[PATCH] beginning of sysctl cleanup - ctl_table_set

New object: set of sysctls [currently - root and per-net-ns].
Contains: pointer to parent set, list of tables and "should I see this set?"
method (->is_seen(set)).
Current lists of tables are subsumed by that; net-ns contains such a beast.
->lookup() for ctl_table_root returns pointer to ctl_table_set instead of
that to ->list of that ctl_table_set.

[folded compile fixes by rdd for configs without sysctl]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

2 files changed, 16 insertions, 3 deletions

diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 24141b4d1a11..c1e0cf408af9 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -947,6 +947,16 @@ struct ctl_table;
 struct nsproxy;
 struct ctl_table_root;
 
+struct ctl_table_set {
+        struct list_head list;
+        struct ctl_table_set *parent;
+        int (*is_seen)(struct ctl_table_set *);
+};
+
+extern void setup_sysctl_set(struct ctl_table_set *p,
+        struct ctl_table_set *parent,
+        int (*is_seen)(struct ctl_table_set *));
+
 extern struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev);
 extern struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
                                                 struct ctl_table_header *prev);
@@ -1049,8 +1059,8 @@ struct ctl_table
 
 struct ctl_table_root {
         struct list_head root_list;
-        struct list_head header_list;
-        struct list_head *(*lookup)(struct ctl_table_root *root,
+        struct ctl_table_set default_set;
+        struct ctl_table_set *(*lookup)(struct ctl_table_root *root,
                                            struct nsproxy *namespaces);
         int (*permissions)(struct ctl_table_root *root,
                         struct nsproxy *namespaces, struct ctl_table *table);
@@ -1066,6 +1076,7 @@ struct ctl_table_header
         struct completion *unregistering;
         struct ctl_table *ctl_table_arg;
         struct ctl_table_root *root;
+        struct ctl_table_set *set;
 };
 
 /* struct ctl_path describes where in the hierarchy a table is added */
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index 3855620b78a9..a8eb43cf0c7e 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -38,7 +38,9 @@ struct net {
         struct proc_dir_entry   *proc_net;
         struct proc_dir_entry   *proc_net_stat;
 
-        struct list_head        sysctl_table_headers;
+#ifdef CONFIG_SYSCTL
+        struct ctl_table_set    sysctls;
+#endif
 
         struct net_device       *loopback_dev;          /* The loopback */