Merge tag 'driver-core-3.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core / sysfs patches from Greg KH:
 "Here's the big driver core and sysfs patch set for 3.14-rc1.

  There's a lot of work here moving sysfs logic out into a "kernfs" to
  allow other subsystems to also have a virtual filesystem with the same
  attributes of sysfs (handle device disconnect, dynamic creation /
  removal as needed / unneeded, etc)

  This is primarily being done for the cgroups filesystem, but the goal
  is to also move debugfs to it when it is ready, solving all of the
  known issues in that filesystem as well.  The code isn't completed
  yet, but all should be stable now (there is a big section that was
  reverted due to problems found when testing)

  There's also some other smaller fixes, and a driver core addition that
  allows for a "collection" of objects, that the DRM people will be
  using soon (it's in this tree to make merges after -rc1 easier)

  All of this has been in linux-next with no reported issues"

* tag 'driver-core-3.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (113 commits)
  kernfs: associate a new kernfs_node with its parent on creation
  kernfs: add struct dentry declaration in kernfs.h
  kernfs: fix get_active failure handling in kernfs_seq_*()
  Revert "kernfs: fix get_active failure handling in kernfs_seq_*()"
  Revert "kernfs: replace kernfs_node->u.completion with kernfs_root->deactivate_waitq"
  Revert "kernfs: remove KERNFS_ACTIVE_REF and add kernfs_lockdep()"
  Revert "kernfs: remove KERNFS_REMOVED"
  Revert "kernfs: restructure removal path to fix possible premature return"
  Revert "kernfs: invoke kernfs_unmap_bin_file() directly from __kernfs_remove()"
  Revert "kernfs: remove kernfs_addrm_cxt"
  Revert "kernfs: make kernfs_get_active() block if the node is deactivated but not removed"
  Revert "kernfs: implement kernfs_{de|re}activate[_self]()"
  Revert "kernfs, sysfs, driver-core: implement kernfs_remove_self() and its wrappers"
  Revert "pci: use device_remove_file_self() instead of device_schedule_callback()"
  Revert "scsi: use device_remove_file_self() instead of device_schedule_callback()"
  Revert "s390: use device_remove_file_self() instead of device_schedule_callback()"
  Revert "sysfs, driver-core: remove unused {sysfs|device}_schedule_callback_owner()"
  Revert "kernfs: remove unnecessary NULL check in __kernfs_remove()"
  kernfs: remove unnecessary NULL check in __kernfs_remove()
  drivers/base: provide an infrastructure for componentised subsystems
  ...

1 files changed, 182 insertions, 779 deletions

diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 35e7d08..810cf6e 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -14,70 +14,23 @@
 #include <linux/kobject.h>
 #include <linux/kallsyms.h>
 #include <linux/slab.h>
-#include <linux/fsnotify.h>
-#include <linux/namei.h>
-#include <linux/poll.h>
 #include <linux/list.h>
 #include <linux/mutex.h>
-#include <linux/limits.h>
-#include <linux/uaccess.h>
 #include <linux/seq_file.h>
-#include <linux/mm.h>
 
 #include "sysfs.h"
+#include "../kernfs/kernfs-internal.h"
 
 /*
- * There's one sysfs_open_file for each open file and one sysfs_open_dirent
- * for each sysfs_dirent with one or more open files.
- *
- * sysfs_dirent->s_attr.open points to sysfs_open_dirent.  s_attr.open is
- * protected by sysfs_open_dirent_lock.
- *
- * filp->private_data points to seq_file whose ->private points to
- * sysfs_open_file.  sysfs_open_files are chained at
- * sysfs_open_dirent->files, which is protected by sysfs_open_file_mutex.
- */
-static DEFINE_SPINLOCK(sysfs_open_dirent_lock);
-static DEFINE_MUTEX(sysfs_open_file_mutex);
-
-struct sysfs_open_dirent {
-	atomic_t		refcnt;
-	atomic_t		event;
-	wait_queue_head_t	poll;
-	struct list_head	files; /* goes through sysfs_open_file.list */
-};
-
-struct sysfs_open_file {
-	struct sysfs_dirent	*sd;
-	struct file		*file;
-	struct mutex		mutex;
-	int			event;
-	struct list_head	list;
-
-	bool			mmapped;
-	const struct vm_operations_struct *vm_ops;
-};
-
-static bool sysfs_is_bin(struct sysfs_dirent *sd)
-{
-	return sysfs_type(sd) == SYSFS_KOBJ_BIN_ATTR;
-}
-
-static struct sysfs_open_file *sysfs_of(struct file *file)
-{
-	return ((struct seq_file *)file->private_data)->private;
-}
-
-/*
- * Determine ktype->sysfs_ops for the given sysfs_dirent.  This function
+ * Determine ktype->sysfs_ops for the given kernfs_node.  This function
  * must be called while holding an active reference.
  */
-static const struct sysfs_ops *sysfs_file_ops(struct sysfs_dirent *sd)
+static const struct sysfs_ops *sysfs_file_ops(struct kernfs_node *kn)
 {
-	struct kobject *kobj = sd->s_parent->s_dir.kobj;
+	struct kobject *kobj = kn->parent->priv;
 
