6 files changed, 424 insertions, 91 deletions

diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index aa85f2874a9f..b6b6796e1616 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -6,7 +6,7 @@
  * Copyright (c) 2007 SUSE Linux Products GmbH
  * Copyright (c) 2007 Tejun Heo <teheo@suse.de>
  *
- * Please see Documentation/filesystems/sysfs.txt for more information.
+ * Please see Documentation/filesystems/sysfs.rst for more information.
  */
 
 #define pr_fmt(fmt)	"sysfs: " fmt
@@ -56,8 +56,7 @@ int sysfs_create_dir_ns(struct kobject *kobj, const void *ns)
 
 	kobject_get_ownership(kobj, &uid, &gid);
 
-	kn = kernfs_create_dir_ns(parent, kobject_name(kobj),
-				  S_IRWXU | S_IRUGO | S_IXUGO, uid, gid,
+	kn = kernfs_create_dir_ns(parent, kobject_name(kobj), 0755, uid, gid,
 				  kobj, ns);
 	if (IS_ERR(kn)) {
 		if (PTR_ERR(kn) == -EEXIST)
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 130fc6fbcc03..a12ac0356c69 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -6,7 +6,7 @@
  * Copyright (c) 2007 SUSE Linux Products GmbH
  * Copyright (c) 2007 Tejun Heo <teheo@suse.de>
  *
- * Please see Documentation/filesystems/sysfs.txt for more information.
+ * Please see Documentation/filesystems/sysfs.rst for more information.
  */
 
 #include <linux/module.h>
@@ -15,6 +15,7 @@
 #include <linux/list.h>
 #include <linux/mutex.h>
 #include <linux/seq_file.h>
+#include <linux/mm.h>
 
 #include "sysfs.h"
 
@@ -44,6 +45,9 @@ static int sysfs_kf_seq_show(struct seq_file *sf, void *v)
 	ssize_t count;
 	char *buf;
 
+	if (WARN_ON_ONCE(!ops->show))
+		return -EINVAL;
+
 	/* acquire buffer and ensure that it's >= PAGE_SIZE and clear */
 	count = seq_get_buf(sf, &buf);
 	if (count < PAGE_SIZE) {
@@ -52,15 +56,9 @@ static int sysfs_kf_seq_show(struct seq_file *sf, void *v)
 	}
 	memset(buf, 0, PAGE_SIZE);
 
-	/*
-	 * Invoke show().  Control may reach here via seq file lseek even
-	 * if @ops->show() isn't implemented.
-	 */
-	if (ops->show) {
-		count = ops->show(kobj, of->kn->priv, buf);
-		if (count < 0)
-			return count;
-	}
+	count = ops->show(kobj, of->kn->priv, buf);
+	if (count < 0)
+		return count;
 
 	/*
 	 * The code works fine with PAGE_SIZE return but it's likely to
@@ -169,6 +167,16 @@ static int sysfs_kf_bin_mmap(struct kernfs_open_file *of,
 	return battr->mmap(of->file, kobj, battr, vma);
 }
 
+static int sysfs_kf_bin_open(struct kernfs_open_file *of)
+{
+	struct bin_attribute *battr = of->kn->priv;
+
+	if (battr->f_mapping)
+		of->file->f_mapping = battr->f_mapping();
+
+	return 0;
+}
+
 void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr)
 {
 	struct kernfs_node *kn = kobj->sd, *tmp;
@@ -240,70 +248,86 @@ static const struct kernfs_ops sysfs_bin_kfops_mmap = {
 	.read		= sysfs_kf_bin_read,
 	.write		= sysfs_kf_bin_write,
 	.mmap		= sysfs_kf_bin_mmap,
+	.open		= sysfs_kf_bin_open,
 };
 
