1 files changed, 347 insertions, 450 deletions

diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index cf3786625bf..e9ef59b3abb 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -1,559 +1,456 @@
 /*
- * file.c - operations for regular (text) files.
+ * fs/sysfs/file.c - sysfs regular (text) file implementation
+ *
+ * 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.
+ *
+ * Please see Documentation/filesystems/sysfs.txt for more information.
  */
 
 #include <linux/module.h>
-#include <linux/fsnotify.h>
 #include <linux/kobject.h>
-#include <linux/namei.h>
-#include <linux/poll.h>
-#include <asm/uaccess.h>
-#include <asm/semaphore.h>
+#include <linux/kallsyms.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/seq_file.h>
 
 #include "sysfs.h"
-
-#define to_subsys(k) container_of(k,struct subsystem,kset.kobj)
-#define to_sattr(a) container_of(a,struct subsys_attribute,attr)
+#include "../kernfs/kernfs-internal.h"
 
 /*
- * Subsystem file operations.
- * These operations allow subsystems to have files that can be 
- * read/written. 
+ * Determine ktype->sysfs_ops for the given kernfs_node.  This function
+ * must be called while holding an active reference.
  */
-static ssize_t 
-subsys_attr_show(struct kobject * kobj, struct attribute * attr, char * page)
+static const struct sysfs_ops *sysfs_file_ops(struct kernfs_node *kn)
 {
-	struct subsystem * s = to_subsys(kobj);
-	struct subsys_attribute * sattr = to_sattr(attr);
-	ssize_t ret = -EIO;
+	struct kobject *kobj = kn->parent->priv;
 
-	if (sattr->show)
-		ret = sattr->show(s,page);
-	return ret;
+	if (kn->flags & KERNFS_LOCKDEP)
+		lockdep_assert_held(kn);
+	return kobj->ktype ? kobj->ktype->sysfs_ops : NULL;
 }
 
-static ssize_t 
-subsys_attr_store(struct kobject * kobj, struct attribute * attr, 
-		  const char * page, size_t count)
+/*
+ * Reads on sysfs are handled through seq_file, which takes care of hairy
+ * details like buffering and seeking.  The following function pipes
+ * sysfs_ops->show() result through seq_file.
+ */
+static int sysfs_kf_seq_show(struct seq_file *sf, void *v)
 {
-	struct subsystem * s = to_subsys(kobj);
-	struct subsys_attribute * sattr = to_sattr(attr);
-	ssize_t ret = -EIO;
+	struct kernfs_open_file *of = sf->private;
+	struct kobject *kobj = of->kn->parent->priv;
+	const struct sysfs_ops *ops = sysfs_file_ops(of->kn);
+	ssize_t count;
+	char *buf;
 
-	if (sattr->store)
-		ret = sattr->store(s,page,count);
-	return ret;
-}
+	/* acquire buffer and ensure that it's >= PAGE_SIZE and clear */
+	count = seq_get_buf(sf, &buf);
+	if (count < PAGE_SIZE) {
+		seq_commit(sf, -1);
+		return 0;
+	}
+	memset(buf, 0, PAGE_SIZE);
 
-static struct sysfs_ops subsys_sysfs_ops = {
-	.show	= subsys_attr_show,
-	.store	= subsys_attr_store,
-};
+	/*
+	 * 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;
+	}
 
+	/*
+	 * The code works fine with PAGE_SIZE return but it's likely to
+	 * indicate truncated result or overflow in normal use cases.
+	 */
+	if (count >= (ssize_t)PAGE_SIZE) {
+		print_symbol("fill_read_buffer: %s returned bad count\n",
+			(unsigned long)ops->show);
+		/* Try to struggle along */
+		count = PAGE_SIZE - 1;
+	}
+	seq_commit(sf, count);
+	return 0;
+}
 