-	if (!sysfs_ignore_lockdep(sd))
-		lockdep_assert_held(sd);
+	if (kn->flags & KERNFS_LOCKDEP)
+		lockdep_assert_held(kn);
 	return kobj->ktype ? kobj->ktype->sysfs_ops : NULL;
 }
 
@@ -86,13 +39,13 @@ static const struct sysfs_ops *sysfs_file_ops(struct sysfs_dirent *sd)
  * details like buffering and seeking.  The following function pipes
  * sysfs_ops->show() result through seq_file.
  */
-static int sysfs_seq_show(struct seq_file *sf, void *v)
+static int sysfs_kf_seq_show(struct seq_file *sf, void *v)
 {
-	struct sysfs_open_file *of = sf->private;
-	struct kobject *kobj = of->sd->s_parent->s_dir.kobj;
-	const struct sysfs_ops *ops;
-	char *buf;
+	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;
 
 	/* acquire buffer and ensure that it's >= PAGE_SIZE */
 	count = seq_get_buf(sf, &buf);
@@ -102,34 +55,15 @@ static int sysfs_seq_show(struct seq_file *sf, void *v)
 	}
 
 	/*
-	 * Need @of->sd for attr and ops, its parent for kobj.  @of->mutex
-	 * nests outside active ref and is just to ensure that the ops
-	 * aren't called concurrently for the same open file.
+	 * Invoke show().  Control may reach here via seq file lseek even
+	 * if @ops->show() isn't implemented.
 	 */
-	mutex_lock(&of->mutex);
-	if (!sysfs_get_active(of->sd)) {
-		mutex_unlock(&of->mutex);
-		return -ENODEV;
+	if (ops->show) {
+		count = ops->show(kobj, of->kn->priv, buf);
+		if (count < 0)
+			return count;
 	}
 
-	of->event = atomic_read(&of->sd->s_attr.open->event);
-
-	/*
-	 * Lookup @ops and invoke show().  Control may reach here via seq
-	 * file lseek even if @ops->show() isn't implemented.
-	 */
-	ops = sysfs_file_ops(of->sd);
-	if (ops->show)
-		count = ops->show(kobj, of->sd->s_attr.attr, buf);
-	else
-		count = 0;
-
-	sysfs_put_active(of->sd);
-	mutex_unlock(&of->mutex);
-
-	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.
@@ -144,726 +78,194 @@ static int sysfs_seq_show(struct seq_file *sf, void *v)
 	return 0;
 }
 
-/*
- * Read method for bin files.  As reading a bin file can have side-effects,
- * the exact offset and bytes specified in read(2) call should be passed to
- * the read callback making it difficult to use seq_file.  Implement
- * simplistic custom buffering for bin files.
- */
-static ssize_t sysfs_bin_read(struct file *file, char __user *userbuf,
-			      size_t bytes, loff_t *off)
+static ssize_t sysfs_kf_bin_read(struct kernfs_open_file *of, char *buf,
+				 size_t count, loff_t pos)
 {
-	struct sysfs_open_file *of = sysfs_of(file);
-	struct bin_attribute *battr = of->sd->s_attr.bin_attr;
-	struct kobject *kobj = of->sd->s_parent->s_dir.kobj;
-	loff_t size = file_inode(file)->i_size;
-	int count = min_t(size_t, bytes, PAGE_SIZE);
-	loff_t offs = *off;
-	char *buf;
+	struct bin_attribute *battr = of->kn->priv;
+	struct kobject *kobj = of->kn->parent->priv;
+	loff_t size = file_inode(of->file)->i_size;
 
-	if (!bytes)
+	if (!count)
 		return 0;
 
 	if (size) {
-		if (offs > size)
+		if (pos > size)
 			return 0;
-		if (offs + count > size)
-			count = size - offs;
-	}
-
-	buf = kmalloc(count, GFP_KERNEL);
-	if (!buf)
-		return -ENOMEM;
-
-	/* need of->sd for battr, its parent for kobj */
-	mutex_lock(&of->mutex);
-	if (!sysfs_get_active(of->sd)) {
-		count = -ENODEV;
-		mutex_unlock(&of->mutex);
-		goto out_free;
-	}
-
-	if (battr->read)
-		count = battr->read(file, kobj, battr, buf, offs, count);
-	else
-		count = -EIO;
-
-	sysfs_put_active(of->sd);
-	mutex_unlock(&of->mutex);
-
-	if (count < 0)
-		goto out_free;
-
-	if (copy_to_user(userbuf, buf, count)) {
-		count = -EFAULT;
-		goto out_free;
+		if (pos + count > size)
+			count = size - pos;
 	}
 
-	pr_debug("offs = %lld, *off = %lld, count = %d\n", offs, *off, count);
-
-	*off = offs + count;
+	if (!battr->read)
+		return -EIO;
 
