text: /*
   * fs/sysfs/sysfs.h - sysfs internal header file
   *
   * Copyright (c) 2001-3 Patrick Mochel
   * Copyright (c) 2007 SUSE Linux Products GmbH
   * Copyright (c) 2007 Tejun Heo <teheo@suse.de>
   *
   * This file is released under the GPLv2.
   */
  
  #include <linux/lockdep.h>
  #include <linux/kobject_ns.h>
  #include <linux/fs.h>
  #include <linux/rbtree.h>
  
  struct sysfs_open_dirent;
  
  /* type-specific structures for sysfs_dirent->s_* union members */
  struct sysfs_elem_dir {
  	struct kobject		*kobj;
  
  	unsigned long		subdirs;
  	/* children rbtree starts here and goes through sd->s_rb */
  	struct rb_root		children;
  };
  
  struct sysfs_elem_symlink {
  	struct sysfs_dirent	*target_sd;
  };
  
  struct sysfs_elem_attr {
  	struct attribute	*attr;
  	struct sysfs_open_dirent *open;
  };
  
  struct sysfs_elem_bin_attr {
  	struct bin_attribute	*bin_attr;
  	struct hlist_head	buffers;
  };
  
  struct sysfs_inode_attrs {
  	struct iattr	ia_iattr;
  	void		*ia_secdata;
  	u32		ia_secdata_len;
  };
  
  /*
   * sysfs_dirent - the building block of sysfs hierarchy.  Each and
   * every sysfs node is represented by single sysfs_dirent.
   *
   * As long as s_count reference is held, the sysfs_dirent itself is
   * accessible.  Dereferencing s_elem or any other outer entity
   * requires s_active reference.
   */
  struct sysfs_dirent {
  	atomic_t		s_count;
  	atomic_t		s_active;
  #ifdef CONFIG_DEBUG_LOCK_ALLOC
  	struct lockdep_map	dep_map;
  #endif
  	struct sysfs_dirent	*s_parent;
  	const char		*s_name;
  
  	struct rb_node		s_rb;
  
  	union {
  		struct completion	*completion;
  		struct sysfs_dirent	*removed_list;
  	} u;
  
  	const void		*s_ns; /* namespace tag */
  	unsigned int		s_hash; /* ns + name hash */
  	union {
  		struct sysfs_elem_dir		s_dir;
  		struct sysfs_elem_symlink	s_symlink;
  		struct sysfs_elem_attr		s_attr;
  		struct sysfs_elem_bin_attr	s_bin_attr;
  	};
  
  	unsigned short		s_flags;
  	umode_t 		s_mode;
  	unsigned int		s_ino;
  	struct sysfs_inode_attrs *s_iattr;
  };
  
  #define SD_DEACTIVATED_BIAS		INT_MIN
  
  #define SYSFS_TYPE_MASK			0x00ff
  #define SYSFS_DIR			0x0001
  #define SYSFS_KOBJ_ATTR			0x0002
  #define SYSFS_KOBJ_BIN_ATTR		0x0004
  #define SYSFS_KOBJ_LINK			0x0008
  #define SYSFS_COPY_NAME			(SYSFS_DIR | SYSFS_KOBJ_LINK)
  #define SYSFS_ACTIVE_REF		(SYSFS_KOBJ_ATTR | SYSFS_KOBJ_BIN_ATTR)
  
  /* identify any namespace tag on sysfs_dirents */
  #define SYSFS_NS_TYPE_MASK		0xf00
  #define SYSFS_NS_TYPE_SHIFT		8
  
  #define SYSFS_FLAG_MASK			~(SYSFS_NS_TYPE_MASK|SYSFS_TYPE_MASK)
  #define SYSFS_FLAG_REMOVED		0x02000
  
  static inline unsigned int sysfs_type(struct sysfs_dirent *sd)
  {
  	return sd->s_flags & SYSFS_TYPE_MASK;
  }
  
  /*
   * Return any namespace tags on this dirent.
   * enum kobj_ns_type is defined in linux/kobject.h
   */
  static inline enum kobj_ns_type sysfs_ns_type(struct sysfs_dirent *sd)
  {
  	return (sd->s_flags & SYSFS_NS_TYPE_MASK) >> SYSFS_NS_TYPE_SHIFT;
  }
  
