diff options
| author | Johannes Berg <johannes@sipsolutions.net> | 2009-07-10 09:51:33 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2009-07-12 14:03:25 -0700 |
| commit | 11a28d373ed2539a110d56419457e2e7db221ac7 (patch) | |
| tree | d1460cb057299c89ff34b20821e30c8bfc7e589a | |
| parent | 6c04bb18ddd633b7feac2c8fe2ae0bf61d20ca7a (diff) | |
| download | linux-11a28d373ed2539a110d56419457e2e7db221ac7.tar.bz2 | |
net: make namespace iteration possible under RCU
All we need to take care of is using proper RCU list
add/del primitives and inserting a synchronize_rcu()
at one place to make sure the exit notifiers are run
after everybody has stopped iterating the list.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/net/net_namespace.h | 3 | ||||
| -rw-r--r-- | net/core/net_namespace.c | 14 |
2 files changed, 14 insertions, 3 deletions
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index ded434b032a4..b34a6ee73754 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -208,6 +208,9 @@ static inline struct net *read_pnet(struct net * const *pnet) #define for_each_net(VAR) \ list_for_each_entry(VAR, &net_namespace_list, list) +#define for_each_net_rcu(VAR) \ + list_for_each_entry_rcu(VAR, &net_namespace_list, list) + #ifdef CONFIG_NET_NS #define __net_init #define __net_exit diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index b7292a2719dc..5cd0b22e649d 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -6,6 +6,7 @@ #include <linux/delay.h> #include <linux/sched.h> #include <linux/idr.h> +#include <linux/rculist.h> #include <net/net_namespace.h> #include <net/netns/generic.h> @@ -127,7 +128,7 @@ static struct net *net_create(void) rv = setup_net(net); if (rv == 0) { rtnl_lock(); - list_add_tail(&net->list, &net_namespace_list); + list_add_tail_rcu(&net->list, &net_namespace_list); rtnl_unlock(); } mutex_unlock(&net_mutex); @@ -156,9 +157,16 @@ static void cleanup_net(struct work_struct *work) /* Don't let anyone else find us. */ rtnl_lock(); - list_del(&net->list); + list_del_rcu(&net->list); rtnl_unlock(); + /* + * Another CPU might be rcu-iterating the list, wait for it. + * This needs to be before calling the exit() notifiers, so + * the rcu_barrier() below isn't sufficient alone. + */ + synchronize_rcu(); + /* Run all of the network namespace exit methods */ list_for_each_entry_reverse(ops, &pernet_list, list) { if (ops->exit) @@ -219,7 +227,7 @@ static int __init net_ns_init(void) panic("Could not setup the initial network namespace"); rtnl_lock(); - list_add_tail(&init_net.list, &net_namespace_list); + list_add_tail_rcu(&init_net.list, &net_namespace_list); rtnl_unlock(); mutex_unlock(&net_mutex); |