- out_free:
-	kfree(buf);
-	return count;
+	return battr->read(of->file, kobj, battr, buf, pos, count);
 }
 
-/**
- * flush_write_buffer - push buffer to kobject
- * @of: open file
- * @buf: data buffer for file
- * @off: file offset to write to
- * @count: number of bytes
- *
- * Get the correct pointers for the kobject and the attribute we're dealing
- * with, then call the store() method for it with @buf.
- */
-static int flush_write_buffer(struct sysfs_open_file *of, char *buf, loff_t off,
-			      size_t count)
+/* 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)
 {
-	struct kobject *kobj = of->sd->s_parent->s_dir.kobj;
-	int rc = 0;
-
-	/*
-	 * Need @of->sd for attr and ops, its parent for kobj.  @of->mutex
-	 * nests outside active ref and is just to ensure that the ops
-	 * aren't called concurrently for the same open file.
-	 */
-	mutex_lock(&of->mutex);
-	if (!sysfs_get_active(of->sd)) {
-		mutex_unlock(&of->mutex);
-		return -ENODEV;
-	}
+	const struct sysfs_ops *ops = sysfs_file_ops(of->kn);
+	struct kobject *kobj = of->kn->parent->priv;
 
-	if (sysfs_is_bin(of->sd)) {
-		struct bin_attribute *battr = of->sd->s_attr.bin_attr;
-
-		rc = -EIO;
-		if (battr->write)
-			rc = battr->write(of->file, kobj, battr, buf, off,
-					  count);
-	} else {
-		const struct sysfs_ops *ops = sysfs_file_ops(of->sd);
-
-		rc = ops->store(kobj, of->sd->s_attr.attr, buf, count);
-	}
-
-	sysfs_put_active(of->sd);
-	mutex_unlock(&of->mutex);
+	if (!count)
+		return 0;
 
-	return rc;
+	return ops->store(kobj, of->kn->priv, buf, count);
 }
 
-/**
- * sysfs_write_file - write an attribute
- * @file: file pointer
- * @user_buf: data to write
- * @count: number of bytes
- * @ppos: starting offset
- *
- * Copy data in from userland and pass it to the matching
- * sysfs_ops->store() by invoking 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 ssize_t sysfs_write_file(struct file *file, const char __user *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_open_file *of = sysfs_of(file);
-	ssize_t len = min_t(size_t, count, PAGE_SIZE);
-	loff_t size = file_inode(file)->i_size;
-	char *buf;
+	struct bin_attribute *battr = of->kn->priv;
+	struct kobject *kobj = of->kn->parent->priv;
+	loff_t size = file_inode(of->file)->i_size;
 
-	if (sysfs_is_bin(of->sd) && size) {
-		if (size <= *ppos)
+	if (size) {
+		if (size <= pos)
 			return 0;
-		len = min_t(ssize_t, len, size - *ppos);
+		count = min_t(ssize_t, count, size - pos);
 	}
-
-	if (!len)
+	if (!count)
 		return 0;
 
-	buf = kmalloc(len + 1, GFP_KERNEL);
-	if (!buf)
-		return -ENOMEM;
+	if (!battr->write)
+		return -EIO;
 
-	if (copy_from_user(buf, user_buf, len)) {
-		len = -EFAULT;
-		goto out_free;
-	}
-	buf[len] = '\0';	/* guarantee string termination */
-
-	len = flush_write_buffer(of, buf, *ppos, len);
-	if (len > 0)
-		*ppos += len;
-out_free:
-	kfree(buf);
-	return len;
-}
-
-static void sysfs_bin_vma_open(struct vm_area_struct *vma)
-{
-	struct file *file = vma->vm_file;
-	struct sysfs_open_file *of = sysfs_of(file);
-
-	if (!of->vm_ops)
-		return;
-
-	if (!sysfs_get_active(of->sd))
-		return;
-
-	if (of->vm_ops->open)
-		of->vm_ops->open(vma);
-
-	sysfs_put_active(of->sd);
+	return battr->write(of->file, kobj, battr, buf, pos, count);
 }
 
-static int sysfs_bin_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+static int sysfs_kf_bin_mmap(struct kernfs_open_file *of,
+			     struct vm_area_struct *vma)
 {
-	struct file *file = vma->vm_file;
-	struct sysfs_open_file *of = sysfs_of(file);
-	int ret;
+	struct bin_attribute *battr = of->kn->priv;
+	struct kobject *kobj = of->kn->parent->priv;
 
-	if (!of->vm_ops)
-		return VM_FAULT_SIGBUS;
-
-	if (!sysfs_get_active(of->sd))
-		return VM_FAULT_SIGBUS;
-
-	ret = VM_FAULT_SIGBUS;
-	if (of->vm_ops->fault)
-		ret = of->vm_ops->fault(vma, vmf);
-
-	sysfs_put_active(of->sd);
-	return ret;
+	return battr->mmap(of->file, kobj, battr, vma);
 }
 