-struct sysfs_buffer {
-	size_t			count;
-	loff_t			pos;
-	char			* page;
-	struct sysfs_ops	* ops;
-	struct semaphore	sem;
-	int			needs_read_fill;
-	int			event;
-};
+static ssize_t sysfs_kf_bin_read(struct kernfs_open_file *of, char *buf,
+				 size_t count, loff_t pos)
+{
+	struct bin_attribute *battr = of->kn->priv;
+	struct kobject *kobj = of->kn->parent->priv;
+	loff_t size = file_inode(of->file)->i_size;
 
+	if (!count)
+		return 0;
 
-/**
- *	fill_read_buffer - allocate and fill buffer from object.
- *	@dentry:	dentry pointer.
- *	@buffer:	data buffer for file.
- *
- *	Allocate @buffer->page, if it hasn't been already, then call the
- *	kobject's show() method to fill the buffer with this attribute's 
- *	data. 
- *	This is called only once, on the file's first read. 
- */
-static int fill_read_buffer(struct dentry * dentry, struct sysfs_buffer * buffer)
-{
-	struct sysfs_dirent * sd = dentry->d_fsdata;
-	struct attribute * attr = to_attr(dentry);
-	struct kobject * kobj = to_kobj(dentry->d_parent);
-	struct sysfs_ops * ops = buffer->ops;
-	int ret = 0;
-	ssize_t count;
+	if (size) {
+		if (pos > size)
+			return 0;
+		if (pos + count > size)
+			count = size - pos;
+	}
 
-	if (!buffer->page)
-		buffer->page = (char *) get_zeroed_page(GFP_KERNEL);
-	if (!buffer->page)
-		return -ENOMEM;
-
-	buffer->event = atomic_read(&sd->s_event);
-	count = ops->show(kobj,attr,buffer->page);
-	buffer->needs_read_fill = 0;
-	BUG_ON(count > (ssize_t)PAGE_SIZE);
-	if (count >= 0)
-		buffer->count = count;
-	else
-		ret = count;
-	return ret;
-}
+	if (!battr->read)
+		return -EIO;
 
+	return battr->read(of->file, kobj, battr, buf, pos, count);
+}
 
-/**
- *	flush_read_buffer - push buffer to userspace.
- *	@buffer:	data buffer for file.
- *	@buf:		user-passed buffer.
- *	@count:		number of bytes requested.
- *	@ppos:		file position.
- *
- *	Copy the buffer we filled in fill_read_buffer() to userspace.
- *	This is done at the reader's leisure, copying and advancing 
- *	the amount they specify each time.
- *	This may be called continuously until the buffer is empty.
- */
-static int flush_read_buffer(struct sysfs_buffer * buffer, char __user * buf,
-			     size_t count, loff_t * ppos)
+/* kernfs write callback for regular sysfs files */
+static ssize_t sysfs_kf_write(struct kernfs_open_file *of, char *buf,
+			      size_t count, loff_t pos)
 {
-	int error;
+	const struct sysfs_ops *ops = sysfs_file_ops(of->kn);
+	struct kobject *kobj = of->kn->parent->priv;
 
-	if (*ppos > buffer->count)
+	if (!count)
 		return 0;
 
-	if (count > (buffer->count - *ppos))
-		count = buffer->count - *ppos;
-
-	error = copy_to_user(buf,buffer->page + *ppos,count);
-	if (!error)
-		*ppos += count;
-	return error ? -EFAULT : count;
+	return ops->store(kobj, of->kn->priv, buf, count);
 }
 
