[UNIX]: Make the unix sysctl tables per-namespace

This is the core.

 * add the ctl_table_header on the struct net;
 * make the unix_sysctl_register and _unregister clone the table;
 * moves calls to them into per-net init and exit callbacks;
 * move the .data pointer in the proper place.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 28 insertions, 8 deletions

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 73620d61762b..b8a2189fb5c0 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -2139,10 +2139,14 @@ static int unix_net_init(struct net *net)
         int error = -ENOMEM;
 
         net->sysctl_unix_max_dgram_qlen = 10;
+        if (unix_sysctl_register(net))
+                goto out;
 
 #ifdef CONFIG_PROC_FS
-        if (!proc_net_fops_create(net, "unix", 0, &unix_seq_fops))
+        if (!proc_net_fops_create(net, "unix", 0, &unix_seq_fops)) {
+                unix_sysctl_unregister(net);
                 goto out;
+        }
 #endif
         error = 0;
 out:
@@ -2151,6 +2155,7 @@ out:
 
 static void unix_net_exit(struct net *net)
 {
+        unix_sysctl_unregister(net);
         proc_net_remove(net, "unix");
 }
 
@@ -2175,7 +2180,6 @@ static int __init af_unix_init(void)
 
         sock_register(&unix_family_ops);
         register_pernet_subsys(&unix_net_ops);
-        unix_sysctl_register(&init_net);
 out:
         return rc;
 }
@@ -2183,7 +2187,6 @@ out:
 static void __exit af_unix_exit(void)
 {
         sock_unregister(PF_UNIX);
-        unix_sysctl_unregister(&init_net);
         proto_unregister(&unix_proto);
         unregister_pernet_subsys(&unix_net_ops);
 }
diff --git a/net/unix/sysctl_net_unix.c b/net/unix/sysctl_net_unix.c
index 43dd356730fd..553ef6a487d0 100644
--- a/net/unix/sysctl_net_unix.c
+++ b/net/unix/sysctl_net_unix.c
@@ -32,16 +32,33 @@ static struct ctl_path unix_path[] = {
         { },
 };
 
-static struct ctl_table_header * unix_sysctl_header;
-
 int unix_sysctl_register(struct net *net)
 {
-        unix_sysctl_header = register_sysctl_paths(unix_path, unix_table);
-        return unix_sysctl_header == NULL ? -ENOMEM : 0;
+        struct ctl_table *table;
+
+        table = kmemdup(unix_table, sizeof(unix_table), GFP_KERNEL);
+        if (table == NULL)
+                goto err_alloc;
+
+        table[0].data = &net->sysctl_unix_max_dgram_qlen;
+        net->unix_ctl = register_net_sysctl_table(net, unix_path, table);
+        if (net->unix_ctl == NULL)
+                goto err_reg;
+
+        return 0;
+
+err_reg:
+        kfree(table);
+err_alloc:
+        return -ENOMEM;
 }
 
 void unix_sysctl_unregister(struct net *net)
 {
-        unregister_sysctl_table(unix_sysctl_header);
+        struct ctl_table *table;
+
+        table = net->unix_ctl->ctl_table_arg;
+        unregister_sysctl_table(net->unix_ctl);
+        kfree(table);
 }