diff mbox series

[net-next,2/2] net: Drop NETDEV_UNREGISTER_FINAL

Message ID 152179796956.13076.17482079697536507473.stgit@localhost.localdomain
State Superseded, archived
Delegated to: David Miller
Headers show
Series None | expand

Commit Message

Kirill Tkhai March 23, 2018, 9:39 a.m. UTC 
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>
---
 drivers/infiniband/hw/qedr/main.c |    4 ++--
 include/linux/netdevice.h         |    1 -
 include/rdma/ib_verbs.h           |    4 ++--
 net/core/dev.c                    |    6 ------
 4 files changed, 4 insertions(+), 11 deletions(-)

Comments

Jason Gunthorpe March 23, 2018, 4:15 p.m. UTC | #1 
On Fri, Mar 23, 2018 at 12:39:33PM +0300, Kirill Tkhai wrote:
> 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>
>  drivers/infiniband/hw/qedr/main.c |    4 ++--
>  include/linux/netdevice.h         |    1 -
>  include/rdma/ib_verbs.h           |    4 ++--
>  net/core/dev.c                    |    6 ------
>  4 files changed, 4 insertions(+), 11 deletions(-)

No problem to take the rdma part of this through netdev

Acked-by: Jason Gunthorpe <jgg@mellanox.com>

Jason
diff mbox series

Patch

diff --git a/drivers/infiniband/hw/qedr/main.c b/drivers/infiniband/hw/qedr/main.c
index db4bf97c0e15..eb32abb0099a 100644
--- 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 dd5a04c971d5..2a2d9cf50aa2 100644
--- 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 73b2387e3f74..a1c5e8320f86 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -2126,8 +2126,8 @@  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 bcc9fe68240b..c444da3e4b82 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -8086,7 +8086,6 @@  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
@@ -8158,10 +8157,6 @@  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);
@@ -8603,7 +8598,6 @@  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 */