-static int sysfs_bin_page_mkwrite(struct vm_area_struct *vma,
-				  struct vm_fault *vmf)
+void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr)
 {
-	struct file *file = vma->vm_file;
-	struct sysfs_open_file *of = sysfs_of(file);
-	int ret;
-
-	if (!of->vm_ops)
-		return VM_FAULT_SIGBUS;
+	struct kernfs_node *kn = kobj->sd, *tmp;
 
-	if (!sysfs_get_active(of->sd))
-		return VM_FAULT_SIGBUS;
-
-	ret = 0;
-	if (of->vm_ops->page_mkwrite)
-		ret = of->vm_ops->page_mkwrite(vma, vmf);
+	if (kn && dir)
+		kn = kernfs_find_and_get(kn, dir);
 	else
-		file_update_time(file);
-
-	sysfs_put_active(of->sd);
-	return ret;
-}
-
-static int sysfs_bin_access(struct vm_area_struct *vma, unsigned long addr,
-			    void *buf, int len, int write)
-{
-	struct file *file = vma->vm_file;
-	struct sysfs_open_file *of = sysfs_of(file);
-	int ret;
-
-	if (!of->vm_ops)
-		return -EINVAL;
-
-	if (!sysfs_get_active(of->sd))
-		return -EINVAL;
-
-	ret = -EINVAL;
-	if (of->vm_ops->access)
-		ret = of->vm_ops->access(vma, addr, buf, len, write);
-
-	sysfs_put_active(of->sd);
-	return ret;
-}
-
-#ifdef CONFIG_NUMA
-static int sysfs_bin_set_policy(struct vm_area_struct *vma,
-				struct mempolicy *new)
-{
-	struct file *file = vma->vm_file;
-	struct sysfs_open_file *of = sysfs_of(file);
-	int ret;
-
-	if (!of->vm_ops)
-		return 0;
-
-	if (!sysfs_get_active(of->sd))
-		return -EINVAL;
-
-	ret = 0;
-	if (of->vm_ops->set_policy)
-		ret = of->vm_ops->set_policy(vma, new);
-
-	sysfs_put_active(of->sd);
-	return ret;
-}
-
-static struct mempolicy *sysfs_bin_get_policy(struct vm_area_struct *vma,
-					      unsigned long addr)
-{
-	struct file *file = vma->vm_file;
-	struct sysfs_open_file *of = sysfs_of(file);
-	struct mempolicy *pol;
-
-	if (!of->vm_ops)
-		return vma->vm_policy;
-
-	if (!sysfs_get_active(of->sd))
-		return vma->vm_policy;
-
-	pol = vma->vm_policy;
-	if (of->vm_ops->get_policy)
-		pol = of->vm_ops->get_policy(vma, addr);
-
-	sysfs_put_active(of->sd);
-	return pol;
-}
-
-static int sysfs_bin_migrate(struct vm_area_struct *vma, const nodemask_t *from,
-			     const nodemask_t *to, unsigned long flags)
-{
-	struct file *file = vma->vm_file;
-	struct sysfs_open_file *of = sysfs_of(file);
-	int ret;
-
-	if (!of->vm_ops)
-		return 0;
-
-	if (!sysfs_get_active(of->sd))
-		return 0;
-
-	ret = 0;
-	if (of->vm_ops->migrate)
-		ret = of->vm_ops->migrate(vma, from, to, flags);
-
-	sysfs_put_active(of->sd);
-	return ret;
-}
-#endif
-
-static const struct vm_operations_struct sysfs_bin_vm_ops = {
-	.open		= sysfs_bin_vma_open,
-	.fault		= sysfs_bin_fault,
-	.page_mkwrite	= sysfs_bin_page_mkwrite,
-	.access		= sysfs_bin_access,
-#ifdef CONFIG_NUMA
-	.set_policy	= sysfs_bin_set_policy,
-	.get_policy	= sysfs_bin_get_policy,
-	.migrate	= sysfs_bin_migrate,
-#endif
-};
-
-static int sysfs_bin_mmap(struct file *file, struct vm_area_struct *vma)
-{
-	struct sysfs_open_file *of = sysfs_of(file);
-	struct bin_attribute *battr = of->sd->s_attr.bin_attr;
-	struct kobject *kobj = of->sd->s_parent->s_dir.kobj;
-	int rc;
-
-	mutex_lock(&of->mutex);
-
-	/* need of->sd for battr, its parent for kobj */
-	rc = -ENODEV;
-	if (!sysfs_get_active(of->sd))
-		goto out_unlock;
-
-	if (!battr->mmap)
-		goto out_put;
-
-	rc = battr->mmap(file, kobj, battr, vma);
-	if (rc)
-		goto out_put;
-
-	/*
-	 * PowerPC's pci_mmap of legacy_mem uses shmem_zero_setup()
-	 * to satisfy versions of X which crash if the mmap fails: that
-	 * substitutes a new vm_file, and we don't then want bin_vm_ops.
-	 */
-	if (vma->vm_file != file)
-		goto out_put;
-
-	rc = -EINVAL;
-	if (of->mmapped && of->vm_ops != vma->vm_ops)
-		goto out_put;
+		kernfs_get(kn);
 
