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 #define SYSFS_FLAG_MASK ~SYSFS_TYPE_MASK 94 #define SYSFS_FLAG_NS 0x01000 95 #define SYSFS_FLAG_REMOVED 0x02000 96 97 static inline unsigned int sysfs_type(struct sysfs_dirent *sd) 98 { 99 return sd->s_flags & SYSFS_TYPE_MASK; 100 } 101 102 #ifdef CONFIG_DEBUG_LOCK_ALLOC 103 104 #define sysfs_dirent_init_lockdep(sd) \ 105 do { \ 106 struct attribute *attr = sd->s_attr.attr; \ 107 struct lock_class_key *key = attr->key; \ 108 if (!key) \ 109 key = &attr->skey; \ 110 \ 111 lockdep_init_map(&sd->dep_map, "s_active", key, 0); \ 112 } while (0) 113 114 /* Test for attributes that want to ignore lockdep for read-locking */ 115 static inline bool sysfs_ignore_lockdep(struct sysfs_dirent *sd) 116 { 117 int type = sysfs_type(sd); 118 119 return (type == SYSFS_KOBJ_ATTR || type == SYSFS_KOBJ_BIN_ATTR) && 120 sd->s_attr.attr->ignore_lockdep; 121 } 122 123 #else 124 125 #define sysfs_dirent_init_lockdep(sd) do {} while (0) 126 127 static inline bool sysfs_ignore_lockdep(struct sysfs_dirent *sd) 128 { 129 return true; 130 } 131 132 #endif 133 134 /* 135 * Context structure to be used while adding/removing nodes. 136 */ 137 struct sysfs_addrm_cxt { 138 struct sysfs_dirent *removed; 139 }; 140 141 /* 142 * mount.c 143 */ 144 145 /* 146 * Each sb is associated with one namespace tag, currently the network 147 * namespace of the task which mounted this sysfs instance. If multiple 148 * tags become necessary, make the following an array and compare 149 * sysfs_dirent tag against every entry. 150 */ 151 struct sysfs_super_info { 152 void *ns; 153 }; 154 #define sysfs_info(SB) ((struct sysfs_super_info *)(SB->s_fs_info)) 155 extern struct sysfs_dirent sysfs_root; 156 extern struct kmem_cache *sysfs_dir_cachep; 157 158 /* 159 * dir.c 160 */ 161 extern struct mutex sysfs_mutex; 162 extern spinlock_t sysfs_symlink_target_lock; 163 extern const struct dentry_operations sysfs_dentry_ops; 164 165 extern const struct file_operations sysfs_dir_operations; 166 extern const struct inode_operations sysfs_dir_inode_operations; 167 168 struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd); 169 void sysfs_put_active(struct sysfs_dirent *sd); 170 void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt); 171 void sysfs_warn_dup(struct sysfs_dirent *parent, const char *name); 172 int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd, 173 struct sysfs_dirent *parent_sd); 174 int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd, 175 struct sysfs_dirent *parent_sd); 176 void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt); 177 178 struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd, 179 const unsigned char *name, 180 const void *ns); 181 struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type); 182 183 void release_sysfs_dirent(struct sysfs_dirent *sd); 184 185 int sysfs_create_subdir(struct kobject *kobj, const char *name, 186 struct sysfs_dirent **p_sd); 187 188 static inline struct sysfs_dirent *__sysfs_get(struct sysfs_dirent *sd) 189 { 190 if (sd) { 191 WARN_ON(!atomic_read(&sd->s_count)); 192 atomic_inc(&sd->s_count); 193 } 194 return sd; 195 } 196 #define sysfs_get(sd) __sysfs_get(sd) 197 198 static inline void __sysfs_put(struct sysfs_dirent *sd) 199 { 200 if (sd && atomic_dec_and_test(&sd->s_count)) 201 release_sysfs_dirent(sd); 202 } 203 #define sysfs_put(sd) __sysfs_put(sd) 204 205 /* 206 * inode.c 207 */ 208 struct inode *sysfs_get_inode(struct super_block *sb, struct sysfs_dirent *sd); 209 void sysfs_evict_inode(struct inode *inode); 210 int sysfs_permission(struct inode *inode, int mask); 211 int sysfs_setattr(struct dentry *dentry, struct iattr *iattr); 212 int sysfs_getattr(struct vfsmount *mnt, struct dentry *dentry, 213 struct kstat *stat); 214 int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value, 215 size_t size, int flags); 216 int sysfs_inode_init(void); 217 218 /* 219 * file.c 220 */ 221 extern const struct file_operations sysfs_file_operations; 222 extern const struct file_operations sysfs_bin_operations; 223 224 int sysfs_add_file(struct sysfs_dirent *dir_sd, 225 const struct attribute *attr, int type); 226 227 int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, 228 const struct attribute *attr, int type, 229 umode_t amode, const void *ns); 230 void sysfs_unmap_bin_file(struct sysfs_dirent *sd); 231 232 /* 233 * symlink.c 234 */ 235 extern const struct inode_operations sysfs_symlink_inode_operations; 236 int sysfs_create_link_sd(struct sysfs_dirent *sd, struct kobject *target, 237 const char *name); 238