 int sysfs_add_file_mode_ns(struct kernfs_node *parent,
-			   const struct attribute *attr, bool is_bin,
-			   umode_t mode, kuid_t uid, kgid_t gid, const void *ns)
+		const struct attribute *attr, umode_t mode, kuid_t uid,
+		kgid_t gid, const void *ns)
 {
+	struct kobject *kobj = parent->priv;
+	const struct sysfs_ops *sysfs_ops = kobj->ktype->sysfs_ops;
 	struct lock_class_key *key = NULL;
-	const struct kernfs_ops *ops;
+	const struct kernfs_ops *ops = NULL;
 	struct kernfs_node *kn;
-	loff_t size;
-
-	if (!is_bin) {
-		struct kobject *kobj = parent->priv;
-		const struct sysfs_ops *sysfs_ops = kobj->ktype->sysfs_ops;
-
-		/* every kobject with an attribute needs a ktype assigned */
-		if (WARN(!sysfs_ops, KERN_ERR
-			 "missing sysfs attribute operations for kobject: %s\n",
-			 kobject_name(kobj)))
-			return -EINVAL;
-
-		if (sysfs_ops->show && sysfs_ops->store) {
-			if (mode & SYSFS_PREALLOC)
-				ops = &sysfs_prealloc_kfops_rw;
-			else
-				ops = &sysfs_file_kfops_rw;
-		} else if (sysfs_ops->show) {
-			if (mode & SYSFS_PREALLOC)
-				ops = &sysfs_prealloc_kfops_ro;
-			else
-				ops = &sysfs_file_kfops_ro;
-		} else if (sysfs_ops->store) {
-			if (mode & SYSFS_PREALLOC)
-				ops = &sysfs_prealloc_kfops_wo;
-			else
-				ops = &sysfs_file_kfops_wo;
-		} else
-			ops = &sysfs_file_kfops_empty;
-
-		size = PAGE_SIZE;
+
+	/* every kobject with an attribute needs a ktype assigned */
+	if (WARN(!sysfs_ops, KERN_ERR
+			"missing sysfs attribute operations for kobject: %s\n",
+			kobject_name(kobj)))
+		return -EINVAL;
+
+	if (mode & SYSFS_PREALLOC) {
+		if (sysfs_ops->show && sysfs_ops->store)
+			ops = &sysfs_prealloc_kfops_rw;
+		else if (sysfs_ops->show)
+			ops = &sysfs_prealloc_kfops_ro;
+		else if (sysfs_ops->store)
+			ops = &sysfs_prealloc_kfops_wo;
 	} else {
-		struct bin_attribute *battr = (void *)attr;
-
-		if (battr->mmap)
-			ops = &sysfs_bin_kfops_mmap;
-		else if (battr->read && battr->write)
-			ops = &sysfs_bin_kfops_rw;
-		else if (battr->read)
-			ops = &sysfs_bin_kfops_ro;
-		else if (battr->write)
-			ops = &sysfs_bin_kfops_wo;
-		else
-			ops = &sysfs_file_kfops_empty;
-
-		size = battr->size;
+		if (sysfs_ops->show && sysfs_ops->store)
+			ops = &sysfs_file_kfops_rw;
+		else if (sysfs_ops->show)
+			ops = &sysfs_file_kfops_ro;
+		else if (sysfs_ops->store)
+			ops = &sysfs_file_kfops_wo;
 	}
 
+	if (!ops)
+		ops = &sysfs_file_kfops_empty;
+
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 	if (!attr->ignore_lockdep)
 		key = attr->key ?: (struct lock_class_key *)&attr->skey;
 #endif
 
