1/* SPDX-License-Identifier: GPL-2.0-or-later */
  2/*
  3 * configfs_internal.h - Internal stuff for configfs
  4 *
  5 * Based on sysfs:
  6 * 	sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
  7 *
  8 * configfs Copyright (C) 2005 Oracle.  All rights reserved.
  9 */
 10
 11#ifdef pr_fmt
 12#undef pr_fmt
 13#endif
 14
 15#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 16
 17#include <linux/slab.h>
 18#include <linux/list.h>
 19#include <linux/spinlock.h>
 20
 21struct configfs_fragment {
 22	atomic_t frag_count;
 23	struct rw_semaphore frag_sem;
 24	bool frag_dead;
 25};
 26
 27void put_fragment(struct configfs_fragment *);
 28struct configfs_fragment *get_fragment(struct configfs_fragment *);
 29
 30struct configfs_dirent {
 31	atomic_t		s_count;
 32	int			s_dependent_count;
 33	struct list_head	s_sibling;
 34	struct list_head	s_children;
 35	int			s_links;
 36	void			* s_element;
 37	int			s_type;
 38	umode_t			s_mode;
 39	struct dentry		* s_dentry;
 40	struct iattr		* s_iattr;
 41#ifdef CONFIG_LOCKDEP
 42	int			s_depth;
 43#endif
 44	struct configfs_fragment *s_frag;
 45};
 46
 47#define CONFIGFS_ROOT		0x0001
 48#define CONFIGFS_DIR		0x0002
 49#define CONFIGFS_ITEM_ATTR	0x0004
 50#define CONFIGFS_ITEM_BIN_ATTR	0x0008
 51#define CONFIGFS_ITEM_LINK	0x0020
 52#define CONFIGFS_USET_DIR	0x0040
 53#define CONFIGFS_USET_DEFAULT	0x0080
 54#define CONFIGFS_USET_DROPPING	0x0100
 55#define CONFIGFS_USET_IN_MKDIR	0x0200
 56#define CONFIGFS_USET_CREATING	0x0400
 57#define CONFIGFS_NOT_PINNED	(CONFIGFS_ITEM_ATTR | CONFIGFS_ITEM_BIN_ATTR)
 58
 59extern struct mutex configfs_symlink_mutex;
 60extern spinlock_t configfs_dirent_lock;
 61
 62extern struct kmem_cache *configfs_dir_cachep;
 63
 64extern int configfs_is_root(struct config_item *item);
 65
 66extern struct inode * configfs_new_inode(umode_t mode, struct configfs_dirent *, struct super_block *);
 67extern struct inode *configfs_create(struct dentry *, umode_t mode);
 68
 69extern int configfs_create_file(struct config_item *, const struct configfs_attribute *);
 70extern int configfs_create_bin_file(struct config_item *,
 71				    const struct configfs_bin_attribute *);
 72extern int configfs_make_dirent(struct configfs_dirent *, struct dentry *,
 73				void *, umode_t, int, struct configfs_fragment *);
 74extern int configfs_dirent_is_ready(struct configfs_dirent *);
 75
 76extern void configfs_hash_and_remove(struct dentry * dir, const char * name);
 77
 78extern const unsigned char * configfs_get_name(struct configfs_dirent *sd);
 79extern void configfs_drop_dentry(struct configfs_dirent *sd, struct dentry *parent);
 80extern int configfs_setattr(struct mnt_idmap *idmap,
 81			    struct dentry *dentry, struct iattr *iattr);
 82
 83extern struct dentry *configfs_pin_fs(void);
 84extern void configfs_release_fs(void);
 85
 86extern const struct file_operations configfs_dir_operations;
 87extern const struct file_operations configfs_file_operations;
 88extern const struct file_operations configfs_bin_file_operations;
 89extern const struct inode_operations configfs_dir_inode_operations;
 90extern const struct inode_operations configfs_root_inode_operations;
 91extern const struct inode_operations configfs_symlink_inode_operations;
 92extern const struct dentry_operations configfs_dentry_ops;
 93
 94extern int configfs_symlink(struct mnt_idmap *idmap,
 95			    struct inode *dir, struct dentry *dentry,
 96			    const char *symname);
 97extern int configfs_unlink(struct inode *dir, struct dentry *dentry);
 98
 99int configfs_create_link(struct configfs_dirent *target, struct dentry *parent,
100		struct dentry *dentry, char *body);
101
102static inline struct config_item * to_item(struct dentry * dentry)
103{
104	struct configfs_dirent * sd = dentry->d_fsdata;
105	return ((struct config_item *) sd->s_element);
106}
107
108static inline struct configfs_attribute * to_attr(struct dentry * dentry)
109{
110	struct configfs_dirent * sd = dentry->d_fsdata;
111	return ((struct configfs_attribute *) sd->s_element);
112}
113
114static inline struct configfs_bin_attribute *to_bin_attr(struct dentry *dentry)
115{
116	struct configfs_attribute *attr = to_attr(dentry);
117
118	return container_of(attr, struct configfs_bin_attribute, cb_attr);
119}
120
121static inline struct config_item *configfs_get_config_item(struct dentry *dentry)
122{
123	struct config_item * item = NULL;
124
125	spin_lock(&dentry->d_lock);
126	if (!d_unhashed(dentry)) {
127		struct configfs_dirent * sd = dentry->d_fsdata;
128		item = config_item_get(sd->s_element);
129	}
130	spin_unlock(&dentry->d_lock);
131
132	return item;
133}
134
135static inline void release_configfs_dirent(struct configfs_dirent * sd)
136{
137	if (!(sd->s_type & CONFIGFS_ROOT)) {
138		kfree(sd->s_iattr);
139		put_fragment(sd->s_frag);
140		kmem_cache_free(configfs_dir_cachep, sd);
141	}
142}
143
144static inline struct configfs_dirent * configfs_get(struct configfs_dirent * sd)
145{
146	if (sd) {
147		WARN_ON(!atomic_read(&sd->s_count));
148		atomic_inc(&sd->s_count);
149	}
150	return sd;
151}
152
153static inline void configfs_put(struct configfs_dirent * sd)
154{
155	WARN_ON(!atomic_read(&sd->s_count));
156	if (atomic_dec_and_test(&sd->s_count))
157		release_configfs_dirent(sd);
158}
159