[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>

[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>
Al Viro
1 parent 7ac6cd653d
Showing 4 changed files with 57 additions and 25 deletions Side-by-side Diff
include/linux/sysctl.h
include/net/net_namespace.h
kernel/sysctl.c
net/sysctl_net.c
@@ -947,6 +947,16 @@
 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_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 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 */
@@ -38,7 +38,9 @@
 	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 */
  
@@ -160,12 +160,13 @@
 static struct ctl_table_root sysctl_table_root;
 static struct ctl_table_header root_table_header = {
 	.ctl_table = root_table,
-	.ctl_entry = LIST_HEAD_INIT(sysctl_table_root.header_list),
+	.ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
 	.root = &sysctl_table_root,
+	.set = &sysctl_table_root.default_set,
 };
 static struct ctl_table_root sysctl_table_root = {
 	.root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
-	.header_list = LIST_HEAD_INIT(root_table_header.ctl_entry),
+	.default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
 };
  
 static struct ctl_table kern_table[];
  
@@ -1403,14 +1404,20 @@
 	spin_unlock(&sysctl_lock);
 }
  
+static struct ctl_table_set *
+lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
+{
+	struct ctl_table_set *set = &root->default_set;
+	if (root->lookup)
+		set = root->lookup(root, namespaces);
+	return set;
+}
+
 static struct list_head *
 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
 {
-	struct list_head *header_list;
-	header_list = &root->header_list;
-	if (root->lookup)
-		header_list = root->lookup(root, namespaces);
-	return header_list;
+	struct ctl_table_set *set = lookup_header_set(root, namespaces);
+	return &set->list;
 }
  
 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
@@ -1720,7 +1727,6 @@
 	struct nsproxy *namespaces,
 	const struct ctl_path *path, struct ctl_table *table)
 {
-	struct list_head *header_list;
 	struct ctl_table_header *header;
 	struct ctl_table *new, **prevp;
 	unsigned int n, npath;
@@ -1772,8 +1778,8 @@
 	}
 #endif
 	spin_lock(&sysctl_lock);
-	header_list = lookup_header_list(root, namespaces);
-	list_add_tail(&header->ctl_entry, header_list);
+	header->set = lookup_header_set(root, namespaces);
+	list_add_tail(&header->ctl_entry, &header->set->list);
 	spin_unlock(&sysctl_lock);
  
 	return header;
@@ -1832,6 +1838,15 @@
 	kfree(header);
 }
  
+void setup_sysctl_set(struct ctl_table_set *p,
+	struct ctl_table_set *parent,
+	int (*is_seen)(struct ctl_table_set *))
+{
+	INIT_LIST_HEAD(&p->list);
+	p->parent = parent ? parent : &sysctl_table_root.default_set;
+	p->is_seen = is_seen;
+}
+
 #else /* !CONFIG_SYSCTL */
 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
 {
@@ -1845,6 +1860,12 @@
 }
  
 void unregister_sysctl_table(struct ctl_table_header * table)
+{
+}
+
+void setup_sysctl_set(struct ctl_table_set *p,
+	struct ctl_table_set *parent,
+	int (*is_seen)(struct ctl_table_set *))
 {
 }
  
@@ -29,12 +29,17 @@
 #include <linux/if_tr.h>
 #endif
  
-static struct list_head *
+static struct ctl_table_set *
 net_ctl_header_lookup(struct ctl_table_root *root, struct nsproxy *namespaces)
 {
-	return &namespaces->net_ns->sysctl_table_headers;
+	return &namespaces->net_ns->sysctls;
 }
  
+static int is_seen(struct ctl_table_set *set)
+{
+	return &current->nsproxy->net_ns->sysctls == set;
+}
+
 /* Return standard mode bits for table entry. */
 static int net_ctl_permissions(struct ctl_table_root *root,
 			       struct nsproxy *nsproxy,
@@ -53,13 +58,6 @@
 	.permissions = net_ctl_permissions,
 };
  
-static LIST_HEAD(net_sysctl_ro_tables);
-static struct list_head *net_ctl_ro_header_lookup(struct ctl_table_root *root,
-		struct nsproxy *namespaces)
-{
-	return &net_sysctl_ro_tables;
-}
-
 static int net_ctl_ro_header_perms(struct ctl_table_root *root,
 		struct nsproxy *namespaces, struct ctl_table *table)
 {
  
