From 65b7b5b90fcd17b25ef43b0cd02bda47bf286675 Mon Sep 17 00:00:00 2001 From: Kirill Tkhai Date: Mon, 19 Feb 2018 12:58:45 +0300 Subject: net: Make cleanup_list and net::cleanup_list of llist type This simplifies cleanup queueing and makes cleanup lists to use llist primitives. Since llist has its own cmpxchg() ordering, cleanup_list_lock is not more need. Also, struct llist_node is smaller, than struct list_head, so we save some bytes in struct net with this patch. Signed-off-by: Kirill Tkhai Signed-off-by: David S. Miller --- net/core/net_namespace.c | 20 ++++++-------------- 1 file changed, 6 insertions(+), 14 deletions(-) (limited to 'net/core/net_namespace.c') diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index e89a516620dd..abf8a46e94e2 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -481,21 +481,18 @@ static void unhash_nsid(struct net *net, struct net *last) spin_unlock_bh(&net->nsid_lock); } -static DEFINE_SPINLOCK(cleanup_list_lock); -static LIST_HEAD(cleanup_list); /* Must hold cleanup_list_lock to touch */ +static LLIST_HEAD(cleanup_list); static void cleanup_net(struct work_struct *work) { const struct pernet_operations *ops; struct net *net, *tmp, *last; - struct list_head net_kill_list; + struct llist_node *net_kill_list; LIST_HEAD(net_exit_list); unsigned write; /* Atomically snapshot the list of namespaces to cleanup */ - spin_lock_irq(&cleanup_list_lock); - list_replace_init(&cleanup_list, &net_kill_list); - spin_unlock_irq(&cleanup_list_lock); + net_kill_list = llist_del_all(&cleanup_list); again: write = READ_ONCE(nr_sync_pernet_ops); if (write) @@ -510,7 +507,7 @@ again: /* Don't let anyone else find us. */ rtnl_lock(); - list_for_each_entry(net, &net_kill_list, cleanup_list) + llist_for_each_entry(net, net_kill_list, cleanup_list) list_del_rcu(&net->list); /* Cache last net. After we unlock rtnl, no one new net * added to net_namespace_list can assign nsid pointer @@ -525,7 +522,7 @@ again: last = list_last_entry(&net_namespace_list, struct net, list); rtnl_unlock(); - list_for_each_entry(net, &net_kill_list, cleanup_list) { + llist_for_each_entry(net, net_kill_list, cleanup_list) { unhash_nsid(net, last); list_add_tail(&net->exit_list, &net_exit_list); } @@ -585,12 +582,7 @@ static DECLARE_WORK(net_cleanup_work, cleanup_net); void __put_net(struct net *net) { /* Cleanup the network namespace in process context */ - unsigned long flags; - - spin_lock_irqsave(&cleanup_list_lock, flags); - list_add(&net->cleanup_list, &cleanup_list); - spin_unlock_irqrestore(&cleanup_list_lock, flags); - + llist_add(&net->cleanup_list, &cleanup_list); queue_work(netns_wq, &net_cleanup_work); } EXPORT_SYMBOL_GPL(__put_net); -- cgit v1.2.3-59-g8ed1b