2 files changed, 67 insertions, 2 deletions

diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h
new file mode 100644
index 000000000000..8cb673875715
--- /dev/null
+++ b/include/linux/kernfs.h
@@ -0,0 +1,60 @@
+/*
+ * kernfs.h - pseudo filesystem decoupled from vfs locking
+ *
+ * This file is released under the GPLv2.
+ */
+
+#ifndef __LINUX_KERNFS_H
+#define __LINUX_KERNFS_H
+
+#include <linux/kernel.h>
+#include <linux/err.h>
+
+struct file;
+struct iattr;
+
+struct sysfs_dirent;
+
+#ifdef CONFIG_SYSFS
+
+struct sysfs_dirent *kernfs_create_link(struct sysfs_dirent *parent,
+					const char *name,
+					struct sysfs_dirent *target);
+void kernfs_remove(struct sysfs_dirent *sd);
+int kernfs_remove_by_name_ns(struct sysfs_dirent *parent, const char *name,
+			     const void *ns);
+int kernfs_rename_ns(struct sysfs_dirent *sd, struct sysfs_dirent *new_parent,
+		     const char *new_name, const void *new_ns);
+int kernfs_setattr(struct sysfs_dirent *sd, const struct iattr *iattr);
+
+#else	/* CONFIG_SYSFS */
+
+static inline struct sysfs_dirent *
+kernfs_create_link(struct sysfs_dirent *parent, const char *name,
+		   struct sysfs_dirent *target)
+{ return ERR_PTR(-ENOSYS); }
+
+static inline void kernfs_remove(struct sysfs_dirent *sd) { }
+
+static inline int kernfs_remove_by_name_ns(struct sysfs_dirent *parent,
+					   const char *name, const void *ns)
+{ return -ENOSYS; }
+
+static inline int kernfs_rename_ns(struct sysfs_dirent *sd,
+				   struct sysfs_dirent *new_parent,
+				   const char *new_name, const void *new_ns)
+{ return -ENOSYS; }
+
+static inline int kernfs_setattr(struct sysfs_dirent *sd,
+				 const struct iattr *iattr)
+{ return -ENOSYS; }
+
+#endif	/* CONFIG_SYSFS */
+
+static inline int kernfs_remove_by_name(struct sysfs_dirent *parent,
+					const char *name)
+{
+	return kernfs_remove_by_name_ns(parent, name, NULL);
+}
+
+#endif	/* __LINUX_KERNFS_H */
diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h
index 6695040a0317..e17381a92e1a 100644
--- a/include/linux/sysfs.h
+++ b/include/linux/sysfs.h
@@ -12,6 +12,7 @@
 #ifndef _SYSFS_H_
 #define _SYSFS_H_
 
+#include <linux/kernfs.h>
 #include <linux/compiler.h>
 #include <linux/errno.h>
 #include <linux/list.h>
@@ -175,8 +176,6 @@ struct sysfs_ops {
 	ssize_t	(*store)(struct kobject *, struct attribute *, const char *, size_t);
 };
 
-struct sysfs_dirent;
-
 #ifdef CONFIG_SYSFS
 
 int sysfs_schedule_callback(struct kobject *kobj, void (*func)(void *),
@@ -220,6 +219,8 @@ int sysfs_rename_link_ns(struct kobject *kobj, struct kobject *target,
 void sysfs_delete_link(struct kobject *dir, struct kobject *targ,
 			const char *name);
 
+void sysfs_enable_ns(struct sysfs_dirent *sd);
+
 int __must_check sysfs_create_group(struct kobject *kobj,
 				    const struct attribute_group *grp);
 int __must_check sysfs_create_groups(struct kobject *kobj,
@@ -353,6 +354,10 @@ static inline void sysfs_delete_link(struct kobject *k, struct kobject *t,
 {
 }
 
+static inline void sysfs_enable_ns(struct sysfs_dirent *sd)
+{
+}
+
 static inline int sysfs_create_group(struct kobject *kobj,
 				     const struct attribute_group *grp)
 {