net: Convert atomic_t net::count to refcount_t
Since net could be obtained from RCU lists,
and there is a race with net destruction,
the patch converts net::count to refcount_t.
This provides sanity checks for the cases of
incrementing counter of already dead net,
when maybe_get_net() has to used instead
of get_net().
Drivers: allyesconfig and allmodconfig are OK.
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 799b752..7bf8b85 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -961,7 +961,7 @@ net_rx_queue_update_kobjects(struct net_device *dev, int old_num, int new_num)
while (--i >= new_num) {
struct kobject *kobj = &dev->_rx[i].kobj;
- if (!atomic_read(&dev_net(dev)->count))
+ if (!refcount_read(&dev_net(dev)->count))
kobj->uevent_suppress = 1;
if (dev->sysfs_rx_queue_group)
sysfs_remove_group(kobj, dev->sysfs_rx_queue_group);
@@ -1367,7 +1367,7 @@ netdev_queue_update_kobjects(struct net_device *dev, int old_num, int new_num)
while (--i >= new_num) {
struct netdev_queue *queue = dev->_tx + i;
- if (!atomic_read(&dev_net(dev)->count))
+ if (!refcount_read(&dev_net(dev)->count))
queue->kobj.uevent_suppress = 1;
#ifdef CONFIG_BQL
sysfs_remove_group(&queue->kobj, &dql_group);
@@ -1558,7 +1558,7 @@ void netdev_unregister_kobject(struct net_device *ndev)
{
struct device *dev = &ndev->dev;
- if (!atomic_read(&dev_net(ndev)->count))
+ if (!refcount_read(&dev_net(ndev)->count))
dev_set_uevent_suppress(dev, 1);
kobject_get(&dev->kobj);