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
  15 struct sysfs_open_dirent;
  16
  17 /* type-specific structures for sysfs_dirent->s_* union members */
  18 struct sysfs_elem_dir {
  19         struct kobject          *kobj;
  20         /* children list starts here and goes through sd->s_sibling */
  21         struct sysfs_dirent     *children;
  22 };
  23
  24 struct sysfs_elem_symlink {
  25         struct sysfs_dirent     *target_sd;
  26 };
  27
  28 struct sysfs_elem_attr {
  29         struct attribute        *attr;
  30         struct sysfs_open_dirent *open;
  31 };
  32
  33 struct sysfs_elem_bin_attr {
  34         struct bin_attribute    *bin_attr;
  35         struct hlist_head       buffers;
  36 };
  37
  38 struct sysfs_inode_attrs {
  39         struct iattr    ia_iattr;
  40         void            *ia_secdata;
  41         u32             ia_secdata_len;
  42 };
  43
  44 /*
  45  * sysfs_dirent - the building block of sysfs hierarchy.  Each and
  46  * every sysfs node is represented by single sysfs_dirent.
  47  *
  48  * As long as s_count reference is held, the sysfs_dirent itself is
  49  * accessible.  Dereferencing s_elem or any other outer entity
  50  * requires s_active reference.
  51  */
  52 struct sysfs_dirent {
  53         atomic_t                s_count;
  54         atomic_t                s_active;
  55 #ifdef CONFIG_DEBUG_LOCK_ALLOC
  56         struct lockdep_map      dep_map;
  57 #endif
  58         struct sysfs_dirent     *s_parent;
  59         struct sysfs_dirent     *s_sibling;
  60         const char              *s_name;
  61
  62         const void              *s_ns; /* namespace tag */
  63         union {
  64                 struct sysfs_elem_dir           s_dir;
  65                 struct sysfs_elem_symlink       s_symlink;
  66                 struct sysfs_elem_attr          s_attr;
  67                 struct sysfs_elem_bin_attr      s_bin_attr;
  68         };
  69
  70         unsigned int            s_flags;
  71         unsigned short          s_mode;
  72         ino_t                   s_ino;
  73         struct sysfs_inode_attrs *s_iattr;
  74 };
  75
  76 #define SD_DEACTIVATED_BIAS             INT_MIN
  77
  78 #define SYSFS_TYPE_MASK                 0x00ff
  79 #define SYSFS_DIR                       0x0001
  80 #define SYSFS_KOBJ_ATTR                 0x0002
  81 #define SYSFS_KOBJ_BIN_ATTR             0x0004
  82 #define SYSFS_KOBJ_LINK                 0x0008
  83 #define SYSFS_COPY_NAME                 (SYSFS_DIR | SYSFS_KOBJ_LINK)
  84 #define SYSFS_ACTIVE_REF                (SYSFS_KOBJ_ATTR | SYSFS_KOBJ_BIN_ATTR)
  85
  86 /* identify any namespace tag on sysfs_dirents */
  87 #define SYSFS_NS_TYPE_MASK              0xff00
  88 #define SYSFS_NS_TYPE_SHIFT             8
  89
  90 #define SYSFS_FLAG_MASK                 ~(SYSFS_NS_TYPE_MASK|SYSFS_TYPE_MASK)
  91 #define SYSFS_FLAG_REMOVED              0x020000
  92
  93 static inline unsigned int sysfs_type(struct sysfs_dirent *sd)
  94 {
  95         return sd->s_flags & SYSFS_TYPE_MASK;
  96 }
  97
  98 /*
  99  * Return any namespace tags on this dirent.
 100  * enum kobj_ns_type is defined in linux/kobject.h
 101  */
 102 static inline enum kobj_ns_type sysfs_ns_type(struct sysfs_dirent *sd)
 103 {
 104         return (sd->s_flags & SYSFS_NS_TYPE_MASK) >> SYSFS_NS_TYPE_SHIFT;
 105 }
 106
 107 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 108 #define sysfs_dirent_init_lockdep(sd)                           \
 109 do {                                                            \
 110         struct attribute *attr = sd->s_attr.attr;               \
 111         struct lock_class_key *key = attr->key;                 \
 112         if (!key)                                               \
 113                 key = &attr->skey;                              \
 114                                                                 \
 115         lockdep_init_map(&sd->dep_map, "s_active", key, 0);     \
 116 } while(0)
 117 #else
 118 #define sysfs_dirent_init_lockdep(sd) do {} while(0)
 119 #endif
 120
 121 /*
 122  * Context structure to be used while adding/removing nodes.