  
@@ -70,19 +68,18 @@
 }
  
 static struct ctl_table_root net_sysctl_ro_root = {
-	.lookup = net_ctl_ro_header_lookup,
 	.permissions = net_ctl_ro_header_perms,
 };
  
 static int sysctl_net_init(struct net *net)
 {
-	INIT_LIST_HEAD(&net->sysctl_table_headers);
+	setup_sysctl_set(&net->sysctls, NULL, is_seen);
 	return 0;
 }
  
 static void sysctl_net_exit(struct net *net)
 {
-	WARN_ON(!list_empty(&net->sysctl_table_headers));
+	WARN_ON(!list_empty(&net->sysctls.list));
 	return;
 }
  
@@ -98,6 +95,7 @@
 	if (ret)
 		goto out;
 	register_sysctl_root(&net_sysctl_root);
+	setup_sysctl_set(&net_sysctl_ro_root.default_set, NULL, NULL);
 	register_sysctl_root(&net_sysctl_ro_root);
 out:
 	return ret;
...	...	@@ -947,6 +947,16 @@
947	947	struct nsproxy;
948	948	struct ctl_table_root;
949	949
	950	+struct ctl_table_set {
	951	+ struct list_head list;
	952	+ struct ctl_table_set *parent;
	953	+ int (is_seen)(struct ctl_table_set );
	954	+};
	955	+
	956	+extern void setup_sysctl_set(struct ctl_table_set *p,
	957	+ struct ctl_table_set *parent,
	958	+ int (is_seen)(struct ctl_table_set ));
	959	+
950	960	extern struct ctl_table_header sysctl_head_next(struct ctl_table_header prev);
951	961	extern struct ctl_table_header __sysctl_head_next(struct nsproxy namespaces,
952	962	struct ctl_table_header *prev);
...	...	@@ -1049,8 +1059,8 @@
1049	1059
1050	1060	struct ctl_table_root {
1051	1061	struct list_head root_list;
1052		- struct list_head header_list;
1053		- struct list_head (lookup)(struct ctl_table_root *root,
	1062	+ struct ctl_table_set default_set;
	1063	+ struct ctl_table_set (lookup)(struct ctl_table_root *root,
1054	1064	struct nsproxy *namespaces);
1055	1065	int (permissions)(struct ctl_table_root root,
1056	1066	struct nsproxy namespaces, struct ctl_table table);
...	...	@@ -1066,6 +1076,7 @@
1066	1076	struct completion *unregistering;
1067	1077	struct ctl_table *ctl_table_arg;
1068	1078	struct ctl_table_root *root;
	1079	+ struct ctl_table_set *set;
1069	1080	};
1070	1081
1071	1082	/* struct ctl_path describes where in the hierarchy a table is added */
...	...	@@ -38,7 +38,9 @@
38	38	struct proc_dir_entry *proc_net;
39	39	struct proc_dir_entry *proc_net_stat;
40	40
41		- struct list_head sysctl_table_headers;
	41	+#ifdef CONFIG_SYSCTL
	42	+ struct ctl_table_set sysctls;
	43	+#endif
42	44
43	45	struct net_device loopback_dev; / The loopback */
44	46
...	...	@@ -160,12 +160,13 @@
160	160	static struct ctl_table_root sysctl_table_root;
161	161	static struct ctl_table_header root_table_header = {
162	162	.ctl_table = root_table,
163		- .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.header_list),
	163	+ .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
164	164	.root = &sysctl_table_root,
	165	+ .set = &sysctl_table_root.default_set,
165	166	};
166	167	static struct ctl_table_root sysctl_table_root = {
167	168	.root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
168		- .header_list = LIST_HEAD_INIT(root_table_header.ctl_entry),
	169	+ .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
169	170	};
170	171
171	172	static struct ctl_table kern_table[];
172	173
...	...	@@ -1403,14 +1404,20 @@
1403	1404	spin_unlock(&sysctl_lock);
1404	1405	}
1405	1406
	1407	+static struct ctl_table_set *
	1408	+lookup_header_set(struct ctl_table_root root, struct nsproxy namespaces)
	1409	+{
	1410	+ struct ctl_table_set *set = &root->default_set;
	1411	+ if (root->lookup)
	1412	+ set = root->lookup(root, namespaces);
	1413	+ return set;
	1414	+}
	1415	+
1406	1416	static struct list_head *
1407	1417	lookup_header_list(struct ctl_table_root root, struct nsproxy namespaces)
1408	1418	{
1409		- struct list_head *header_list;
1410		- header_list = &root->header_list;
1411		- if (root->lookup)
