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 union { 33 struct attribute *attr; 34 struct bin_attribute *bin_attr; 35 }; 36 struct sysfs_open_dirent *open; 37 }; 38 39 struct sysfs_inode_attrs { 40 struct iattr ia_iattr; 41 void *ia_secdata; 42 u32 ia_secdata_len; 43 }; 44 45 /* 46 * sysfs_dirent - the building block of sysfs hierarchy. Each and 47 * every sysfs node is represented by single sysfs_dirent. 48 * 49 * As long as s_count reference is held, the sysfs_dirent itself is 50 * accessible. Dereferencing s_elem or any other outer entity 51 * requires s_active reference. 52 */ 53 struct sysfs_dirent { 54 atomic_t s_count; 55 atomic_t s_active; 56 #ifdef CONFIG_DEBUG_LOCK_ALLOC 57 struct lockdep_map dep_map; 58 #endif 59 struct sysfs_dirent *s_parent; 60 const char *s_name; 61 62 struct rb_node s_rb; 63 64 union { 65 struct completion *completion; 66 struct sysfs_dirent *removed_list; 67 } u; 68 69 const void *s_ns; /* namespace tag */ 70 unsigned int s_hash; /* ns + name hash */ 71 union { 72 struct sysfs_elem_dir s_dir; 73 struct sysfs_elem_symlink s_symlink; 74 struct sysfs_elem_attr s_attr; 75 }; 76 77 unsigned short s_flags; 78 umode_t s_mode; 79 unsigned int s_ino; 80 struct sysfs_inode_attrs *s_iattr; 81 }; 82 83 #define SD_DEACTIVATED_BIAS INT_MIN 84 85 #define SYSFS_TYPE_MASK 0x00ff 86 #define SYSFS_DIR 0x0001 87 #define SYSFS_KOBJ_ATTR 0x0002 88 #define SYSFS_KOBJ_BIN_ATTR 0x0004 89 #define SYSFS_KOBJ_LINK 0x0008 90 #define SYSFS_COPY_NAME (SYSFS_DIR | SYSFS_KOBJ_LINK) 91 #define SYSFS_ACTIVE_REF (SYSFS_KOBJ_ATTR | SYSFS_KOBJ_BIN_ATTR) 92 93 /* identify any namespace tag on sysfs_dirents */ 94 #define SYSFS_NS_TYPE_MASK 0xf00 95 #define SYSFS_NS_TYPE_SHIFT 8 96 97 #define SYSFS_FLAG_MASK ~(SYSFS_NS_TYPE_MASK|SYSFS_TYPE_MASK) 98 #define SYSFS_FLAG_REMOVED 0x02000 99 100 static inline unsigned int sysfs_type(struct sysfs_dirent *sd) 101 { 102 return sd->s_flags & SYSFS_TYPE_MASK; 103 } 104 105 /* 106 * Return any namespace tags on this dirent. 107 * enum kobj_ns_type is defined in linux/kobject.h 108 */ 109 static inline enum kobj_ns_type sysfs_ns_type(struct sysfs_dirent *sd) 110 { 111 return (sd->s_flags & SYSFS_NS_TYPE_MASK) >> SYSFS_NS_TYPE_SHIFT; 112 } 113 114 #ifdef CONFIG_DEBUG_LOCK_ALLOC 115 116 #define sysfs_dirent_init_lockdep(sd) \ 117 do { \ 118 struct attribute *attr = sd->s_attr.attr; \ 119 struct lock_class_key *key = attr->key; \ 120 if (!key) \ 121 key = &attr->skey; \ 122 \ 123 lockdep_init_map(&sd->dep_map, "s_active", key, 0); \ 124 } while (0) 125 126 /* Test for attributes that want to ignore lockdep for read-locking */ 127 static inline bool sysfs_ignore_lockdep(struct sysfs_dirent *sd) 128 { 129 int type = sysfs_type(sd); 130 131 return (type == SYSFS_KOBJ_ATTR || type == SYSFS_KOBJ_BIN_ATTR) && 132 sd->s_attr.attr->ignore_lockdep; 133 } 134 135 #else 136 137 #define sysfs_dirent_init_lockdep(sd) do {} while (0) 138 139 static inline bool sysfs_ignore_lockdep(struct sysfs_dirent *sd) 140 { 141 return true; 142 } 143 144 #endif 145 146 /* 147 * Context structure to be used while adding/removing nodes. 148 */ 149 struct sysfs_addrm_cxt { 150 struct sysfs_dirent *removed; 151 }; 152 153 /* 154 * mount.c 155 */ 156 157 /* 158 * Each sb is associated with a set of namespace tags (i.e. 159 * the network namespace of the task which mounted this sysfs 160 * instance). 