From bc51dddf98c907b598e645ae4b277ed1295b6d5f Mon Sep 17 00:00:00 2001 From: WANG Cong Date: Thu, 1 Sep 2016 21:53:45 -0700 Subject: [PATCH] netns: avoid disabling irq for netns id We never read or change netns id in hardirq context, the only place we read netns id in softirq context is in vxlan_xmit(). So, it should be enough to just disable BH. Cc: Nicolas Dichtel Signed-off-by: Cong Wang Signed-off-by: David S. Miller --- net/core/net_namespace.c | 35 +++++++++++++++-------------------- 1 file changed, 15 insertions(+), 20 deletions(-) diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index f3fa43506f16..42bdda0e616b 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -215,14 +215,13 @@ static void rtnl_net_notifyid(struct net *net, int cmd, int id); */ int peernet2id_alloc(struct net *net, struct net *peer) { - unsigned long flags; bool alloc; int id; - spin_lock_irqsave(&net->nsid_lock, flags); + spin_lock_bh(&net->nsid_lock); alloc = atomic_read(&peer->count) == 0 ? false : true; id = __peernet2id_alloc(net, peer, &alloc); - spin_unlock_irqrestore(&net->nsid_lock, flags); + spin_unlock_bh(&net->nsid_lock); if (alloc && id >= 0) rtnl_net_notifyid(net, RTM_NEWNSID, id); return id; @@ -231,12 +230,11 @@ int peernet2id_alloc(struct net *net, struct net *peer) /* This function returns, if assigned, the id of a peer netns. */ int peernet2id(struct net *net, struct net *peer) { - unsigned long flags; int id; - spin_lock_irqsave(&net->nsid_lock, flags); + spin_lock_bh(&net->nsid_lock); id = __peernet2id(net, peer); - spin_unlock_irqrestore(&net->nsid_lock, flags); + spin_unlock_bh(&net->nsid_lock); return id; } EXPORT_SYMBOL(peernet2id); @@ -251,18 +249,17 @@ bool peernet_has_id(struct net *net, struct net *peer) struct net *get_net_ns_by_id(struct net *net, int id) { - unsigned long flags; struct net *peer; if (id < 0) return NULL; rcu_read_lock(); - spin_lock_irqsave(&net->nsid_lock, flags); + spin_lock_bh(&net->nsid_lock); peer = idr_find(&net->netns_ids, id); if (peer) get_net(peer); - spin_unlock_irqrestore(&net->nsid_lock, flags); + spin_unlock_bh(&net->nsid_lock); rcu_read_unlock(); return peer; @@ -406,17 +403,17 @@ static void cleanup_net(struct work_struct *work) for_each_net(tmp) { int id; - spin_lock_irq(&tmp->nsid_lock); + spin_lock_bh(&tmp->nsid_lock); id = __peernet2id(tmp, net); if (id >= 0) idr_remove(&tmp->netns_ids, id); - spin_unlock_irq(&tmp->nsid_lock); + spin_unlock_bh(&tmp->nsid_lock); if (id >= 0) rtnl_net_notifyid(tmp, RTM_DELNSID, id); } - spin_lock_irq(&net->nsid_lock); + spin_lock_bh(&net->nsid_lock); idr_destroy(&net->netns_ids); - spin_unlock_irq(&net->nsid_lock); + spin_unlock_bh(&net->nsid_lock); } rtnl_unlock(); @@ -544,7 +541,6 @@ static int rtnl_net_newid(struct sk_buff *skb, struct nlmsghdr *nlh) { struct net *net = sock_net(skb->sk); struct nlattr *tb[NETNSA_MAX + 1]; - unsigned long flags; struct net *peer; int nsid, err; @@ -565,15 +561,15 @@ static int rtnl_net_newid(struct sk_buff *skb, struct nlmsghdr *nlh) if (IS_ERR(peer)) return PTR_ERR(peer); - spin_lock_irqsave(&net->nsid_lock, flags); + spin_lock_bh(&net->nsid_lock); if (__peernet2id(net, peer) >= 0) { - spin_unlock_irqrestore(&net->nsid_lock, flags); + spin_unlock_bh(&net->nsid_lock); err = -EEXIST; goto out; } err = alloc_netid(net, peer, nsid); - spin_unlock_irqrestore(&net->nsid_lock, flags); + spin_unlock_bh(&net->nsid_lock); if (err >= 0) { rtnl_net_notifyid(net, RTM_NEWNSID, err); err = 0; @@ -695,11 +691,10 @@ static int rtnl_net_dumpid(struct sk_buff *skb, struct netlink_callback *cb) .idx = 0, .s_idx = cb->args[0], }; - unsigned long flags; - spin_lock_irqsave(&net->nsid_lock, flags); + spin_lock_bh(&net->nsid_lock); idr_for_each(&net->netns_ids, rtnl_net_dumpid_one, &net_cb); - spin_unlock_irqrestore(&net->nsid_lock, flags); + spin_unlock_bh(&net->nsid_lock); cb->args[0] = net_cb.idx; return skb->len;