xref: /linux/fs/sysfs/sysfs.h (revision 913df4453f85f1fe79b35ecf3c9a0c0b707d22a2)
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 #include <linux/fs.h>
12 
13 struct sysfs_open_dirent;
14 
15 /* type-specific structures for sysfs_dirent->s_* union members */
16 struct sysfs_elem_dir {
17 	struct kobject		*kobj;
18 	/* children list starts here and goes through sd->s_sibling */
19 	struct sysfs_dirent	*children;
20 };
21 
22 struct sysfs_elem_symlink {
23 	struct sysfs_dirent	*target_sd;
24 };
25 
26 struct sysfs_elem_attr {
27 	struct attribute	*attr;
28 	struct sysfs_open_dirent *open;
29 };
30 
31 struct sysfs_elem_bin_attr {
32 	struct bin_attribute	*bin_attr;
33 	struct hlist_head	buffers;
34 };
35 
36 struct sysfs_inode_attrs {
37 	struct iattr	ia_iattr;
38 	void		*ia_secdata;
39 	u32		ia_secdata_len;
40 };
41 
42 /*
43  * sysfs_dirent - the building block of sysfs hierarchy.  Each and
44  * every sysfs node is represented by single sysfs_dirent.
45  *
46  * As long as s_count reference is held, the sysfs_dirent itself is
47  * accessible.  Dereferencing s_elem or any other outer entity
48  * requires s_active reference.
49  */
50 struct sysfs_dirent {
51 	atomic_t		s_count;
52 	atomic_t		s_active;
53 	struct sysfs_dirent	*s_parent;
54 	struct sysfs_dirent	*s_sibling;
55 	const char		*s_name;
56 
57 	union {
58 		struct sysfs_elem_dir		s_dir;
59 		struct sysfs_elem_symlink	s_symlink;
60 		struct sysfs_elem_attr		s_attr;
61 		struct sysfs_elem_bin_attr	s_bin_attr;
62 	};
63 
64 	unsigned int		s_flags;
65 	ino_t			s_ino;
66 	umode_t			s_mode;
67 	struct sysfs_inode_attrs *s_iattr;
68 };
69 
70 #define SD_DEACTIVATED_BIAS		INT_MIN
71 
72 #define SYSFS_TYPE_MASK			0x00ff
73 #define SYSFS_DIR			0x0001
74 #define SYSFS_KOBJ_ATTR			0x0002
75 #define SYSFS_KOBJ_BIN_ATTR		0x0004
76 #define SYSFS_KOBJ_LINK			0x0008
77 #define SYSFS_COPY_NAME			(SYSFS_DIR | SYSFS_KOBJ_LINK)
78 
79 #define SYSFS_FLAG_MASK			~SYSFS_TYPE_MASK
80 #define SYSFS_FLAG_REMOVED		0x0200
81 
82 static inline unsigned int sysfs_type(struct sysfs_dirent *sd)
83 {
84 	return sd->s_flags & SYSFS_TYPE_MASK;
85 }
86 
87 /*
88  * Context structure to be used while adding/removing nodes.
89  */
90 struct sysfs_addrm_cxt {
91 	struct sysfs_dirent	*parent_sd;
92 	struct inode		*parent_inode;
93 	struct sysfs_dirent	*removed;
94 	int			cnt;
95 };
96 
97 /*
98  * mount.c
99  */
100 extern struct sysfs_dirent sysfs_root;
101 extern struct super_block *sysfs_sb;
102 extern struct kmem_cache *sysfs_dir_cachep;
103 
104 /*
105  * dir.c
106  */
107 extern struct mutex sysfs_mutex;
108 extern struct mutex sysfs_rename_mutex;
109 extern spinlock_t sysfs_assoc_lock;
110 
111 extern const struct file_operations sysfs_dir_operations;
112 extern const struct inode_operations sysfs_dir_inode_operations;
113 
114 struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd);
115 struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd);
116 void sysfs_put_active_two(struct sysfs_dirent *sd);
117 void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
118 		       struct sysfs_dirent *parent_sd);
119 int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
120 int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
121 void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
122 void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt);
123 
124 struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd,
125 				       const unsigned char *name);
126 struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
127 				      const unsigned char *name);
128 struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type);
129 
130 void release_sysfs_dirent(struct sysfs_dirent *sd);
131 
132 int sysfs_create_subdir(struct kobject *kobj, const char *name,
133 			struct sysfs_dirent **p_sd);
134 void sysfs_remove_subdir(struct sysfs_dirent *sd);
135 
136 static inline struct sysfs_dirent *__sysfs_get(struct sysfs_dirent *sd)
137 {
138 	if (sd) {
139 		WARN_ON(!atomic_read(&sd->s_count));
140 		atomic_inc(&sd->s_count);
141 	}
142 	return sd;
143 }
144 #define sysfs_get(sd) __sysfs_get(sd)
145 
146 static inline void __sysfs_put(struct sysfs_dirent *sd)
147 {
148 	if (sd && atomic_dec_and_test(&sd->s_count))
149 		release_sysfs_dirent(sd);
150 }
151 #define sysfs_put(sd) __sysfs_put(sd)
152 
153 /*
154  * inode.c
155  */
156 struct inode *sysfs_get_inode(struct sysfs_dirent *sd);
157 void sysfs_delete_inode(struct inode *inode);
158 int sysfs_setattr(struct dentry *dentry, struct iattr *iattr);
159 int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value,
160 		size_t size, int flags);
161 int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name);
162 int sysfs_inode_init(void);
163 
164 /*
165  * file.c
166  */
167 extern const struct file_operations sysfs_file_operations;
168 
169 int sysfs_add_file(struct sysfs_dirent *dir_sd,
170 		   const struct attribute *attr, int type);
171 
172 int sysfs_add_file_mode(struct sysfs_dirent *dir_sd,
173 			const struct attribute *attr, int type, mode_t amode);
174 /*
175  * bin.c
176  */
177 extern const struct file_operations bin_fops;
178 void unmap_bin_file(struct sysfs_dirent *attr_sd);
179 
180 /*
181  * symlink.c
182  */
183 extern const struct inode_operations sysfs_symlink_inode_operations;
184