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         struct hlist_head       buffers;
  32 };
  33
  34 /*
  35  * sysfs_dirent - the building block of sysfs hierarchy.  Each and
  36  * every sysfs node is represented by single sysfs_dirent.
  37  *
  38  * As long as s_count reference is held, the sysfs_dirent itself is
  39  * accessible.  Dereferencing s_elem or any other outer entity
  40  * requires s_active reference.
  41  */
  42 struct sysfs_dirent {
  43         atomic_t                s_count;
  44         atomic_t                s_active;
  45         struct sysfs_dirent     *s_parent;
  46         struct sysfs_dirent     *s_sibling;
  47         const char              *s_name;
  48
  49         union {
  50                 struct sysfs_elem_dir           s_dir;
  51                 struct sysfs_elem_symlink       s_symlink;
  52                 struct sysfs_elem_attr          s_attr;
  53                 struct sysfs_elem_bin_attr      s_bin_attr;
  54         };
  55
  56         unsigned int            s_flags;
  57         ino_t                   s_ino;
  58         umode_t                 s_mode;
  59         struct iattr            *s_iattr;
  60 };
  61
  62 #define SD_DEACTIVATED_BIAS             INT_MIN
  63
  64 #define SYSFS_TYPE_MASK                 0x00ff
  65 #define SYSFS_DIR                       0x0001
  66 #define SYSFS_KOBJ_ATTR                 0x0002
  67 #define SYSFS_KOBJ_BIN_ATTR             0x0004
  68 #define SYSFS_KOBJ_LINK                 0x0008
  69 #define SYSFS_COPY_NAME                 (SYSFS_DIR | SYSFS_KOBJ_LINK)
  70
  71 #define SYSFS_FLAG_MASK                 ~SYSFS_TYPE_MASK
  72 #define SYSFS_FLAG_REMOVED              0x0200
  73
  74 static inline unsigned int sysfs_type(struct sysfs_dirent *sd)
  75 {
  76         return sd->s_flags & SYSFS_TYPE_MASK;
  77 }
  78
  79 /*
  80  * Context structure to be used while adding/removing nodes.
  81  */
  82 struct sysfs_addrm_cxt {
  83         struct sysfs_dirent     *parent_sd;
  84         struct inode            *parent_inode;
  85         struct sysfs_dirent     *removed;
  86         int                     cnt;
  87 };
  88
  89 /*
  90  * mount.c
  91  */
  92 extern struct sysfs_dirent sysfs_root;
  93 extern struct super_block *sysfs_sb;
  94 extern struct kmem_cache *sysfs_dir_cachep;
  95
  96 /*
  97  * dir.c
  98  */
  99 extern struct mutex sysfs_mutex;
 100 extern struct mutex sysfs_rename_mutex;
 101 extern spinlock_t sysfs_assoc_lock;
 102
 103 extern const struct file_operations sysfs_dir_operations;
 104 extern const struct inode_operations sysfs_dir_inode_operations;
 105
 106 struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd);
 107 struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd);
 108 void sysfs_put_active_two(struct sysfs_dirent *sd);
 109 void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
 110                        struct sysfs_dirent *parent_sd);
 111 int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *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 #define sysfs_get(sd) __sysfs_get(sd)
 137
 138 static inline void __sysfs_put(struct sysfs_dirent *sd)
 139 {
 140         if (sd && atomic_dec_and_test(&sd->s_count))
 141                 release_sysfs_dirent(sd);
 142 }
 143 #define sysfs_put(sd) __sysfs_put(sd)
 144
 145 /*
 146  * inode.c
 147  */
 148 struct inode *sysfs_get_inode(struct sysfs_dirent *sd);
 149 void sysfs_delete_inode(struct inode *inode);
 150 int sysfs_setattr(struct dentry *dentry, struct iattr *iattr);
 151 int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name);
 152 int sysfs_inode_init(void);
 153
 154 /*
 155  * file.c
 156  */
 157 extern const struct file_operations sysfs_file_operations;
 158
 159 int sysfs_add_file(struct sysfs_dirent *dir_sd,
 160                    const struct attribute *attr, int type);
 161
 162 int sysfs_add_file_mode(struct sysfs_dirent *dir_sd,
 163                         const struct attribute *attr, int type, mode_t amode);
 164 /*
 165  * bin.c
 166  */
 167 extern const struct file_operations bin_fops;
 168 void unmap_bin_file(struct sysfs_dirent *attr_sd);
 169
 170 /*
 171  * symlink.c
 172  */
 173 extern const struct inode_operations sysfs_symlink_inode_operations;