 	kn = __kernfs_create_file(parent, attr->name, mode & 0777, uid, gid,
-				  size, ops, (void *)attr, ns, key);
+				  PAGE_SIZE, ops, (void *)attr, ns, key);
+	if (IS_ERR(kn)) {
+		if (PTR_ERR(kn) == -EEXIST)
+			sysfs_warn_dup(parent, attr->name);
+		return PTR_ERR(kn);
+	}
+	return 0;
+}
+
+int sysfs_add_bin_file_mode_ns(struct kernfs_node *parent,
+		const struct bin_attribute *battr, umode_t mode,
+		kuid_t uid, kgid_t gid, const void *ns)
+{
+	const struct attribute *attr = &battr->attr;
+	struct lock_class_key *key = NULL;
+	const struct kernfs_ops *ops;
+	struct kernfs_node *kn;
+
+	if (battr->mmap)
+		ops = &sysfs_bin_kfops_mmap;
+	else if (battr->read && battr->write)
+		ops = &sysfs_bin_kfops_rw;
+	else if (battr->read)
+		ops = &sysfs_bin_kfops_ro;
+	else if (battr->write)
+		ops = &sysfs_bin_kfops_wo;
+	else
+		ops = &sysfs_file_kfops_empty;
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	if (!attr->ignore_lockdep)
+		key = attr->key ?: (struct lock_class_key *)&attr->skey;
+#endif
+
+	kn = __kernfs_create_file(parent, attr->name, mode & 0777, uid, gid,
+				  battr->size, ops, (void *)attr, ns, key);
 	if (IS_ERR(kn)) {
 		if (PTR_ERR(kn) == -EEXIST)
 			sysfs_warn_dup(parent, attr->name);
@@ -328,9 +352,7 @@ int sysfs_create_file_ns(struct kobject *kobj, const struct attribute *attr,
 		return -EINVAL;
 
 	kobject_get_ownership(kobj, &uid, &gid);
-	return sysfs_add_file_mode_ns(kobj->sd, attr, false, attr->mode,
-				      uid, gid, ns);
-
+	return sysfs_add_file_mode_ns(kobj->sd, attr, attr->mode, uid, gid, ns);
 }
 EXPORT_SYMBOL_GPL(sysfs_create_file_ns);
 
@@ -373,8 +395,8 @@ int sysfs_add_file_to_group(struct kobject *kobj,
 		return -ENOENT;
 
 	kobject_get_ownership(kobj, &uid, &gid);
-	error = sysfs_add_file_mode_ns(parent, attr, false,
-				       attr->mode, uid, gid, NULL);
+	error = sysfs_add_file_mode_ns(parent, attr, attr->mode, uid, gid,
+				       NULL);
 	kernfs_put(parent);
 
 	return error;
@@ -492,6 +514,7 @@ bool sysfs_remove_file_self(struct kobject *kobj, const struct attribute *attr)
 	kernfs_put(kn);
 	return ret;
 }
+EXPORT_SYMBOL_GPL(sysfs_remove_file_self);
 
 void sysfs_remove_files(struct kobject *kobj, const struct attribute * const *ptr)
 {
@@ -542,8 +565,8 @@ int sysfs_create_bin_file(struct kobject *kobj,
 		return -EINVAL;
 
 	kobject_get_ownership(kobj, &uid, &gid);
-	return sysfs_add_file_mode_ns(kobj->sd, &attr->attr, true,
-				      attr->attr.mode, uid, gid, NULL);
+	return sysfs_add_bin_file_mode_ns(kobj->sd, attr, attr->attr.mode, uid,
+					   gid, NULL);
 }
 EXPORT_SYMBOL_GPL(sysfs_create_bin_file);
 