  #ifdef CONFIG_DEBUG_LOCK_ALLOC
  #define sysfs_dirent_init_lockdep(sd)				\
  do {								\
  	struct attribute *attr = sd->s_attr.attr;		\
  	struct lock_class_key *key = attr->key;			\
  	if (!key)						\
  		key = &attr->skey;				\
  								\
  	lockdep_init_map(&sd->dep_map, "s_active", key, 0);	\
  } while(0)
  #else
  #define sysfs_dirent_init_lockdep(sd) do {} while(0)
  #endif
  
  /*
   * Context structure to be used while adding/removing nodes.
   */
  struct sysfs_addrm_cxt {
  	struct sysfs_dirent	*parent_sd;
  	struct sysfs_dirent	*removed;
  };
  
  /*
   * mount.c
   */
  
  /*
   * Each sb is associated with a set of namespace tags (i.e.
   * the network namespace of the task which mounted this sysfs
   * instance).
   */
  struct sysfs_super_info {
  	void *ns[KOBJ_NS_TYPES];
  };
  #define sysfs_info(SB) ((struct sysfs_super_info *)(SB->s_fs_info))
  extern struct sysfs_dirent sysfs_root;
  extern struct kmem_cache *sysfs_dir_cachep;
  
  /*
   * dir.c
   */
  extern struct mutex sysfs_mutex;
  extern spinlock_t sysfs_assoc_lock;
  extern const struct dentry_operations sysfs_dentry_ops;
  
  extern const struct file_operations sysfs_dir_operations;
  extern const struct inode_operations sysfs_dir_inode_operations;
  
  struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd);
  struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd);
  void sysfs_put_active(struct sysfs_dirent *sd);
  void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
  		       struct sysfs_dirent *parent_sd);
  int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
  int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
  void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
  void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt);
  
  struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd,
  				       const void *ns,
  				       const unsigned char *name);
  struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
  				      const void *ns,
  				      const unsigned char *name);
  struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type);
  
  void release_sysfs_dirent(struct sysfs_dirent *sd);
  
  int sysfs_create_subdir(struct kobject *kobj, const char *name,
  			struct sysfs_dirent **p_sd);
  void sysfs_remove_subdir(struct sysfs_dirent *sd);
  
  int sysfs_rename(struct sysfs_dirent *sd,
  	struct sysfs_dirent *new_parent_sd, const void *ns, const char *new_name);
  
  static inline struct sysfs_dirent *__sysfs_get(struct sysfs_dirent *sd)
  {
  	if (sd) {
  		WARN_ON(!atomic_read(&sd->s_count));
  		atomic_inc(&sd->s_count);
  	}
  	return sd;
  }
  #define sysfs_get(sd) __sysfs_get(sd)
  
  static inline void __sysfs_put(struct sysfs_dirent *sd)
  {
  	if (sd && atomic_dec_and_test(&sd->s_count))
  		release_sysfs_dirent(sd);
  }
  #define sysfs_put(sd) __sysfs_put(sd)
  
  /*
   * inode.c
   */
  struct inode *sysfs_get_inode(struct super_block *sb, struct sysfs_dirent *sd);
  void sysfs_evict_inode(struct inode *inode);
  int sysfs_sd_setattr(struct sysfs_dirent *sd, struct iattr *iattr);
  int sysfs_permission(struct inode *inode, int mask);
  int sysfs_setattr(struct dentry *dentry, struct iattr *iattr);
  int sysfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat);
  int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value,
  		size_t size, int flags);
  int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const void *ns, const char *name);
  int sysfs_inode_init(void);
  
  /*
   * file.c
   */
  extern const struct file_operations sysfs_file_operations;
  
  int sysfs_add_file(struct sysfs_dirent *dir_sd,
  		   const struct attribute *attr, int type);
  
  int sysfs_add_file_mode(struct sysfs_dirent *dir_sd,
  			const struct attribute *attr, int type, umode_t amode);
  /*
   * bin.c
   */
  extern const struct file_operations bin_fops;
  void unmap_bin_file(struct sysfs_dirent *attr_sd);
  
  /*
   * symlink.c
   */
  extern const struct inode_operations sysfs_symlink_inode_operations;
  int sysfs_create_link_sd(struct sysfs_dirent *sd, struct kobject *target,
  			 const char *name);
  