Merge tag 'driver-core-3.13-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 / sysfs update for 3.13-rc1.

  There's lots of dev_groups updates for different subsystems, as they
  all get slowly migrated over to the safe versions of the attribute
  groups (removing userspace races with the creation of the sysfs
  files.) Also in here are some kobject updates, devres expansions, and
  the first round of Tejun's sysfs reworking to enable it to be used by
  other subsystems as a backend for an in-kernel filesystem.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'driver-core-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (83 commits)
  sysfs: rename sysfs_assoc_lock and explain what it's about
  sysfs: use generic_file_llseek() for sysfs_file_operations
  sysfs: return correct error code on unimplemented mmap()
  mdio_bus: convert bus code to use dev_groups
  device: Make dev_WARN/dev_WARN_ONCE print device as well as driver name
  sysfs: separate out dup filename warning into a separate function
  sysfs: move sysfs_hash_and_remove() to fs/sysfs/dir.c
  sysfs: remove unused sysfs_get_dentry() prototype
  sysfs: honor bin_attr.attr.ignore_lockdep
  sysfs: merge sysfs_elem_bin_attr into sysfs_elem_attr
  devres: restore zeroing behavior of devres_alloc()
  sysfs: fix sysfs_write_file for bin file
  input: gameport: convert bus code to use dev_groups
  input: serio: remove bus usage of dev_attrs
  input: serio: use DEVICE_ATTR_RO()
  i2o: convert bus code to use dev_groups
  memstick: convert bus code to use dev_groups
  tifm: convert bus code to use dev_groups
  virtio: convert bus code to use dev_groups
  ipack: convert bus code to use dev_groups
  ...

9 files changed, 934 insertions, 1121 deletions

diff --git a/fs/sysfs/Makefile b/fs/sysfs/Makefile
index 7a1ceb946b8..8876ac18337 100644
--- a/fs/sysfs/Makefile
+++ b/fs/sysfs/Makefile
@@ -2,5 +2,4 @@
 # Makefile for the sysfs virtual filesystem
 #
 
