sysctl: remove register_sysctl_paths()

The deprecation for register_sysctl_paths() is over. We can rejoice as
we nuke register_sysctl_paths(). The routine register_sysctl_table()
was the only user left of register_sysctl_paths(), so we can now just
open code and move the implementation over to what used to be
to __register_sysctl_paths().

The old dynamic struct ctl_table_set *set is now the point to
sysctl_table_root.default_set.

The old dynamic const struct ctl_path *path was being used in the
routine register_sysctl_paths() with a static:

static const struct ctl_path null_path[] = { {} };

Since this is a null path we can now just simplfy the old routine
and remove its use as its always empty.

This saves us a total of 230 bytes.

$ ./scripts/bloat-o-meter vmlinux.old vmlinux
add/remove: 2/7 grow/shrink: 1/1 up/down: 1015/-1245 (-230)
Function                                     old     new   delta
register_leaf_sysctl_tables.constprop          -     524    +524
register_sysctl_table                         22     497    +475
__pfx_register_leaf_sysctl_tables.constprop       -      16     +16
null_path                                      8       -      -8
__pfx_register_sysctl_paths                   16       -     -16
__pfx_register_leaf_sysctl_tables             16       -     -16
__pfx___register_sysctl_paths                 16       -     -16
__register_sysctl_base                        29      12     -17
register_sysctl_paths                         18       -     -18
register_leaf_sysctl_tables                  534       -    -534
__register_sysctl_paths                      620       -    -620
Total: Before=21259666, After=21259436, chg -0.00%
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

fs/proc/proc_sysctl.c

@@ -1575,25 +1575,18 @@ static int register_leaf_sysctl_tables(const char *path, char *pos,
 }
 
 /**
- * __register_sysctl_paths - register a sysctl table hierarchy
- * @set: Sysctl tree to register on
- * @path: The path to the directory the sysctl table is in.
+ * register_sysctl_table - register a sysctl table hierarchy
  * @table: the top-level table structure
  *
  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
  * array. A completely 0 filled entry terminates the table.
  * We are slowly deprecating this call so avoid its use.
- *
- * See __register_sysctl_table for more details.
  */
-struct ctl_table_header *__register_sysctl_paths(
-	struct ctl_table_set *set,
-	const struct ctl_path *path, struct ctl_table *table)
+struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
 {
 	struct ctl_table *ctl_table_arg = table;
 	int nr_subheaders = count_subheaders(table);
 	struct ctl_table_header *header = NULL, **subheaders, **subheader;
-	const struct ctl_path *component;
 	char *new_path, *pos;
 
 	pos = new_path = kmalloc(PATH_MAX, GFP_KERNEL);
@@ -1601,11 +1594,6 @@ struct ctl_table_header *__register_sysctl_paths(
 		return NULL;
 
 	pos[0] = '\0';
-	for (component = path; component->procname; component++) {
-		pos = append_path(new_path, pos, component->procname);
-		if (!pos)
-			goto out;
-	}
 	while (table->procname && table->child && !table[1].procname) {
 		pos = append_path(new_path, pos, table->procname);
 		if (!pos)
@@ -1613,7 +1601,7 @@ struct ctl_table_header *__register_sysctl_paths(
 		table = table->child;
 	}
 	if (nr_subheaders == 1) {
-		header = __register_sysctl_table(set, new_path, table);
+		header = __register_sysctl_table(&sysctl_table_root.default_set, new_path, table);
 		if (header)
 			header->ctl_table_arg = ctl_table_arg;
 	} else {
@@ -1627,7 +1615,7 @@ struct ctl_table_header *__register_sysctl_paths(
 		header->ctl_table_arg = ctl_table_arg;
 
 		if (register_leaf_sysctl_tables(new_path, pos, &subheader,
-						set, table))
+						&sysctl_table_root.default_set, table))
 			goto err_register_leaves;
 	}
 
@@ -1646,41 +1634,6 @@ struct ctl_table_header *__register_sysctl_paths(
 	header = NULL;
 	goto out;
 }
-
-/**
- * register_sysctl_paths - register a sysctl table hierarchy
- * @path: The path to the directory the sysctl table is in.
- * @table: the top-level table structure
- *
- * Register a sysctl table hierarchy. @table should be a filled in ctl_table
- * array. A completely 0 filled entry terminates the table.
- * We are slowly deprecating this caller so avoid future uses of it.
- *
- * See __register_sysctl_paths for more details.
- */
-struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
-						struct ctl_table *table)
-{
-	return __register_sysctl_paths(&sysctl_table_root.default_set,
-					path, table);
-}
-EXPORT_SYMBOL(register_sysctl_paths);
-
-/**
- * register_sysctl_table - register a sysctl table hierarchy
- * @table: the top-level table structure
- *
- * Register a sysctl table hierarchy. @table should be a filled in ctl_table
- * array. A completely 0 filled entry terminates the table.
- *
- * See register_sysctl_paths for more details.
- */
-struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
-{
-	static const struct ctl_path null_path[] = { {} };
-
-	return register_sysctl_paths(null_path, table);
-}
 EXPORT_SYMBOL(register_sysctl_table);
 
 int __register_sysctl_base(struct ctl_table *base_table)

include/linux/sysctl.h

@@ -221,14 +221,8 @@ extern void retire_sysctl_set(struct ctl_table_set *set);
 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_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);
 
 extern int sysctl_init_bases(void);
@@ -277,12 +271,6 @@ static inline struct ctl_table_header *register_sysctl_mount_point(const char *p
 	return NULL;
 }
 
-static inline struct ctl_table_header *register_sysctl_paths(
-			const struct ctl_path *path, struct ctl_table *table)
-{
-	return NULL;
-}
-
 static inline struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table)
 {
 	return NULL;

scripts/check-sysctl-docs

@@ -156,22 +156,6 @@ curtable && /\.procname[\t ]*=[\t ]*".+"/ {
     }
 }
 
-/register_sysctl_paths\(.*\)/ {
-    match($0, /register_sysctl_paths\(([^)]+), ([^)]+)\)/, tables)
-    if (debug) print "Attaching table " tables[2] " to path " tables[1]
-    if (paths[tables[1]] == table) {
-	for (entry in entries[tables[2]]) {
-	    printentry(entry)
-	}
-    }
-    split(paths[tables[1]], components, "/")
-    if (length(components) > 1 && components[1] == table) {
-	# Count the first subdirectory as seen
-	seen[components[2]]++
-    }
-}
-
-
 END {
     for (entry in documented) {
 	if (!seen[entry]) {