xref: /openbmc/linux/fs/sysfs/sysfs.h (revision e4c0d0e2)
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/kobject_ns.h>
13 #include <linux/fs.h>
14 
15 struct sysfs_open_dirent;
16 
17 /* type-specific structures for sysfs_dirent->s_* union members */
18 struct sysfs_elem_dir {
19 	struct kobject		*kobj;
20 	/* children list starts here and goes through sd->s_sibling */
21 	struct sysfs_dirent	*children;
22 };
23 
24 struct sysfs_elem_symlink {
25 	struct sysfs_dirent	*target_sd;
26 };
27 
28 struct sysfs_elem_attr {
29 	struct attribute	*attr;
30 	struct sysfs_open_dirent *open;
31 };
32 
33 struct sysfs_elem_bin_attr {
34 	struct bin_attribute	*bin_attr;
35 	struct hlist_head	buffers;
36 };
37 
38 struct sysfs_inode_attrs {
39 	struct iattr	ia_iattr;
40 	void		*ia_secdata;
41 	u32		ia_secdata_len;
42 };
43 
44 /*
45  * sysfs_dirent - the building block of sysfs hierarchy.  Each and
46  * every sysfs node is represented by single sysfs_dirent.
47  *
48  * As long as s_count reference is held, the sysfs_dirent itself is
49  * accessible.  Dereferencing s_elem or any other outer entity
50  * requires s_active reference.
51  */
52 struct sysfs_dirent {
53 	atomic_t		s_count;
54 	atomic_t		s_active;
55 #ifdef CONFIG_DEBUG_LOCK_ALLOC
56 	struct lockdep_map	dep_map;
57 #endif
58 	struct sysfs_dirent	*s_parent;
59 	struct sysfs_dirent	*s_sibling;
60 	const char		*s_name;
61 
62 	const void		*s_ns; /* namespace tag */
63 	union {
64 		struct sysfs_elem_dir		s_dir;
65 		struct sysfs_elem_symlink	s_symlink;
66 		struct sysfs_elem_attr		s_attr;
67 		struct sysfs_elem_bin_attr	s_bin_attr;
68 	};
69 
70 	unsigned int		s_flags;
71 	unsigned short		s_mode;
72 	ino_t			s_ino;
73 	struct sysfs_inode_attrs *s_iattr;
74 };
75 
76 #define SD_DEACTIVATED_BIAS		INT_MIN
77 
78 #define SYSFS_TYPE_MASK			0x00ff
79 #define SYSFS_DIR			0x0001
80 #define SYSFS_KOBJ_ATTR			0x0002
81 #define SYSFS_KOBJ_BIN_ATTR		0x0004
82 #define SYSFS_KOBJ_LINK			0x0008
83 #define SYSFS_COPY_NAME			(SYSFS_DIR | SYSFS_KOBJ_LINK)
84 #define SYSFS_ACTIVE_REF		(SYSFS_KOBJ_ATTR | SYSFS_KOBJ_BIN_ATTR)
85 
86 /* identify any namespace tag on sysfs_dirents */
87 #define SYSFS_NS_TYPE_MASK		0xff00
88 #define SYSFS_NS_TYPE_SHIFT		8
89 
90 #define SYSFS_FLAG_MASK			~(SYSFS_NS_TYPE_MASK|SYSFS_TYPE_MASK)
91 #define SYSFS_FLAG_REMOVED		0x020000
92 
93 static inline unsigned int sysfs_type(struct sysfs_dirent *sd)
94 {
95 	return sd->s_flags & SYSFS_TYPE_MASK;
96 }
97 
98 /*
99  * Return any namespace tags on this dirent.
100  * enum kobj_ns_type is defined in linux/kobject.h
101  */
102 static inline enum kobj_ns_type sysfs_ns_type(struct sysfs_dirent *sd)
103 {
104 	return (sd->s_flags & SYSFS_NS_TYPE_MASK) >> SYSFS_NS_TYPE_SHIFT;
105 }
106 
107 #ifdef CONFIG_DEBUG_LOCK_ALLOC
108 #define sysfs_dirent_init_lockdep(sd)				\
109 do {								\
110 	struct attribute *attr = sd->s_attr.attr;		\
111 	struct lock_class_key *key = attr->key;			\
112 	if (!key)						\
113 		key = &attr->skey;				\
114 								\
115 	lockdep_init_map(&sd->dep_map, "s_active", key, 0);	\
116 } while(0)
117 #else
118 #define sysfs_dirent_init_lockdep(sd) do {} while(0)
119 #endif
120 
121 /*
122  * Context structure to be used while adding/removing nodes.
