xref: /openbmc/linux/fs/sysfs/sysfs.h (revision 82ced6fd)
1 /*
2  * fs/sysfs/sysfs.h - sysfs internal header file
3  *
4  * Copyright (c) 2001-3 Patrick Mochel
5  * Copyright (c) 2007 SUSE Linux Products GmbH
6  * Copyright (c) 2007 Tejun Heo <teheo@suse.de>
7  *
8  * This file is released under the GPLv2.
9  */
10 
11 struct sysfs_open_dirent;
12 
13 /* type-specific structures for sysfs_dirent->s_* union members */
14 struct sysfs_elem_dir {
15 	struct kobject		*kobj;
16 	/* children list starts here and goes through sd->s_sibling */
17 	struct sysfs_dirent	*children;
18 };
19 
20 struct sysfs_elem_symlink {
21 	struct sysfs_dirent	*target_sd;
22 };
23 
24 struct sysfs_elem_attr {
25 	struct attribute	*attr;
26 	struct sysfs_open_dirent *open;
27 };
28 
29 struct sysfs_elem_bin_attr {
30 	struct bin_attribute	*bin_attr;
31 	struct hlist_head	buffers;
32 };
33 
34 /*
35  * sysfs_dirent - the building block of sysfs hierarchy.  Each and
36  * every sysfs node is represented by single sysfs_dirent.
37  *
38  * As long as s_count reference is held, the sysfs_dirent itself is
39  * accessible.  Dereferencing s_elem or any other outer entity
40  * requires s_active reference.
41  */
42 struct sysfs_dirent {
43 	atomic_t		s_count;
44 	atomic_t		s_active;
45 	struct sysfs_dirent	*s_parent;
46 	struct sysfs_dirent	*s_sibling;
47 	const char		*s_name;
48 
49 	union {
50 		struct sysfs_elem_dir		s_dir;
51 		struct sysfs_elem_symlink	s_symlink;
52 		struct sysfs_elem_attr		s_attr;
53 		struct sysfs_elem_bin_attr	s_bin_attr;
54 	};
55 
56 	unsigned int		s_flags;
57 	ino_t			s_ino;
58 	umode_t			s_mode;
59 	struct iattr		*s_iattr;
60 };
61 
62 #define SD_DEACTIVATED_BIAS		INT_MIN
63 
64 #define SYSFS_TYPE_MASK			0x00ff
65 #define SYSFS_DIR			0x0001
66 #define SYSFS_KOBJ_ATTR			0x0002
67 #define SYSFS_KOBJ_BIN_ATTR		0x0004
68 #define SYSFS_KOBJ_LINK			0x0008
69 #define SYSFS_COPY_NAME			(SYSFS_DIR | SYSFS_KOBJ_LINK)
70 
71 #define SYSFS_FLAG_MASK			~SYSFS_TYPE_MASK
72 #define SYSFS_FLAG_REMOVED		0x0200
73 
74 static inline unsigned int sysfs_type(struct sysfs_dirent *sd)
75 {
76 	return sd->s_flags & SYSFS_TYPE_MASK;
77 }
78 
79 /*
80  * Context structure to be used while adding/removing nodes.
81  */
82 struct sysfs_addrm_cxt {
83 	struct sysfs_dirent	*parent_sd;
84 	struct inode		*parent_inode;
85 	struct sysfs_dirent	*removed;
86 	int			cnt;
87 };
88 
89 /*
90  * mount.c
91  */
92 extern struct sysfs_dirent sysfs_root;
93 extern struct super_block *sysfs_sb;
94 extern struct kmem_cache *sysfs_dir_cachep;
95 
96 /*
97  * dir.c
98  */
99 extern struct mutex sysfs_mutex;
100 extern struct mutex sysfs_rename_mutex;
101 extern spinlock_t sysfs_assoc_lock;
102 
103 extern const struct file_operations sysfs_dir_operations;
104 extern const struct inode_operations sysfs_dir_inode_operations;
105 
106 struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd);
107 struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd);
108 void sysfs_put_active_two(struct sysfs_dirent *sd);
109 void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
110 		       struct sysfs_dirent *parent_sd);
111 int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
112 int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
113 void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
114 void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt);
115 
116 struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd,
117 				       const unsigned char *name);
118 struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
119 				      const unsigned char *name);
120 struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type);
121 
122 void release_sysfs_dirent(struct sysfs_dirent *sd);
123 
124 int sysfs_create_subdir(struct kobject *kobj, const char *name,
125 			struct sysfs_dirent **p_sd);
126 void sysfs_remove_subdir(struct sysfs_dirent *sd);
127 
128 static inline struct sysfs_dirent *__sysfs_get(struct sysfs_dirent *sd)
129 {
130 	if (sd) {
131 		WARN_ON(!atomic_read(&sd->s_count));
132 		atomic_inc(&sd->s_count);
133 	}
134 	return sd;
135 }
136 #define sysfs_get(sd) __sysfs_get(sd)
137 
138 static inline void __sysfs_put(struct sysfs_dirent *sd)
139 {
140 	if (sd && atomic_dec_and_test(&sd->s_count))
141 		release_sysfs_dirent(sd);
142 }
143 #define sysfs_put(sd) __sysfs_put(sd)
144 
145 /*
146  * inode.c
147  */
148 struct inode *sysfs_get_inode(struct sysfs_dirent *sd);
149 void sysfs_delete_inode(struct inode *inode);
150 int sysfs_setattr(struct dentry *dentry, struct iattr *iattr);
151 int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name);
152 int sysfs_inode_init(void);
153 
154 /*
155  * file.c
156  */
157 extern const struct file_operations sysfs_file_operations;
158 
159 int sysfs_add_file(struct sysfs_dirent *dir_sd,
160 		   const struct attribute *attr, int type);
161 
162 int sysfs_add_file_mode(struct sysfs_dirent *dir_sd,
163 			const struct attribute *attr, int type, mode_t amode);
164 /*
165  * bin.c
166  */
167 extern const struct file_operations bin_fops;
168 void unmap_bin_file(struct sysfs_dirent *attr_sd);
169 
170 /*
171  * symlink.c
172  */
173 extern const struct inode_operations sysfs_symlink_inode_operations;
174