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authorStephen Hemminger <shemminger@osdl.org>2006-02-09 17:08:52 -0800
committerDavid S. Miller <davem@davemloft.net>2006-02-09 17:08:52 -0800
commitb3f1be4b5412e34647764457bec901e06b03e624 (patch)
treeb3f1529ff0882ebb5aed190d8a61b52f703503ce /net/bridge/br_if.c
parent[TCP]: rcvbuf lock when tcp_moderate_rcvbuf enabled (diff)
downloadlinux-dev-b3f1be4b5412e34647764457bec901e06b03e624.tar.xz
linux-dev-b3f1be4b5412e34647764457bec901e06b03e624.zip
[BRIDGE]: fix for RCU and deadlock on device removal
Change Bridge receive path to correctly handle RCU removal of device from bridge. Also fixes deadlock between carrier_check and del_nbp. This replaces the previous deleted flag fix. Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/bridge/br_if.c')
-rw-r--r--net/bridge/br_if.c21
1 files changed, 11 insertions, 10 deletions
diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
index da687c8dc6ff..70b7ef917234 100644
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -79,9 +79,14 @@ static int port_cost(struct net_device *dev)
*/
static void port_carrier_check(void *arg)
{
- struct net_bridge_port *p = arg;
+ struct net_device *dev = arg;
+ struct net_bridge_port *p;
rtnl_lock();
+ p = dev->br_port;
+ if (!p)
+ goto done;
+
if (netif_carrier_ok(p->dev)) {
u32 cost = port_cost(p->dev);
@@ -97,6 +102,7 @@ static void port_carrier_check(void *arg)
br_stp_disable_port(p);
spin_unlock_bh(&p->br->lock);
}
+done:
rtnl_unlock();
}
@@ -104,7 +110,6 @@ static void destroy_nbp(struct net_bridge_port *p)
{
struct net_device *dev = p->dev;
- dev->br_port = NULL;
p->br = NULL;
p->dev = NULL;
dev_put(dev);
@@ -133,24 +138,20 @@ static void del_nbp(struct net_bridge_port *p)
struct net_bridge *br = p->br;
struct net_device *dev = p->dev;
- /* Race between RTNL notify and RCU callback */
- if (p->deleted)
- return;
-
dev_set_promiscuity(dev, -1);
cancel_delayed_work(&p->carrier_check);
- flush_scheduled_work();
spin_lock_bh(&br->lock);
br_stp_disable_port(p);
- p->deleted = 1;
spin_unlock_bh(&br->lock);
br_fdb_delete_by_port(br, p);
list_del_rcu(&p->list);
+ rcu_assign_pointer(dev->br_port, NULL);
+
call_rcu(&p->rcu, destroy_nbp_rcu);
}
@@ -254,11 +255,10 @@ static struct net_bridge_port *new_nbp(struct net_bridge *br,
p->dev = dev;
p->path_cost = port_cost(dev);
p->priority = 0x8000 >> BR_PORT_BITS;
- dev->br_port = p;
p->port_no = index;
br_init_port(p);
p->state = BR_STATE_DISABLED;
- INIT_WORK(&p->carrier_check, port_carrier_check, p);
+ INIT_WORK(&p->carrier_check, port_carrier_check, dev);
kobject_init(&p->kobj);
return p;
@@ -397,6 +397,7 @@ int br_add_if(struct net_bridge *br, struct net_device *dev)
else if ((err = br_sysfs_addif(p)))
del_nbp(p);
else {
+ rcu_assign_pointer(dev->br_port, p);
dev_set_promiscuity(dev, 1);
list_add_rcu(&p->list, &br->port_list);