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/fs.h>
  12
  13 struct sysfs_open_dirent;
  14
  15 /* type-specific structures for sysfs_dirent->s_* union members */
  16 struct sysfs_elem_dir {
  17         struct kobject          *kobj;
  18         /* children list starts here and goes through sd->s_sibling */
  19         struct sysfs_dirent     *children;
  20 };
  21
  22 struct sysfs_elem_symlink {
  23         struct sysfs_dirent     *target_sd;
  24 };
  25
  26 struct sysfs_elem_attr {
  27         struct attribute        *attr;
  28         struct sysfs_open_dirent *open;
  29 };
  30
  31 struct sysfs_elem_bin_attr {
  32         struct bin_attribute    *bin_attr;
  33         struct hlist_head       buffers;
  34 };
  35
  36 struct sysfs_inode_attrs {
  37         struct iattr    ia_iattr;
  38         void            *ia_secdata;
  39         u32             ia_secdata_len;
  40 };
  41
  42 /*
  43  * sysfs_dirent - the building block of sysfs hierarchy.  Each and
  44  * every sysfs node is represented by single sysfs_dirent.
  45  *
  46  * As long as s_count reference is held, the sysfs_dirent itself is
  47  * accessible.  Dereferencing s_elem or any other outer entity
  48  * requires s_active reference.
  49  */
  50 struct sysfs_dirent {
  51         atomic_t                s_count;
  52         atomic_t                s_active;
  53         struct sysfs_dirent     *s_parent;
  54         struct sysfs_dirent     *s_sibling;
  55         const char              *s_name;
  56
  57         union {
  58                 struct sysfs_elem_dir           s_dir;
  59                 struct sysfs_elem_symlink       s_symlink;
  60                 struct sysfs_elem_attr          s_attr;
  61                 struct sysfs_elem_bin_attr      s_bin_attr;
  62         };
  63
  64         unsigned int            s_flags;
  65         ino_t                   s_ino;
  66         umode_t                 s_mode;
  67         struct sysfs_inode_attrs *s_iattr;
  68 };
  69
  70 #define SD_DEACTIVATED_BIAS             INT_MIN
  71
  72 #define SYSFS_TYPE_MASK                 0x00ff
  73 #define SYSFS_DIR                       0x0001
  74 #define SYSFS_KOBJ_ATTR                 0x0002
  75 #define SYSFS_KOBJ_BIN_ATTR             0x0004
  76 #define SYSFS_KOBJ_LINK                 0x0008
  77 #define SYSFS_COPY_NAME                 (SYSFS_DIR | SYSFS_KOBJ_LINK)
  78
  79 #define SYSFS_FLAG_MASK                 ~SYSFS_TYPE_MASK
  80 #define SYSFS_FLAG_REMOVED              0x0200
  81
  82 static inline unsigned int sysfs_type(struct sysfs_dirent *sd)
  83 {
  84         return sd->s_flags & SYSFS_TYPE_MASK;
  85 }
  86
  87 /*
  88  * Context structure to be used while adding/removing nodes.
  89  */
  90 struct sysfs_addrm_cxt {
  91         struct sysfs_dirent     *parent_sd;
  92         struct inode            *parent_inode;
  93         struct sysfs_dirent     *removed;
  94         int                     cnt;
  95 };
  96
  97 /*
  98  * mount.c
  99  */
 100 extern struct sysfs_dirent sysfs_root;
 101 extern struct super_block *sysfs_sb;
 102 extern struct kmem_cache *sysfs_dir_cachep;
 103
 104 /*
 105  * dir.c
 106  */
 107 extern struct mutex sysfs_mutex;
 108 extern struct mutex sysfs_rename_mutex;
 109 extern spinlock_t sysfs_assoc_lock;
 110
 111 extern const struct file_operations sysfs_dir_operations;
 112 extern const struct inode_operations sysfs_dir_inode_operations;
 113
 114 struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd);
 115 struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd);
 116 void sysfs_put_active_two(struct sysfs_dirent *sd);
 117 void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
 118                        struct sysfs_dirent *parent_sd);
 119 int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
 120 int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
 121 void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
 122 void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt);
 123
 124 struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd,
 125                                        const unsigned char *name);
 126 struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
 127                                       const unsigned char *name);
 128 struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type);
 129
 130 void release_sysfs_dirent(struct sysfs_dirent *sd);
 131
 132 int sysfs_create_subdir(struct kobject *kobj, const char *name,
 133                         struct sysfs_dirent **p_sd);
 134 void sysfs_remove_subdir(struct sysfs_dirent *sd);
 135
 136 static inline struct sysfs_dirent *__sysfs_get(struct sysfs_dirent *sd)
 137 {
 138         if (sd) {
 139                 WARN_ON(!atomic_read(&sd->s_count));
 140                 atomic_inc(&sd->s_count);
 141         }
 142         return sd;
 143 }
 144 #define sysfs_get(sd) __sysfs_get(sd)
 145
 146 static inline void __sysfs_put(struct sysfs_dirent *sd)
 147 {
 148         if (sd && atomic_dec_and_test(&sd->s_count))
 149                 release_sysfs_dirent(sd);
 150 }
 151 #define sysfs_put(sd) __sysfs_put(sd)
 152
 153 /*
 154  * inode.c
 155  */
 156 struct inode *sysfs_get_inode(struct sysfs_dirent *sd);
 157 void sysfs_delete_inode(struct inode *inode);
 158 int sysfs_setattr(struct dentry *dentry, struct iattr *iattr);
 159 int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value,
 160                 size_t size, int flags);
 161 int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name);
 162 int sysfs_inode_init(void);
 163
 164 /*
 165  * file.c
 166  */
 167 extern const struct file_operations sysfs_file_operations;
 168
 169 int sysfs_add_file(struct sysfs_dirent *dir_sd,
 170                    const struct attribute *attr, int type);
 171
 172 int sysfs_add_file_mode(struct sysfs_dirent *dir_sd,
 173                         const struct attribute *attr, int type, mode_t amode);
 174 /*
 175  * bin.c
 176  */
 177 extern const struct file_operations bin_fops;
 178 void unmap_bin_file(struct sysfs_dirent *attr_sd);
 179
 180 /*
 181  * symlink.c
 182  */
 183 extern const struct inode_operations sysfs_symlink_inode_operations;