-obj-y		:= inode.o file.o dir.o symlink.o mount.o bin.o \
-		   group.o
+obj-y		:= inode.o file.o dir.o symlink.o mount.o group.o
diff --git a/fs/sysfs/bin.c b/fs/sysfs/bin.c
deleted file mode 100644
index c590cabd57b..00000000000
--- a/fs/sysfs/bin.c
+++ /dev/null
@@ -1,502 +0,0 @@
-/*
- * fs/sysfs/bin.c - sysfs binary file implementation
- *
- * Copyright (c) 2003 Patrick Mochel
- * Copyright (c) 2003 Matthew Wilcox
- * Copyright (c) 2004 Silicon Graphics, Inc.
- * 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.
- */
-
-#undef DEBUG
-
-#include <linux/errno.h>
-#include <linux/fs.h>
-#include <linux/kernel.h>
-#include <linux/kobject.h>
-#include <linux/module.h>
-#include <linux/slab.h>
-#include <linux/mutex.h>
-#include <linux/mm.h>
-#include <linux/uaccess.h>
-
-#include "sysfs.h"
-
-/*
- * There's one bin_buffer for each open file.
- *
- * filp->private_data points to bin_buffer and
- * sysfs_dirent->s_bin_attr.buffers points to a the bin_buffer s
- * sysfs_dirent->s_bin_attr.buffers is protected by sysfs_bin_lock
- */
-static DEFINE_MUTEX(sysfs_bin_lock);
-
-struct bin_buffer {
-	struct mutex			mutex;
-	void				*buffer;
-	int				mmapped;
-	const struct vm_operations_struct *vm_ops;
-	struct file			*file;
-	struct hlist_node		list;
-};
-
-static int
-fill_read(struct file *file, char *buffer, loff_t off, size_t count)
-{
-	struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
-	struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr;
-	struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
-	int rc;
-
-	/* need attr_sd for attr, its parent for kobj */
-	if (!sysfs_get_active(attr_sd))
-		return -ENODEV;
-
-	rc = -EIO;
-	if (attr->read)
-		rc = attr->read(file, kobj, attr, buffer, off, count);
-
-	sysfs_put_active(attr_sd);
-
-	return rc;
-}
-
-static ssize_t
-read(struct file *file, char __user *userbuf, size_t bytes, loff_t *off)
-{
-	struct bin_buffer *bb = file->private_data;
-	int size = file_inode(file)->i_size;
-	loff_t offs = *off;
-	int count = min_t(size_t, bytes, PAGE_SIZE);
-	char *temp;
-
-	if (!bytes)
-		return 0;
-
-	if (size) {
-		if (offs > size)
-			return 0;
-		if (offs + count > size)
-			count = size - offs;
-	}
-
-	temp = kmalloc(count, GFP_KERNEL);
-	if (!temp)
-		return -ENOMEM;
-
-	mutex_lock(&bb->mutex);
-
-	count = fill_read(file, bb->buffer, offs, count);
-	if (count < 0) {
-		mutex_unlock(&bb->mutex);
-		goto out_free;
-	}
-
-	memcpy(temp, bb->buffer, count);
-
-	mutex_unlock(&bb->mutex);
-
-	if (copy_to_user(userbuf, temp, count)) {
-		count = -EFAULT;
-		goto out_free;
-	}
-
-	pr_debug("offs = %lld, *off = %lld, count = %d\n", offs, *off, count);
-
-	*off = offs + count;
-
- out_free:
-	kfree(temp);
-	return count;
-}
-
-static int
-flush_write(struct file *file, char *buffer, loff_t offset, size_t count)
-{
-	struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
-	struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr;
-	struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
-	int rc;
-
-	/* need attr_sd for attr, its parent for kobj */
-	if (!sysfs_get_active(attr_sd))
-		return -ENODEV;
-
-	rc = -EIO;
-	if (attr->write)
-		rc = attr->write(file, kobj, attr, buffer, offset, count);
-
-	sysfs_put_active(attr_sd);
-
-	return rc;
-}
-
-static ssize_t write(struct file *file, const char __user *userbuf,
-		     size_t bytes, loff_t *off)
-{
-	struct bin_buffer *bb = file->private_data;
-	int size = file_inode(file)->i_size;
-	loff_t offs = *off;
-	int count = min_t(size_t, bytes, PAGE_SIZE);
-	char *temp;
-
-	if (!bytes)
-		return 0;
-
-	if (size) {
-		if (offs > size)
-			return 0;
-		if (offs + count > size)
-			count = size - offs;
-	}
-
-	temp = memdup_user(userbuf, count);
-	if (IS_ERR(temp))
-		return PTR_ERR(temp);
-
-	mutex_lock(&bb->mutex);
-
-	memcpy(bb->buffer, temp, count);
-
-	count = flush_write(file, bb->buffer, offs, count);
-	mutex_unlock(&bb->mutex);
-
-	if (count > 0)
-		*off = offs + count;
-
-	kfree(temp);
-	return count;
-}
-
-static void bin_vma_open(struct vm_area_struct *vma)
-{
-	struct file *file = vma->vm_file;
-	struct bin_buffer *bb = file->private_data;
-	struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
-
-	if (!bb->vm_ops)
-		return;
-
-	if (!sysfs_get_active(attr_sd))
-		return;
-
-	if (bb->vm_ops->open)
-		bb->vm_ops->open(vma);
-
-	sysfs_put_active(attr_sd);
-}
-
-static int bin_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
-{
-	struct file *file = vma->vm_file;
-	struct bin_buffer *bb = file->private_data;
-	struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
-	int ret;
-
-	if (!bb->vm_ops)
-		return VM_FAULT_SIGBUS;
-
-	if (!sysfs_get_active(attr_sd))
-		return VM_FAULT_SIGBUS;
-
-	ret = VM_FAULT_SIGBUS;
-	if (bb->vm_ops->fault)
-		ret = bb->vm_ops->fault(vma, vmf);
-
-	sysfs_put_active(attr_sd);
-	return ret;
-}
-
-static int bin_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
-{
-	struct file *file = vma->vm_file;
-	struct bin_buffer *bb = file->private_data;
-	struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
-	int ret;
-
-	if (!bb->vm_ops)
-		return VM_FAULT_SIGBUS;
-
-	if (!sysfs_get_active(attr_sd))
-		return VM_FAULT_SIGBUS;
-
-	ret = 0;
-	if (bb->vm_ops->page_mkwrite)
-		ret = bb->vm_ops->page_mkwrite(vma, vmf);
-	else
-		file_update_time(file);
-
-	sysfs_put_active(attr_sd);
-	return ret;
-}
-
-static int bin_access(struct vm_area_struct *vma, unsigned long addr,
-		  void *buf, int len, int write)
-{
-	struct file *file = vma->vm_file;
-	struct bin_buffer *bb = file->private_data;
-	struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
-	int ret;
-