-/**
- *	sysfs_read_file - read an attribute. 
- *	@file:	file pointer.
- *	@buf:	buffer to fill.
- *	@count:	number of bytes to read.
- *	@ppos:	starting offset in file.
- *
- *	Userspace wants to read an attribute file. The attribute descriptor
- *	is in the file's ->d_fsdata. The target object is in the directory's
- *	->d_fsdata.
- *
- *	We call fill_read_buffer() to allocate and fill the buffer from the
- *	object's show() method exactly once (if the read is happening from
- *	the beginning of the file). That should fill the entire buffer with
- *	all the data the object has to offer for that attribute.
- *	We then call flush_read_buffer() to copy the buffer to userspace
- *	in the increments specified.
- */
-
-static ssize_t
-sysfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos)
+/* kernfs write callback for bin sysfs files */
+static ssize_t sysfs_kf_bin_write(struct kernfs_open_file *of, char *buf,
+				  size_t count, loff_t pos)
 {
-	struct sysfs_buffer * buffer = file->private_data;
-	ssize_t retval = 0;
-
-	down(&buffer->sem);
-	if (buffer->needs_read_fill) {
-		if ((retval = fill_read_buffer(file->f_dentry,buffer)))
-			goto out;
+	struct bin_attribute *battr = of->kn->priv;
+	struct kobject *kobj = of->kn->parent->priv;
+	loff_t size = file_inode(of->file)->i_size;
+
+	if (size) {
+		if (size <= pos)
+			return 0;
+		count = min_t(ssize_t, count, size - pos);
 	}
-	pr_debug("%s: count = %d, ppos = %lld, buf = %s\n",
-		 __FUNCTION__,count,*ppos,buffer->page);
-	retval = flush_read_buffer(buffer,buf,count,ppos);
-out:
-	up(&buffer->sem);
-	return retval;
-}
+	if (!count)
+		return 0;
 
+	if (!battr->write)
+		return -EIO;
 
-/**
- *	fill_write_buffer - copy buffer from userspace.
- *	@buffer:	data buffer for file.
- *	@buf:		data from user.
- *	@count:		number of bytes in @userbuf.
- *
- *	Allocate @buffer->page if it hasn't been already, then
- *	copy the user-supplied buffer into it.
- */
+	return battr->write(of->file, kobj, battr, buf, pos, count);
+}
 
-static int 
-fill_write_buffer(struct sysfs_buffer * buffer, const char __user * buf, size_t count)
+static int sysfs_kf_bin_mmap(struct kernfs_open_file *of,
+			     struct vm_area_struct *vma)
 {
-	int error;
-
-	if (!buffer->page)
-		buffer->page = (char *)get_zeroed_page(GFP_KERNEL);
-	if (!buffer->page)
-		return -ENOMEM;
+	struct bin_attribute *battr = of->kn->priv;
+	struct kobject *kobj = of->kn->parent->priv;
 
-	if (count >= PAGE_SIZE)
-		count = PAGE_SIZE - 1;
-	error = copy_from_user(buffer->page,buf,count);
-	buffer->needs_read_fill = 1;
-	return error ? -EFAULT : count;
+	return battr->mmap(of->file, kobj, battr, vma);
 }
 
+void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr)
+{
+	struct kernfs_node *kn = kobj->sd, *tmp;
 
-/**
- *	flush_write_buffer - push buffer to kobject.
- *	@dentry:	dentry to the attribute
- *	@buffer:	data buffer for file.
- *	@count:		number of bytes
- *
- *	Get the correct pointers for the kobject and the attribute we're
- *	dealing with, then call the store() method for the attribute, 
- *	passing the buffer that we acquired in fill_write_buffer().
- */
+	if (kn && dir)
+		kn = kernfs_find_and_get(kn, dir);
+	else
+		kernfs_get(kn);
 
-static int 
-flush_write_buffer(struct dentry * dentry, struct sysfs_buffer * buffer, size_t count)
-{
-	struct attribute * attr = to_attr(dentry);
-	struct kobject * kobj = to_kobj(dentry->d_parent);
-	struct sysfs_ops * ops = buffer->ops;
+	if (kn && attr) {
+		tmp = kernfs_find_and_get(kn, attr);
+		kernfs_put(kn);
+		kn = tmp;
+	}
 