@@ -558,3 +581,192 @@ void sysfs_remove_bin_file(struct kobject *kobj,
 	kernfs_remove_by_name(kobj->sd, attr->attr.name);
 }
 EXPORT_SYMBOL_GPL(sysfs_remove_bin_file);
+
+static int internal_change_owner(struct kernfs_node *kn, kuid_t kuid,
+				 kgid_t kgid)
+{
+	struct iattr newattrs = {
+		.ia_valid = ATTR_UID | ATTR_GID,
+		.ia_uid = kuid,
+		.ia_gid = kgid,
+	};
+	return kernfs_setattr(kn, &newattrs);
+}
+
+/**
+ *	sysfs_link_change_owner - change owner of a sysfs file.
+ *	@kobj:	object of the kernfs_node the symlink is located in.
+ *	@targ:	object of the kernfs_node the symlink points to.
+ *	@name:	name of the link.
+ *	@kuid:	new owner's kuid
+ *	@kgid:	new owner's kgid
+ *
+ * This function looks up the sysfs symlink entry @name under @kobj and changes
+ * the ownership to @kuid/@kgid. The symlink is looked up in the namespace of
+ * @targ.
+ *
+ * Returns 0 on success or error code on failure.
+ */
+int sysfs_link_change_owner(struct kobject *kobj, struct kobject *targ,
+			    const char *name, kuid_t kuid, kgid_t kgid)
+{
+	struct kernfs_node *kn = NULL;
+	int error;
+
+	if (!name || !kobj->state_in_sysfs || !targ->state_in_sysfs)
+		return -EINVAL;
+
+	error = -ENOENT;
+	kn = kernfs_find_and_get_ns(kobj->sd, name, targ->sd->ns);
+	if (!kn)
+		goto out;
+
+	error = -EINVAL;
+	if (kernfs_type(kn) != KERNFS_LINK)
+		goto out;
+	if (kn->symlink.target_kn->priv != targ)
+		goto out;
+
+	error = internal_change_owner(kn, kuid, kgid);
+
+out:
+	kernfs_put(kn);
+	return error;
+}
+
+/**
+ *	sysfs_file_change_owner - change owner of a sysfs file.
+ *	@kobj:	object.
+ *	@name:	name of the file to change.
+ *	@kuid:	new owner's kuid
+ *	@kgid:	new owner's kgid
+ *
+ * This function looks up the sysfs entry @name under @kobj and changes the
+ * ownership to @kuid/@kgid.
+ *
+ * Returns 0 on success or error code on failure.
+ */
+int sysfs_file_change_owner(struct kobject *kobj, const char *name, kuid_t kuid,
+			    kgid_t kgid)
+{
+	struct kernfs_node *kn;
+	int error;
+
+	if (!name)
+		return -EINVAL;
+
+	if (!kobj->state_in_sysfs)
+		return -EINVAL;
+
+	kn = kernfs_find_and_get(kobj->sd, name);
+	if (!kn)
+		return -ENOENT;
+
+	error = internal_change_owner(kn, kuid, kgid);
+
+	kernfs_put(kn);
+
+	return error;
+}
+EXPORT_SYMBOL_GPL(sysfs_file_change_owner);
+
+/**
+ *	sysfs_change_owner - change owner of the given object.
+ *	@kobj:	object.
+ *	@kuid:	new owner's kuid
+ *	@kgid:	new owner's kgid
+ *
+ * Change the owner of the default directory, files, groups, and attributes of
+ * @kobj to @kuid/@kgid. Note that sysfs_change_owner mirrors how the sysfs
+ * entries for a kobject are added by driver core. In summary,
+ * sysfs_change_owner() takes care of the default directory entry for @kobj,
+ * the default attributes associated with the ktype of @kobj and the default
+ * attributes associated with the ktype of @kobj.
+ * Additional properties not added by driver core have to be changed by the
+ * driver or subsystem which created them. This is similar to how
+ * driver/subsystem specific entries are removed.
+ *
+ * Returns 0 on success or error code on failure.
+ */
+int sysfs_change_owner(struct kobject *kobj, kuid_t kuid, kgid_t kgid)
+{
+	int error;
+	const struct kobj_type *ktype;
+
+	if (!kobj->state_in_sysfs)
+		return -EINVAL;
+
+	/* Change the owner of the kobject itself. */
+	error = internal_change_owner(kobj->sd, kuid, kgid);
+	if (error)
+		return error;
+
+	ktype = get_ktype(kobj);
+	if (ktype) {
+		/*
+		 * Change owner of the default groups associated with the
+		 * ktype of @kobj.
+		 */
+		error = sysfs_groups_change_owner(kobj, ktype->default_groups,
+						  kuid, kgid);
+		if (error)
+			return error;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(sysfs_change_owner);
+
+/**
+ *	sysfs_emit - scnprintf equivalent, aware of PAGE_SIZE buffer.
+ *	@buf:	start of PAGE_SIZE buffer.
+ *	@fmt:	format
+ *	@...:	optional arguments to @format
+ *
+ *
+ * Returns number of characters written to @buf.
+ */
+int sysfs_emit(char *buf, const char *fmt, ...)
+{
+	va_list args;
+	int len;
+
+	if (WARN(!buf || offset_in_page(buf),
+		 "invalid sysfs_emit: buf:%p\n", buf))
+		return 0;
+
+	va_start(args, fmt);
+	len = vscnprintf(buf, PAGE_SIZE, fmt, args);
+	va_end(args);
+
+	return len;
+}
+EXPORT_SYMBOL_GPL(sysfs_emit);
+
+/**
+ *	sysfs_emit_at - scnprintf equivalent, aware of PAGE_SIZE buffer.
+ *	@buf:	start of PAGE_SIZE buffer.
+ *	@at:	offset in @buf to start write in bytes
+ *		@at must be >= 0 && < PAGE_SIZE
+ *	@fmt:	format
+ *	@...:	optional arguments to @fmt
+ *
+ *
+ * Returns number of characters written starting at &@buf[@at].
+ */
+int sysfs_emit_at(char *buf, int at, const char *fmt, ...)
+{
+	va_list args;
+	int len;
+
+	if (WARN(!buf || offset_in_page(buf) || at < 0 || at >= PAGE_SIZE,
+		 "invalid sysfs_emit_at: buf:%p at:%d\n", buf, at))
+		return 0;
+
+	va_start(args, fmt);
+	len = vscnprintf(buf + at, PAGE_SIZE - at, fmt, args);
+	va_end(args);
+
+	return len;
+}
+EXPORT_SYMBOL_GPL(sysfs_emit_at);
diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c
index c4ab045926b7..eeb0e3099421 100644
--- a/fs/sysfs/group.c
+++ b/fs/sysfs/group.c
@@ -13,6 +13,7 @@
 #include <linux/dcache.h>
 #include <linux/namei.h>
 #include <linux/err.h>
+#include <linux/fs.h>
 #include "sysfs.h"
 
