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/fs.h>
  13
  14 struct sysfs_open_dirent;
  15
  16 /* type-specific structures for sysfs_dirent->s_* union members */
  17 struct sysfs_elem_dir {
  18         struct kobject          *kobj;
  19         /* children list starts here and goes through sd->s_sibling */
  20         struct sysfs_dirent     *children;
  21 };
  22
  23 struct sysfs_elem_symlink {
  24         struct sysfs_dirent     *target_sd;
  25 };
  26
  27 struct sysfs_elem_attr {
  28         struct attribute        *attr;
  29         struct sysfs_open_dirent *open;
  30 };
  31
  32 struct sysfs_elem_bin_attr {
  33         struct bin_attribute    *bin_attr;
  34         struct hlist_head       buffers;
  35 };
  36
  37 struct sysfs_inode_attrs {
  38         struct iattr    ia_iattr;
  39         void            *ia_secdata;
  40         u32             ia_secdata_len;
  41 };
  42
  43 /*
  44  * sysfs_dirent - the building block of sysfs hierarchy.  Each and
  45  * every sysfs node is represented by single sysfs_dirent.
  46  *
  47  * As long as s_count reference is held, the sysfs_dirent itself is
  48  * accessible.  Dereferencing s_elem or any other outer entity
  49  * requires s_active reference.
  50  */
  51 struct sysfs_dirent {
  52         atomic_t                s_count;
  53         atomic_t                s_active;
  54 #ifdef CONFIG_DEBUG_LOCK_ALLOC
  55         struct lockdep_map      dep_map;
  56 #endif
  57         struct sysfs_dirent     *s_parent;
  58         struct sysfs_dirent     *s_sibling;
  59         const char              *s_name;
  60
  61         const void              *s_ns; /* namespace tag */
  62         union {
  63                 struct sysfs_elem_dir           s_dir;
  64                 struct sysfs_elem_symlink       s_symlink;
  65                 struct sysfs_elem_attr          s_attr;
  66                 struct sysfs_elem_bin_attr      s_bin_attr;
  67         };
  68
  69         unsigned int            s_flags;
  70         unsigned short          s_mode;
  71         ino_t                   s_ino;
  72         struct sysfs_inode_attrs *s_iattr;
  73 };
  74
  75 #define SD_DEACTIVATED_BIAS             INT_MIN
  76
  77 #define SYSFS_TYPE_MASK                 0x00ff
  78 #define SYSFS_DIR                       0x0001
  79 #define SYSFS_KOBJ_ATTR                 0x0002
  80 #define SYSFS_KOBJ_BIN_ATTR             0x0004
  81 #define SYSFS_KOBJ_LINK                 0x0008
  82 #define SYSFS_COPY_NAME                 (SYSFS_DIR | SYSFS_KOBJ_LINK)
  83 #define SYSFS_ACTIVE_REF                (SYSFS_KOBJ_ATTR | SYSFS_KOBJ_BIN_ATTR)
  84
  85 /* identify any namespace tag on sysfs_dirents */
  86 #define SYSFS_NS_TYPE_MASK              0xff00
  87 #define SYSFS_NS_TYPE_SHIFT             8
  88
  89 #define SYSFS_FLAG_MASK                 ~(SYSFS_NS_TYPE_MASK|SYSFS_TYPE_MASK)
  90 #define SYSFS_FLAG_REMOVED              0x020000
  91
  92 static inline unsigned int sysfs_type(struct sysfs_dirent *sd)
  93 {
  94         return sd->s_flags & SYSFS_TYPE_MASK;
  95 }
  96
  97 /*
  98  * Return any namespace tags on this dirent.
  99  * enum kobj_ns_type is defined in linux/kobject.h
 100  */
 101 static inline enum kobj_ns_type sysfs_ns_type(struct sysfs_dirent *sd)
 102 {
 103         return (sd->s_flags & SYSFS_NS_TYPE_MASK) >> SYSFS_NS_TYPE_SHIFT;
 104 }
 105
 106 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 107 #define sysfs_dirent_init_lockdep(sd)                           \
 108 do {                                                            \
 109         struct attribute *attr = sd->s_attr.attr;               \
 110         struct lock_class_key *key = attr->key;                 \
 111         if (!key)                                               \
 112                 key = &attr->skey;                              \
 113                                                                 \
 114         lockdep_init_map(&sd->dep_map, "s_active", key, 0);     \
 115 } while(0)
 116 #else
 117 #define sysfs_dirent_init_lockdep(sd) do {} while(0)
 118 #endif
 119
 120 /*
 121  * Context structure to be used while adding/removing nodes.