-	/*
-	 * It is not possible to successfully wrap close.
-	 * So error if someone is trying to use close.
-	 */
-	rc = -EINVAL;
-	if (vma->vm_ops && vma->vm_ops->close)
-		goto out_put;
-
-	rc = 0;
-	of->mmapped = 1;
-	of->vm_ops = vma->vm_ops;
-	vma->vm_ops = &sysfs_bin_vm_ops;
-out_put:
-	sysfs_put_active(of->sd);
-out_unlock:
-	mutex_unlock(&of->mutex);
-
-	return rc;
-}
-
-/**
- *	sysfs_get_open_dirent - get or create sysfs_open_dirent
- *	@sd: target sysfs_dirent
- *	@of: sysfs_open_file for this instance of open
- *
- *	If @sd->s_attr.open exists, increment its reference count;
- *	otherwise, create one.  @of is chained to the files list.
- *
- *	LOCKING:
- *	Kernel thread context (may sleep).
- *
- *	RETURNS:
- *	0 on success, -errno on failure.
- */
-static int sysfs_get_open_dirent(struct sysfs_dirent *sd,
-				 struct sysfs_open_file *of)
-{
-	struct sysfs_open_dirent *od, *new_od = NULL;
-
- retry:
-	mutex_lock(&sysfs_open_file_mutex);
-	spin_lock_irq(&sysfs_open_dirent_lock);
-
-	if (!sd->s_attr.open && new_od) {
-		sd->s_attr.open = new_od;
-		new_od = NULL;
+	if (kn && attr) {
+		tmp = kernfs_find_and_get(kn, attr);
+		kernfs_put(kn);
+		kn = tmp;
 	}
 
-	od = sd->s_attr.open;
-	if (od) {
-		atomic_inc(&od->refcnt);
-		list_add_tail(&of->list, &od->files);
-	}
-
-	spin_unlock_irq(&sysfs_open_dirent_lock);
-	mutex_unlock(&sysfs_open_file_mutex);
-
-	if (od) {
-		kfree(new_od);
-		return 0;
+	if (kn) {
+		kernfs_notify(kn);
+		kernfs_put(kn);
 	}
+}
+EXPORT_SYMBOL_GPL(sysfs_notify);
 
-	/* not there, initialize a new one and retry */
-	new_od = kmalloc(sizeof(*new_od), GFP_KERNEL);
-	if (!new_od)
-		return -ENOMEM;
+static const struct kernfs_ops sysfs_file_kfops_empty = {
+};
 
-	atomic_set(&new_od->refcnt, 0);
-	atomic_set(&new_od->event, 1);
-	init_waitqueue_head(&new_od->poll);
-	INIT_LIST_HEAD(&new_od->files);
-	goto retry;
-}
+static const struct kernfs_ops sysfs_file_kfops_ro = {
+	.seq_show	= sysfs_kf_seq_show,
+};
 
-/**
- *	sysfs_put_open_dirent - put sysfs_open_dirent
- *	@sd: target sysfs_dirent
- *	@of: associated sysfs_open_file
- *
- *	Put @sd->s_attr.open and unlink @of from the files list.  If
- *	reference count reaches zero, disassociate and free it.
- *
- *	LOCKING:
- *	None.
- */
-static void sysfs_put_open_dirent(struct sysfs_dirent *sd,
-				  struct sysfs_open_file *of)
-{
-	struct sysfs_open_dirent *od = sd->s_attr.open;
-	unsigned long flags;
+static const struct kernfs_ops sysfs_file_kfops_wo = {
+	.write		= sysfs_kf_write,
+};
 
-	mutex_lock(&sysfs_open_file_mutex);
-	spin_lock_irqsave(&sysfs_open_dirent_lock, flags);
+static const struct kernfs_ops sysfs_file_kfops_rw = {
+	.seq_show	= sysfs_kf_seq_show,
+	.write		= sysfs_kf_write,
+};
 
-	if (of)
-		list_del(&of->list);
+static const struct kernfs_ops sysfs_bin_kfops_ro = {
+	.read		= sysfs_kf_bin_read,
+};
 
-	if (atomic_dec_and_test(&od->refcnt))
-		sd->s_attr.open = NULL;
-	else
-		od = NULL;
+static const struct kernfs_ops sysfs_bin_kfops_wo = {
+	.write		= sysfs_kf_bin_write,
+};
 
-	spin_unlock_irqrestore(&sysfs_open_dirent_lock, flags);
-	mutex_unlock(&sysfs_open_file_mutex);
+static const struct kernfs_ops sysfs_bin_kfops_rw = {
+	.read		= sysfs_kf_bin_read,
+	.write		= sysfs_kf_bin_write,
+};
 