 
@@ -60,8 +61,8 @@ static int create_files(struct kernfs_node *parent, struct kobject *kobj,
 			     (*attr)->name, mode);
 
 			mode &= SYSFS_PREALLOC | 0664;
-			error = sysfs_add_file_mode_ns(parent, *attr, false,
-						       mode, uid, gid, NULL);
+			error = sysfs_add_file_mode_ns(parent, *attr, mode, uid,
+						       gid, NULL);
 			if (unlikely(error))
 				break;
 		}
@@ -89,10 +90,9 @@ static int create_files(struct kernfs_node *parent, struct kobject *kobj,
 			     (*bin_attr)->attr.name, mode);
 
 			mode &= SYSFS_PREALLOC | 0664;
-			error = sysfs_add_file_mode_ns(parent,
-					&(*bin_attr)->attr, true,
-					mode,
-					uid, gid, NULL);
+			error = sysfs_add_bin_file_mode_ns(parent, *bin_attr,
+							   mode, uid, gid,
+							   NULL);
 			if (error)
 				break;
 		}
@@ -339,8 +339,8 @@ int sysfs_merge_group(struct kobject *kobj,
 	kobject_get_ownership(kobj, &uid, &gid);
 
 	for ((i = 0, attr = grp->attrs); *attr && !error; (++i, ++attr))
-		error = sysfs_add_file_mode_ns(parent, *attr, false,
-					       (*attr)->mode, uid, gid, NULL);
+		error = sysfs_add_file_mode_ns(parent, *attr, (*attr)->mode,
+					       uid, gid, NULL);
 	if (error) {
 		while (--i >= 0)
 			kernfs_remove_by_name(parent, (*--attr)->name);
@@ -415,15 +415,18 @@ void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name,
 EXPORT_SYMBOL_GPL(sysfs_remove_link_from_group);
 
