xref: /openbmc/linux/fs/sysfs/sysfs.h (revision 7dd65feb)
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/lockdep.h>
12 #include <linux/fs.h>
13 
14 struct sysfs_open_dirent;
15 
16 /* type-specific structures for sysfs_dirent->s_* union members */
17 struct sysfs_elem_dir {
18 	struct kobject		*kobj;
19 	/* children list starts here and goes through sd->s_sibling */
20 	struct sysfs_dirent	*children;
21 };
22 
23 struct sysfs_elem_symlink {
24 	struct sysfs_dirent	*target_sd;
25 };
26 
27 struct sysfs_elem_attr {
28 	struct attribute	*attr;
29 	struct sysfs_open_dirent *open;
30 };
31 
32 struct sysfs_elem_bin_attr {
33 	struct bin_attribute	*bin_attr;
34 	struct hlist_head	buffers;
35 };
36 
37 struct sysfs_inode_attrs {
38 	struct iattr	ia_iattr;
39 	void		*ia_secdata;
40 	u32		ia_secdata_len;
41 };
42 
43 /*
44  * sysfs_dirent - the building block of sysfs hierarchy.  Each and
45  * every sysfs node is represented by single sysfs_dirent.
46  *
47  * As long as s_count reference is held, the sysfs_dirent itself is
48  * accessible.  Dereferencing s_elem or any other outer entity
49  * requires s_active reference.
50  */
51 struct sysfs_dirent {
52 	atomic_t		s_count;
53 	atomic_t		s_active;
54 #ifdef CONFIG_DEBUG_LOCK_ALLOC
55 	struct lockdep_map	dep_map;
56 #endif
57 	struct sysfs_dirent	*s_parent;
58 	struct sysfs_dirent	*s_sibling;
59 	const char		*s_name;
60 
61 	union {
62 		struct sysfs_elem_dir		s_dir;
63 		struct sysfs_elem_symlink	s_symlink;
64 		struct sysfs_elem_attr		s_attr;
65 		struct sysfs_elem_bin_attr	s_bin_attr;
66 	};
67 
68 	unsigned int		s_flags;
69 	ino_t			s_ino;
70 	umode_t			s_mode;
71 	struct sysfs_inode_attrs *s_iattr;
72 };
73 
74 #define SD_DEACTIVATED_BIAS		INT_MIN
75 
76 #define SYSFS_TYPE_MASK			0x00ff
77 #define SYSFS_DIR			0x0001
78 #define SYSFS_KOBJ_ATTR			0x0002
79 #define SYSFS_KOBJ_BIN_ATTR		0x0004
80 #define SYSFS_KOBJ_LINK			0x0008
81 #define SYSFS_COPY_NAME			(SYSFS_DIR | SYSFS_KOBJ_LINK)
82 
83 #define SYSFS_FLAG_MASK			~SYSFS_TYPE_MASK
84 #define SYSFS_FLAG_REMOVED		0x0200
85 
86 static inline unsigned int sysfs_type(struct sysfs_dirent *sd)
87 {
88 	return sd->s_flags & SYSFS_TYPE_MASK;
89 }
90 
91 #ifdef CONFIG_DEBUG_LOCK_ALLOC
92 #define sysfs_dirent_init_lockdep(sd)				\
93 do {								\
94 	static struct lock_class_key __key;			\
95 								\
96 	lockdep_init_map(&sd->dep_map, "s_active", &__key, 0);	\
97 } while(0)
98 #else
99 #define sysfs_dirent_init_lockdep(sd) do {} while(0)
100 #endif
101 
102 /*
103  * Context structure to be used while adding/removing nodes.
104  */
105 struct sysfs_addrm_cxt {
106 	struct sysfs_dirent	*parent_sd;
107 	struct sysfs_dirent	*removed;
108 };
109 
110 /*
111  * mount.c
112  */
113 extern struct sysfs_dirent sysfs_root;
114 extern struct super_block *sysfs_sb;
115 extern struct kmem_cache *sysfs_dir_cachep;
116 
117 /*
118  * dir.c
119  */
120 extern struct mutex sysfs_mutex;
121 extern spinlock_t sysfs_assoc_lock;
122 
123 extern const struct file_operations sysfs_dir_operations;
124 extern const struct inode_operations sysfs_dir_inode_operations;
125 
126 struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd);
127 struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd);
128 void sysfs_put_active_two(struct sysfs_dirent *sd);
129 void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
130 		       struct sysfs_dirent *parent_sd);
131 int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
132 int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
133 void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
134 void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt);
135 
136 struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd,
137 				       const unsigned char *name);
138 struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
139 				      const unsigned char *name);
140 struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type);
141 
142 void release_sysfs_dirent(struct sysfs_dirent *sd);
143 
144 int sysfs_create_subdir(struct kobject *kobj, const char *name,
145 			struct sysfs_dirent **p_sd);
146 void sysfs_remove_subdir(struct sysfs_dirent *sd);
147 
148 int sysfs_rename(struct sysfs_dirent *sd,
149 	struct sysfs_dirent *new_parent_sd, const char *new_name);
150 
151 static inline struct sysfs_dirent *__sysfs_get(struct sysfs_dirent *sd)
152 {
153 	if (sd) {
154 		WARN_ON(!atomic_read(&sd->s_count));
155 		atomic_inc(&sd->s_count);
156 	}
157 	return sd;
158 }
159 #define sysfs_get(sd) __sysfs_get(sd)
160 
161 static inline void __sysfs_put(struct sysfs_dirent *sd)
162 {
163 	if (sd && atomic_dec_and_test(&sd->s_count))
164 		release_sysfs_dirent(sd);
165 }
166 #define sysfs_put(sd) __sysfs_put(sd)
167 
168 /*
169  * inode.c
170  */
171 struct inode *sysfs_get_inode(struct sysfs_dirent *sd);
172 void sysfs_delete_inode(struct inode *inode);
173 int sysfs_sd_setattr(struct sysfs_dirent *sd, struct iattr *iattr);
174 int sysfs_permission(struct inode *inode, int mask);
175 int sysfs_setattr(struct dentry *dentry, struct iattr *iattr);
176 int sysfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat);
177 int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value,
178 		size_t size, int flags);
179 int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name);
180 int sysfs_inode_init(void);
181 
182 /*
183  * file.c
184  */
185 extern const struct file_operations sysfs_file_operations;
186 
187 int sysfs_add_file(struct sysfs_dirent *dir_sd,
188 		   const struct attribute *attr, int type);
189 
190 int sysfs_add_file_mode(struct sysfs_dirent *dir_sd,
191 			const struct attribute *attr, int type, mode_t amode);
192 /*
193  * bin.c
194  */
195 extern const struct file_operations bin_fops;
196 void unmap_bin_file(struct sysfs_dirent *attr_sd);
197 
198 /*
199  * symlink.c
200  */
201 extern const struct inode_operations sysfs_symlink_inode_operations;
202