 123  */
 124 struct sysfs_addrm_cxt {
 125         struct sysfs_dirent     *parent_sd;
 126         struct sysfs_dirent     *removed;
 127 };
 128
 129 /*
 130  * mount.c
 131  */
 132
 133 /*
 134  * Each sb is associated with a set of namespace tags (i.e.
 135  * the network namespace of the task which mounted this sysfs
 136  * instance).
 137  */
 138 struct sysfs_super_info {
 139         void *ns[KOBJ_NS_TYPES];
 140 };
 141 #define sysfs_info(SB) ((struct sysfs_super_info *)(SB->s_fs_info))
 142 extern struct sysfs_dirent sysfs_root;
 143 extern struct kmem_cache *sysfs_dir_cachep;
 144
 145 /*
 146  * dir.c
 147  */
 148 extern struct mutex sysfs_mutex;
 149 extern spinlock_t sysfs_assoc_lock;
 150
 151 extern const struct file_operations sysfs_dir_operations;
 152 extern const struct inode_operations sysfs_dir_inode_operations;
 153
 154 struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd);
 155 struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd);
 156 void sysfs_put_active(struct sysfs_dirent *sd);
 157 void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
 158                        struct sysfs_dirent *parent_sd);
 159 int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
 160 int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
 161 void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
 162 void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt);
 163
 164 struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd,
 165                                        const void *ns,
 166                                        const unsigned char *name);
 167 struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
 168                                       const void *ns,
 169                                       const unsigned char *name);
 170 struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type);
 171
 172 void release_sysfs_dirent(struct sysfs_dirent *sd);
 173
 174 int sysfs_create_subdir(struct kobject *kobj, const char *name,
 175                         struct sysfs_dirent **p_sd);
 176 void sysfs_remove_subdir(struct sysfs_dirent *sd);
 177
 178 int sysfs_rename(struct sysfs_dirent *sd,
 179         struct sysfs_dirent *new_parent_sd, const void *ns, const char *new_name);
 180
 181 static inline struct sysfs_dirent *__sysfs_get(struct sysfs_dirent *sd)
 182 {
 183         if (sd) {
 184                 WARN_ON(!atomic_read(&sd->s_count));
 185                 atomic_inc(&sd->s_count);
 186         }
 187         return sd;
 188 }
 189 #define sysfs_get(sd) __sysfs_get(sd)
 190
 191 static inline void __sysfs_put(struct sysfs_dirent *sd)
 192 {
 193         if (sd && atomic_dec_and_test(&sd->s_count))
 194                 release_sysfs_dirent(sd);
 195 }
 196 #define sysfs_put(sd) __sysfs_put(sd)
 197
 198 /*
 199  * inode.c
 200  */
 201 struct inode *sysfs_get_inode(struct super_block *sb, struct sysfs_dirent *sd);
 202 void sysfs_evict_inode(struct inode *inode);
 203 int sysfs_sd_setattr(struct sysfs_dirent *sd, struct iattr *iattr);
 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, struct kstat *stat);
 207 int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value,
 208                 size_t size, int flags);
 209 int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const void *ns, const char *name);
 210 int sysfs_inode_init(void);
 211
 212 /*
 213  * file.c
 214  */
 215 extern const struct file_operations sysfs_file_operations;
 216
 217 int sysfs_add_file(struct sysfs_dirent *dir_sd,
 218                    const struct attribute *attr, int type);
 219
 220 int sysfs_add_file_mode(struct sysfs_dirent *dir_sd,
 221                         const struct attribute *attr, int type, mode_t amode);
 222 /*
 223  * bin.c
 224  */
 225 extern const struct file_operations bin_fops;
 226 void unmap_bin_file(struct sysfs_dirent *attr_sd);
 227
 228 /*
 229  * symlink.c
 230  */
 231 extern const struct inode_operations sysfs_symlink_inode_operations;