+struct sysfs_open_dirent;
+struct sysfs_inode_attrs;
+
+enum kernfs_node_type {
+ SYSFS_DIR = 0x0001,
+ SYSFS_KOBJ_ATTR = 0x0002,
+ SYSFS_KOBJ_LINK = 0x0004,
+};
+
+#define SYSFS_TYPE_MASK 0x000f
+#define SYSFS_COPY_NAME (SYSFS_DIR | SYSFS_KOBJ_LINK)
+#define SYSFS_ACTIVE_REF SYSFS_KOBJ_ATTR
+#define SYSFS_FLAG_MASK ~SYSFS_TYPE_MASK
+
+enum kernfs_node_flag {
+ SYSFS_FLAG_REMOVED = 0x0010,
+ SYSFS_FLAG_NS = 0x0020,
+ SYSFS_FLAG_HAS_SEQ_SHOW = 0x0040,
+ SYSFS_FLAG_HAS_MMAP = 0x0080,
+ SYSFS_FLAG_LOCKDEP = 0x0100,
+};
+
+/* type-specific structures for sysfs_dirent->s_* union members */
+struct sysfs_elem_dir {
+ unsigned long subdirs;
+ /* children rbtree starts here and goes through sd->s_rb */
+ struct rb_root children;
+
+ /*
+ * The kernfs hierarchy this directory belongs to. This fits
+ * better directly in sysfs_dirent but is here to save space.
+ */
+ struct kernfs_root *root;
+};
+
+struct sysfs_elem_symlink {
+ struct sysfs_dirent *target_sd;
+};
+
+struct sysfs_elem_attr {
+ const struct kernfs_ops *ops;
+ struct sysfs_open_dirent *open;
+ loff_t size;
+};
+
+/*
+ * sysfs_dirent - the building block of sysfs hierarchy. Each and every
+ * sysfs node is represented by single sysfs_dirent. Most fields are
+ * private to kernfs and shouldn't be accessed directly by kernfs users.
+ *
+ * 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
+ /* the following two fields are published */
+ 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;
+ };
+
+ void *priv;
+
+ unsigned short s_flags;
+ umode_t s_mode;
+ unsigned int s_ino;
+ struct sysfs_inode_attrs *s_iattr;
+};