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bridge: add RCU annotation to bridge multicast table
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Add modern __rcu annotatations to bridge multicast table.
Use newer hlist macros to avoid direct access to hlist internals.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Eric Dumazet authored and David S. Miller committed Nov 15, 2010
1 parent 8a22c99 commit e805168
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Showing 3 changed files with 56 additions and 32 deletions.
4 changes: 2 additions & 2 deletions net/bridge/br_forward.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand All @@ -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)
Expand Down
78 changes: 51 additions & 27 deletions net/bridge/br_multicast.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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)
{
Expand Down Expand Up @@ -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)
Expand Down Expand Up @@ -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--;

Expand All @@ -249,16 +253,20 @@ static void br_multicast_group_expired(unsigned long data)
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;

Expand Down Expand Up @@ -294,10 +302,10 @@ static void br_multicast_port_group_expired(unsigned long data)
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;

Expand Down Expand Up @@ -569,14 +577,15 @@ 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;
unsigned max;
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)))
Expand Down Expand Up @@ -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;
Expand All @@ -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;

Expand Down Expand Up @@ -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;

Expand All @@ -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)
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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;

Expand All @@ -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)
Expand All @@ -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;
Expand Down Expand Up @@ -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;

Expand All @@ -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)
Expand Down Expand Up @@ -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;
Expand All @@ -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;

Expand Down Expand Up @@ -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;

Expand Down Expand Up @@ -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)
Expand All @@ -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;
Expand All @@ -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))
Expand All @@ -1782,16 +1804,18 @@ 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;

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;
Expand Down
6 changes: 3 additions & 3 deletions net/bridge/br_private.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand All @@ -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;
Expand Down Expand Up @@ -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;

Expand Down

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