xref: /linux/fs/sysfs/sysfs.h (revision 5a0e3ad6af8660be21ca98a971cd00f331318c05)
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 	unsigned short		s_mode;
70 	ino_t			s_ino;
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 #define SYSFS_ACTIVE_REF		(SYSFS_KOBJ_ATTR | SYSFS_KOBJ_BIN_ATTR)
83 
84 #define SYSFS_FLAG_MASK			~SYSFS_TYPE_MASK
85 #define SYSFS_FLAG_REMOVED		0x0200
86 
87 static inline unsigned int sysfs_type(struct sysfs_dirent *sd)
88 {
89 	return sd->s_flags & SYSFS_TYPE_MASK;
90 }
91 
92 #ifdef CONFIG_DEBUG_LOCK_ALLOC
93 #define sysfs_dirent_init_lockdep(sd)				\
94 do {								\
95 	struct attribute *attr = sd->s_attr.attr;		\
96 	struct lock_class_key *key = attr->key;			\
97 	if (!key)						\
98 		key = &attr->skey;				\
99 								\
100 	lockdep_init_map(&sd->dep_map, "s_active", key, 0);	\
101 } while(0)
102 #else
103 #define sysfs_dirent_init_lockdep(sd) do {} while(0)
104 #endif
105 
106 /*
107  * Context structure to be used while adding/removing nodes.
108  */
109 struct sysfs_addrm_cxt {
110 	struct sysfs_dirent	*parent_sd;
111 	struct sysfs_dirent	*removed;
112 };
113 
114 /*
115  * mount.c
116  */
117 extern struct sysfs_dirent sysfs_root;
118 extern struct kmem_cache *sysfs_dir_cachep;
119 
120 /*
121  * dir.c
122  */
123 extern struct mutex sysfs_mutex;
124 extern spinlock_t sysfs_assoc_lock;
125 
126 extern const struct file_operations sysfs_dir_operations;
127 extern const struct inode_operations sysfs_dir_inode_operations;
128 
129 struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd);
130 struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd);
131 void sysfs_put_active(struct sysfs_dirent *sd);
132 void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
133 		       struct sysfs_dirent *parent_sd);
134 int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
135 int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
136 void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
137 void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt);
138 
139 struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd,
140 				       const unsigned char *name);
141 struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
142 				      const unsigned char *name);
143 struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type);
144 
145 void release_sysfs_dirent(struct sysfs_dirent *sd);
146 
147 int sysfs_create_subdir(struct kobject *kobj, const char *name,
148 			struct sysfs_dirent **p_sd);
149 void sysfs_remove_subdir(struct sysfs_dirent *sd);
150 
151 int sysfs_rename(struct sysfs_dirent *sd,
152 	struct sysfs_dirent *new_parent_sd, const char *new_name);
153 
154 static inline struct sysfs_dirent *__sysfs_get(struct sysfs_dirent *sd)
155 {
156 	if (sd) {
157 		WARN_ON(!atomic_read(&sd->s_count));
158 		atomic_inc(&sd->s_count);
159 	}
160 	return sd;
161 }
162 #define sysfs_get(sd) __sysfs_get(sd)
163 
164 static inline void __sysfs_put(struct sysfs_dirent *sd)
165 {
166 	if (sd && atomic_dec_and_test(&sd->s_count))
167 		release_sysfs_dirent(sd);
168 }
169 #define sysfs_put(sd) __sysfs_put(sd)
170 
171 /*
172  * inode.c
173  */
174 struct inode *sysfs_get_inode(struct super_block *sb, struct sysfs_dirent *sd);
175 void sysfs_delete_inode(struct inode *inode);
176 int sysfs_sd_setattr(struct sysfs_dirent *sd, struct iattr *iattr);
177 int sysfs_permission(struct inode *inode, int mask);
178 int sysfs_setattr(struct dentry *dentry, struct iattr *iattr);
179 int sysfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat);
180 int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value,
181 		size_t size, int flags);
182 int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name);
183 int sysfs_inode_init(void);
184 
185 /*
186  * file.c
187  */
188 extern const struct file_operations sysfs_file_operations;
189 
190 int sysfs_add_file(struct sysfs_dirent *dir_sd,
191 		   const struct attribute *attr, int type);
192 
193 int sysfs_add_file_mode(struct sysfs_dirent *dir_sd,
194 			const struct attribute *attr, int type, mode_t amode);
195 /*
196  * bin.c
197  */
198 extern const struct file_operations bin_fops;
199 void unmap_bin_file(struct sysfs_dirent *attr_sd);
200 
201 /*
202  * symlink.c
203  */
204 extern const struct inode_operations sysfs_symlink_inode_operations;
205