 /**
- * __compat_only_sysfs_link_entry_to_kobj - add a symlink to a kobject pointing
+ * compat_only_sysfs_link_entry_to_kobj - add a symlink to a kobject pointing
  * to a group or an attribute
  * @kobj:		The kobject containing the group.
  * @target_kobj:	The target kobject.
  * @target_name:	The name of the target group or attribute.
+ * @symlink_name:	The name of the symlink file (target_name will be
+ *			considered if symlink_name is NULL).
  */
-int __compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj,
-				      struct kobject *target_kobj,
-				      const char *target_name)
+int compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj,
+					 struct kobject *target_kobj,
+					 const char *target_name,
+					 const char *symlink_name)
 {
 	struct kernfs_node *target;
 	struct kernfs_node *entry;
@@ -442,18 +445,135 @@ int __compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj,
 	if (!target)
 		return -ENOENT;
 
-	entry = kernfs_find_and_get(target_kobj->sd, target_name);
+	entry = kernfs_find_and_get(target, target_name);
 	if (!entry) {
 		kernfs_put(target);
 		return -ENOENT;
 	}
 
-	link = kernfs_create_link(kobj->sd, target_name, entry);
+	if (!symlink_name)
+		symlink_name = target_name;
+
+	link = kernfs_create_link(kobj->sd, symlink_name, entry);
 	if (PTR_ERR(link) == -EEXIST)
-		sysfs_warn_dup(kobj->sd, target_name);
+		sysfs_warn_dup(kobj->sd, symlink_name);
 
 	kernfs_put(entry);
 	kernfs_put(target);
 	return PTR_ERR_OR_ZERO(link);
 }
-EXPORT_SYMBOL_GPL(__compat_only_sysfs_link_entry_to_kobj);
+EXPORT_SYMBOL_GPL(compat_only_sysfs_link_entry_to_kobj);
+
+static int sysfs_group_attrs_change_owner(struct kernfs_node *grp_kn,
+					  const struct attribute_group *grp,
+					  struct iattr *newattrs)
+{
+	struct kernfs_node *kn;
+	int error;
+
+	if (grp->attrs) {
+		struct attribute *const *attr;
+
+		for (attr = grp->attrs; *attr; attr++) {
+			kn = kernfs_find_and_get(grp_kn, (*attr)->name);
+			if (!kn)
+				return -ENOENT;
+
+			error = kernfs_setattr(kn, newattrs);
+			kernfs_put(kn);
+			if (error)
+				return error;
+		}
+	}
+
+	if (grp->bin_attrs) {
+		struct bin_attribute *const *bin_attr;
+
+		for (bin_attr = grp->bin_attrs; *bin_attr; bin_attr++) {
+			kn = kernfs_find_and_get(grp_kn, (*bin_attr)->attr.name);
+			if (!kn)
+				return -ENOENT;
+
+			error = kernfs_setattr(kn, newattrs);
+			kernfs_put(kn);
+			if (error)
+				return error;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * sysfs_group_change_owner - change owner of an attribute group.
+ * @kobj:	The kobject containing the group.
+ * @grp:	The attribute group.
+ * @kuid:	new owner's kuid
+ * @kgid:	new owner's kgid
+ *
+ * Returns 0 on success or error code on failure.
+ */
+int sysfs_group_change_owner(struct kobject *kobj,
+			     const struct attribute_group *grp, kuid_t kuid,
+			     kgid_t kgid)
+{
+	struct kernfs_node *grp_kn;
+	int error;
+	struct iattr newattrs = {
+		.ia_valid = ATTR_UID | ATTR_GID,
+		.ia_uid = kuid,
+		.ia_gid = kgid,
+	};
+
+	if (!kobj->state_in_sysfs)
+		return -EINVAL;
+
+	if (grp->name) {
+		grp_kn = kernfs_find_and_get(kobj->sd, grp->name);
+	} else {
+		kernfs_get(kobj->sd);
+		grp_kn = kobj->sd;
+	}
+	if (!grp_kn)
+		return -ENOENT;
+
+	error = kernfs_setattr(grp_kn, &newattrs);
+	if (!error)
+		error = sysfs_group_attrs_change_owner(grp_kn, grp, &newattrs);
+
+	kernfs_put(grp_kn);
+
+	return error;
+}
+EXPORT_SYMBOL_GPL(sysfs_group_change_owner);
+
+/**
+ * sysfs_groups_change_owner - change owner of a set of attribute groups.
+ * @kobj:	The kobject containing the groups.
+ * @groups:	The attribute groups.
+ * @kuid:	new owner's kuid
+ * @kgid:	new owner's kgid
+ *
+ * Returns 0 on success or error code on failure.
+ */
+int sysfs_groups_change_owner(struct kobject *kobj,
+			      const struct attribute_group **groups,
+			      kuid_t kuid, kgid_t kgid)
+{
+	int error = 0, i;
+
+	if (!kobj->state_in_sysfs)
+		return -EINVAL;
+
+	if (!groups)
+		return 0;
+
+	for (i = 0; groups[i]; i++) {
+		error = sysfs_group_change_owner(kobj, groups[i], kuid, kgid);
+		if (error)
+			break;
+	}
+
+	return error;
+}
+EXPORT_SYMBOL_GPL(sysfs_groups_change_owner);
diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c
index db81cfbab9d6..98467bb76737 100644
--- a/fs/sysfs/mount.c
+++ b/fs/sysfs/mount.c
@@ -6,7 +6,7 @@
  * Copyright (c) 2007 SUSE Linux Products GmbH
  * Copyright (c) 2007 Tejun Heo <teheo@suse.de>
  *
- * Please see Documentation/filesystems/sysfs.txt for more information.
+ * Please see Documentation/filesystems/sysfs.rst for more information.
  */
 
