struct net_bridge_port_group __rcu *next; struct hlist_node mglist; struct rcu_head rcu; struct timer_list timer; @@ -86,7 +86,7 @@ struct net_bridge_mdb_entry struct hlist_node hlist[2]; struct hlist_node mglist; struct net_bridge *br; - struct net_bridge_port_group *ports; + struct net_bridge_port_group __rcu *ports; struct rcu_head rcu; struct timer_list timer; struct timer_list query_timer; @@ -227,7 +227,7 @@ struct net_bridge unsigned long multicast_startup_query_interval; spinlock_t multicast_lock; - struct net_bridge_mdb_htable *mdb; + struct net_bridge_mdb_htable __rcu *mdb; struct hlist_head router_list; struct hlist_head mglist; -- 2.30.2