fs/sysfs/sysfs.h

   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
  24         struct rb_root          inode_tree;
  25         struct rb_root          name_tree;
  26 };
  27
  28 struct sysfs_elem_symlink {
  29         struct sysfs_dirent     *target_sd;
  30 };
  31
  32 struct sysfs_elem_attr {
  33         struct attribute        *attr;
  34         struct sysfs_open_dirent *open;
  35 };
  36
  37 struct sysfs_elem_bin_attr {
  38         struct bin_attribute    *bin_attr;
  39         struct hlist_head       buffers;
  40 };
  41
  42 struct sysfs_inode_attrs {
  43         struct iattr    ia_iattr;
  44         void            *ia_secdata;
  45         u32             ia_secdata_len;
  46 };
  47
  48 /*
  49  * sysfs_dirent - the building block of sysfs hierarchy.  Each and
  50  * every sysfs node is represented by single sysfs_dirent.
  51  *
  52  * As long as s_count reference is held, the sysfs_dirent itself is
  53  * accessible.  Dereferencing s_elem or any other outer entity
  54  * requires s_active reference.
  55  */
  56 struct sysfs_dirent {
  57         atomic_t                s_count;
  58         atomic_t                s_active;
  59 #ifdef CONFIG_DEBUG_LOCK_ALLOC
  60         struct lockdep_map      dep_map;
  61 #endif
  62         struct sysfs_dirent     *s_parent;
  63         const char              *s_name;
  64
  65         struct rb_node          inode_node;
  66         struct rb_node          name_node;
  67
  68         union {
  69                 struct completion       *completion;
  70                 struct sysfs_dirent     *removed_list;
  71         } u;
  72
  73         const void              *s_ns; /* namespace tag */
  74         union {
  75                 struct sysfs_elem_dir           s_dir;
  76                 struct sysfs_elem_symlink       s_symlink;
  77                 struct sysfs_elem_attr          s_attr;
  78                 struct sysfs_elem_bin_attr      s_bin_attr;
  79         };
  80
  81         unsigned int            s_flags;
  82         unsigned short          s_mode;
  83         ino_t                   s_ino;
  84         struct sysfs_inode_attrs *s_iattr;
  85 };
  86
  87 #define SD_DEACTIVATED_BIAS             INT_MIN
  88
  89 #define SYSFS_TYPE_MASK                 0x00ff
  90 #define SYSFS_DIR                       0x0001
  91 #define SYSFS_KOBJ_ATTR                 0x0002
  92 #define SYSFS_KOBJ_BIN_ATTR             0x0004
  93 #define SYSFS_KOBJ_LINK                 0x0008
  94 #define SYSFS_COPY_NAME                 (SYSFS_DIR | SYSFS_KOBJ_LINK)
  95 #define SYSFS_ACTIVE_REF                (SYSFS_KOBJ_ATTR | SYSFS_KOBJ_BIN_ATTR)
  96
  97 /* identify any namespace tag on sysfs_dirents */
  98 #define SYSFS_NS_TYPE_MASK              0xff00
  99 #define SYSFS_NS_TYPE_SHIFT             8
 100
 101 #define SYSFS_FLAG_MASK                 ~(SYSFS_NS_TYPE_MASK|SYSFS_TYPE_MASK)
 102 #define SYSFS_FLAG_REMOVED              0x020000
 103
 104 static inline unsigned int sysfs_type(struct sysfs_dirent *sd)
 105 {
 106         return sd->s_flags & SYSFS_TYPE_MASK;
 107 }
 108
 109 /*
 110  * Return any namespace tags on this dirent.
 111  * enum kobj_ns_type is defined in linux/kobject.h
 112  */
 113 static inline enum kobj_ns_type sysfs_ns_type(struct sysfs_dirent *sd)
 114 {
 115         return (sd->s_flags & SYSFS_NS_TYPE_MASK) >> SYSFS_NS_TYPE_SHIFT;
 116 }
 117
 118 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 119 #define sysfs_dirent_init_lockdep(sd)                           \
 120 do {                                                            \
 121         struct attribute *attr = sd->s_attr.attr;               \
 122         struct lock_class_key *key = attr->key;                 \
 123         if (!key)                                               \
 124                 key = &attr->skey;                              \
 125                                                                 \
 126         lockdep_init_map(&sd->dep_map, "s_active", key, 0);     \
 127 } while(0)
 128 #else
 129 #define sysfs_dirent_init_lockdep(sd) do {} while(0)
 130 #endif
 131
 132 /*
 133  * Context structure to be used while adding/removing nodes.
