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 #include <linux/rbtree.h>
15
16 struct sysfs_open_dirent;
17
18 /* type-specific structures for sysfs_dirent->s_* union members */
19 struct sysfs_elem_dir {
20 struct kobject *kobj;
21
22 unsigned long subdirs;
23 /* children rbtree starts here and goes through sd->s_rb */
24 struct rb_root children;
25 };
26
27 struct sysfs_elem_symlink {
28 struct sysfs_dirent *target_sd;
29 };
30
31 struct sysfs_elem_attr {
32 struct attribute *attr;
33 struct sysfs_open_dirent *open;
34 };
35
36 struct sysfs_elem_bin_attr {
37 struct bin_attribute *bin_attr;
38 struct hlist_head buffers;
39 };
40
41 struct sysfs_inode_attrs {
42 struct iattr ia_iattr;
43 void *ia_secdata;
44 u32 ia_secdata_len;
45 };
46
47 /*
48 * sysfs_dirent - the building block of sysfs hierarchy. Each and
49 * every sysfs node is represented by single sysfs_dirent.
50 *
51 * As long as s_count reference is held, the sysfs_dirent itself is
52 * accessible. Dereferencing s_elem or any other outer entity
53 * requires s_active reference.
54 */
55 struct sysfs_dirent {
56 atomic_t s_count;
57 atomic_t s_active;
58 #ifdef CONFIG_DEBUG_LOCK_ALLOC
59 struct lockdep_map dep_map;
60 #endif
61 struct sysfs_dirent *s_parent;
62 const char *s_name;
63
64 struct rb_node s_rb;
65
66 union {
67 struct completion *completion;
68 struct sysfs_dirent *removed_list;
69 } u;
70
71 const void *s_ns; /* namespace tag */
72 unsigned int s_hash; /* ns + name hash */
73 union {
74 struct sysfs_elem_dir s_dir;
75 struct sysfs_elem_symlink s_symlink;
76 struct sysfs_elem_attr s_attr;
77 struct sysfs_elem_bin_attr s_bin_attr;
78 };
79
80 unsigned short s_flags;
81 umode_t s_mode;
82 unsigned int s_ino;
83 struct sysfs_inode_attrs *s_iattr;
84 };
85
86 #define SD_DEACTIVATED_BIAS INT_MIN
87
88 #define SYSFS_TYPE_MASK 0x00ff
89 #define SYSFS_DIR 0x0001
90 #define SYSFS_KOBJ_ATTR 0x0002
91 #define SYSFS_KOBJ_BIN_ATTR 0x0004
92 #define SYSFS_KOBJ_LINK 0x0008
93 #define SYSFS_COPY_NAME (SYSFS_DIR | SYSFS_KOBJ_LINK)
94 #define SYSFS_ACTIVE_REF (SYSFS_KOBJ_ATTR | SYSFS_KOBJ_BIN_ATTR)
95
96 /* identify any namespace tag on sysfs_dirents */
97 #define SYSFS_NS_TYPE_MASK 0xf00
98 #define SYSFS_NS_TYPE_SHIFT 8
99
100 #define SYSFS_FLAG_MASK ~(SYSFS_NS_TYPE_MASK|SYSFS_TYPE_MASK)
101 #define SYSFS_FLAG_REMOVED 0x02000
102
sysfs_type(struct sysfs_dirent * sd)103 static inline unsigned int sysfs_type(struct sysfs_dirent *sd)
104 {
105 return sd->s_flags & SYSFS_TYPE_MASK;
106 }
107
108 /*
109 * Return any namespace tags on this dirent.
110 * enum kobj_ns_type is defined in linux/kobject.h
111 */
sysfs_ns_type(struct sysfs_dirent * sd)112 static inline enum kobj_ns_type sysfs_ns_type(struct sysfs_dirent *sd)
113 {
114 return (sd->s_flags & SYSFS_NS_TYPE_MASK) >> SYSFS_NS_TYPE_SHIFT;
115 }
116
117 #ifdef CONFIG_DEBUG_LOCK_ALLOC
118 #define sysfs_dirent_init_lockdep(sd) \
119 do { \
120 struct attribute *attr = sd->s_attr.attr; \
121 struct lock_class_key *key = attr->key; \
122 if (!key) \
123 key = &attr->skey; \
124 \
125 lockdep_init_map(&sd->dep_map, "s_active", key, 0); \
126 } while(0)
127 #else
128 #define sysfs_dirent_init_lockdep(sd) do {} while(0)
129 #endif
130
131 /*
132 * Context structure to be used while adding/removing nodes.
