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 unsigned long subdirs; 21 /* children rbtree starts here and goes through sd->s_rb */ 22 struct rb_root children; 23 }; 24 25 struct sysfs_elem_symlink { 26 struct sysfs_dirent *target_sd; 27 }; 28 29 struct sysfs_elem_attr { 30 struct sysfs_open_dirent *open; 31 }; 32 33 struct sysfs_inode_attrs { 34 struct iattr ia_iattr; 35 void *ia_secdata; 36 u32 ia_secdata_len; 37 }; 38 39 /* 40 * sysfs_dirent - the building block of sysfs hierarchy. Each and 41 * every sysfs node is represented by single sysfs_dirent. 42 * 43 * As long as s_count reference is held, the sysfs_dirent itself is 44 * accessible. Dereferencing s_elem or any other outer entity 45 * requires s_active reference. 46 */ 47 struct sysfs_dirent { 48 atomic_t s_count; 49 atomic_t s_active; 50 #ifdef CONFIG_DEBUG_LOCK_ALLOC 51 struct lockdep_map dep_map; 52 #endif 53 struct sysfs_dirent *s_parent; 54 const char *s_name; 55 56 struct rb_node s_rb; 57 58 union { 59 struct completion *completion; 60 struct sysfs_dirent *removed_list; 61 } u; 62 63 const void *s_ns; /* namespace tag */ 64 unsigned int s_hash; /* ns + name hash */ 65 union { 66 struct sysfs_elem_dir s_dir; 67 struct sysfs_elem_symlink s_symlink; 68 struct sysfs_elem_attr s_attr; 69 }; 70 71 void *priv; 72 73 unsigned short s_flags; 74 umode_t s_mode; 75 unsigned int s_ino; 76 struct sysfs_inode_attrs *s_iattr; 77 }; 78 79 #define SD_DEACTIVATED_BIAS INT_MIN 80 81 #define SYSFS_TYPE_MASK 0x00ff 82 #define SYSFS_DIR 0x0001 83 #define SYSFS_KOBJ_ATTR 0x0002 84 #define SYSFS_KOBJ_BIN_ATTR 0x0004 85 #define SYSFS_KOBJ_LINK 0x0008 86 #define SYSFS_COPY_NAME (SYSFS_DIR | SYSFS_KOBJ_LINK) 87 #define SYSFS_ACTIVE_REF (SYSFS_KOBJ_ATTR | SYSFS_KOBJ_BIN_ATTR) 88 89 #define SYSFS_FLAG_MASK ~SYSFS_TYPE_MASK 90 #define SYSFS_FLAG_NS 0x01000 91 #define SYSFS_FLAG_REMOVED 0x02000 92 93 static inline unsigned int sysfs_type(struct sysfs_dirent *sd) 94 { 95 return sd->s_flags & SYSFS_TYPE_MASK; 96 } 97 98 #ifdef CONFIG_DEBUG_LOCK_ALLOC 99 100 #define sysfs_dirent_init_lockdep(sd) \ 101 do { \ 102 struct attribute *attr = sd->priv; \ 103 struct lock_class_key *key = attr->key; \ 104 if (!key) \ 105 key = &attr->skey; \ 106 \ 107 lockdep_init_map(&sd->dep_map, "s_active", key, 0); \ 108 } while (0) 109 110 /* Test for attributes that want to ignore lockdep for read-locking */ 111 static inline bool sysfs_ignore_lockdep(struct sysfs_dirent *sd) 112 { 113 struct attribute *attr = sd->priv; 114 int type = sysfs_type(sd); 115 116 return (type == SYSFS_KOBJ_ATTR || type == SYSFS_KOBJ_BIN_ATTR) && 117 attr->ignore_lockdep; 118 } 119 120 #else 121 122 #define sysfs_dirent_init_lockdep(sd) do {} while (0) 123 124 static inline bool sysfs_ignore_lockdep(struct sysfs_dirent *sd) 125 { 126 return true; 127 } 128 129 #endif 130 131 /* 132 * Context structure to be used while adding/removing nodes. 133 */ 134 struct sysfs_addrm_cxt { 135 struct sysfs_dirent *removed; 136 }; 137 138 /* 139 * mount.c 140 */ 141 142 /* 143 * Each sb is associated with one namespace tag, currently the network 144 * namespace of the task which mounted this sysfs instance. If multiple 145 * tags become necessary, make the following an array and compare 146 * sysfs_dirent tag against every entry. 147 */ 148 struct sysfs_super_info { 149 void *ns; 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_symlink_target_lock; 160 extern const struct dentry_operations sysfs_dentry_ops; 161 162 extern const struct file_operations sysfs_dir_operations; 163 extern const struct inode_operations sysfs_dir_inode_operations; 164 165 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 void sysfs_warn_dup(struct sysfs_dirent *parent, const char *name); 169 int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd, 170 struct sysfs_dirent *parent_sd); 171 int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd, 172 struct sysfs_dirent *parent_sd); 173 void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt); 174 175 struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd, 176 const unsigned char *name, 177 const void *ns); 178 struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type); 179 180 void release_sysfs_dirent(struct sysfs_dirent *sd); 181 182 static inline struct sysfs_dirent *__sysfs_get(struct sysfs_dirent *sd) 183 { 184 if (sd) { 185 WARN_ON(!atomic_read(&sd->s_count)); 186 atomic_inc(&sd->s_count); 187 } 188 return sd; 189 } 190 #define sysfs_get(sd) __sysfs_get(sd) 191 192 static inline void __sysfs_put(struct sysfs_dirent *sd) 193 { 194 if (sd && atomic_dec_and_test(&sd->s_count)) 195 release_sysfs_dirent(sd); 196 } 197 #define sysfs_put(sd) __sysfs_put(sd) 198 199 /* 200 * inode.c 201 */ 202 struct inode *sysfs_get_inode(struct super_block *sb, struct sysfs_dirent *sd); 203 void sysfs_evict_inode(struct inode *inode); 204 int sysfs_permission(struct inode *inode, int mask); 205 int sysfs_setattr(struct dentry *dentry, struct iattr *iattr); 206 int sysfs_getattr(struct vfsmount *mnt, struct dentry *dentry, 207 struct kstat *stat); 208 int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value, 209 size_t size, int flags); 210 int sysfs_inode_init(void); 211 212 /* 213 * file.c 214 */ 215 extern const struct file_operations sysfs_file_operations; 216 extern const struct file_operations sysfs_bin_operations; 217 218 int sysfs_add_file(struct sysfs_dirent *dir_sd, 219 const struct attribute *attr, int type); 220 221 int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, 222 const struct attribute *attr, int type, 223 umode_t amode, const void *ns); 224 void sysfs_unmap_bin_file(struct sysfs_dirent *sd); 225 226 /* 227 * symlink.c 228 */ 229 extern const struct inode_operations sysfs_symlink_inode_operations; 230 int sysfs_create_link_sd(struct sysfs_dirent *sd, struct kobject *target, 231 const char *name); 232