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 struct sysfs_open_dirent;
  12
  13 /* type-specific structures for sysfs_dirent->s_* union members */
  14 struct 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
  20 struct sysfs_elem_symlink {
  21         struct sysfs_dirent     *target_sd;
  22 };
  23
  24 struct sysfs_elem_attr {
  25         struct attribute        *attr;
  26         struct sysfs_open_dirent *open;
  27 };
  28
  29 struct 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  */
  41 struct 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
  73 static 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  */
  81 struct 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  */
  91 extern struct sysfs_dirent sysfs_root;
  92 extern struct super_block *sysfs_sb;
  93 extern struct kmem_cache *sysfs_dir_cachep;
  94
  95 /*
  96  * dir.c
  97  */
  98 extern struct mutex sysfs_mutex;
  99 extern struct mutex sysfs_rename_mutex;
 100 extern spinlock_t sysfs_assoc_lock;
 101
 102 extern const struct file_operations sysfs_dir_operations;
 103 extern const struct inode_operations sysfs_dir_inode_operations;
 104
 105 struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd);
 106 struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd);
 107 void sysfs_put_active(struct sysfs_dirent *sd);
 108 struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd);
 109 void sysfs_put_active_two(struct sysfs_dirent *sd);
 110 void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
 111                        struct sysfs_dirent *parent_sd);
 112 int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
 113 void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
 114 void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt);
 115
 116 struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd,
 117                                        const unsigned char *name);
 118 struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
 119                                       const unsigned char *name);
 120 struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type);
 121
 122 void release_sysfs_dirent(struct sysfs_dirent *sd);
 123
 124 int sysfs_create_subdir(struct kobject *kobj, const char *name,
 125                         struct sysfs_dirent **p_sd);
 126 void sysfs_remove_subdir(struct sysfs_dirent *sd);
 127
 128 static inline struct sysfs_dirent *sysfs_get(struct sysfs_dirent *sd)
 129 {
 130         if (sd) {
 131                 WARN_ON(!atomic_read(&sd->s_count));
 132                 atomic_inc(&sd->s_count);
 133         }
 134         return sd;
 135 }
 136
 137 static inline void sysfs_put(struct sysfs_dirent *sd)
 138 {
 139         if (sd && atomic_dec_and_test(&sd->s_count))
 140                 release_sysfs_dirent(sd);
 141 }
 142
 143 /*
 144  * inode.c
 145  */
 146 struct inode *sysfs_get_inode(struct sysfs_dirent *sd);
 147 int sysfs_setattr(struct dentry *dentry, struct iattr *iattr);
 148 int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name);
 149 int sysfs_inode_init(void);
 150
 151 /*
 152  * file.c
 153  */
 154 extern const struct file_operations sysfs_file_operations;
 155
 156 int sysfs_add_file(struct sysfs_dirent *dir_sd,
 157                    const struct attribute *attr, int type);
 158
 159 /*
 160  * bin.c
 161  */
 162 extern const struct file_operations bin_fops;
 163
 164 /*
 165  * symlink.c
 166  */
 167 extern const struct inode_operations sysfs_symlink_inode_operations;