-	kfree(od);
-}
+static const struct kernfs_ops sysfs_bin_kfops_mmap = {
+	.read		= sysfs_kf_bin_read,
+	.write		= sysfs_kf_bin_write,
+	.mmap		= sysfs_kf_bin_mmap,
+};
 
-static int sysfs_open_file(struct inode *inode, struct file *file)
+int sysfs_add_file_mode_ns(struct kernfs_node *parent,
+			   const struct attribute *attr, bool is_bin,
+			   umode_t mode, const void *ns)
 {
-	struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
-	struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
-	struct sysfs_open_file *of;
-	bool has_read, has_write;
-	int error = -EACCES;
-
-	/* need attr_sd for attr and ops, its parent for kobj */
-	if (!sysfs_get_active(attr_sd))
-		return -ENODEV;
+	struct lock_class_key *key = NULL;
+	const struct kernfs_ops *ops;
+	struct kernfs_node *kn;
+	loff_t size;
 
-	if (sysfs_is_bin(attr_sd)) {
-		struct bin_attribute *battr = attr_sd->s_attr.bin_attr;
-
-		has_read = battr->read || battr->mmap;
-		has_write = battr->write || battr->mmap;
-	} else {
-		const struct sysfs_ops *ops = sysfs_file_ops(attr_sd);
+	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(!ops, KERN_ERR
+		if (WARN(!sysfs_ops, KERN_ERR
 			 "missing sysfs attribute operations for kobject: %s\n",
 			 kobject_name(kobj)))
-			goto err_out;
-
-		has_read = ops->show;
-		has_write = ops->store;
-	}
-
-	/* check perms and supported operations */
-	if ((file->f_mode & FMODE_WRITE) &&
-	    (!(inode->i_mode & S_IWUGO) || !has_write))
-		goto err_out;
-
-	if ((file->f_mode & FMODE_READ) &&
-	    (!(inode->i_mode & S_IRUGO) || !has_read))
-		goto err_out;
-
-	/* allocate a sysfs_open_file for the file */
-	error = -ENOMEM;
-	of = kzalloc(sizeof(struct sysfs_open_file), GFP_KERNEL);
-	if (!of)
-		goto err_out;
-
-	/*
-	 * The following is done to give a different lockdep key to
-	 * @of->mutex for files which implement mmap.  This is a rather
-	 * crude way to avoid false positive lockdep warning around
-	 * mm->mmap_sem - mmap nests @of->mutex under mm->mmap_sem and
-	 * reading /sys/block/sda/trace/act_mask grabs sr_mutex, under
-	 * which mm->mmap_sem nests, while holding @of->mutex.  As each
-	 * open file has a separate mutex, it's okay as long as those don't
-	 * happen on the same file.  At this point, we can't easily give
-	 * each file a separate locking class.  Let's differentiate on
-	 * whether the file is bin or not for now.
-	 */
-	if (sysfs_is_bin(attr_sd))
-		mutex_init(&of->mutex);
-	else
-		mutex_init(&of->mutex);
-
-	of->sd = attr_sd;
-	of->file = file;
-
-	/*
-	 * Always instantiate seq_file even if read access doesn't use
-	 * seq_file or is not requested.  This unifies private data access
-	 * and readable regular files are the vast majority anyway.
-	 */
-	if (sysfs_is_bin(attr_sd))
-		error = single_open(file, NULL, of);
-	else
-		error = single_open(file, sysfs_seq_show, of);
-	if (error)
-		goto err_free;
-
-	/* seq_file clears PWRITE unconditionally, restore it if WRITE */
-	if (file->f_mode & FMODE_WRITE)
-		file->f_mode |= FMODE_PWRITE;
-
-	/* make sure we have open dirent struct */
-	error = sysfs_get_open_dirent(attr_sd, of);
-	if (error)
-		goto err_close;
-
-	/* open succeeded, put active references */
-	sysfs_put_active(attr_sd);
-	return 0;
-
-err_close:
-	single_release(inode, file);
-err_free:
-	kfree(of);
-err_out:
-	sysfs_put_active(attr_sd);
-	return error;
-}
-
-static int sysfs_release(struct inode *inode, struct file *filp)
-{
-	struct sysfs_dirent *sd = filp->f_path.dentry->d_fsdata;
-	struct sysfs_open_file *of = sysfs_of(filp);
-
-	sysfs_put_open_dirent(sd, of);
-	single_release(inode, filp);
-	kfree(of);
-
-	return 0;
-}
-
-void sysfs_unmap_bin_file(struct sysfs_dirent *sd)
-{
-	struct sysfs_open_dirent *od;
-	struct sysfs_open_file *of;
-
-	if (!sysfs_is_bin(sd))
-		return;
-
-	spin_lock_irq(&sysfs_open_dirent_lock);
-	od = sd->s_attr.open;
-	if (od)
-		atomic_inc(&od->refcnt);
-	spin_unlock_irq(&sysfs_open_dirent_lock);
-	if (!od)
-		return;
-
-	mutex_lock(&sysfs_open_file_mutex);
-	list_for_each_entry(of, &od->files, list) {
-		struct inode *inode = file_inode(of->file);
-		unmap_mapping_range(inode->i_mapping, 0, 0, 1);
+			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;
 	}
-	mutex_unlock(&sysfs_open_file_mutex);
-
-	sysfs_put_open_dirent(sd, NULL);
-}
-
-/* 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, or seek to 0 and read again.
- * 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 (Neither 'poll' nor 'select' return
- * an appropriate error code).  When in doubt, set a suitable timeout value.
- */
-static unsigned int sysfs_poll(struct file *filp, poll_table *wait)
-{
-	struct sysfs_open_file *of = sysfs_of(filp);
-	struct sysfs_dirent *attr_sd = filp->f_path.dentry->d_fsdata;
-	struct sysfs_open_dirent *od = attr_sd->s_attr.open;
-
-	/* need parent for the kobj, grab both */
-	if (!sysfs_get_active(attr_sd))
-		goto trigger;
-
-	poll_wait(filp, &od->poll, wait);
 