 122  */
 123 struct sysfs_addrm_cxt {
 124         struct sysfs_dirent     *parent_sd;
 125         struct sysfs_dirent     *removed;
 126 };
 127
 128 /*
 129  * mount.c
 130  */
 131
 132 /*
 133  * Each sb is associated with a set of namespace tags (i.e.
 134  * the network namespace of the task which mounted this sysfs
 135  * instance).
 136  */
 137 struct sysfs_super_info {
 138         const void *ns[KOBJ_NS_TYPES];
 139 };
 140 #define sysfs_info(SB) ((struct sysfs_super_info *)(SB->s_fs_info))
 141 extern struct sysfs_dirent sysfs_root;
 142 extern struct kmem_cache *sysfs_dir_cachep;
 143
 144 /*
 145  * dir.c
 146  */
 147 extern struct mutex sysfs_mutex;
 148 extern spinlock_t sysfs_assoc_lock;
 149
 150 extern const struct file_operations sysfs_dir_operations;
 151 extern const struct inode_operations sysfs_dir_inode_operations;
 152
 153 struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd);
 154 struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd);
 155 void sysfs_put_active(struct sysfs_dirent *sd);
 156 void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
 157                        struct sysfs_dirent *parent_sd);
 158 int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
 159 int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
 160 void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
 161 void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt);
 162
 163 struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd,
 164                                        const void *ns,
 165                                        const unsigned char *name);
 166 struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
 167                                       const void *ns,
 168                                       const unsigned char *name);
 169 struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type);
 170
 171 void release_sysfs_dirent(struct sysfs_dirent *sd);
 172
 173 int sysfs_create_subdir(struct kobject *kobj, const char *name,
 174                         struct sysfs_dirent **p_sd);
 175 void sysfs_remove_subdir(struct sysfs_dirent *sd);
 176
 177 int sysfs_rename(struct sysfs_dirent *sd,
 178         struct sysfs_dirent *new_parent_sd, const void *ns, const char *new_name);
 179
 180 static inline struct sysfs_dirent *__sysfs_get(struct sysfs_dirent *sd)
 181 {
 182         if (sd) {
 183                 WARN_ON(!atomic_read(&sd->s_count));
 184                 atomic_inc(&sd->s_count);
 185         }
 186         return sd;
 187 }
 188 #define sysfs_get(sd) __sysfs_get(sd)
 189
 190 static inline void __sysfs_put(struct sysfs_dirent *sd)
 191 {
 192         if (sd && atomic_dec_and_test(&sd->s_count))
 193                 release_sysfs_dirent(sd);
 194 }
 195 #define sysfs_put(sd) __sysfs_put(sd)
 196
 197 /*
 198  * inode.c
 199  */
 200 struct inode *sysfs_get_inode(struct super_block *sb, struct sysfs_dirent *sd);
 201 void sysfs_evict_inode(struct inode *inode);
 202 int sysfs_sd_setattr(struct sysfs_dirent *sd, struct iattr *iattr);
 203 int sysfs_permission(struct inode *inode, int mask);
 204 int sysfs_setattr(struct dentry *dentry, struct iattr *iattr);
 205 int sysfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat);
 206 int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value,
 207                 size_t size, int flags);
 208 int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const void *ns, const char *name);
 209 int sysfs_inode_init(void);
 210
 211 /*
 212  * file.c
 213  */
 214 extern const struct file_operations sysfs_file_operations;
 215
 216 int sysfs_add_file(struct sysfs_dirent *dir_sd,
 217                    const struct attribute *attr, int type);
 218
 219 int sysfs_add_file_mode(struct sysfs_dirent *dir_sd,
 220                         const struct attribute *attr, int type, mode_t amode);
 221 /*
 222  * bin.c
 223  */
 224 extern const struct file_operations bin_fops;
 225 void unmap_bin_file(struct sysfs_dirent *attr_sd);
 226
 227 /*
 228  * symlink.c
 229  */
 230 extern const struct inode_operations sysfs_symlink_inode_operations;