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         union {
  62                 struct sysfs_elem_dir           s_dir;
  63                 struct sysfs_elem_symlink       s_symlink;
  64                 struct sysfs_elem_attr          s_attr;
  65                 struct sysfs_elem_bin_attr      s_bin_attr;
  66         };
  67
  68         unsigned int            s_flags;
  69         ino_t                   s_ino;
  70         umode_t                 s_mode;
  71         struct sysfs_inode_attrs *s_iattr;
  72 };
  73
  74 #define SD_DEACTIVATED_BIAS             INT_MIN
  75
  76 #define SYSFS_TYPE_MASK                 0x00ff
  77 #define SYSFS_DIR                       0x0001
  78 #define SYSFS_KOBJ_ATTR                 0x0002
  79 #define SYSFS_KOBJ_BIN_ATTR             0x0004
  80 #define SYSFS_KOBJ_LINK                 0x0008
  81 #define SYSFS_COPY_NAME                 (SYSFS_DIR | SYSFS_KOBJ_LINK)
  82 #define SYSFS_ACTIVE_REF                (SYSFS_KOBJ_ATTR | SYSFS_KOBJ_BIN_ATTR)
  83
  84 #define SYSFS_FLAG_MASK                 ~SYSFS_TYPE_MASK
  85 #define SYSFS_FLAG_REMOVED              0x0200
  86
  87 static inline unsigned int sysfs_type(struct sysfs_dirent *sd)
  88 {
  89         return sd->s_flags & SYSFS_TYPE_MASK;
  90 }
  91
  92 #ifdef CONFIG_DEBUG_LOCK_ALLOC
  93 #define sysfs_dirent_init_lockdep(sd)                           \
  94 do {                                                            \
  95         static struct lock_class_key __key;                     \
  96                                                                 \
  97         lockdep_init_map(&sd->dep_map, "s_active", &__key, 0);  \
  98 } while(0)
  99 #else
 100 #define sysfs_dirent_init_lockdep(sd) do {} while(0)
 101 #endif
 102
 103 /*
 104  * Context structure to be used while adding/removing nodes.
 105  */
 106 struct sysfs_addrm_cxt {
 107         struct sysfs_dirent     *parent_sd;
 108         struct sysfs_dirent     *removed;
 109 };
 110
 111 /*
 112  * mount.c
 113  */
 114 extern struct sysfs_dirent sysfs_root;
 115 extern struct super_block *sysfs_sb;
 116 extern struct kmem_cache *sysfs_dir_cachep;
 117
 118 /*
 119  * dir.c
 120  */
 121 extern struct mutex sysfs_mutex;
 122 extern spinlock_t sysfs_assoc_lock;
 123
 124 extern const struct file_operations sysfs_dir_operations;
 125 extern const struct inode_operations sysfs_dir_inode_operations;
 126
 127 struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd);
 128 struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd);
 129 void sysfs_put_active(struct sysfs_dirent *sd);
 130 void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
 131                        struct sysfs_dirent *parent_sd);
 132 int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
 133 int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
 134 void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
 135 void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt);
 136
 137 struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd,
 138                                        const unsigned char *name);
 139 struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
 140                                       const unsigned char *name);
 141 struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type);
 142
 143 void release_sysfs_dirent(struct sysfs_dirent *sd);
 144
 145 int sysfs_create_subdir(struct kobject *kobj, const char *name,
 146                         struct sysfs_dirent **p_sd);
 147 void sysfs_remove_subdir(struct sysfs_dirent *sd);
 148
 149 int sysfs_rename(struct sysfs_dirent *sd,
 150         struct sysfs_dirent *new_parent_sd, const char *new_name);
 151
 152 static inline struct sysfs_dirent *__sysfs_get(struct sysfs_dirent *sd)
 153 {
 154         if (sd) {
 155                 WARN_ON(!atomic_read(&sd->s_count));
 156                 atomic_inc(&sd->s_count);
 157         }
 158         return sd;
 159 }
 160 #define sysfs_get(sd) __sysfs_get(sd)
 161
 162 static inline void __sysfs_put(struct sysfs_dirent *sd)
 163 {
 164         if (sd && atomic_dec_and_test(&sd->s_count))
 165                 release_sysfs_dirent(sd);
 166 }
 167 #define sysfs_put(sd) __sysfs_put(sd)
 168
 169 /*
 170  * inode.c
 171  */
 172 struct inode *sysfs_get_inode(struct sysfs_dirent *sd);
 173 void sysfs_delete_inode(struct inode *inode);
 174 int sysfs_sd_setattr(struct sysfs_dirent *sd, struct iattr *iattr);
 175 int sysfs_permission(struct inode *inode, int mask);
 176 int sysfs_setattr(struct dentry *dentry, struct iattr *iattr);
 177 int sysfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat);
 178 int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value,
 179                 size_t size, int flags);
 180 int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name);
 181 int sysfs_inode_init(void);
 182
 183 /*
 184  * file.c
 185  */
 186 extern const struct file_operations sysfs_file_operations;
 187
 188 int sysfs_add_file(struct sysfs_dirent *dir_sd,
 189                    const struct attribute *attr, int type);
 190
 191 int sysfs_add_file_mode(struct sysfs_dirent *dir_sd,
 192                         const struct attribute *attr, int type, mode_t amode);
 193 /*
 194  * bin.c
 195  */
 196 extern const struct file_operations bin_fops;
 197 void unmap_bin_file(struct sysfs_dirent *attr_sd);
 198
 199 /*
 200  * symlink.c
 201  */
 202 extern const struct inode_operations sysfs_symlink_inode_operations;