From e51b962438741f5482c82fb225c1d59136f0fd87 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 13 Feb 2024 06:32:44 +0000 Subject: [PATCH] net: remove dev_base_lock from register_netdevice() and friends. RTNL already protects writes to dev->reg_state, we no longer need to hold dev_base_lock to protect the readers. unlist_netdevice() second argument can be removed. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/core/dev.c | 20 +++++++------------- 1 file changed, 7 insertions(+), 13 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index 26f93446b743e..02cf9fd68da63 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -414,7 +414,7 @@ static void list_netdevice(struct net_device *dev) /* Device list removal * caller must respect a RCU grace period before freeing/reusing dev */ -static void unlist_netdevice(struct net_device *dev, bool lock) +static void unlist_netdevice(struct net_device *dev) { struct netdev_name_node *name_node; struct net *net = dev_net(dev); @@ -427,13 +427,11 @@ static void unlist_netdevice(struct net_device *dev, bool lock) netdev_name_node_del(name_node); /* Unlink dev from the device chain */ - if (lock) - write_lock(&dev_base_lock); + write_lock(&dev_base_lock); list_del_rcu(&dev->dev_list); netdev_name_node_del(dev->name_node); hlist_del_rcu(&dev->index_hlist); - if (lock) - write_unlock(&dev_base_lock); + write_unlock(&dev_base_lock); dev_base_seq_inc(dev_net(dev)); } @@ -10338,9 +10336,9 @@ int register_netdevice(struct net_device *dev) goto err_ifindex_release; ret = netdev_register_kobject(dev); - write_lock(&dev_base_lock); + WRITE_ONCE(dev->reg_state, ret ? NETREG_UNREGISTERED : NETREG_REGISTERED); - write_unlock(&dev_base_lock); + if (ret) goto err_uninit_notify; @@ -10629,9 +10627,7 @@ void netdev_run_todo(void) continue; } - write_lock(&dev_base_lock); WRITE_ONCE(dev->reg_state, NETREG_UNREGISTERED); - write_unlock(&dev_base_lock); linkwatch_sync_dev(dev); } @@ -11138,10 +11134,8 @@ void unregister_netdevice_many_notify(struct list_head *head, list_for_each_entry(dev, head, unreg_list) { /* And unlink it from device chain. */ - write_lock(&dev_base_lock); - unlist_netdevice(dev, false); + unlist_netdevice(dev); WRITE_ONCE(dev->reg_state, NETREG_UNREGISTERING); - write_unlock(&dev_base_lock); } flush_all_backlogs(); @@ -11323,7 +11317,7 @@ int __dev_change_net_namespace(struct net_device *dev, struct net *net, dev_close(dev); /* And unlink it from device chain */ - unlist_netdevice(dev, true); + unlist_netdevice(dev); synchronize_net(); -- 2.30.2