-	return ops->store(kobj,attr,buffer->page,count);
+	if (kn) {
+		kernfs_notify(kn);
+		kernfs_put(kn);
+	}
 }
+EXPORT_SYMBOL_GPL(sysfs_notify);
 
+static const struct kernfs_ops sysfs_file_kfops_empty = {
+};
 
-/**
- *	sysfs_write_file - write an attribute.
- *	@file:	file pointer
- *	@buf:	data to write
- *	@count:	number of bytes
- *	@ppos:	starting offset
- *
- *	Similar to sysfs_read_file(), though working in the opposite direction.
- *	We allocate and fill the data from the user in fill_write_buffer(),
- *	then push it to the kobject in flush_write_buffer().
- *	There is no easy way for us to know if userspace is only doing a partial
- *	write, so we don't support them. We expect the entire buffer to come
- *	on the first write. 
- *	Hint: if you're writing a value, first read the file, modify only the
- *	the value you're changing, then write entire buffer back. 
- */
+static const struct kernfs_ops sysfs_file_kfops_ro = {
+	.seq_show	= sysfs_kf_seq_show,
+};
 
-static ssize_t
-sysfs_write_file(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
-{
-	struct sysfs_buffer * buffer = file->private_data;
-	ssize_t len;
-
-	down(&buffer->sem);
-	len = fill_write_buffer(buffer, buf, count);
-	if (len > 0)
-		len = flush_write_buffer(file->f_dentry, buffer, len);
-	if (len > 0)
-		*ppos += len;
-	up(&buffer->sem);
-	return len;
-}
+static const struct kernfs_ops sysfs_file_kfops_wo = {
+	.write		= sysfs_kf_write,
+};
 
-static int check_perm(struct inode * inode, struct file * file)
-{
-	struct kobject *kobj = sysfs_get_kobject(file->f_dentry->d_parent);
-	struct attribute * attr = to_attr(file->f_dentry);
-	struct sysfs_buffer * buffer;
-	struct sysfs_ops * ops = NULL;
-	int error = 0;
-
-	if (!kobj || !attr)
-		goto Einval;
-
-	/* Grab the module reference for this attribute if we have one */
-	if (!try_module_get(attr->owner)) {
-		error = -ENODEV;
-		goto Done;
-	}
+static const struct kernfs_ops sysfs_file_kfops_rw = {
+	.seq_show	= sysfs_kf_seq_show,
+	.write		= sysfs_kf_write,
+};
 
-	/* if the kobject has no ktype, then we assume that it is a subsystem
-	 * itself, and use ops for it.
-	 */
-	if (kobj->kset && kobj->kset->ktype)
-		ops = kobj->kset->ktype->sysfs_ops;
-	else if (kobj->ktype)
-		ops = kobj->ktype->sysfs_ops;
-	else
-		ops = &subsys_sysfs_ops;
+static const struct kernfs_ops sysfs_bin_kfops_ro = {
+	.read		= sysfs_kf_bin_read,
+};
 
-	/* No sysfs operations, either from having no subsystem,
-	 * or the subsystem have no operations.
-	 */
-	if (!ops)
-		goto Eaccess;
+static const struct kernfs_ops sysfs_bin_kfops_wo = {
+	.write		= sysfs_kf_bin_write,
+};
 
-	/* File needs write support.
-	 * The inode's perms must say it's ok, 
-	 * and we must have a store method.
-	 */
-	if (file->f_mode & FMODE_WRITE) {
+static const struct kernfs_ops sysfs_bin_kfops_rw = {
+	.read		= sysfs_kf_bin_read,
+	.write		= sysfs_kf_bin_write,
+};
 
-		if (!(inode->i_mode & S_IWUGO) || !ops->store)
-			goto Eaccess;
+static const struct kernfs_ops sysfs_bin_kfops_mmap = {
+	.read		= sysfs_kf_bin_read,
+	.write		= sysfs_kf_bin_write,
+	.mmap		= sysfs_kf_bin_mmap,
+};
 