161 */ 162 struct sysfs_super_info { 163 void *ns[KOBJ_NS_TYPES]; 164 }; 165 #define sysfs_info(SB) ((struct sysfs_super_info *)(SB->s_fs_info)) 166 extern struct sysfs_dirent sysfs_root; 167 extern struct kmem_cache *sysfs_dir_cachep; 168 169 /* 170 * dir.c 171 */ 172 extern struct mutex sysfs_mutex; 173 extern spinlock_t sysfs_symlink_target_lock; 174 extern const struct dentry_operations sysfs_dentry_ops; 175 176 extern const struct file_operations sysfs_dir_operations; 177 extern const struct inode_operations sysfs_dir_inode_operations; 178 179 struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd); 180 void sysfs_put_active(struct sysfs_dirent *sd); 181 void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt); 182 void sysfs_warn_dup(struct sysfs_dirent *parent, const char *name); 183 int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd, 184 struct sysfs_dirent *parent_sd); 185 int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd, 186 struct sysfs_dirent *parent_sd); 187 void sysfs_remove(struct sysfs_dirent *sd); 188 int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name, 189 const void *ns); 190 void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt); 191 192 struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd, 193 const unsigned char *name, 194 const void *ns); 195 struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type); 196 197 void release_sysfs_dirent(struct sysfs_dirent *sd); 198 199 int sysfs_create_subdir(struct kobject *kobj, const char *name, 200 struct sysfs_dirent **p_sd); 201 202 int sysfs_rename(struct sysfs_dirent *sd, struct sysfs_dirent *new_parent_sd, 203 const char *new_name, const void *new_ns); 204 205 static inline struct sysfs_dirent *__sysfs_get(struct sysfs_dirent *sd) 206 { 207 if (sd) { 208 WARN_ON(!atomic_read(&sd->s_count)); 209 atomic_inc(&sd->s_count); 210 } 211 return sd; 212 } 213 #define sysfs_get(sd) __sysfs_get(sd) 214 215 static inline void __sysfs_put(struct sysfs_dirent *sd) 216 { 217 if (sd && atomic_dec_and_test(&sd->s_count)) 218 release_sysfs_dirent(sd); 219 } 220 #define sysfs_put(sd) __sysfs_put(sd) 221 222 /* 223 * inode.c 224 */ 225 struct inode *sysfs_get_inode(struct super_block *sb, struct sysfs_dirent *sd); 226 void sysfs_evict_inode(struct inode *inode); 227 int sysfs_sd_setattr(struct sysfs_dirent *sd, struct iattr *iattr); 228 int sysfs_permission(struct inode *inode, int mask); 229 int sysfs_setattr(struct dentry *dentry, struct iattr *iattr); 230 int sysfs_getattr(struct vfsmount *mnt, struct dentry *dentry, 231 struct kstat *stat); 232 int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value, 233 size_t size, int flags); 234 int sysfs_inode_init(void); 235 236 /* 237 * file.c 238 */ 239 extern const struct file_operations sysfs_file_operations; 240 extern const struct file_operations sysfs_bin_operations; 241 242 int sysfs_add_file(struct sysfs_dirent *dir_sd, 243 const struct attribute *attr, int type); 244 245 int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, 246 const struct attribute *attr, int type, 247 umode_t amode, const void *ns); 248 void sysfs_unmap_bin_file(struct sysfs_dirent *sd); 249 250 /* 251 * symlink.c 252 */ 253 extern const struct inode_operations sysfs_symlink_inode_operations; 254 int sysfs_create_link_sd(struct sysfs_dirent *sd, struct kobject *target, 255 const char *name); 256