1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/* -*- mode: c; c-basic-offset:8; -*-
3 * vim: noexpandtab sw=8 ts=8 sts=0:
4 *
5 * configfs_internal.h - Internal stuff for configfs
6 *
7 * Based on sysfs:
8 * 	sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
9 *
10 * configfs Copyright (C) 2005 Oracle.  All rights reserved.
11 */
12
13#ifdef pr_fmt
14#undef pr_fmt
15#endif
16
17#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18
19#include <linux/slab.h>
20#include <linux/list.h>
21#include <linux/spinlock.h>
22
23struct configfs_fragment {
24	atomic_t frag_count;
25	struct rw_semaphore frag_sem;
26	bool frag_dead;
27};
28
29void put_fragment(struct configfs_fragment *);
30struct configfs_fragment *get_fragment(struct configfs_fragment *);
31
32struct configfs_dirent {
33	atomic_t		s_count;
34	int			s_dependent_count;
35	struct list_head	s_sibling;
36	struct list_head	s_children;
37	int			s_links;
38	void			* s_element;
39	int			s_type;
40	umode_t			s_mode;
41	struct dentry		* s_dentry;
42	struct iattr		* s_iattr;
43#ifdef CONFIG_LOCKDEP
44	int			s_depth;
45#endif
46	struct configfs_fragment *s_frag;
47};
48
49#define CONFIGFS_ROOT		0x0001
50#define CONFIGFS_DIR		0x0002
51#define CONFIGFS_ITEM_ATTR	0x0004
52#define CONFIGFS_ITEM_BIN_ATTR	0x0008
53#define CONFIGFS_ITEM_LINK	0x0020
54#define CONFIGFS_USET_DIR	0x0040
55#define CONFIGFS_USET_DEFAULT	0x0080
56#define CONFIGFS_USET_DROPPING	0x0100
57#define CONFIGFS_USET_IN_MKDIR	0x0200
58#define CONFIGFS_USET_CREATING	0x0400
59#define CONFIGFS_NOT_PINNED	(CONFIGFS_ITEM_ATTR | CONFIGFS_ITEM_BIN_ATTR)
60
61extern struct mutex configfs_symlink_mutex;
62extern spinlock_t configfs_dirent_lock;
63
64extern struct kmem_cache *configfs_dir_cachep;
65
66extern int configfs_is_root(struct config_item *item);
67
68extern struct inode * configfs_new_inode(umode_t mode, struct configfs_dirent *, struct super_block *);
69extern struct inode *configfs_create(struct dentry *, umode_t mode);
70
71extern int configfs_create_file(struct config_item *, const struct configfs_attribute *);
72extern int configfs_create_bin_file(struct config_item *,
73				    const struct configfs_bin_attribute *);
74extern int configfs_make_dirent(struct configfs_dirent *, struct dentry *,
75				void *, umode_t, int, struct configfs_fragment *);
76extern int configfs_dirent_is_ready(struct configfs_dirent *);
77
78extern void configfs_hash_and_remove(struct dentry * dir, const char * name);
79
80extern const unsigned char * configfs_get_name(struct configfs_dirent *sd);
81extern void configfs_drop_dentry(struct configfs_dirent *sd, struct dentry *parent);
82extern int configfs_setattr(struct dentry *dentry, struct iattr *iattr);
83
84extern struct dentry *configfs_pin_fs(void);
85extern void configfs_release_fs(void);
86
87extern const struct file_operations configfs_dir_operations;
88extern const struct file_operations configfs_file_operations;
89extern const struct file_operations configfs_bin_file_operations;
90extern const struct inode_operations configfs_dir_inode_operations;
91extern const struct inode_operations configfs_root_inode_operations;
92extern const struct inode_operations configfs_symlink_inode_operations;
93extern const struct dentry_operations configfs_dentry_ops;
94
95extern int configfs_symlink(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
160