 134  */
 135 struct sysfs_addrm_cxt {
 136         struct sysfs_dirent     *parent_sd;
 137         struct sysfs_dirent     *removed;
 138 };
 139
 140 /*
 141  * mount.c
 142  */
 143
 144 /*
 145  * Each sb is associated with a set of namespace tags (i.e.
 146  * the network namespace of the task which mounted this sysfs
 147  * instance).
 148  */
 149 struct sysfs_super_info {
 150         void *ns[KOBJ_NS_TYPES];
 151 };
 152 #define sysfs_info(SB) ((struct sysfs_super_info *)(SB->s_fs_info))
 153 extern struct sysfs_dirent sysfs_root;
 154 extern struct kmem_cache *sysfs_dir_cachep;
 155
 156 /*
 157  * dir.c
 158  */
 159 extern struct mutex sysfs_mutex;
 160 extern spinlock_t sysfs_assoc_lock;
 161
 162 extern const struct file_operations sysfs_dir_operations;
 163 extern const struct inode_operations sysfs_dir_inode_operations;
 164
 165 struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd);
 166 struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd);
 167 void sysfs_put_active(struct sysfs_dirent *sd);
 168 void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
 169                        struct sysfs_dirent *parent_sd);
 170 int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
 171 int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
 172 void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *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 void *ns,
 177                                        const unsigned char *name);
 178 struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
 179                                       const void *ns,
 180                                       const unsigned char *name);
 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 void sysfs_remove_subdir(struct sysfs_dirent *sd);
 188
 189 int sysfs_rename(struct sysfs_dirent *sd,
 190         struct sysfs_dirent *new_parent_sd, const void *ns, const char *new_name);
 191
 192 static inline struct sysfs_dirent *__sysfs_get(struct sysfs_dirent *sd)
 193 {
 194         if (sd) {
 195                 WARN_ON(!atomic_read(&sd->s_count));
 196                 atomic_inc(&sd->s_count);
 197         }
 198         return sd;
 199 }
 200 #define sysfs_get(sd) __sysfs_get(sd)
 201
 202 static inline void __sysfs_put(struct sysfs_dirent *sd)
 203 {
 204         if (sd && atomic_dec_and_test(&sd->s_count))
 205                 release_sysfs_dirent(sd);
 206 }
 207 #define sysfs_put(sd) __sysfs_put(sd)
 208
 209 /*
 210  * inode.c
 211  */
 212 struct inode *sysfs_get_inode(struct super_block *sb, struct sysfs_dirent *sd);
 213 void sysfs_evict_inode(struct inode *inode);
 214 int sysfs_sd_setattr(struct sysfs_dirent *sd, struct iattr *iattr);
 215 int sysfs_permission(struct inode *inode, int mask);
 216 int sysfs_setattr(struct dentry *dentry, struct iattr *iattr);
 217 int sysfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat);
 218 int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value,
 219                 size_t size, int flags);
 220 int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const void *ns, const char *name);
 221 int sysfs_inode_init(void);
 222
 223 /*
 224  * file.c
 225  */
 226 extern const struct file_operations sysfs_file_operations;
 227
 228 int sysfs_add_file(struct sysfs_dirent *dir_sd,
 229                    const struct attribute *attr, int type);
 230
 231 int sysfs_add_file_mode(struct sysfs_dirent *dir_sd,
 232                         const struct attribute *attr, int type, mode_t amode);
 233 /*
 234  * bin.c
 235  */
 236 extern const struct file_operations bin_fops;
 237 void unmap_bin_file(struct sysfs_dirent *attr_sd);
 238
 239 /*
 240  * symlink.c
 241  */
 242 extern const struct inode_operations sysfs_symlink_inode_operations;