[Patch net-next v2 2/2] bonding: remove useless stats_lock_key

[Cong Wang]

After commit b3e80d44f5b1
("bonding: fix lockdep warning in bond_get_stats()") the dynamic
key is no longer necessary, as we compute nest level at run-time.
So, we can just remove it to save some lockdep key entries.

Test commands:
 ip link add bond0 type bond
 ip link add bond1 type bond
 ip link set bond0 master bond1
 ip link set bond0 nomaster
 ip link set bond1 master bond0

Reported-and-tested-by: syzbot+aaa6fa4949cc5d9b7...@syzkaller.appspotmail.com
Cc: Dmitry Vyukov <dvyu...@google.com>
Acked-by: Taehee Yoo <ap420...@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangc...@gmail.com>
---
 drivers/net/bonding/bond_main.c | 3 ---
 include/net/bonding.h           | 1 -
 2 files changed, 4 deletions(-)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index d01871321d22..baa93191dfdd 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -4491,7 +4491,6 @@ static void bond_uninit(struct net_device *bond_dev)
 
        list_del(&bond->bond_list);
 
-       lockdep_unregister_key(&bond->stats_lock_key);
        bond_debug_unregister(bond);
 }
 
@@ -4896,8 +4895,6 @@ static int bond_init(struct net_device *bond_dev)
                return -ENOMEM;
 
        spin_lock_init(&bond->stats_lock);
-       lockdep_register_key(&bond->stats_lock_key);
-       lockdep_set_class(&bond->stats_lock, &bond->stats_lock_key);
        netdev_lockdep_set_classes(bond_dev);
 
        list_add_tail(&bond->bond_list, &bn->dev_list);
diff --git a/include/net/bonding.h b/include/net/bonding.h
index dc2ce31a1f52..0b696da5c115 100644
--- a/include/net/bonding.h
+++ b/include/net/bonding.h
@@ -237,7 +237,6 @@ struct bonding {
        struct   dentry *debug_dir;
 #endif /* CONFIG_DEBUG_FS */
        struct rtnl_link_stats64 bond_stats;
-       struct lock_class_key stats_lock_key;
 };
 
 #define bond_slave_get_rcu(dev) \
-- 
2.26.2