aboutsummaryrefslogtreecommitdiff
path: root/fs/sysfs/sysfs.h
blob: 7664d1b3d59402249cee82aa0adc872240331b2b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
/*
 * fs/sysfs/sysfs.h - sysfs internal header file
 *
 * Copyright (c) 2001-3 Patrick Mochel
 * Copyright (c) 2007 SUSE Linux Products GmbH
 * Copyright (c) 2007 Tejun Heo <teheo@suse.de>
 *
 * This file is released under the GPLv2.
 */

#include <linux/lockdep.h>
#include <linux/kobject_ns.h>
#include <linux/fs.h>
#include <linux/rbtree.h>

struct sysfs_open_dirent;

/* type-specific structures for sysfs_dirent->s_* union members */
struct sysfs_elem_dir {
	struct kobject		*kobj;

	unsigned long		subdirs;
	/* children rbtree starts here and goes through sd->s_rb */
	struct rb_root		children;
};

struct sysfs_elem_symlink {
	struct sysfs_dirent	*target_sd;
};

struct sysfs_elem_attr {
	struct attribute	*attr;
	struct sysfs_open_dirent *open;
};

struct sysfs_elem_bin_attr {
	struct bin_attribute	*bin_attr;
	struct hlist_head	buffers;
};

struct sysfs_inode_attrs {
	struct iattr	ia_iattr;
	void		*ia_secdata;
	u32		ia_secdata_len;
};

/*
 * sysfs_dirent - the building block of sysfs hierarchy.  Each and
 * every sysfs node is represented by single sysfs_dirent.
 *
 * As long as s_count reference is held, the sysfs_dirent itself is
 * accessible.  Dereferencing s_elem or any other outer entity
 * requires s_active reference.
 */
struct sysfs_dirent {
	atomic_t		s_count;
	atomic_t		s_active;
#ifdef CONFIG_DEBUG_LOCK_ALLOC
	struct lockdep_map	dep_map;
#endif
	struct sysfs_dirent	*s_parent;
	const char		*s_name;

	struct rb_node		s_rb;

	union {
		struct completion	*completion;
		struct sysfs_dirent	*removed_list;
	} u;

	const void		*s_ns; /* namespace tag */
	unsigned int		s_hash; /* ns + name hash */
	union {
		struct sysfs_elem_dir		s_dir;
		struct sysfs_elem_symlink	s_symlink;
		struct sysfs_elem_attr		s_attr;
		struct sysfs_elem_bin_attr	s_bin_attr;
	};

	unsigned short		s_flags;
	umode_t			s_mode;
	unsigned int		s_ino;
	struct sysfs_inode_attrs *s_iattr;
};

#define SD_DEACTIVATED_BIAS		INT_MIN

#define SYSFS_TYPE_MASK			0x00ff
#define SYSFS_DIR			0x0001
#define SYSFS_KOBJ_ATTR			0x0002
#define SYSFS_KOBJ_BIN_ATTR		0x0004
#define SYSFS_KOBJ_LINK			0x0008
#define SYSFS_COPY_NAME			(SYSFS_DIR | SYSFS_KOBJ_LINK)
#define SYSFS_ACTIVE_REF		(SYSFS_KOBJ_ATTR | SYSFS_KOBJ_BIN_ATTR)

#define SYSFS_FLAG_MASK			~SYSFS_TYPE_MASK
#define SYSFS_FLAG_HAS_NS		0x01000
#define SYSFS_FLAG_REMOVED		0x02000

static inline unsigned int sysfs_type(struct sysfs_dirent *sd)
{
	return sd->s_flags & SYSFS_TYPE_MASK;
}

#ifdef CONFIG_DEBUG_LOCK_ALLOC
#define sysfs_dirent_init_lockdep(sd)				\
do {								\
	struct attribute *attr = sd->s_attr.attr;		\
	struct lock_class_key *key = attr->key;			\
	if (!key)						\
		key = &attr->skey;				\
								\
	lockdep_init_map(&sd->dep_map, "s_active", key, 0);	\
} while (0)
#else
#define sysfs_dirent_init_lockdep(sd) do {} while (0)
#endif

/*
 * Context structure to be used while adding/removing nodes.
 */
struct sysfs_addrm_cxt {
	struct sysfs_dirent	*parent_sd;
	struct sysfs_dirent	*removed;
};

/*
 * mount.c
 */

/*
 * Each sb is associated with one namespace tag, currently the network
 * namespace of the task which mounted this sysfs instance.  If multiple
 * tags become necessary, make the following an array and compare
 * sysfs_dirent tag against every entry.
 */
struct sysfs_super_info {
	void *ns;
};
#define sysfs_info(SB) ((struct sysfs_super_info *)(SB->s_fs_info))
extern struct sysfs_dirent sysfs_root;
extern struct kmem_cache *sysfs_dir_cachep;

/*
 * dir.c
 */
extern struct mutex sysfs_mutex;
extern spinlock_t sysfs_assoc_lock;
extern const struct dentry_operations sysfs_dentry_ops;

extern const struct file_operations sysfs_dir_operations;
extern const struct inode_operations sysfs_dir_inode_operations;

struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd);
struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd);
void sysfs_put_active(struct sysfs_dirent *sd);
void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
		       struct sysfs_dirent *parent_sd);
int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt);

struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd,
				       const void *ns,
				       const unsigned char *name);
struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
				      const void *ns,
				      const unsigned char *name);
struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type);

void release_sysfs_dirent(struct sysfs_dirent *sd);

int sysfs_create_subdir(struct kobject *kobj, const char *name,
			struct sysfs_dirent **p_sd);
void sysfs_remove_subdir(struct sysfs_dirent *sd);

int sysfs_rename(struct sysfs_dirent *sd, struct sysfs_dirent *new_parent_sd,
		 const void *ns, const char *new_name);

static inline struct sysfs_dirent *__sysfs_get(struct sysfs_dirent *sd)
{
	if (sd) {
		WARN_ON(!atomic_read(&sd->s_count));
		atomic_inc(&sd->s_count);
	}
	return sd;
}
#define sysfs_get(sd) __sysfs_get(sd)

static inline void __sysfs_put(struct sysfs_dirent *sd)
{
	if (sd && atomic_dec_and_test(&sd->s_count))
		release_sysfs_dirent(sd);
}
#define sysfs_put(sd) __sysfs_put(sd)

/*
 * inode.c
 */
struct inode *sysfs_get_inode(struct super_block *sb, struct sysfs_dirent *sd);
void sysfs_evict_inode(struct inode *inode);
int sysfs_sd_setattr(struct sysfs_dirent *sd, struct iattr *iattr);
int sysfs_permission(struct inode *inode, int mask);
int sysfs_setattr(struct dentry *dentry, struct iattr *iattr);
int sysfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
		  struct kstat *stat);
int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value,
		   size_t size, int flags);
int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const void *ns,
			  const char *name);
int sysfs_inode_init(void);

/*
 * file.c
 */
extern const struct file_operations sysfs_file_operations;

int sysfs_add_file(struct sysfs_dirent *dir_sd,
		   const struct attribute *attr, int type);

int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd,
			   const struct attribute *attr, int type,
			   umode_t amode, const void *ns);
/*
 * bin.c
 */
extern const struct file_operations bin_fops;
void unmap_bin_file(struct sysfs_dirent *attr_sd);

/*
 * symlink.c
 */
extern const struct inode_operations sysfs_symlink_inode_operations;
int sysfs_create_link_sd(struct sysfs_dirent *sd, struct kobject *target,
			 const char *name);