1412		- header_list = root->lookup(root, namespaces);
1413		- return header_list;
	1419	+ struct ctl_table_set *set = lookup_header_set(root, namespaces);
	1420	+ return &set->list;
1414	1421	}
1415	1422
1416	1423	struct ctl_table_header __sysctl_head_next(struct nsproxy namespaces,
...	...	@@ -1720,7 +1727,6 @@
1720	1727	struct nsproxy *namespaces,
1721	1728	const struct ctl_path path, struct ctl_table table)
1722	1729	{
1723		- struct list_head *header_list;
1724	1730	struct ctl_table_header *header;
1725	1731	struct ctl_table new, *prevp;
1726	1732	unsigned int n, npath;
...	...	@@ -1772,8 +1778,8 @@
1772	1778	}
1773	1779	#endif
1774	1780	spin_lock(&sysctl_lock);
1775		- header_list = lookup_header_list(root, namespaces);
1776		- list_add_tail(&header->ctl_entry, header_list);
	1781	+ header->set = lookup_header_set(root, namespaces);
	1782	+ list_add_tail(&header->ctl_entry, &header->set->list);
1777	1783	spin_unlock(&sysctl_lock);
1778	1784
1779	1785	return header;
...	...	@@ -1832,6 +1838,15 @@
1832	1838	kfree(header);
1833	1839	}
1834	1840
	1841	+void setup_sysctl_set(struct ctl_table_set *p,
	1842	+ struct ctl_table_set *parent,
	1843	+ int (is_seen)(struct ctl_table_set ))
	1844	+{
	1845	+ INIT_LIST_HEAD(&p->list);
	1846	+ p->parent = parent ? parent : &sysctl_table_root.default_set;
	1847	+ p->is_seen = is_seen;
	1848	+}
	1849	+
1835	1850	#else /* !CONFIG_SYSCTL */
1836	1851	struct ctl_table_header register_sysctl_table(struct ctl_table table)
1837	1852	{
...	...	@@ -1845,6 +1860,12 @@
1845	1860	}
1846	1861
1847	1862	void unregister_sysctl_table(struct ctl_table_header * table)
	1863	+{
	1864	+}
	1865	+
	1866	+void setup_sysctl_set(struct ctl_table_set *p,
	1867	+ struct ctl_table_set *parent,
	1868	+ int (is_seen)(struct ctl_table_set ))
1848	1869	{
1849	1870	}
1850	1871
...	...	@@ -29,12 +29,17 @@
29	29	#include <linux/if_tr.h>
30	30	#endif
31	31
32		-static struct list_head *
	32	+static struct ctl_table_set *
33	33	net_ctl_header_lookup(struct ctl_table_root root, struct nsproxy namespaces)
34	34	{
35		- return &namespaces->net_ns->sysctl_table_headers;
	35	+ return &namespaces->net_ns->sysctls;
36	36	}
37	37
	38	+static int is_seen(struct ctl_table_set *set)
	39	+{
	40	+ return &current->nsproxy->net_ns->sysctls == set;
	41	+}
	42	+
38	43	/* Return standard mode bits for table entry. */
39	44	static int net_ctl_permissions(struct ctl_table_root *root,
40	45	struct nsproxy *nsproxy,
...	...	@@ -53,13 +58,6 @@
53	58	.permissions = net_ctl_permissions,
54	59	};
55	60
56		-static LIST_HEAD(net_sysctl_ro_tables);
57		-static struct list_head net_ctl_ro_header_lookup(struct ctl_table_root root,
58		- struct nsproxy *namespaces)
59		-{
60		- return &net_sysctl_ro_tables;
61		-}
62		-
63	61	static int net_ctl_ro_header_perms(struct ctl_table_root *root,
64	62	struct nsproxy namespaces, struct ctl_table table)
65	63	{
66	64
67	65
...	...	@@ -70,19 +68,18 @@
70	68	}
71	69
72	70	static struct ctl_table_root net_sysctl_ro_root = {
73		- .lookup = net_ctl_ro_header_lookup,
74	71	.permissions = net_ctl_ro_header_perms,
75	72	};
76	73
77	74	static int sysctl_net_init(struct net *net)
78	75	{
79		- INIT_LIST_HEAD(&net->sysctl_table_headers);
	76	+ setup_sysctl_set(&net->sysctls, NULL, is_seen);
80	77	return 0;
81	78	}
82	79
83	80	static void sysctl_net_exit(struct net *net)
84	81	{
85		- WARN_ON(!list_empty(&net->sysctl_table_headers));
	82	+ WARN_ON(!list_empty(&net->sysctls.list));
86	83	return;
87	84	}
88	85
...	...	@@ -98,6 +95,7 @@
98	95	if (ret)
99	96	goto out;
100	97	register_sysctl_root(&net_sysctl_root);
	98	+ setup_sysctl_set(&net_sysctl_ro_root.default_set, NULL, NULL);
101	99	register_sysctl_root(&net_sysctl_ro_root);
102	100	out:
103	101	return ret;