-	if (!bb->vm_ops)
-		return -EINVAL;
-
-	if (!sysfs_get_active(attr_sd))
-		return -EINVAL;
-
-	ret = -EINVAL;
-	if (bb->vm_ops->access)
-		ret = bb->vm_ops->access(vma, addr, buf, len, write);
-
-	sysfs_put_active(attr_sd);
-	return ret;
-}
-
-#ifdef CONFIG_NUMA
-static int bin_set_policy(struct vm_area_struct *vma, struct mempolicy *new)
-{
-	struct file *file = vma->vm_file;
-	struct bin_buffer *bb = file->private_data;
-	struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
-	int ret;
-
-	if (!bb->vm_ops)
-		return 0;
-
-	if (!sysfs_get_active(attr_sd))
-		return -EINVAL;
-
-	ret = 0;
-	if (bb->vm_ops->set_policy)
-		ret = bb->vm_ops->set_policy(vma, new);
-
-	sysfs_put_active(attr_sd);
-	return ret;
-}
-
-static struct mempolicy *bin_get_policy(struct vm_area_struct *vma,
-					unsigned long addr)
-{
-	struct file *file = vma->vm_file;
-	struct bin_buffer *bb = file->private_data;
-	struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
-	struct mempolicy *pol;
-
-	if (!bb->vm_ops)
-		return vma->vm_policy;
-
-	if (!sysfs_get_active(attr_sd))
-		return vma->vm_policy;
-
-	pol = vma->vm_policy;
-	if (bb->vm_ops->get_policy)
-		pol = bb->vm_ops->get_policy(vma, addr);
-
-	sysfs_put_active(attr_sd);
-	return pol;
-}
-
-static int 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 bin_buffer *bb = file->private_data;
-	struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
-	int ret;
-
-	if (!bb->vm_ops)
-		return 0;
-
-	if (!sysfs_get_active(attr_sd))
-		return 0;
-
-	ret = 0;
-	if (bb->vm_ops->migrate)
-		ret = bb->vm_ops->migrate(vma, from, to, flags);
-
-	sysfs_put_active(attr_sd);
-	return ret;
-}
-#endif
-
-static const struct vm_operations_struct bin_vm_ops = {
-	.open		= bin_vma_open,
-	.fault		= bin_fault,
-	.page_mkwrite	= bin_page_mkwrite,
-	.access		= bin_access,
-#ifdef CONFIG_NUMA
-	.set_policy	= bin_set_policy,
-	.get_policy	= bin_get_policy,
-	.migrate	= bin_migrate,
-#endif
-};
-
-static int mmap(struct file *file, struct vm_area_struct *vma)
-{
-	struct bin_buffer *bb = file->private_data;
-	struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
-	struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr;
-	struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
-	int rc;
-
-	mutex_lock(&bb->mutex);
-
-	/* need attr_sd for attr, its parent for kobj */
-	rc = -ENODEV;
-	if (!sysfs_get_active(attr_sd))
-		goto out_unlock;
-
-	rc = -EINVAL;
-	if (!attr->mmap)
-		goto out_put;
-
-	rc = attr->mmap(file, kobj, attr, 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 (bb->mmapped && bb->vm_ops != vma->vm_ops)
-		goto out_put;
-
-	/*
-	 * 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;
-	bb->mmapped = 1;
-	bb->vm_ops = vma->vm_ops;
-	vma->vm_ops = &bin_vm_ops;
-out_put:
-	sysfs_put_active(attr_sd);
-out_unlock:
-	mutex_unlock(&bb->mutex);
-
-	return rc;
-}
-
-static int open(struct inode *inode, struct file *file)
-{
-	struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
-	struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr;
-	struct bin_buffer *bb = NULL;
-	int error;
-
-	/* binary file operations requires both @sd and its parent */
-	if (!sysfs_get_active(attr_sd))
-		return -ENODEV;
-
-	error = -EACCES;
-	if ((file->f_mode & FMODE_WRITE) && !(attr->write || attr->mmap))
-		goto err_out;
-	if ((file->f_mode & FMODE_READ) && !(attr->read || attr->mmap))
-		goto err_out;
-
-	error = -ENOMEM;
-	bb = kzalloc(sizeof(*bb), GFP_KERNEL);
-	if (!bb)
-		goto err_out;
-
-	bb->buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
-	if (!bb->buffer)
-		goto err_out;
-
-	mutex_init(&bb->mutex);
-	bb->file = file;
-	file->private_data = bb;
-
-	mutex_lock(&sysfs_bin_lock);
-	hlist_add_head(&bb->list, &attr_sd->s_bin_attr.buffers);
-	mutex_unlock(&sysfs_bin_lock);
-
-	/* open succeeded, put active references */
-	sysfs_put_active(attr_sd);
-	return 0;
-
- err_out:
-	sysfs_put_active(attr_sd);
-	kfree(bb);
-	return error;
-}
-
-static int release(struct inode *inode, struct file *file)
-{
-	struct bin_buffer *bb = file->private_data;
-
-	mutex_lock(&sysfs_bin_lock);
-	hlist_del(&bb->list);
-	mutex_unlock(&sysfs_bin_lock);
-
-	kfree(bb->buffer);
-	kfree(bb);
-	return 0;
-}
-
-const struct file_operations bin_fops = {
-	.read		= read,
-	.write		= write,
-	.mmap		= mmap,
-	.llseek		= generic_file_llseek,
-	.open		= open,
-	.release	= release,
-};
-
-
-void unmap_bin_file(struct sysfs_dirent *attr_sd)
-{
-	struct bin_buffer *bb;
-
-	if (sysfs_type(attr_sd) != SYSFS_KOBJ_BIN_ATTR)
-		return;
-
-	mutex_lock(&sysfs_bin_lock);
-
-	hlist_for_each_entry(bb, &attr_sd->s_bin_attr.buffers, list) {
-		struct inode *inode = file_inode(bb->file);
-
-		unmap_mapping_range(inode->i_mapping, 0, 0, 1);
-	}
-
-	mutex_unlock(&sysfs_bin_lock);
-}
-
-/**
- *	sysfs_create_bin_file - create binary file for object.
- *	@kobj:	object.
- *	@attr:	attribute descriptor.
- */
-int sysfs_create_bin_file(struct kobject *kobj,
-			  const struct bin_attribute *attr)
-{
-	BUG_ON(!kobj || !kobj->sd || !attr);
-
-	return sysfs_add_file(kobj->sd, &attr->attr, SYSFS_KOBJ_BIN_ATTR);
-}
-EXPORT_SYMBOL_GPL(sysfs_create_bin_file);
-
-/**
- *	sysfs_remove_bin_file - remove binary file for object.
- *	@kobj:	object.
- *	@attr:	attribute descriptor.
- */
-void sysfs_remove_bin_file(struct kobject *kobj,
-			   const struct bin_attribute *attr)
-{
-	sysfs_hash_and_remove(kobj->sd, NULL, attr->attr.name);
-}
-EXPORT_SYMBOL_GPL(sysfs_remove_bin_file);
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 4d83cedb9fc..08c66969d52 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -26,21 +26,21 @@
 #include "sysfs.h"
 
