xref: /openbmc/linux/fs/sysfs/sysfs.h (revision 990e53f8)
1 struct sysfs_elem_dir {
2 	struct kobject		* kobj;
3 };
4 
5 struct sysfs_elem_symlink {
6 	struct sysfs_dirent	* target_sd;
7 };
8 
9 struct sysfs_elem_attr {
10 	struct attribute	* attr;
11 };
12 
13 struct sysfs_elem_bin_attr {
14 	struct bin_attribute	* bin_attr;
15 };
16 
17 /*
18  * As long as s_count reference is held, the sysfs_dirent itself is
19  * accessible.  Dereferencing s_elem or any other outer entity
20  * requires s_active reference.
21  */
22 struct sysfs_dirent {
23 	atomic_t		s_count;
24 	atomic_t		s_active;
25 	struct sysfs_dirent	* s_parent;
26 	struct sysfs_dirent	* s_sibling;
27 	struct sysfs_dirent	* s_children;
28 	const char		* s_name;
29 
30 	union {
31 		struct sysfs_elem_dir		dir;
32 		struct sysfs_elem_symlink	symlink;
33 		struct sysfs_elem_attr		attr;
34 		struct sysfs_elem_bin_attr	bin_attr;
35 	}			s_elem;
36 
37 	unsigned int		s_flags;
38 	umode_t			s_mode;
39 	ino_t			s_ino;
40 	struct dentry		* s_dentry;
41 	struct iattr		* s_iattr;
42 	atomic_t		s_event;
43 };
44 
45 #define SD_DEACTIVATED_BIAS	INT_MIN
46 
47 struct sysfs_addrm_cxt {
48 	struct sysfs_dirent	*parent_sd;
49 	struct inode		*parent_inode;
50 	struct sysfs_dirent	*removed;
51 	int			cnt;
52 };
53 
54 extern struct vfsmount * sysfs_mount;
55 extern struct sysfs_dirent sysfs_root;
56 extern struct kmem_cache *sysfs_dir_cachep;
57 
58 extern struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd);
59 extern struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd);
60 extern void sysfs_put_active(struct sysfs_dirent *sd);
61 extern struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd);
62 extern void sysfs_put_active_two(struct sysfs_dirent *sd);
63 extern void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
64 			      struct sysfs_dirent *parent_sd);
65 extern int sysfs_add_one(struct sysfs_addrm_cxt *acxt,
66 			  struct sysfs_dirent *sd);
67 extern void sysfs_remove_one(struct sysfs_addrm_cxt *acxt,
68 			     struct sysfs_dirent *sd);
69 extern void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt);
70 
71 extern struct inode * sysfs_get_inode(struct sysfs_dirent *sd);
72 extern void sysfs_instantiate(struct dentry *dentry, struct inode *inode);
73 
74 extern void release_sysfs_dirent(struct sysfs_dirent * sd);
75 extern struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd,
76 					      const unsigned char *name);
77 extern struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
78 					     const unsigned char *name);
79 extern struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode,
80 					     int type);
81 
82 extern int sysfs_add_file(struct sysfs_dirent *dir_sd,
83 			  const struct attribute *attr, int type);
84 extern int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name);
85 extern struct sysfs_dirent *sysfs_find(struct sysfs_dirent *dir, const char * name);
86 
87 extern int sysfs_create_subdir(struct kobject *kobj, const char *name,
88 			       struct sysfs_dirent **p_sd);
89 extern void sysfs_remove_subdir(struct sysfs_dirent *sd);
90 
91 extern int sysfs_setattr(struct dentry *dentry, struct iattr *iattr);
92 
93 extern spinlock_t sysfs_assoc_lock;
94 extern struct mutex sysfs_mutex;
95 extern struct super_block * sysfs_sb;
96 extern const struct file_operations sysfs_dir_operations;
97 extern const struct file_operations sysfs_file_operations;
98 extern const struct file_operations bin_fops;
99 extern const struct inode_operations sysfs_dir_inode_operations;
100 extern const struct inode_operations sysfs_symlink_inode_operations;
101 
102 static inline unsigned int sysfs_type(struct sysfs_dirent *sd)
103 {
104 	return sd->s_flags & SYSFS_TYPE_MASK;
105 }
106 
107 static inline struct sysfs_dirent * sysfs_get(struct sysfs_dirent * sd)
108 {
109 	if (sd) {
110 		WARN_ON(!atomic_read(&sd->s_count));
111 		atomic_inc(&sd->s_count);
112 	}
113 	return sd;
114 }
115 
116 static inline void sysfs_put(struct sysfs_dirent * sd)
117 {
118 	if (sd && atomic_dec_and_test(&sd->s_count))
119 		release_sysfs_dirent(sd);
120 }
121