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         /* 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
 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  */
 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 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 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, struct sysfs_dirent *new_parent_sd,
 190                  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,
 218                   struct kstat *stat);
 219 int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value,
 220                    size_t size, int flags);
 221 int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const void *ns,
 222                           const char *name);
 223 int sysfs_inode_init(void);
 224
 225 /*
 226  * file.c
 227  */
 228 extern const struct file_operations sysfs_file_operations;
 229
 230 int sysfs_add_file(struct sysfs_dirent *dir_sd,
 231                    const struct attribute *attr, int type);
 232
 233 int sysfs_add_file_mode(struct sysfs_dirent *dir_sd,
 234                         const struct attribute *attr, int type, umode_t amode);
 235 /*
 236  * bin.c
 237  */
 238 extern const struct file_operations bin_fops;
 239 void unmap_bin_file(struct sysfs_dirent *attr_sd);
 240
 241 /*
 242  * symlink.c
 243  */
 244 extern const struct inode_operations sysfs_symlink_inode_operations;
 245 int sysfs_create_link_sd(struct sysfs_dirent *sd, struct kobject *target,
 246                          const char *name);