+int sysfs_add_file_mode_ns(struct kernfs_node *parent,
+			   const struct attribute *attr, bool is_bin,
+			   umode_t mode, const void *ns)
+{
+	struct lock_class_key *key = NULL;
+	const struct kernfs_ops *ops;
+	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)
+			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;
+		else
+			ops = &sysfs_file_kfops_empty;
+
+		size = PAGE_SIZE;
+	} 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;
 	}
 
-	/* File needs read support.
-	 * The inode's perms must say it's ok, and we there
-	 * must be a show method for it.
-	 */
-	if (file->f_mode & FMODE_READ) {
-		if (!(inode->i_mode & S_IRUGO) || !ops->show)
-			goto Eaccess;
+#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, size, ops,
+				  (void *)attr, ns, true, key);
+	if (IS_ERR(kn)) {
+		if (PTR_ERR(kn) == -EEXIST)
+			sysfs_warn_dup(parent, attr->name);
+		return PTR_ERR(kn);
 	}
+	return 0;
+}
 
-	/* No error? Great, allocate a buffer for the file, and store it
-	 * it in file->private_data for easy access.
-	 */
-	buffer = kzalloc(sizeof(struct sysfs_buffer), GFP_KERNEL);
-	if (buffer) {
-		init_MUTEX(&buffer->sem);
-		buffer->needs_read_fill = 1;
-		buffer->ops = ops;
-		file->private_data = buffer;
-	} else
-		error = -ENOMEM;
-	goto Done;
-
- Einval:
-	error = -EINVAL;
-	goto Done;
- Eaccess:
-	error = -EACCES;
-	module_put(attr->owner);
- Done:
-	if (error && kobj)
-		kobject_put(kobj);
-	return error;
+int sysfs_add_file(struct kernfs_node *parent, const struct attribute *attr,
+		   bool is_bin)
+{
+	return sysfs_add_file_mode_ns(parent, attr, is_bin, attr->mode, NULL);
 }
 
-static int sysfs_open_file(struct inode * inode, struct file * filp)
+/**
+ * sysfs_create_file_ns - create an attribute file for an object with custom ns
+ * @kobj: object we're creating for
+ * @attr: attribute descriptor
+ * @ns: namespace the new file should belong to
+ */
+int sysfs_create_file_ns(struct kobject *kobj, const struct attribute *attr,
+			 const void *ns)
 {
-	return check_perm(inode,filp);
+	BUG_ON(!kobj || !kobj->sd || !attr);
+
+	return sysfs_add_file_mode_ns(kobj->sd, attr, false, attr->mode, ns);
+
 }
+EXPORT_SYMBOL_GPL(sysfs_create_file_ns);
 
-static int sysfs_release(struct inode * inode, struct file * filp)
+int sysfs_create_files(struct kobject *kobj, const struct attribute **ptr)
 {
-	struct kobject * kobj = to_kobj(filp->f_dentry->d_parent);
-	struct attribute * attr = to_attr(filp->f_dentry);
-	struct module * owner = attr->owner;
-	struct sysfs_buffer * buffer = filp->private_data;
-
-	if (kobj) 
-		kobject_put(kobj);
-	/* After this point, attr should not be accessed. */
-	module_put(owner);
-
-	if (buffer) {
-		if (buffer->page)
-			free_page((unsigned long)buffer->page);
-		kfree(buffer);
-	}
-	return 0;
+	int err = 0;
+	int i;
+
+	for (i = 0; ptr[i] && !err; i++)
+		err = sysfs_create_file(kobj, ptr[i]);
+	if (err)
+		while (--i >= 0)
+			sysfs_remove_file(kobj, ptr[i]);
+	return err;
 }
+EXPORT_SYMBOL_GPL(sysfs_create_files);
 