 DEFINE_MUTEX(sysfs_mutex);
-DEFINE_SPINLOCK(sysfs_assoc_lock);
+DEFINE_SPINLOCK(sysfs_symlink_target_lock);
 
-#define to_sysfs_dirent(X) rb_entry((X), struct sysfs_dirent, s_rb);
+#define to_sysfs_dirent(X) rb_entry((X), struct sysfs_dirent, s_rb)
 
 static DEFINE_SPINLOCK(sysfs_ino_lock);
 static DEFINE_IDA(sysfs_ino_ida);
 
 /**
  *	sysfs_name_hash
- *	@ns:   Namespace tag to hash
  *	@name: Null terminated string to hash
+ *	@ns:   Namespace tag to hash
  *
  *	Returns 31 bit hash of ns + name (so it fits in an off_t )
  */
-static unsigned int sysfs_name_hash(const void *ns, const char *name)
+static unsigned int sysfs_name_hash(const char *name, const void *ns)
 {
 	unsigned long hash = init_name_hash();
 	unsigned int len = strlen(name);
@@ -56,8 +56,8 @@ static unsigned int sysfs_name_hash(const void *ns, const char *name)
 	return hash;
 }
 
-static int sysfs_name_compare(unsigned int hash, const void *ns,
-	const char *name, const struct sysfs_dirent *sd)
+static int sysfs_name_compare(unsigned int hash, const char *name,
+			      const void *ns, const struct sysfs_dirent *sd)
 {
 	if (hash != sd->s_hash)
 		return hash - sd->s_hash;
@@ -69,7 +69,7 @@ static int sysfs_name_compare(unsigned int hash, const void *ns,
 static int sysfs_sd_compare(const struct sysfs_dirent *left,
 			    const struct sysfs_dirent *right)
 {
-	return sysfs_name_compare(left->s_hash, left->s_ns, left->s_name,
+	return sysfs_name_compare(left->s_hash, left->s_name, left->s_ns,
 				  right);
 }
 
@@ -111,6 +111,11 @@ static int sysfs_link_sibling(struct sysfs_dirent *sd)
 	/* add new node and rebalance the tree */
 	rb_link_node(&sd->s_rb, parent, node);
 	rb_insert_color(&sd->s_rb, &sd->s_parent->s_dir.children);
+
+	/* if @sd has ns tag, mark the parent to enable ns filtering */
+	if (sd->s_ns)
+		sd->s_parent->s_flags |= SYSFS_FLAG_HAS_NS;
+
 	return 0;
 }
 
