3 files changed, 29 insertions, 8 deletions

diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index e6d9772ddb4c..61a8edc4ba8b 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -971,6 +971,15 @@ void kernfs_destroy_root(struct kernfs_root *root)
 }
 
 /**
+ * kernfs_root_to_node - return the kernfs_node associated with a kernfs_root
+ * @root: root to use to lookup
+ */
+struct kernfs_node *kernfs_root_to_node(struct kernfs_root *root)
+{
+	return root->kn;
+}
+
+/**
  * kernfs_create_dir_ns - create a directory
  * @parent: parent in which to create a new directory
  * @name: name of the new directory
diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c
index 9414a7a60a9f..88423069407c 100644
--- a/fs/kernfs/file.c
+++ b/fs/kernfs/file.c
@@ -120,13 +120,8 @@ static void *kernfs_seq_start(struct seq_file *sf, loff_t *ppos)
 		if (next == ERR_PTR(-ENODEV))
 			kernfs_seq_stop_active(sf, next);
 		return next;
-	} else {
-		/*
-		 * The same behavior and code as single_open().  Returns
-		 * !NULL if pos is at the beginning; otherwise, NULL.
-		 */
-		return NULL + !*ppos;
 	}
+	return single_start(sf, ppos);
 }
 
 static void *kernfs_seq_next(struct seq_file *sf, void *v, loff_t *ppos)
@@ -1002,7 +997,7 @@ struct kernfs_node *__kernfs_create_file(struct kernfs_node *parent,
 #endif
 
 	/*
-	 * kn->attr.ops is accesible only while holding active ref.  We
+	 * kn->attr.ops is accessible only while holding active ref.  We
 	 * need to know whether some ops are implemented outside active
 	 * ref.  Cache their existence in flags.
 	 */
diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h
index f9cc912c31e1..eeaa779b929c 100644
--- a/fs/kernfs/kernfs-internal.h
+++ b/fs/kernfs/kernfs-internal.h
@@ -31,6 +31,24 @@ struct kernfs_iattrs {
 	atomic_t		user_xattr_size;
 };
 
+struct kernfs_root {
+	/* published fields */
+	struct kernfs_node	*kn;
+	unsigned int		flags;	/* KERNFS_ROOT_* flags */
+
+	/* private fields, do not use outside kernfs proper */
+	struct idr		ino_idr;
+	u32			last_id_lowbits;
+	u32			id_highbits;
+	struct kernfs_syscall_ops *syscall_ops;
+
+	/* list of kernfs_super_info of this root, protected by kernfs_rwsem */
+	struct list_head	supers;
+
+	wait_queue_head_t	deactivate_waitq;
+	struct rw_semaphore	kernfs_rwsem;
+};
+
 /* +1 to avoid triggering overflow warning when negating it */
 #define KN_DEACTIVATED_BIAS		(INT_MIN + 1)
 
@@ -122,7 +140,6 @@ int __kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr);
 /*
  * dir.c
  */
-extern struct rw_semaphore kernfs_rwsem;
 extern const struct dentry_operations kernfs_dops;
 extern const struct file_operations kernfs_dir_fops;
 extern const struct inode_operations kernfs_dir_iops;