-/* Sysfs attribute files are pollable.  The idea is that you read
- * the content and then you use 'poll' or 'select' to wait for
- * the content to change.  When the content changes (assuming the
- * manager for the kobject supports notification), poll will
- * return POLLERR|POLLPRI, and select will return the fd whether
- * it is waiting for read, write, or exceptions.
- * Once poll/select indicates that the value has changed, you
- * need to close and re-open the file, as simply seeking and reading
- * again will not get new data, or reset the state of 'poll'.
- * Reminder: this only works for attributes which actively support
- * it, and it is not possible to test an attribute from userspace
- * to see if it supports poll (Nether 'poll' or 'select' return
- * an appropriate error code).  When in doubt, set a suitable timeout value.
+/**
+ * sysfs_add_file_to_group - add an attribute file to a pre-existing group.
+ * @kobj: object we're acting for.
+ * @attr: attribute descriptor.
+ * @group: group name.
  */
-static unsigned int sysfs_poll(struct file *filp, poll_table *wait)
+int sysfs_add_file_to_group(struct kobject *kobj,
+		const struct attribute *attr, const char *group)
 {
-	struct sysfs_buffer * buffer = filp->private_data;
-	struct kobject * kobj = to_kobj(filp->f_dentry->d_parent);
-	struct sysfs_dirent * sd = filp->f_dentry->d_fsdata;
-	int res = 0;
-
-	poll_wait(filp, &kobj->poll, wait);
+	struct kernfs_node *parent;
+	int error;
 
-	if (buffer->event != atomic_read(&sd->s_event)) {
-		res = POLLERR|POLLPRI;
-		buffer->needs_read_fill = 1;
+	if (group) {
+		parent = kernfs_find_and_get(kobj->sd, group);
+	} else {
+		parent = kobj->sd;
+		kernfs_get(parent);
 	}
 
-	return res;
-}
+	if (!parent)
+		return -ENOENT;
 
+	error = sysfs_add_file(parent, attr, false);
+	kernfs_put(parent);
 
-static struct dentry *step_down(struct dentry *dir, const char * name)
-{
-	struct dentry * de;
-
-	if (dir == NULL || dir->d_inode == NULL)
-		return NULL;
-
-	mutex_lock(&dir->d_inode->i_mutex);
-	de = lookup_one_len(name, dir, strlen(name));
-	mutex_unlock(&dir->d_inode->i_mutex);
-	dput(dir);
-	if (IS_ERR(de))
-		return NULL;
-	if (de->d_inode == NULL) {
-		dput(de);
-		return NULL;
-	}
-	return de;
+	return error;
 }
+EXPORT_SYMBOL_GPL(sysfs_add_file_to_group);
 
-void sysfs_notify(struct kobject * k, char *dir, char *attr)
+/**
+ * sysfs_chmod_file - update the modified mode value on an object attribute.
+ * @kobj: object we're acting for.
+ * @attr: attribute descriptor.
+ * @mode: file permissions.
+ *
+ */
+int sysfs_chmod_file(struct kobject *kobj, const struct attribute *attr,
+		     umode_t mode)
 {
-	struct dentry *de = k->dentry;
-	if (de)
-		dget(de);
-	if (de && dir)
-		de = step_down(de, dir);
-	if (de && attr)
-		de = step_down(de, attr);
-	if (de) {
-		struct sysfs_dirent * sd = de->d_fsdata;
-		if (sd)
-			atomic_inc(&sd->s_event);
-		wake_up_interruptible(&k->poll);
-		dput(de);
-	}
-}
-EXPORT_SYMBOL_GPL(sysfs_notify);
-
-const struct file_operations sysfs_file_operations = {
-	.read		= sysfs_read_file,
-	.write		= sysfs_write_file,
-	.llseek		= generic_file_llseek,
-	.open		= sysfs_open_file,
-	.release	= sysfs_release,
-	.poll		= sysfs_poll,
-};
+	struct kernfs_node *kn;
+	struct iattr newattrs;
+	int rc;
 