-	sysfs_put_active(attr_sd);
-
-	if (of->event != atomic_read(&od->event))
-		goto trigger;
-
-	return DEFAULT_POLLMASK;
-
- trigger:
-	return DEFAULT_POLLMASK|POLLERR|POLLPRI;
-}
-
-void sysfs_notify_dirent(struct sysfs_dirent *sd)
-{
-	struct sysfs_open_dirent *od;
-	unsigned long flags;
-
-	spin_lock_irqsave(&sysfs_open_dirent_lock, flags);
-
-	if (!WARN_ON(sysfs_type(sd) != SYSFS_KOBJ_ATTR)) {
-		od = sd->s_attr.open;
-		if (od) {
-			atomic_inc(&od->event);
-			wake_up_interruptible(&od->poll);
-		}
+#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);
 	}
-
-	spin_unlock_irqrestore(&sysfs_open_dirent_lock, flags);
-}
-EXPORT_SYMBOL_GPL(sysfs_notify_dirent);
-
-void sysfs_notify(struct kobject *k, const char *dir, const char *attr)
-{
-	struct sysfs_dirent *sd = k->sd;
-
-	mutex_lock(&sysfs_mutex);
-
-	if (sd && dir)
-		sd = sysfs_find_dirent(sd, dir, NULL);
-	if (sd && attr)
-		sd = sysfs_find_dirent(sd, attr, NULL);
-	if (sd)
-		sysfs_notify_dirent(sd);
-
-	mutex_unlock(&sysfs_mutex);
-}
-EXPORT_SYMBOL_GPL(sysfs_notify);
-
-const struct file_operations sysfs_file_operations = {
-	.read		= seq_read,
-	.write		= sysfs_write_file,
-	.llseek		= generic_file_llseek,
-	.open		= sysfs_open_file,
-	.release	= sysfs_release,
-	.poll		= sysfs_poll,
-};
-
-const struct file_operations sysfs_bin_operations = {
-	.read		= sysfs_bin_read,
-	.write		= sysfs_write_file,
-	.llseek		= generic_file_llseek,
-	.mmap		= sysfs_bin_mmap,
-	.open		= sysfs_open_file,
-	.release	= sysfs_release,
-	.poll		= sysfs_poll,
-};
-
-int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd,
-			   const struct attribute *attr, int type,
-			   umode_t amode, const void *ns)
-{
-	umode_t mode = (amode & S_IALLUGO) | S_IFREG;
-	struct sysfs_addrm_cxt acxt;
-	struct sysfs_dirent *sd;
-	int rc;
-
-	sd = sysfs_new_dirent(attr->name, mode, type);
-	if (!sd)
-		return -ENOMEM;
-
-	sd->s_ns = ns;
-	sd->s_attr.attr = (void *)attr;
-	sysfs_dirent_init_lockdep(sd);
-
-	sysfs_addrm_start(&acxt);
-	rc = sysfs_add_one(&acxt, sd, dir_sd);
-	sysfs_addrm_finish(&acxt);
-
-	if (rc)
-		sysfs_put(sd);
-
-	return rc;
+	return 0;
 }
 
-
-int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr,
-		   int type)
+int sysfs_add_file(struct kernfs_node *parent, const struct attribute *attr,
+		   bool is_bin)
 {
-	return sysfs_add_file_mode_ns(dir_sd, attr, type, attr->mode, NULL);
+	return sysfs_add_file_mode_ns(parent, attr, is_bin, attr->mode, NULL);
 }
 
 /**
@@ -877,8 +279,7 @@ int sysfs_create_file_ns(struct kobject *kobj, const struct attribute *attr,
 {
 	BUG_ON(!kobj || !kobj->sd || !attr);
 
-	return sysfs_add_file_mode_ns(kobj->sd, attr, SYSFS_KOBJ_ATTR,
-				      attr->mode, ns);
+	return sysfs_add_file_mode_ns(kobj->sd, attr, false, attr->mode, ns);
 
