[PATCH net-next 1/4] net: move net_set_todo inside rollback_registered()

[Jakub Kicinski]

Commit 93ee31f14f6f ("[NET]: Fix free_netdev on register_netdev
failure.") moved net_set_todo() outside of rollback_registered()
so that rollback_registered() can be used in the failure path of
register_netdevice() but without risking a double free.

Since commit cf124db566e6 ("net: Fix inconsistent teardown and
release of private netdev state."), however, we have a better
way of handling that condition, since destructors don't call
free_netdev() directly.

After the change in commit c269a24ce057 ("net: make free_netdev()
more lenient with unregistering devices") we can now move
net_set_todo() back.

Signed-off-by: Jakub Kicinski <k...@kernel.org>
---
 net/core/dev.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/net/core/dev.c b/net/core/dev.c
index 6b90520a01b1..5f928b51c6b0 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -9546,8 +9546,10 @@ static void rollback_registered_many(struct list_head 
*head)
 
        synchronize_net();
 
-       list_for_each_entry(dev, head, unreg_list)
+       list_for_each_entry(dev, head, unreg_list) {
                dev_put(dev);
+               net_set_todo(dev);
+       }
 }
 
 static void rollback_registered(struct net_device *dev)
@@ -10104,7 +10106,6 @@ int register_netdevice(struct net_device *dev)
                /* Expect explicit free_netdev() on failure */
                dev->needs_free_netdev = false;
                rollback_registered(dev);
-               net_set_todo(dev);
                goto out;
        }
        /*
@@ -10727,8 +10728,6 @@ void unregister_netdevice_queue(struct net_device *dev, 
struct list_head *head)
                list_move_tail(&dev->unreg_list, head);
        } else {
                rollback_registered(dev);
-               /* Finish processing unregister after unlock */
-               net_set_todo(dev);
        }
 }
 EXPORT_SYMBOL(unregister_netdevice_queue);
@@ -10742,12 +10741,8 @@ EXPORT_SYMBOL(unregister_netdevice_queue);
  */
 void unregister_netdevice_many(struct list_head *head)
 {
-       struct net_device *dev;
-
        if (!list_empty(head)) {
                rollback_registered_many(head);
-               list_for_each_entry(dev, head, unreg_list)
-                       net_set_todo(dev);
                list_del(head);
        }
 }
-- 
2.26.2