LXR linux/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
  11struct sysfs_open_dirent;
  12
  13/* type-specific structures for sysfs_dirent->s_* union members */
  14struct sysfs_elem_dir {
  15        struct kobject          *kobj;
  16        /* children list starts here and goes through sd->s_sibling */
  17        struct sysfs_dirent     *children;
  18};
  19
  20struct sysfs_elem_symlink {
  21        struct sysfs_dirent     *target_sd;
  22};
  23
  24struct sysfs_elem_attr {
  25        struct attribute        *attr;
  26        struct sysfs_open_dirent *open;
  27};
  28
  29struct sysfs_elem_bin_attr {
  30        struct bin_attribute    *bin_attr;
  31};
  32
  33/*
  34 * sysfs_dirent - the building block of sysfs hierarchy.  Each and
  35 * every sysfs node is represented by single sysfs_dirent.
  36 *
  37 * As long as s_count reference is held, the sysfs_dirent itself is
  38 * accessible.  Dereferencing s_elem or any other outer entity
  39 * requires s_active reference.
  40 */
  41struct sysfs_dirent {
  42        atomic_t                s_count;
  43        atomic_t                s_active;
  44        struct sysfs_dirent     *s_parent;
  45        struct sysfs_dirent     *s_sibling;
  46        const char              *s_name;
  47
  48        union {
  49                struct sysfs_elem_dir           s_dir;
  50                struct sysfs_elem_symlink       s_symlink;
  51                struct sysfs_elem_attr          s_attr;
  52                struct sysfs_elem_bin_attr      s_bin_attr;
  53        };
  54
  55        unsigned int            s_flags;
  56        ino_t                   s_ino;
  57        umode_t                 s_mode;
  58        struct iattr            *s_iattr;
  59};
  60
  61#define SD_DEACTIVATED_BIAS             INT_MIN
  62
  63#define SYSFS_TYPE_MASK                 0x00ff
  64#define SYSFS_DIR                       0x0001
  65#define SYSFS_KOBJ_ATTR                 0x0002
  66#define SYSFS_KOBJ_BIN_ATTR             0x0004
  67#define SYSFS_KOBJ_LINK                 0x0008
  68#define SYSFS_COPY_NAME                 (SYSFS_DIR | SYSFS_KOBJ_LINK)
  69
  70#define SYSFS_FLAG_MASK                 ~SYSFS_TYPE_MASK
  71#define SYSFS_FLAG_REMOVED              0x0200
  72
  73static inline unsigned int sysfs_type(struct sysfs_dirent *sd)
  74{
  75        return sd->s_flags & SYSFS_TYPE_MASK;
  76}
  77
  78/*
  79 * Context structure to be used while adding/removing nodes.
  80 */
  81struct sysfs_addrm_cxt {
  82        struct sysfs_dirent     *parent_sd;
  83        struct inode            *parent_inode;
  84        struct sysfs_dirent     *removed;
  85        int                     cnt;
  86};
  87
  88/*
  89 * mount.c
  90 */
  91extern struct sysfs_dirent sysfs_root;
  92extern struct super_block *sysfs_sb;
  93extern struct kmem_cache *sysfs_dir_cachep;
  94
  95/*
  96 * dir.c
  97 */
  98extern struct mutex sysfs_mutex;
  99extern struct mutex sysfs_rename_mutex;
 100extern spinlock_t sysfs_assoc_lock;
 101
 102extern const struct file_operations sysfs_dir_operations;
 103extern const struct inode_operations sysfs_dir_inode_operations;
 104
 105struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd);
 106struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd);
 107void sysfs_put_active_two(struct sysfs_dirent *sd);
 108void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
 109                       struct sysfs_dirent *parent_sd);
 110int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
 111int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
 112void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
 113void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt);
 114
 115struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd,
 116                                       const unsigned char *name);
 117struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
 118                                      const unsigned char *name);
 119struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type);
 120
 121void release_sysfs_dirent(struct sysfs_dirent *sd);
 122
 123int sysfs_create_subdir(struct kobject *kobj, const char *name,
 124                        struct sysfs_dirent **p_sd);
 125void sysfs_remove_subdir(struct sysfs_dirent *sd);
 126
 127static inline struct sysfs_dirent *sysfs_get(struct sysfs_dirent *sd)
 128{
 129        if (sd) {
 130                WARN_ON(!atomic_read(&sd->s_count));
 131                atomic_inc(&sd->s_count);
 132        }
 133        return sd;
 134}
 135
 136static inline void sysfs_put(struct sysfs_dirent *sd)
 137{
 138        if (sd && atomic_dec_and_test(&sd->s_count))
 139                release_sysfs_dirent(sd);
 140}
 141
 142/*
 143 * inode.c
 144 */
 145struct inode *sysfs_get_inode(struct sysfs_dirent *sd);
 146int sysfs_setattr(struct dentry *dentry, struct iattr *iattr);
 147int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name);
 148int sysfs_inode_init(void);
 149
 150/*
 151 * file.c
 152 */
 153extern const struct file_operations sysfs_file_operations;
 154
 155int sysfs_add_file(struct sysfs_dirent *dir_sd,
 156                   const struct attribute *attr, int type);
 157
 158int sysfs_add_file_mode(struct sysfs_dirent *dir_sd,
 159                        const struct attribute *attr, int type, mode_t amode);
 160/*
 161 * bin.c
 162 */
 163extern const struct file_operations bin_fops;
 164
 165/*
 166 * symlink.c
 167 */
 168extern const struct inode_operations sysfs_symlink_inode_operations;
 169