[PATCH v3 net-next 05/23] net: add net device refcount tracker to struct netdev_queue

From: Eric Dumazet <eric.dumazet@gmail.com>
To: "David S . Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>
Cc: netdev <netdev@vger.kernel.org>,
	Eric Dumazet <edumazet@google.com>,
	Eric Dumazet <eric.dumazet@gmail.com>,
	Dmitry Vyukov <dvyukov@google.com>
Subject: [PATCH v3 net-next 05/23] net: add net device refcount tracker to struct netdev_queue
Date: Sat,  4 Dec 2021 20:21:59 -0800	[thread overview]
Message-ID: <20211205042217.982127-6-eric.dumazet@gmail.com> (raw)
In-Reply-To: <20211205042217.982127-1-eric.dumazet@gmail.com>

From: Eric Dumazet <edumazet@google.com>

This will help debugging pesky netdev reference leaks.

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 include/linux/netdevice.h | 2 ++
 net/core/net-sysfs.c      | 4 ++--
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 3d691fadd56907212b8562432bb5fe0ced0fd962..b4f704337f657ebc46e02c9e5e7f5d2c2c64685e 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -586,6 +586,8 @@ struct netdev_queue {
  * read-mostly part
  */
 	struct net_device	*dev;
+	netdevice_tracker	dev_tracker;
+
 	struct Qdisc __rcu	*qdisc;
 	struct Qdisc		*qdisc_sleeping;
 #ifdef CONFIG_SYSFS
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 27a7ac2e516f65dbfdb2a2319e6faa27c7dd8f31..3b2cdbbdc858e06fb0a482a9b7fc778e501ba1e0 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -1607,7 +1607,7 @@ static void netdev_queue_release(struct kobject *kobj)
 	struct netdev_queue *queue = to_netdev_queue(kobj);
 
 	memset(kobj, 0, sizeof(*kobj));
-	dev_put(queue->dev);
+	dev_put_track(queue->dev, &queue->dev_tracker);
 }
 
 static const void *netdev_queue_namespace(struct kobject *kobj)
@@ -1647,7 +1647,7 @@ static int netdev_queue_add_kobject(struct net_device *dev, int index)
 	/* Kobject_put later will trigger netdev_queue_release call
 	 * which decreases dev refcount: Take that reference here
 	 */
-	dev_hold(queue->dev);
+	dev_hold_track(queue->dev, &queue->dev_tracker, GFP_KERNEL);
 
 	kobj->kset = dev->queues_kset;
 	error = kobject_init_and_add(kobj, &netdev_queue_ktype, NULL,
-- 
2.34.1.400.ga245620fadb-goog

