Merge git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/sysctl

Pull sysctl updates from Eric Biederman:

 - Rewrite of sysctl for speed and clarity.

   Insert/remove/Lookup in sysctl are all now O(NlogN) operations, and
   are no longer bottlenecks in the process of adding and removing
   network devices.

   sysctl is now focused on being a filesystem instead of system call
   and the code can all be found in fs/proc/proc_sysctl.c.  Hopefully
   this means the code is now approachable.

   Much thanks is owed to Lucian Grinjincu for keeping at this until
   something was found that was usable.

 - The recent proc_sys_poll oops found by the fuzzer during hibernation
   is fixed.

* git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/sysctl: (36 commits)
  sysctl: protect poll() in entries that may go away
  sysctl: Don't call sysctl_follow_link unless we are a link.
  sysctl: Comments to make the code clearer.
  sysctl: Correct error return from get_subdir
  sysctl: An easier to read version of find_subdir
  sysctl: fix memset parameters in setup_sysctl_set()
  sysctl: remove an unused variable
  sysctl: Add register_sysctl for normal sysctl users
  sysctl: Index sysctl directories with rbtrees.
  sysctl: Make the header lists per directory.
  sysctl: Move sysctl_check_dups into insert_header
  sysctl: Modify __register_sysctl_paths to take a set instead of a root and an nsproxy
  sysctl: Replace root_list with links between sysctl_table_sets.
  sysctl: Add sysctl_print_dir and use it in get_subdir
  sysctl: Stop requiring explicit management of sysctl directories
  sysctl: Add a root pointer to ctl_table_set
  sysctl: Rewrite proc_sys_readdir in terms of first_entry and next_entry
  sysctl: Rewrite proc_sys_lookup introducing find_entry and lookup_entry.
  sysctl: Normalize the root_table data structure.
  sysctl: Factor out insert_header and erase_header
  ...

1 files changed, 67 insertions, 39 deletions

diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index bb9127dd814b..c34b4c82b0dc 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -932,34 +932,14 @@ enum
 #include <linux/list.h>
 #include <linux/rcupdate.h>
 #include <linux/wait.h>
+#include <linux/rbtree.h>
 
 /* For the /proc/sys support */
 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 *));
-
 struct ctl_table_header;
-
-extern void sysctl_head_get(struct ctl_table_header *);
-extern void sysctl_head_put(struct ctl_table_header *);
-extern int sysctl_is_seen(struct ctl_table_header *);
-extern struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *);
-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);
-extern void sysctl_head_finish(struct ctl_table_header *prev);
-extern int sysctl_perm(struct ctl_table_root *root,
-		struct ctl_table *table, int op);
+struct ctl_dir;
 
 typedef struct ctl_table ctl_table;
 
@@ -1023,8 +1003,6 @@ static inline void *proc_sys_poll_event(struct ctl_table_poll *poll)
 	return (void *)(unsigned long)atomic_read(&poll->event);
 }
 
-void proc_sys_poll_notify(struct ctl_table_poll *poll);
-
 #define __CTL_TABLE_POLL_INITIALIZER(name) {				\
 	.event = ATOMIC_INIT(0),					\
 	.wait = __WAIT_QUEUE_HEAD_INITIALIZER(name.wait) }
@@ -1039,21 +1017,16 @@ struct ctl_table
 	void *data;
 	int maxlen;
 	umode_t mode;
-	struct ctl_table *child;
-	struct ctl_table *parent;	/* Automatically set */
+	struct ctl_table *child;	/* Deprecated */
 	proc_handler *proc_handler;	/* Callback for text formatting */
 	struct ctl_table_poll *poll;
 	void *extra1;
 	void *extra2;
 };
 
-struct ctl_table_root {
-	struct list_head root_list;
-	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);
+struct ctl_node {
+	struct rb_node node;
+	struct ctl_table_header *header;
 };
 
 /* struct ctl_table_header is used to maintain dynamic lists of
@@ -1063,9 +1036,9 @@ struct ctl_table_header
 	union {
 		struct {
 			struct ctl_table *ctl_table;
-			struct list_head ctl_entry;
 			int used;
 			int count;
+			int nreg;
 		};
 		struct rcu_head rcu;
 	};
@@ -1073,9 +1046,27 @@ struct ctl_table_header
 	struct ctl_table *ctl_table_arg;
 	struct ctl_table_root *root;
 	struct ctl_table_set *set;
-	struct ctl_table *attached_by;
-	struct ctl_table *attached_to;
-	struct ctl_table_header *parent;
+	struct ctl_dir *parent;
+	struct ctl_node *node;
+};
+
+struct ctl_dir {
+	/* Header must be at the start of ctl_dir */
+	struct ctl_table_header header;
+	struct rb_root root;
+};
+
+struct ctl_table_set {
+	int (*is_seen)(struct ctl_table_set *);
+	struct ctl_dir dir;
+};
+
+struct ctl_table_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);
 };
 
 /* struct ctl_path describes where in the hierarchy a table is added */
@@ -1083,16 +1074,53 @@ struct ctl_path {
 	const char *procname;
 };
 
+#ifdef CONFIG_SYSCTL
+
+void proc_sys_poll_notify(struct ctl_table_poll *poll);
+
+extern void setup_sysctl_set(struct ctl_table_set *p,
+	struct ctl_table_root *root,
+	int (*is_seen)(struct ctl_table_set *));
+extern void retire_sysctl_set(struct ctl_table_set *set);
+
 void register_sysctl_root(struct ctl_table_root *root);
+struct ctl_table_header *__register_sysctl_table(
+	struct ctl_table_set *set,
+	const char *path, struct ctl_table *table);
 struct ctl_table_header *__register_sysctl_paths(
-	struct ctl_table_root *root, struct nsproxy *namespaces,
+	struct ctl_table_set *set,
 	const struct ctl_path *path, struct ctl_table *table);
+struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table);
 struct ctl_table_header *register_sysctl_table(struct ctl_table * table);
 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
 						struct ctl_table *table);
 
 void unregister_sysctl_table(struct ctl_table_header * table);
-int sysctl_check_table(struct nsproxy *namespaces, struct ctl_table *table);
+
+extern int sysctl_init(void);
+#else /* CONFIG_SYSCTL */
+static inline struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
+{
+	return NULL;
+}
+
+static inline struct ctl_table_header *register_sysctl_paths(
+			const struct ctl_path *path, struct ctl_table *table)
+{
+	return NULL;
+}
+
+static inline void unregister_sysctl_table(struct ctl_table_header * table)
+{
+}
+
+static inline void setup_sysctl_set(struct ctl_table_set *p,
+	struct ctl_table_root *root,
+	int (*is_seen)(struct ctl_table_set *))
+{
+}
+
+#endif /* CONFIG_SYSCTL */
 
 #endif /* __KERNEL__ */