+	kn = kernfs_find_and_get(kobj->sd, attr->name);
+	if (!kn)
+		return -ENOENT;
 
-int sysfs_add_file(struct dentry * dir, const struct attribute * attr, int type)
-{
-	struct sysfs_dirent * parent_sd = dir->d_fsdata;
-	umode_t mode = (attr->mode & S_IALLUGO) | S_IFREG;
-	int error = -EEXIST;
+	newattrs.ia_mode = (mode & S_IALLUGO) | (kn->mode & ~S_IALLUGO);
+	newattrs.ia_valid = ATTR_MODE;
 
-	mutex_lock(&dir->d_inode->i_mutex);
-	if (!sysfs_dirent_exist(parent_sd, attr->name))
-		error = sysfs_make_dirent(parent_sd, NULL, (void *)attr,
-					  mode, type);
-	mutex_unlock(&dir->d_inode->i_mutex);
+	rc = kernfs_setattr(kn, &newattrs);
 
-	return error;
+	kernfs_put(kn);
+	return rc;
 }
-
+EXPORT_SYMBOL_GPL(sysfs_chmod_file);
 
 /**
- *	sysfs_create_file - create an attribute file for an object.
- *	@kobj:	object we're creating for. 
- *	@attr:	atrribute descriptor.
+ * sysfs_remove_file_ns - remove an object attribute with a custom ns tag
+ * @kobj: object we're acting for
+ * @attr: attribute descriptor
+ * @ns: namespace tag of the file to remove
+ *
+ * Hash the attribute name and namespace tag and kill the victim.
  */
+void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr,
+			  const void *ns)
+{
+	struct kernfs_node *parent = kobj->sd;
+
+	kernfs_remove_by_name_ns(parent, attr->name, ns);
+}
+EXPORT_SYMBOL_GPL(sysfs_remove_file_ns);
 
-int sysfs_create_file(struct kobject * kobj, const struct attribute * attr)
+/**
+ * sysfs_remove_file_self - remove an object attribute from its own method
+ * @kobj: object we're acting for
+ * @attr: attribute descriptor
+ *
+ * See kernfs_remove_self() for details.
+ */
+bool sysfs_remove_file_self(struct kobject *kobj, const struct attribute *attr)
 {
-	BUG_ON(!kobj || !kobj->dentry || !attr);
+	struct kernfs_node *parent = kobj->sd;
+	struct kernfs_node *kn;
+	bool ret;
+
+	kn = kernfs_find_and_get(parent, attr->name);
+	if (WARN_ON_ONCE(!kn))
+		return false;
 
-	return sysfs_add_file(kobj->dentry, attr, SYSFS_KOBJ_ATTR);
+	ret = kernfs_remove_self(kn);
 
+	kernfs_put(kn);
+	return ret;
 }
 
+void sysfs_remove_files(struct kobject *kobj, const struct attribute **ptr)
+{
+	int i;
+	for (i = 0; ptr[i]; i++)
+		sysfs_remove_file(kobj, ptr[i]);
+}
+EXPORT_SYMBOL_GPL(sysfs_remove_files);
 