123  */
124 struct sysfs_addrm_cxt {
125 	struct sysfs_dirent	*parent_sd;
126 	struct sysfs_dirent	*removed;
127 };
128 
129 /*
130  * mount.c
131  */
132 
133 /*
134  * Each sb is associated with a set of namespace tags (i.e.
135  * the network namespace of the task which mounted this sysfs
136  * instance).
137  */
138 struct sysfs_super_info {
139 	void *ns[KOBJ_NS_TYPES];
140 };
141 #define sysfs_info(SB) ((struct sysfs_super_info *)(SB->s_fs_info))
142 extern struct sysfs_dirent sysfs_root;
143 extern struct kmem_cache *sysfs_dir_cachep;
144 
145 /*
146  * dir.c
147  */
148 extern struct mutex sysfs_mutex;
149 extern spinlock_t sysfs_assoc_lock;
150 
151 extern const struct file_operations sysfs_dir_operations;
152 extern const struct inode_operations sysfs_dir_inode_operations;
153 
154 struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd);
155 struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd);
156 void sysfs_put_active(struct sysfs_dirent *sd);
157 void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
158 		       struct sysfs_dirent *parent_sd);
159 int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
160 int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
161 void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
162 void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt);
163 
164 struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd,
165 				       const void *ns,
166 				       const unsigned char *name);
167 struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
168 				      const void *ns,
169 				      const unsigned char *name);
170 struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type);
171 
172 void release_sysfs_dirent(struct sysfs_dirent *sd);
173 
174 int sysfs_create_subdir(struct kobject *kobj, const char *name,
175 			struct sysfs_dirent **p_sd);
176 void sysfs_remove_subdir(struct sysfs_dirent *sd);
177 
178 int sysfs_rename(struct sysfs_dirent *sd,
179 	struct sysfs_dirent *new_parent_sd, const void *ns, const char *new_name);
180 
181 static inline struct sysfs_dirent *__sysfs_get(struct sysfs_dirent *sd)
182 {
183 	if (sd) {
184 		WARN_ON(!atomic_read(&sd->s_count));
185 		atomic_inc(&sd->s_count);
186 	}
187 	return sd;
188 }
189 #define sysfs_get(sd) __sysfs_get(sd)
190 
191 static inline void __sysfs_put(struct sysfs_dirent *sd)
192 {
193 	if (sd && atomic_dec_and_test(&sd->s_count))
194 		release_sysfs_dirent(sd);
195 }
196 #define sysfs_put(sd) __sysfs_put(sd)
197 
198 /*
199  * inode.c
200  */
201 struct inode *sysfs_get_inode(struct super_block *sb, struct sysfs_dirent *sd);
202 void sysfs_evict_inode(struct inode *inode);
203 int sysfs_sd_setattr(struct sysfs_dirent *sd, struct iattr *iattr);
204 int sysfs_permission(struct inode *inode, int mask, unsigned int flags);
205 int sysfs_setattr(struct dentry *dentry, struct iattr *iattr);
206 int sysfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat);
207 int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value,
208 		size_t size, int flags);
209 int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const void *ns, const char *name);
210 int sysfs_inode_init(void);
211 
212 /*
213  * file.c
214  */
215 extern const struct file_operations sysfs_file_operations;
216 
217 int sysfs_add_file(struct sysfs_dirent *dir_sd,
218 		   const struct attribute *attr, int type);
219 
220 int sysfs_add_file_mode(struct sysfs_dirent *dir_sd,
221 			const struct attribute *attr, int type, mode_t amode);
222 /*
223  * bin.c
224  */
225 extern const struct file_operations bin_fops;
226 void unmap_bin_file(struct sysfs_dirent *attr_sd);
227 
228 /*
229  * symlink.c
230  */
231 extern const struct inode_operations sysfs_symlink_inode_operations;
232