@@ -130,26 +135,15 @@ static void sysfs_unlink_sibling(struct sysfs_dirent *sd)
 		sd->s_parent->s_dir.subdirs--;
 
 	rb_erase(&sd->s_rb, &sd->s_parent->s_dir.children);
-}
-
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
 
-/* Test for attributes that want to ignore lockdep for read-locking */
-static bool ignore_lockdep(struct sysfs_dirent *sd)
-{
-	return sysfs_type(sd) == SYSFS_KOBJ_ATTR &&
-			sd->s_attr.attr->ignore_lockdep;
-}
-
-#else
-
-static inline bool ignore_lockdep(struct sysfs_dirent *sd)
-{
-	return true;
+	/*
+	 * Either all or none of the children have tags.  Clearing HAS_NS
+	 * when there's no child left is enough to keep the flag synced.
+	 */
+	if (RB_EMPTY_ROOT(&sd->s_parent->s_dir.children))
+		sd->s_parent->s_flags &= ~SYSFS_FLAG_HAS_NS;
 }
 
-#endif
-
 /**
  *	sysfs_get_active - get an active reference to sysfs_dirent
  *	@sd: sysfs_dirent to get an active reference to
@@ -168,7 +162,7 @@ struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd)
 	if (!atomic_inc_unless_negative(&sd->s_active))
 		return NULL;
 
-	if (likely(!ignore_lockdep(sd)))
+	if (likely(!sysfs_ignore_lockdep(sd)))
 		rwsem_acquire_read(&sd->dep_map, 0, 1, _RET_IP_);
 	return sd;
 }
@@ -187,7 +181,7 @@ void sysfs_put_active(struct sysfs_dirent *sd)
 	if (unlikely(!sd))
 		return;
 
-	if (likely(!ignore_lockdep(sd)))
+	if (likely(!sysfs_ignore_lockdep(sd)))
 		rwsem_release(&sd->dep_map, 1, _RET_IP_);
 	v = atomic_dec_return(&sd->s_active);
 	if (likely(v != SD_DEACTIVATED_BIAS))
@@ -297,7 +291,6 @@ static int sysfs_dentry_delete(const struct dentry *dentry)
 static int sysfs_dentry_revalidate(struct dentry *dentry, unsigned int flags)
 {
 	struct sysfs_dirent *sd;
-	int type;
 
 	if (flags & LOOKUP_RCU)
 		return -ECHILD;
@@ -318,13 +311,8 @@ static int sysfs_dentry_revalidate(struct dentry *dentry, unsigned int flags)
 		goto out_bad;
 
 	/* The sysfs dirent has been moved to a different namespace */
-	type = KOBJ_NS_TYPE_NONE;
-	if (sd->s_parent) {
-		type = sysfs_ns_type(sd->s_parent);
-		if (type != KOBJ_NS_TYPE_NONE &&
-				sysfs_info(dentry->d_sb)->ns[type] != sd->s_ns)
-			goto out_bad;
-	}
+	if (sd->s_ns && sd->s_ns != sysfs_info(dentry->d_sb)->ns)
+		goto out_bad;
 
 	mutex_unlock(&sysfs_mutex);
 out_valid:
@@ -400,22 +388,19 @@ struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type)
 /**
  *	sysfs_addrm_start - prepare for sysfs_dirent add/remove
  *	@acxt: pointer to sysfs_addrm_cxt to be used
- *	@parent_sd: parent sysfs_dirent
  *
- *	This function is called when the caller is about to add or
- *	remove sysfs_dirent under @parent_sd.  This function acquires
- *	sysfs_mutex.  @acxt is used to keep and pass context to
- *	other addrm functions.
+ *	This function is called when the caller is about to add or remove
+ *	sysfs_dirent.  This function acquires sysfs_mutex.  @acxt is used
+ *	to keep and pass context to other addrm functions.
  *
  *	LOCKING:
  *	Kernel thread context (may sleep).  sysfs_mutex is locked on
  *	return.
  */
-void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
-		       struct sysfs_dirent *parent_sd)
+void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt)
+	__acquires(sysfs_mutex)
 {
 	memset(acxt, 0, sizeof(*acxt));
-	acxt->parent_sd = parent_sd;
 
 	mutex_lock(&sysfs_mutex);
 }
@@ -424,10 +409,11 @@ void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
  *	__sysfs_add_one - add sysfs_dirent to parent without warning
  *	@acxt: addrm context to use
  *	@sd: sysfs_dirent to be added
+ *	@parent_sd: the parent sysfs_dirent to add @sd to
  *
- *	Get @acxt->parent_sd and set sd->s_parent to it and increment
- *	nlink of parent inode if @sd is a directory and link into the
- *	children list of the parent.
+ *	Get @parent_sd and set @sd->s_parent to it and increment nlink of
+ *	the parent inode if @sd is a directory and link into the children
+ *	list of the parent.
  *
  *	This function should be called between calls to
  *	sysfs_addrm_start() and sysfs_addrm_finish() and should be
@@ -440,27 +426,21 @@ void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
  *	0 on success, -EEXIST if entry with the given name already
  *	exists.
  */
-int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
+int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd,
+		    struct sysfs_dirent *parent_sd)
 {
 	struct sysfs_inode_attrs *ps_iattr;
 	int ret;
 
