net: Drop NETDEV_UNREGISTER_FINAL

Last user is gone after bdf5bd7f2132 "rds: tcp: remove
register_netdevice_notifier infrastructure.", so we can
remove this netdevice command. This allows to delete
rtnl_lock() in netdev_run_todo(), which is hot path for
net namespace unregistration.

dev_change_net_namespace() and netdev_wait_allrefs()
have rcu_barrier() before NETDEV_UNREGISTER_FINAL call,
and the source commits say they were introduced to
delemit the call with NETDEV_UNREGISTER, but this patch
leaves them on the places, since they require additional
analysis, whether we need in them for something else.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/infiniband/hw/qedr/main.c b/drivers/infiniband/hw/qedr/main.c
index db4bf97..eb32abb 100644 (file)
--- a/drivers/infiniband/hw/qedr/main.c
+++ b/drivers/infiniband/hw/qedr/main.c
@@ -90,8 +90,8 @@ static struct net_device *qedr_get_netdev(struct ib_device *dev, u8 port_num)
        dev_hold(qdev->ndev);
 
        /* The HW vendor's device driver must guarantee
-        * that this function returns NULL before the net device reaches
-        * NETDEV_UNREGISTER_FINAL state.
+        * that this function returns NULL before the net device has finished
+        * NETDEV_UNREGISTER state.
         */
        return qdev->ndev;
 }

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index dd5a04c..2a2d9cf 100644 (file)
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2336,7 +2336,6 @@ enum netdev_cmd {
        NETDEV_PRE_TYPE_CHANGE,
        NETDEV_POST_TYPE_CHANGE,
        NETDEV_POST_INIT,
-       NETDEV_UNREGISTER_FINAL,
        NETDEV_RELEASE,
        NETDEV_NOTIFY_PEERS,
        NETDEV_JOIN,

diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index ff3ed43..6eb1747 100644 (file)
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -2122,8 +2122,8 @@ struct ib_device {
         * net device of device @device at port @port_num or NULL if such
         * a net device doesn't exist. The vendor driver should call dev_hold
         * on this net device. The HW vendor's device driver must guarantee
-        * that this function returns NULL before the net device reaches
-        * NETDEV_UNREGISTER_FINAL state.
+        * that this function returns NULL before the net device has finished
+        * NETDEV_UNREGISTER state.
         */
        struct net_device         *(*get_netdev)(struct ib_device *device,
                                                 u8 port_num);

diff --git a/net/core/dev.c b/net/core/dev.c
index 055e7ae..97a96df 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1584,7 +1584,6 @@ const char *netdev_cmd_to_name(enum netdev_cmd cmd)
        N(RESEND_IGMP) N(PRECHANGEMTU) N(CHANGEINFODATA) N(BONDING_INFO)
        N(PRECHANGEUPPER) N(CHANGELOWERSTATE) N(UDP_TUNNEL_PUSH_INFO)
        N(UDP_TUNNEL_DROP_INFO) N(CHANGE_TX_QUEUE_LEN)
-       N(UNREGISTER_FINAL)
        };
 #undef N
        return "UNKNOWN_NETDEV_EVENT";
@@ -8097,7 +8096,6 @@ static void netdev_wait_allrefs(struct net_device *dev)
                        rcu_barrier();
                        rtnl_lock();
 
-                       call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
                        if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
                                     &dev->state)) {
                                /* We must not have linkwatch events
@@ -8169,10 +8167,6 @@ void netdev_run_todo(void)
                        = list_first_entry(&list, struct net_device, todo_list);
                list_del(&dev->todo_list);
 
-               rtnl_lock();
-               call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
-               __rtnl_unlock();
-
                if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
                        pr_err("network todo '%s' but state %d\n",
                               dev->name, dev->reg_state);
@@ -8614,7 +8608,6 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
         */
        call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
        rcu_barrier();
-       call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
 
        new_nsid = peernet2id_alloc(dev_net(dev), net);
        /* If there is an ifindex conflict assign a new one */