 /**
- * sysfs_update_file - update the modified timestamp on an object attribute.
+ * sysfs_remove_file_from_group - remove an attribute file from a group.
  * @kobj: object we're acting for.
  * @attr: attribute descriptor.
+ * @group: group name.
  */
-int sysfs_update_file(struct kobject * kobj, const struct attribute * attr)
+void sysfs_remove_file_from_group(struct kobject *kobj,
+		const struct attribute *attr, const char *group)
 {
-	struct dentry * dir = kobj->dentry;
-	struct dentry * victim;
-	int res = -ENOENT;
-
-	mutex_lock(&dir->d_inode->i_mutex);
-	victim = lookup_one_len(attr->name, dir, strlen(attr->name));
-	if (!IS_ERR(victim)) {
-		/* make sure dentry is really there */
-		if (victim->d_inode && 
-		    (victim->d_parent->d_inode == dir->d_inode)) {
-			victim->d_inode->i_mtime = CURRENT_TIME;
-			fsnotify_modify(victim);
-
-			/**
-			 * Drop reference from initial sysfs_get_dentry().
-			 */
-			dput(victim);
-			res = 0;
-		} else
-			d_drop(victim);
-		
-		/**
-		 * Drop the reference acquired from sysfs_get_dentry() above.
-		 */
-		dput(victim);
+	struct kernfs_node *parent;
+
+	if (group) {
+		parent = kernfs_find_and_get(kobj->sd, group);
+	} else {
+		parent = kobj->sd;
+		kernfs_get(parent);
 	}
-	mutex_unlock(&dir->d_inode->i_mutex);
 
-	return res;
+	if (parent) {
+		kernfs_remove_by_name(parent, attr->name);
+		kernfs_put(parent);
+	}
 }
-
+EXPORT_SYMBOL_GPL(sysfs_remove_file_from_group);
 
 /**
- * sysfs_chmod_file - update the modified mode value on an object attribute.
- * @kobj: object we're acting for.
- * @attr: attribute descriptor.
- * @mode: file permissions.
- *
+ *	sysfs_create_bin_file - create binary file for object.
+ *	@kobj:	object.
+ *	@attr:	attribute descriptor.
  */
-int sysfs_chmod_file(struct kobject *kobj, struct attribute *attr, mode_t mode)
+int sysfs_create_bin_file(struct kobject *kobj,
+			  const struct bin_attribute *attr)
 {
-	struct dentry *dir = kobj->dentry;
-	struct dentry *victim;
-	struct inode * inode;
-	struct iattr newattrs;
-	int res = -ENOENT;
-
-	mutex_lock(&dir->d_inode->i_mutex);
-	victim = lookup_one_len(attr->name, dir, strlen(attr->name));
-	if (!IS_ERR(victim)) {
-		if (victim->d_inode &&
-		    (victim->d_parent->d_inode == dir->d_inode)) {
-			inode = victim->d_inode;
-			mutex_lock(&inode->i_mutex);
-			newattrs.ia_mode = (mode & S_IALLUGO) |
-						(inode->i_mode & ~S_IALLUGO);
-			newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
-			res = notify_change(victim, &newattrs);
-			mutex_unlock(&inode->i_mutex);
-		}
-		dput(victim);
-	}
-	mutex_unlock(&dir->d_inode->i_mutex);
+	BUG_ON(!kobj || !kobj->sd || !attr);
 
-	return res;
+	return sysfs_add_file(kobj->sd, &attr->attr, true);
 }
-EXPORT_SYMBOL_GPL(sysfs_chmod_file);
-
+EXPORT_SYMBOL_GPL(sysfs_create_bin_file);
 
 /**
- *	sysfs_remove_file - remove an object attribute.
- *	@kobj:	object we're acting for.
+ *	sysfs_remove_bin_file - remove binary file for object.
+ *	@kobj:	object.
  *	@attr:	attribute descriptor.
- *
- *	Hash the attribute name and kill the victim.
  */
-
-void sysfs_remove_file(struct kobject * kobj, const struct attribute * attr)
+void sysfs_remove_bin_file(struct kobject *kobj,
+			   const struct bin_attribute *attr)
 {
-	sysfs_hash_and_remove(kobj->dentry,attr->name);
+	kernfs_remove_by_name(kobj->sd, attr->attr.name);
 }
-
-
-EXPORT_SYMBOL_GPL(sysfs_create_file);
-EXPORT_SYMBOL_GPL(sysfs_remove_file);
-EXPORT_SYMBOL_GPL(sysfs_update_file);
+EXPORT_SYMBOL_GPL(sysfs_remove_bin_file);