summaryrefslogtreecommitdiffstats
path: root/fs/kernfs/kernfs-internal.h
blob: 0d949885389dac5b1c8b39b84fc8bbff4c5033c0 (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
/*
 * fs/kernfs/kernfs-internal.h - kernfs internal header file
 *
 * Copyright (c) 2001-3 Patrick Mochel
 * Copyright (c) 2007 SUSE Linux Products GmbH
 * Copyright (c) 2007, 2013 Tejun Heo <teheo@suse.de>
 *
 * This file is released under the GPLv2.
 */

#ifndef __KERNFS_INTERNAL_H
#define __KERNFS_INTERNAL_H

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

#include <linux/kernfs.h>

struct sysfs_open_dirent;

/* type-specific structures for sysfs_dirent->s_* union members */
struct sysfs_elem_dir {
	unsigned long		subdirs;
	/* children rbtree starts here and goes through sd->s_rb */
	struct rb_root		children;

	/*
	 * The kernfs hierarchy this directory belongs to.  This fits
	 * better directly in sysfs_dirent but is here to save space.
	 */
	struct kernfs_root	*root;
};

struct sysfs_elem_symlink {
	struct sysfs_dirent	*target_sd;
};

struct sysfs_elem_attr {
	const struct kernfs_ops	*ops;
	struct sysfs_open_dirent *open;
	loff_t			size;
};

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;
	};

	void			*priv;

	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			0x000f
#define SYSFS_DIR			0x0001
#define SYSFS_KOBJ_ATTR			0x0002
#define SYSFS_KOBJ_LINK			0x0004
#define SYSFS_COPY_NAME			(SYSFS_DIR | SYSFS_KOBJ_LINK)
#define SYSFS_ACTIVE_REF		SYSFS_KOBJ_ATTR

#define SYSFS_FLAG_MASK			~SYSFS_TYPE_MASK
#define SYSFS_FLAG_REMOVED		0x0010
#define SYSFS_FLAG_NS			0x0020
#define SYSFS_FLAG_HAS_SEQ_SHOW		0x0040
#define SYSFS_FLAG_HAS_MMAP		0x0080
#define SYSFS_FLAG_LOCKDEP		0x0100

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

/**
 * kernfs_root - find out the kernfs_root a sysfs_dirent belongs to
 * @sd: sysfs_dirent of interest
 *
 * Return the kernfs_root @sd belongs to.
 */
static inline struct kernfs_root *kernfs_root(struct sysfs_dirent *sd)
{
	/* if parent exists, it's always a dir; otherwise, @sd is a dir */
	if (sd->s_parent)
		sd = sd->s_parent;
	return sd->s_dir.root;
}

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

#include "../sysfs/sysfs.h"

/*
 * inode.c
 */
struct inode *sysfs_get_inode(struct super_block *sb, struct sysfs_dirent *sd);
void sysfs_evict_inode(struct inode *inode);
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);
void sysfs_inode_init(void);

/*
 * dir.c
 */
extern struct mutex sysfs_mutex;
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 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);
int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd,
		  struct sysfs_dirent *parent_sd);
void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt);
struct sysfs_dirent *sysfs_new_dirent(struct kernfs_root *root,
				      const char *name, umode_t mode, int type);

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

void sysfs_unmap_bin_file(struct sysfs_dirent *sd);

/*
 * symlink.c
 */
extern const struct inode_operations sysfs_symlink_inode_operations;

#endif	/* __KERNFS_INTERNAL_H */