133 */
134 struct sysfs_addrm_cxt {
135 struct sysfs_dirent *parent_sd;
136 struct sysfs_dirent *removed;
137 };
138
139 /*
140 * mount.c
141 */
142
143 /*
144 * Each sb is associated with a set of namespace tags (i.e.
145 * the network namespace of the task which mounted this sysfs
146 * instance).
147 */
148 struct sysfs_super_info {
149 void *ns[KOBJ_NS_TYPES];
150 };
151 #define sysfs_info(SB) ((struct sysfs_super_info *)(SB->s_fs_info))
152 extern struct sysfs_dirent sysfs_root;
153 extern struct kmem_cache *sysfs_dir_cachep;
154
155 /*
156 * dir.c
157 */
158 extern struct mutex sysfs_mutex;
159 extern spinlock_t sysfs_assoc_lock;
160
161 extern const struct file_operations sysfs_dir_operations;
162 extern const struct inode_operations sysfs_dir_inode_operations;
163
164 struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd);
165 struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd);
166 void sysfs_put_active(struct sysfs_dirent *sd);
167 void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
168 struct sysfs_dirent *parent_sd);
169 int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
170 int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
171 void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
172 void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt);
173
174 struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd,
175 const void *ns,
176 const unsigned char *name);
177 struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
178 const void *ns,
179 const unsigned char *name);
180 struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type);
181
182 void release_sysfs_dirent(struct sysfs_dirent *sd);
183
184 int sysfs_create_subdir(struct kobject *kobj, const char *name,
185 struct sysfs_dirent **p_sd);
186 void sysfs_remove_subdir(struct sysfs_dirent *sd);
187
188 int sysfs_rename(struct sysfs_dirent *sd,
189 struct sysfs_dirent *new_parent_sd, const void *ns, const char *new_name);
190
__sysfs_get(struct sysfs_dirent * sd)191 static inline struct sysfs_dirent *__sysfs_get(struct sysfs_dirent *sd)
192 {
193 if (sd) {
194 WARN_ON(!atomic_read(&sd->s_count));
195 atomic_inc(&sd->s_count);
196 }
197 return sd;
198 }
199 #define sysfs_get(sd) __sysfs_get(sd)
200
__sysfs_put(struct sysfs_dirent * sd)201 static inline void __sysfs_put(struct sysfs_dirent *sd)
202 {
203 if (sd && atomic_dec_and_test(&sd->s_count))
204 release_sysfs_dirent(sd);
205 }
206 #define sysfs_put(sd) __sysfs_put(sd)
207
208 /*
209 * inode.c
210 */
211 struct inode *sysfs_get_inode(struct super_block *sb, struct sysfs_dirent *sd);
212 void sysfs_evict_inode(struct inode *inode);
213 int sysfs_sd_setattr(struct sysfs_dirent *sd, struct iattr *iattr);
214 int sysfs_permission(struct inode *inode, int mask);
215 int sysfs_setattr(struct dentry *dentry, struct iattr *iattr);
216 int sysfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat);
217 int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value,
218 size_t size, int flags);
219 int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const void *ns, const char *name);
220 int sysfs_inode_init(void);
221
222 /*
223 * file.c
224 */
225 extern const struct file_operations sysfs_file_operations;
226
227 int sysfs_add_file(struct sysfs_dirent *dir_sd,
228 const struct attribute *attr, int type);
229
230 int sysfs_add_file_mode(struct sysfs_dirent *dir_sd,
231 const struct attribute *attr, int type, umode_t amode);
232 /*
233 * bin.c
234 */
235 extern const struct file_operations bin_fops;
236 void unmap_bin_file(struct sysfs_dirent *attr_sd);
237
238 /*
239 * symlink.c
240 */
241 extern const struct inode_operations sysfs_symlink_inode_operations;
242