From: Tonghao Zhang <xiangxia.m....@gmail.com>
This patch add a member in struct netns_core. and this is
a counter for socket_inuse in the _net_ namespace. The patch
will add/sub counter in the sock_alloc or sock_release. In
the sock_alloc, the private data of inode saves the special
_net_. When releasing it, we can access the special _net_ and
dec the counter of socket in that namespace.
By the way, we dont use the 'current->nsproxy->net_ns' in the
sock_release. In one case，when one task exits, the 'do_exit'
may set the current->nsproxy NULL, and then call the sock_release.
Use the private data of inode, saving few bytes.
Signed-off-by: Tonghao Zhang <zhangtong...@didichuxing.com>
Signed-off-by: Martin Zhang <zhangjunweimar...@didichuxing.com>
Signed-off-by: Tonghao Zhang <xiangxia.m....@gmail.com>
---
include/net/netns/core.h | 1 +
net/socket.c | 80 ++++++++++++++++++++++++++++++++++++------------
2 files changed, 62 insertions(+), 19 deletions(-)
diff --git a/include/net/netns/core.h b/include/net/netns/core.h
index 78eb1ff75475..bef1bc8a1721 100644
--- a/include/net/netns/core.h
+++ b/include/net/netns/core.h
@@ -11,6 +11,7 @@ struct netns_core {
int sysctl_somaxconn;
struct prot_inuse __percpu *inuse;
+ int __percpu *socket_inuse;
};
#endif
diff --git a/net/socket.c b/net/socket.c
index c729625eb5d3..c54f16f06c77 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -163,12 +163,6 @@ static DEFINE_SPINLOCK(net_family_lock);
static const struct net_proto_family __rcu *net_families[NPROTO] __read_mostly;
/*
- * Statistics counters of the socket lists
- */
-
-static DEFINE_PER_CPU(int, sockets_in_use);
-
-/*
* Support routines.
* Move socket addresses back and forth across the kernel/user
* divide and look after the messy bits.
@@ -549,6 +543,51 @@ static const struct inode_operations sockfs_inode_ops = {
.setattr = sockfs_setattr,
};
+#ifdef CONFIG_PROC_FS
+static void socket_inuse_add(struct net *net, int val)
+{
+ __this_cpu_add(*net->core.socket_inuse, val);
+}
+
+static int socket_inuse_get(struct net *net)
+{
+ int cpu, res = 0;
+
+ for_each_possible_cpu(cpu) {
+ res = *per_cpu_ptr(net->core.socket_inuse, cpu);
+ }
+
+ return res >= 0 ? res : 0;
+}
+
+static int __net_init socket_inuse_init_net(struct net *net)
+{
+ net->core.socket_inuse = alloc_percpu(int);
+ return net->core.socket_inuse ? 0 : -ENOMEM;
+}
+
+static void __net_exit socket_inuse_exit_net(struct net *net)
+{
+ free_percpu(net->core.socket_inuse);
+}
+
+static struct pernet_operations socket_inuse_ops = {
+ .init = socket_inuse_init_net,
+ .exit = socket_inuse_exit_net,
+};
+
+static __init int socket_inuse_init(void)
+{
+ if (register_pernet_subsys(&socket_inuse_ops))
+ panic("Cannot initialize socket inuse counters");
+
+ return 0;
+}
+
+core_initcall(socket_inuse_init);
+#endif /* CONFIG_PROC_FS */
+
+
/**
* sock_alloc - allocate a socket
*
@@ -561,6 +600,7 @@ struct socket *sock_alloc(void)
{
struct inode *inode;
struct socket *sock;
+ struct net *net;
inode = new_inode_pseudo(sock_mnt->mnt_sb);
if (!inode)
@@ -575,7 +615,15 @@ struct socket *sock_alloc(void)
inode->i_gid = current_fsgid();
inode->i_op = &sockfs_inode_ops;
- this_cpu_add(sockets_in_use, 1);
+ net = current->nsproxy->net_ns;
+ /*
+ * Save the _net_ to private data of inode. When we destroy the
+ * socket, we can use it to access the _net_ and dec socket_inuse
+ * counter.
+ */
+ inode->i_private = get_net(net);
+ socket_inuse_add(net, 1);
+
return sock;
}
EXPORT_SYMBOL(sock_alloc);
@@ -602,7 +650,10 @@ void sock_release(struct socket *sock)
if (rcu_dereference_protected(sock->wq, 1)->fasync_list)
pr_err("%s: fasync list not empty!\n", __func__);
- this_cpu_sub(sockets_in_use, 1);
+ /* inode->ii_private saves the _net_ address. */
+ socket_inuse_add(SOCK_INODE(sock)->i_private, -1);
+ put_net(SOCK_INODE(sock)->i_private);
+
if (!sock->file) {
iput(SOCK_INODE(sock));
return;
@@ -2645,17 +2696,8 @@ core_initcall(sock_init); /* early initcall */
#ifdef CONFIG_PROC_FS
void socket_seq_show(struct seq_file *seq)
{
- int cpu;
- int counter = 0;
-
- for_each_possible_cpu(cpu)
- counter += per_cpu(sockets_in_use, cpu);
-
- /* It can be negative, by the way. 8) */
- if (counter < 0)
- counter = 0;
-
- seq_printf(seq, "sockets: used %d\n", counter);
+ seq_printf(seq, "sockets: used %d\n",
+ socket_inuse_get(seq->private));
}
#endif /* CONFIG_PROC_FS */
--
2.13.6
