Re: [PATCH net-next] batman-adv: adopt netdev_hold() / netdev_put()

On 06/02/2025 15:04, Eric Dumazet wrote:

Add a device tracker to struct batadv_hard_iface to help debugging of network device refcount imbalances.

Signed-off-by: Eric Dumazet edumazet@google.com

net/batman-adv/hard-interface.c | 14 +++++--------- net/batman-adv/types.h | 3 +++ 2 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c index 96a412beab2de9069c0f88e4cd844fbc0922aa18..9a3ae567eb12d0c65b25292d020462b6ad60b699 100644 --- a/net/batman-adv/hard-interface.c +++ b/net/batman-adv/hard-interface.c @@ -51,7 +51,7 @@ void batadv_hardif_release(struct kref *ref) struct batadv_hard_iface *hard_iface;

hard_iface = container_of(ref, struct batadv_hard_iface, refcount);

• dev_put(hard_iface->net_dev);

• netdev_put(hard_iface->net_dev, &hard_iface->dev_tracker);

  kfree_rcu(hard_iface, rcu); }

@@ -875,15 +875,16 @@ batadv_hardif_add_interface(struct net_device *net_dev) ASSERT_RTNL();

if (!batadv_is_valid_iface(net_dev))

• goto out;
  

• return NULL;
  
  

• dev_hold(net_dev);

  hard_iface = kzalloc(sizeof(*hard_iface), GFP_ATOMIC); if (!hard_iface)

• goto release_dev;
  

• return NULL;
  
  

• netdev_hold(net_dev, &hard_iface->dev_tracker, GFP_ATOMIC); hard_iface->net_dev = net_dev;

• hard_iface->soft_iface = NULL; hard_iface->if_status = BATADV_IF_NOT_IN_USE;

@@ -909,11 +910,6 @@ batadv_hardif_add_interface(struct net_device *net_dev) batadv_hardif_generation++;

return hard_iface;

-release_dev:

• dev_put(net_dev);

-out:

• return NULL; }

  static void batadv_hardif_remove_interface(struct batadv_hard_iface *hard_iface)

diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index f491bff8c51b8bf68eb11dbbeb1a434d446c25f0..a73fc3ab7dd28ae2c8484c0d198a15437d49ea73 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -186,6 +186,9 @@ struct batadv_hard_iface { /** @net_dev: pointer to the net_device */ struct net_device *net_dev;

• /** @dev_tracker device tracker for @net_dev */
• netdevice_tracker dev_tracker;

There are two blanks between type and member name. Is that intended?

• /** @refcount: number of contexts the object is used */ struct kref refcount;

We also have hard_iface->soft_iface storing a pointer to the soft_iface (batX) netdev.

How about converting that to netdev_put/hold as well? See batadv_hardif_enable_interface() / batadv_hardif_disable_interface()

Best Regards,