-	if (!!sysfs_ns_type(acxt->parent_sd) != !!sd->s_ns) {
-		WARN(1, KERN_WARNING "sysfs: ns %s in '%s' for '%s'\n",
-			sysfs_ns_type(acxt->parent_sd) ? "required" : "invalid",
-			acxt->parent_sd->s_name, sd->s_name);
-		return -EINVAL;
-	}
-
-	sd->s_hash = sysfs_name_hash(sd->s_ns, sd->s_name);
-	sd->s_parent = sysfs_get(acxt->parent_sd);
+	sd->s_hash = sysfs_name_hash(sd->s_name, sd->s_ns);
+	sd->s_parent = sysfs_get(parent_sd);
 
 	ret = sysfs_link_sibling(sd);
 	if (ret)
 		return ret;
 
 	/* Update timestamps on the parent */
-	ps_iattr = acxt->parent_sd->s_iattr;
+	ps_iattr = parent_sd->s_iattr;
 	if (ps_iattr) {
 		struct iattr *ps_iattrs = &ps_iattr->ia_iattr;
 		ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME;
@@ -490,14 +470,32 @@ static char *sysfs_pathname(struct sysfs_dirent *sd, char *path)
 	return path;
 }
 
+void sysfs_warn_dup(struct sysfs_dirent *parent, const char *name)
+{
+	char *path;
+
+	path = kzalloc(PATH_MAX, GFP_KERNEL);
+	if (path) {
+		sysfs_pathname(parent, path);
+		strlcat(path, "/", PATH_MAX);
+		strlcat(path, name, PATH_MAX);
+	}
+
+	WARN(1, KERN_WARNING "sysfs: cannot create duplicate filename '%s'\n",
+	     path ? path : name);
+
+	kfree(path);
+}
+
 /**
  *	sysfs_add_one - add sysfs_dirent to parent
  *	@acxt: addrm context to use
  *	@sd: sysfs_dirent to be added
+ *	@parent_sd: the parent sysfs_dirent to add @sd to
  *
- *	Get @acxt->parent_sd and set sd->s_parent to it and increment
- *	nlink of parent inode if @sd is a directory and link into the
- *	children list of the parent.
+ *	Get @parent_sd and set @sd->s_parent to it and increment nlink of
+ *	the parent inode if @sd is a directory and link into the children
+ *	list of the parent.
  *
  *	This function should be called between calls to
  *	sysfs_addrm_start() and sysfs_addrm_finish() and should be
@@ -510,23 +508,15 @@ static char *sysfs_pathname(struct sysfs_dirent *sd, char *path)
  *	0 on success, -EEXIST if entry with the given name already
  *	exists.
  */
-int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
+int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd,
+		  struct sysfs_dirent *parent_sd)
 {
 	int ret;
 
-	ret = __sysfs_add_one(acxt, sd);
-	if (ret == -EEXIST) {
-		char *path = kzalloc(PATH_MAX, GFP_KERNEL);
-		WARN(1, KERN_WARNING
-		     "sysfs: cannot create duplicate filename '%s'\n",
-		     (path == NULL) ? sd->s_name
-				    : (sysfs_pathname(acxt->parent_sd, path),
-				       strlcat(path, "/", PATH_MAX),
-				       strlcat(path, sd->s_name, PATH_MAX),
-				       path));
-		kfree(path);
-	}
+	ret = __sysfs_add_one(acxt, sd, parent_sd);
 
+	if (ret == -EEXIST)
+		sysfs_warn_dup(parent_sd, sd->s_name);
 	return ret;
 }
 
@@ -545,16 +535,22 @@ int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
  *	LOCKING:
  *	Determined by sysfs_addrm_start().
  */
-void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
+static void sysfs_remove_one(struct sysfs_addrm_cxt *acxt,
+			     struct sysfs_dirent *sd)
 {
 	struct sysfs_inode_attrs *ps_iattr;
 
-	BUG_ON(sd->s_flags & SYSFS_FLAG_REMOVED);
+	/*
+	 * Removal can be called multiple times on the same node.  Only the
+	 * first invocation is effective and puts the base ref.
+	 */
+	if (sd->s_flags & SYSFS_FLAG_REMOVED)
+		return;
 
 	sysfs_unlink_sibling(sd);
 
