configfs: make ci_type field, some pointers and function arguments const

The ci_type field of the config_item structure do not modify the fields
of the config_item_type structure it points to. And the other pointers
initialized with ci_type do not modify the fields as well.
So, make the ci_type field and the pointers initialized with ci_type
as const.

Make the struct config_item_type *type function argument of functions
config_{item/group}_init_type_name const as the argument in both the
functions is only stored in the ci_type field of a config_item structure
which is now made const.
Make the argument of configfs_register_default_group const as it is
only passed to the argument of the function config_group_init_type_name
which is now const.

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

fs/configfs/dir.c

@@ -584,7 +584,7 @@ static void detach_attrs(struct config_item * item)
 
 static int populate_attrs(struct config_item *item)
 {
-	struct config_item_type *t = item->ci_type;
+	const struct config_item_type *t = item->ci_type;
 	struct configfs_attribute *attr;
 	struct configfs_bin_attribute *bin_attr;
 	int error = 0;
@@ -901,7 +901,7 @@ static void configfs_detach_group(struct config_item *item)
 static void client_disconnect_notify(struct config_item *parent_item,
 				     struct config_item *item)
 {
-	struct config_item_type *type;
+	const struct config_item_type *type;
 
 	type = parent_item->ci_type;
 	BUG_ON(!type);
@@ -920,7 +920,7 @@ static void client_disconnect_notify(struct config_item *parent_item,
 static void client_drop_item(struct config_item *parent_item,
 			     struct config_item *item)
 {
-	struct config_item_type *type;
+	const struct config_item_type *type;
 
 	type = parent_item->ci_type;
 	BUG_ON(!type);
@@ -1260,7 +1260,7 @@ static int configfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode
 	struct config_item *parent_item;
 	struct configfs_subsystem *subsys;
 	struct configfs_dirent *sd;
-	struct config_item_type *type;
+	const struct config_item_type *type;
 	struct module *subsys_owner = NULL, *new_item_owner = NULL;
 	char *name;
 
@@ -1810,7 +1810,7 @@ EXPORT_SYMBOL(configfs_unregister_group);
 struct config_group *
 configfs_register_default_group(struct config_group *parent_group,
 				const char *name,
-				struct config_item_type *item_type)
+				const struct config_item_type *item_type)
 {
 	int ret;
 	struct config_group *group;

fs/configfs/item.c

@@ -113,7 +113,7 @@ EXPORT_SYMBOL(config_item_set_name);
 
 void config_item_init_type_name(struct config_item *item,
 				const char *name,
-				struct config_item_type *type)
+				const struct config_item_type *type)
 {
 	config_item_set_name(item, "%s", name);
 	item->ci_type = type;
@@ -122,7 +122,7 @@ void config_item_init_type_name(struct config_item *item,
 EXPORT_SYMBOL(config_item_init_type_name);
 
 void config_group_init_type_name(struct config_group *group, const char *name,
-			 struct config_item_type *type)
+			 const struct config_item_type *type)
 {
 	config_item_set_name(&group->cg_item, "%s", name);
 	group->cg_item.ci_type = type;
@@ -148,7 +148,7 @@ EXPORT_SYMBOL(config_item_get_unless_zero);
 
 static void config_item_cleanup(struct config_item *item)
 {
-	struct config_item_type *t = item->ci_type;
+	const struct config_item_type *t = item->ci_type;
 	struct config_group *s = item->ci_group;
 	struct config_item *parent = item->ci_parent;
 

fs/configfs/symlink.c

@@ -138,7 +138,7 @@ int configfs_symlink(struct inode *dir, struct dentry *dentry, const char *symna
 	struct configfs_dirent *sd;
 	struct config_item *parent_item;
 	struct config_item *target_item = NULL;
-	struct config_item_type *type;
+	const struct config_item_type *type;
 
 	sd = dentry->d_parent->d_fsdata;
 	/*
@@ -186,7 +186,7 @@ int configfs_unlink(struct inode *dir, struct dentry *dentry)
 	struct configfs_dirent *sd = dentry->d_fsdata;
 	struct configfs_symlink *sl;
 	struct config_item *parent_item;
-	struct config_item_type *type;
+	const struct config_item_type *type;
 	int ret;
 
 	ret = -EPERM;  /* What lack-of-symlink returns */

include/linux/configfs.h

@@ -58,7 +58,7 @@ struct config_item {
 	struct list_head	ci_entry;
 	struct config_item	*ci_parent;
 	struct config_group	*ci_group;
-	struct config_item_type	*ci_type;
+	const struct config_item_type	*ci_type;
 	struct dentry		*ci_dentry;
 };
 
@@ -72,7 +72,7 @@ static inline char *config_item_name(struct config_item * item)
 
 extern void config_item_init_type_name(struct config_item *item,
 				       const char *name,
-				       struct config_item_type *type);
+				       const struct config_item_type *type);
 
 extern struct config_item *config_item_get(struct config_item *);
 extern struct config_item *config_item_get_unless_zero(struct config_item *);
@@ -101,7 +101,7 @@ struct config_group {
 extern void config_group_init(struct config_group *group);
 extern void config_group_init_type_name(struct config_group *group,
 					const char *name,
-					struct config_item_type *type);
+					const struct config_item_type *type);
 
 static inline struct config_group *to_config_group(struct config_item *item)
 {
@@ -261,7 +261,7 @@ void configfs_remove_default_groups(struct config_group *group);
 struct config_group *
 configfs_register_default_group(struct config_group *parent_group,
 				const char *name,
-				struct config_item_type *item_type);
+				const struct config_item_type *item_type);
 void configfs_unregister_default_group(struct config_group *group);
 
 /* These functions can sleep and can alloc with GFP_KERNEL */