 #include <linux/fs.h>
@@ -103,7 +103,7 @@ int __init sysfs_init(void)
 	if (IS_ERR(sysfs_root))
 		return PTR_ERR(sysfs_root);
 
-	sysfs_root_kn = sysfs_root->kn;
+	sysfs_root_kn = kernfs_root_to_node(sysfs_root);
 
 	err = register_filesystem(&sysfs_fs_type);
 	if (err) {
diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c
index c4deecc80f67..5603530a1a52 100644
--- a/fs/sysfs/symlink.c
+++ b/fs/sysfs/symlink.c
@@ -6,7 +6,7 @@
  * Copyright (c) 2007 SUSE Linux Products GmbH
  * Copyright (c) 2007 Tejun Heo <teheo@suse.de>
  *
- * Please see Documentation/filesystems/sysfs.txt for more information.
+ * Please see Documentation/filesystems/sysfs.rst for more information.
  */
 
 #include <linux/fs.h>
diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
index 0050cc0c0236..3f28c9af5756 100644
--- a/fs/sysfs/sysfs.h
+++ b/fs/sysfs/sysfs.h
@@ -28,9 +28,11 @@ void sysfs_warn_dup(struct kernfs_node *parent, const char *name);
  * file.c
  */
 int sysfs_add_file_mode_ns(struct kernfs_node *parent,
-			   const struct attribute *attr, bool is_bin,
-			   umode_t amode, kuid_t uid, kgid_t gid,
-			   const void *ns);
+		const struct attribute *attr, umode_t amode, kuid_t uid,
+		kgid_t gid, const void *ns);
+int sysfs_add_bin_file_mode_ns(struct kernfs_node *parent,
+		const struct bin_attribute *battr, umode_t mode,
+		kuid_t uid, kgid_t gid, const void *ns);
 
 /*
  * symlink.c