 	/* Update timestamps on the parent */
-	ps_iattr = acxt->parent_sd->s_iattr;
+	ps_iattr = sd->s_parent->s_iattr;
 	if (ps_iattr) {
 		struct iattr *ps_iattrs = &ps_iattr->ia_iattr;
 		ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME;
@@ -577,6 +573,7 @@ void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
  *	sysfs_mutex is released.
  */
 void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt)
+	__releases(sysfs_mutex)
 {
 	/* release resources acquired by sysfs_addrm_start() */
 	mutex_unlock(&sysfs_mutex);
@@ -588,7 +585,7 @@ void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt)
 		acxt->removed = sd->u.removed_list;
 
 		sysfs_deactivate(sd);
-		unmap_bin_file(sd);
+		sysfs_unmap_bin_file(sd);
 		sysfs_put(sd);
 	}
 }
@@ -597,6 +594,7 @@ void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt)
  *	sysfs_find_dirent - find sysfs_dirent with the given name
  *	@parent_sd: sysfs_dirent to search under
  *	@name: name to look for
+ *	@ns: the namespace tag to use
  *
  *	Look for sysfs_dirent with name @name under @parent_sd.
  *
@@ -607,26 +605,19 @@ void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt)
  *	Pointer to sysfs_dirent if found, NULL if not.
  */
 struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd,
-				       const void *ns,
-				       const unsigned char *name)
+				       const unsigned char *name,
+				       const void *ns)
 {
 	struct rb_node *node = parent_sd->s_dir.children.rb_node;
 	unsigned int hash;
 
-	if (!!sysfs_ns_type(parent_sd) != !!ns) {
-		WARN(1, KERN_WARNING "sysfs: ns %s in '%s' for '%s'\n",
-			sysfs_ns_type(parent_sd) ? "required" : "invalid",
-			parent_sd->s_name, name);
-		return NULL;
-	}
-
-	hash = sysfs_name_hash(ns, name);
+	hash = sysfs_name_hash(name, ns);
 	while (node) {
 		struct sysfs_dirent *sd;
 		int result;
 
 		sd = to_sysfs_dirent(node);
-		result = sysfs_name_compare(hash, ns, name, sd);
+		result = sysfs_name_compare(hash, name, ns, sd);
 		if (result < 0)
 			node = node->rb_left;
 		else if (result > 0)
@@ -638,9 +629,10 @@ struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd,
 }
 
 /**
- *	sysfs_get_dirent - find and get sysfs_dirent with the given name
+ *	sysfs_get_dirent_ns - find and get sysfs_dirent with the given name
  *	@parent_sd: sysfs_dirent to search under
  *	@name: name to look for
+ *	@ns: the namespace tag to use
  *
  *	Look for sysfs_dirent with name @name under @parent_sd and get
  *	it if found.
@@ -651,24 +643,24 @@ struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd,
  *	RETURNS:
  *	Pointer to sysfs_dirent if found, NULL if not.
  */
-struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
-				      const void *ns,
-				      const unsigned char *name)
+struct sysfs_dirent *sysfs_get_dirent_ns(struct sysfs_dirent *parent_sd,
+					 const unsigned char *name,
+					 const void *ns)
 {
 	struct sysfs_dirent *sd;
 
 	mutex_lock(&sysfs_mutex);
-	sd = sysfs_find_dirent(parent_sd, ns, name);
+	sd = sysfs_find_dirent(parent_sd, name, ns);
 	sysfs_get(sd);
 	mutex_unlock(&sysfs_mutex);
 
 	return sd;
 }
-EXPORT_SYMBOL_GPL(sysfs_get_dirent);
+EXPORT_SYMBOL_GPL(sysfs_get_dirent_ns);
 
 static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd,
-	enum kobj_ns_type type, const void *ns, const char *name,
-	struct sysfs_dirent **p_sd)
+		      const char *name, const void *ns,
+		      struct sysfs_dirent **p_sd)
 {
 	umode_t mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
 	struct sysfs_addrm_cxt acxt;
@@ -680,13 +672,12 @@ static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd,
 	if (!sd)
 		return -ENOMEM;
 
-	sd->s_flags |= (type << SYSFS_NS_TYPE_SHIFT);
 	sd->s_ns = ns;
 	sd->s_dir.kobj = kobj;
 
 	/* link in */
-	sysfs_addrm_start(&acxt, parent_sd);
-	rc = sysfs_add_one(&acxt, sd);
+	sysfs_addrm_start(&acxt);
+	rc = sysfs_add_one(&acxt, sd, parent_sd);
 	sysfs_addrm_finish(&acxt);
 
 	if (rc == 0)
@@ -700,44 +691,17 @@ static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd,
 int sysfs_create_subdir(struct kobject *kobj, const char *name,
 			struct sysfs_dirent **p_sd)
 {
-	return create_dir(kobj, kobj->sd,
-			  KOBJ_NS_TYPE_NONE, NULL, name, p_sd);
+	return create_dir(kobj, kobj->sd, name, NULL, p_sd);
 }
 
