From patchwork Wed Dec 12 17:17:06 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [RFC,net-next,1/5] netns: allocate an unique id to identify a netns From: Nicolas Dichtel X-Patchwork-Id: 205594 X-Patchwork-Delegate: davem@davemloft.net Message-Id: <1355332630-4256-2-git-send-email-nicolas.dichtel@6wind.com> To: netdev@vger.kernel.org Cc: davem@davemloft.net, ebiederm@xmission.com, aatteka@nicira.com, Nicolas Dichtel Date: Wed, 12 Dec 2012 18:17:06 +0100 This patch simply adds a field nsindex, which will contain a unique index. The goal is to prepare the monitoring of netns activities with rtnelink and to ease netns management by userland apps. Signed-off-by: Nicolas Dichtel --- include/net/net_namespace.h | 1 + net/core/net_namespace.c | 16 ++++++++++++++++ 2 files changed, 17 insertions(+) diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index c5a43f5..5db7a1b 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -55,6 +55,7 @@ struct net { struct list_head exit_list; /* Use only net_mutex */ struct user_namespace *user_ns; /* Owning user namespace */ + int nsindex; /* index to identify this ns */ struct proc_dir_entry *proc_net; struct proc_dir_entry *proc_net_stat; diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index 6456439..f5267e4 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -27,6 +27,7 @@ static DEFINE_MUTEX(net_mutex); LIST_HEAD(net_namespace_list); EXPORT_SYMBOL_GPL(net_namespace_list); +static DEFINE_IDA(net_namespace_ids); struct net init_net = { .dev_base_head = LIST_HEAD_INIT(init_net.dev_base_head), @@ -157,6 +158,15 @@ static __net_init int setup_net(struct net *net, struct user_namespace *user_ns) atomic_set(&net->passive, 1); net->dev_base_seq = 1; net->user_ns = user_ns; +again: + error = ida_get_new_above(&net_namespace_ids, 1, &net->nsindex); + if (error < 0) { + if (error == -EAGAIN) { + ida_pre_get(&net_namespace_ids, GFP_KERNEL); + goto again; + } + return error; + } #ifdef NETNS_REFCNT_DEBUG atomic_set(&net->use_count, 0); @@ -171,6 +181,7 @@ out: return error; out_undo: + ida_remove(&net_namespace_ids, net->nsindex); /* Walk through the list backwards calling the exit functions * for the pernet modules whose init functions did not fail. */ @@ -297,6 +308,11 @@ static void cleanup_net(struct work_struct *work) */ synchronize_rcu(); + list_for_each_entry(net, &net_exit_list, exit_list) { + /* Free the index */ + ida_remove(&net_namespace_ids, net->nsindex); + } + /* Run all of the network namespace exit methods */ list_for_each_entry_reverse(ops, &pernet_list, list) ops_exit_list(ops, &net_exit_list);