 }
 EXPORT_SYMBOL_GPL(sysfs_create_file_ns);
@@ -906,19 +307,21 @@ EXPORT_SYMBOL_GPL(sysfs_create_files);
 int sysfs_add_file_to_group(struct kobject *kobj,
 		const struct attribute *attr, const char *group)
 {
-	struct sysfs_dirent *dir_sd;
+	struct kernfs_node *parent;
 	int error;
 
-	if (group)
-		dir_sd = sysfs_get_dirent(kobj->sd, group);
-	else
-		dir_sd = sysfs_get(kobj->sd);
+	if (group) {
+		parent = kernfs_find_and_get(kobj->sd, group);
+	} else {
+		parent = kobj->sd;
+		kernfs_get(parent);
+	}
 
-	if (!dir_sd)
+	if (!parent)
 		return -ENOENT;
 
-	error = sysfs_add_file(dir_sd, attr, SYSFS_KOBJ_ATTR);
-	sysfs_put(dir_sd);
+	error = sysfs_add_file(parent, attr, false);
+	kernfs_put(parent);
 
 	return error;
 }
@@ -934,23 +337,20 @@ EXPORT_SYMBOL_GPL(sysfs_add_file_to_group);
 int sysfs_chmod_file(struct kobject *kobj, const struct attribute *attr,
 		     umode_t mode)
 {
-	struct sysfs_dirent *sd;
+	struct kernfs_node *kn;
 	struct iattr newattrs;
 	int rc;
 
-	mutex_lock(&sysfs_mutex);
-
-	rc = -ENOENT;
-	sd = sysfs_find_dirent(kobj->sd, attr->name, NULL);
-	if (!sd)
-		goto out;
+	kn = kernfs_find_and_get(kobj->sd, attr->name);
+	if (!kn)
+		return -ENOENT;
 
-	newattrs.ia_mode = (mode & S_IALLUGO) | (sd->s_mode & ~S_IALLUGO);
+	newattrs.ia_mode = (mode & S_IALLUGO) | (kn->mode & ~S_IALLUGO);
 	newattrs.ia_valid = ATTR_MODE;
-	rc = sysfs_sd_setattr(sd, &newattrs);
 
- out:
-	mutex_unlock(&sysfs_mutex);
+	rc = kernfs_setattr(kn, &newattrs);
+
+	kernfs_put(kn);
 	return rc;
 }
 EXPORT_SYMBOL_GPL(sysfs_chmod_file);
@@ -966,9 +366,9 @@ EXPORT_SYMBOL_GPL(sysfs_chmod_file);
 void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr,
 			  const void *ns)
 {
-	struct sysfs_dirent *dir_sd = kobj->sd;
+	struct kernfs_node *parent = kobj->sd;
 
-	sysfs_hash_and_remove(dir_sd, attr->name, ns);
+	kernfs_remove_by_name_ns(parent, attr->name, ns);
 }
 EXPORT_SYMBOL_GPL(sysfs_remove_file_ns);
 
@@ -989,15 +389,18 @@ EXPORT_SYMBOL_GPL(sysfs_remove_files);
 void sysfs_remove_file_from_group(struct kobject *kobj,
 		const struct attribute *attr, const char *group)
 {
-	struct sysfs_dirent *dir_sd;
+	struct kernfs_node *parent;
 
-	if (group)
-		dir_sd = sysfs_get_dirent(kobj->sd, group);
-	else
-		dir_sd = sysfs_get(kobj->sd);
-	if (dir_sd) {
-		sysfs_hash_and_remove(dir_sd, attr->name, NULL);
-		sysfs_put(dir_sd);
+	if (group) {
+		parent = kernfs_find_and_get(kobj->sd, group);
+	} else {
+		parent = kobj->sd;
+		kernfs_get(parent);
+	}
+
+	if (parent) {
+		kernfs_remove_by_name(parent, attr->name);
+		kernfs_put(parent);
 	}
 }
 EXPORT_SYMBOL_GPL(sysfs_remove_file_from_group);
@@ -1012,7 +415,7 @@ int sysfs_create_bin_file(struct kobject *kobj,
 {
 	BUG_ON(!kobj || !kobj->sd || !attr);
 
-	return sysfs_add_file(kobj->sd, &attr->attr, SYSFS_KOBJ_BIN_ATTR);
+	return sysfs_add_file(kobj->sd, &attr->attr, true);
 }
 EXPORT_SYMBOL_GPL(sysfs_create_bin_file);
 
@@ -1024,7 +427,7 @@ EXPORT_SYMBOL_GPL(sysfs_create_bin_file);
 void sysfs_remove_bin_file(struct kobject *kobj,
 			   const struct bin_attribute *attr)
 {
-	sysfs_hash_and_remove(kobj->sd, attr->attr.name, NULL);
+	kernfs_remove_by_name(kobj->sd, attr->attr.name);
 }
 EXPORT_SYMBOL_GPL(sysfs_remove_bin_file);