summaryrefslogtreecommitdiff
path: root/net/ipv6/addrconf.c
diff options
context:
space:
mode:
authorEric Dumazet <edumazet@google.com>2012-08-22 17:19:46 +0000
committerDavid S. Miller <davem@davemloft.net>2012-08-22 21:50:36 -0700
commit0115e8e30d6fcdd4b8faa30d3ffd90859a591f51 (patch)
tree725026e2192e57b98366947ab53c73689ca040a8 /net/ipv6/addrconf.c
parentbf277b0ccea7d2422b85e232017ce3fddbe9c49c (diff)
net: remove delay at device dismantle
I noticed extra one second delay in device dismantle, tracked down to a call to dst_dev_event() while some call_rcu() are still in RCU queues. These call_rcu() were posted by rt_free(struct rtable *rt) calls. We then wait a little (but one second) in netdev_wait_allrefs() before kicking again NETDEV_UNREGISTER. As the call_rcu() are now completed, dst_dev_event() can do the needed device swap on busy dst. To solve this problem, add a new NETDEV_UNREGISTER_FINAL, called after a rcu_barrier(), but outside of RTNL lock. Use NETDEV_UNREGISTER_FINAL with care ! Change dst_dev_event() handler to react to NETDEV_UNREGISTER_FINAL Also remove NETDEV_UNREGISTER_BATCH, as its not used anymore after IP cache removal. With help from Gao feng Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Mahesh Bandewar <maheshb@google.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Gao feng <gaofeng@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6/addrconf.c')
-rw-r--r--net/ipv6/addrconf.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 6bc85f7c31e3..e581009cb09e 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -2566,10 +2566,14 @@ static int addrconf_notify(struct notifier_block *this, unsigned long event,
void *data)
{
struct net_device *dev = (struct net_device *) data;
- struct inet6_dev *idev = __in6_dev_get(dev);
+ struct inet6_dev *idev;
int run_pending = 0;
int err;
+ if (event == NETDEV_UNREGISTER_FINAL)
+ return NOTIFY_DONE;
+
+ idev = __in6_dev_get(dev);
switch (event) {
case NETDEV_REGISTER:
if (!idev && dev->mtu >= IPV6_MIN_MTU) {