xref: /openbmc/linux/fs/sysfs/sysfs.h (revision 8619f979)
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 list_head	s_sibling;
27 	struct list_head	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 	int			s_type;
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 extern struct vfsmount * sysfs_mount;
48 extern struct kmem_cache *sysfs_dir_cachep;
49 
50 extern struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd);
51 extern void sysfs_put_active(struct sysfs_dirent *sd);
52 extern struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd);
53 extern void sysfs_put_active_two(struct sysfs_dirent *sd);
54 extern void sysfs_deactivate(struct sysfs_dirent *sd);
55 
56 extern void sysfs_delete_inode(struct inode *inode);
57 extern void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode);
58 extern struct inode * sysfs_get_inode(struct sysfs_dirent *sd);
59 extern void sysfs_instantiate(struct dentry *dentry, struct inode *inode);
60 
61 extern void release_sysfs_dirent(struct sysfs_dirent * sd);
62 extern int sysfs_dirent_exist(struct sysfs_dirent *, const unsigned char *);
63 extern struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode,
64 					     int type);
65 extern void sysfs_attach_dirent(struct sysfs_dirent *sd,
66 				struct sysfs_dirent *parent_sd,
67 				struct dentry *dentry);
68 
69 extern int sysfs_add_file(struct dentry *, const struct attribute *, int);
70 extern int sysfs_hash_and_remove(struct dentry * dir, const char * name);
71 extern struct sysfs_dirent *sysfs_find(struct sysfs_dirent *dir, const char * name);
72 
73 extern int sysfs_create_subdir(struct kobject *, const char *, struct dentry **);
74 extern void sysfs_remove_subdir(struct dentry *);
75 
76 extern void sysfs_drop_dentry(struct sysfs_dirent *sd);
77 extern int sysfs_setattr(struct dentry *dentry, struct iattr *iattr);
78 
79 extern spinlock_t sysfs_lock;
80 extern spinlock_t kobj_sysfs_assoc_lock;
81 extern struct rw_semaphore sysfs_rename_sem;
82 extern struct super_block * sysfs_sb;
83 extern const struct file_operations sysfs_dir_operations;
84 extern const struct file_operations sysfs_file_operations;
85 extern const struct file_operations bin_fops;
86 extern const struct inode_operations sysfs_dir_inode_operations;
87 extern const struct inode_operations sysfs_symlink_inode_operations;
88 
89 static inline struct sysfs_dirent * sysfs_get(struct sysfs_dirent * sd)
90 {
91 	if (sd) {
92 		WARN_ON(!atomic_read(&sd->s_count));
93 		atomic_inc(&sd->s_count);
94 	}
95 	return sd;
96 }
97 
98 static inline void sysfs_put(struct sysfs_dirent * sd)
99 {
100 	if (sd && atomic_dec_and_test(&sd->s_count))
101 		release_sysfs_dirent(sd);
102 }
103 
104 static inline int sysfs_is_shadowed_inode(struct inode *inode)
105 {
106 	return S_ISDIR(inode->i_mode) && inode->i_op->follow_link;
107 }
108