 /**
- *	sysfs_read_ns_type: return associated ns_type
- *	@kobj: the kobject being queried
- *
- *	Each kobject can be tagged with exactly one namespace type
- *	(i.e. network or user).  Return the ns_type associated with
- *	this object if any
+ * sysfs_create_dir_ns - create a directory for an object with a namespace tag
+ * @kobj: object we're creating directory for
+ * @ns: the namespace tag to use
  */
-static enum kobj_ns_type sysfs_read_ns_type(struct kobject *kobj)
+int sysfs_create_dir_ns(struct kobject *kobj, const void *ns)
 {
-	const struct kobj_ns_type_operations *ops;
-	enum kobj_ns_type type;
-
-	ops = kobj_child_ns_ops(kobj);
-	if (!ops)
-		return KOBJ_NS_TYPE_NONE;
-
-	type = ops->type;
-	BUG_ON(type <= KOBJ_NS_TYPE_NONE);
-	BUG_ON(type >= KOBJ_NS_TYPES);
-	BUG_ON(!kobj_ns_type_registered(type));
-
-	return type;
-}
-
-/**
- *	sysfs_create_dir - create a directory for an object.
- *	@kobj:		object we're creating directory for.
- */
-int sysfs_create_dir(struct kobject *kobj)
-{
-	enum kobj_ns_type type;
 	struct sysfs_dirent *parent_sd, *sd;
-	const void *ns = NULL;
 	int error = 0;
 
 	BUG_ON(!kobj);
@@ -750,11 +714,7 @@ int sysfs_create_dir(struct kobject *kobj)
 	if (!parent_sd)
 		return -ENOENT;
 
-	if (sysfs_ns_type(parent_sd))
-		ns = kobj->ktype->namespace(kobj);
-	type = sysfs_read_ns_type(kobj);
-
-	error = create_dir(kobj, parent_sd, type, ns, kobject_name(kobj), &sd);
+	error = create_dir(kobj, parent_sd, kobject_name(kobj), ns, &sd);
 	if (!error)
 		kobj->sd = sd;
 	return error;
@@ -768,15 +728,14 @@ static struct dentry *sysfs_lookup(struct inode *dir, struct dentry *dentry,
 	struct sysfs_dirent *parent_sd = parent->d_fsdata;
 	struct sysfs_dirent *sd;
 	struct inode *inode;
-	enum kobj_ns_type type;
-	const void *ns;
+	const void *ns = NULL;
 
 	mutex_lock(&sysfs_mutex);
 
-	type = sysfs_ns_type(parent_sd);
-	ns = sysfs_info(dir->i_sb)->ns[type];
+	if (parent_sd->s_flags & SYSFS_FLAG_HAS_NS)
+		ns = sysfs_info(dir->i_sb)->ns;
 
-	sd = sysfs_find_dirent(parent_sd, ns, dentry->d_name.name);
+	sd = sysfs_find_dirent(parent_sd, dentry->d_name.name, ns);
 
 	/* no such entry */
 	if (!sd) {
@@ -807,41 +766,128 @@ const struct inode_operations sysfs_dir_inode_operations = {
 	.setxattr	= sysfs_setxattr,
 };
 
-static void remove_dir(struct sysfs_dirent *sd)
+static struct sysfs_dirent *sysfs_leftmost_descendant(struct sysfs_dirent *pos)
 {
-	struct sysfs_addrm_cxt acxt;
+	struct sysfs_dirent *last;
 
-	sysfs_addrm_start(&acxt, sd->s_parent);
-	sysfs_remove_one(&acxt, sd);
-	sysfs_addrm_finish(&acxt);
+	while (true) {
+		struct rb_node *rbn;
+
+		last = pos;
+
+		if (sysfs_type(pos) != SYSFS_DIR)
+			break;
+
+		rbn = rb_first(&pos->s_dir.children);
+		if (!rbn)
+			break;
+
+		pos = to_sysfs_dirent(rbn);
+	}
+
+	return last;
 }
 
-void sysfs_remove_subdir(struct sysfs_dirent *sd)
+/**
+ * sysfs_next_descendant_post - find the next descendant for post-order walk
+ * @pos: the current position (%NULL to initiate traversal)
+ * @root: sysfs_dirent whose descendants to walk
+ *
+ * Find the next descendant to visit for post-order traversal of @root's
+ * descendants.  @root is included in the iteration and the last nod