Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/driver-2.6

* master.kernel.org:/pub/scm/linux/kernel/git/gregkh/driver-2.6: (61 commits)
  sysfs: add parameter "struct bin_attribute *" in .read/.write methods for sysfs binary attributes
  sysfs: make directory dentries and inodes reclaimable
  sysfs: implement sysfs_get_dentry()
  sysfs: move sysfs_drop_dentry() to dir.c and make it static
  sysfs: restructure add/remove paths and fix inode update
  sysfs: use sysfs_mutex to protect the sysfs_dirent tree
  sysfs: consolidate sysfs spinlocks
  sysfs: make kobj point to sysfs_dirent instead of dentry
  sysfs: implement sysfs_find_dirent() and sysfs_get_dirent()
  sysfs: implement SYSFS_FLAG_REMOVED flag
  sysfs: rename sysfs_dirent->s_type to s_flags and make room for flags
  sysfs: make sysfs_drop_dentry() access inodes using ilookup()
  sysfs: Fix oops in sysfs_drop_dentry on x86_64
  sysfs: use singly-linked list for sysfs_dirent tree
  sysfs: slim down sysfs_dirent->s_active
  sysfs: move s_active functions to fs/sysfs/dir.c
  sysfs: fix root sysfs_dirent -> root dentry association
  sysfs: use iget_locked() instead of new_inode()
  sysfs: reorganize sysfs_new_indoe() and sysfs_create()
  sysfs: fix parent refcounting during rename and move
  ...

12 files changed, 1563 insertions, 1006 deletions

diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index ec8896b264d..1d533a2ec3a 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -368,6 +368,69 @@ void debugfs_remove(struct dentry *dentry)
 }
 EXPORT_SYMBOL_GPL(debugfs_remove);
 
+/**
+ * debugfs_rename - rename a file/directory in the debugfs filesystem
+ * @old_dir: a pointer to the parent dentry for the renamed object. This
+ *          should be a directory dentry.
+ * @old_dentry: dentry of an object to be renamed.
+ * @new_dir: a pointer to the parent dentry where the object should be
+ *          moved. This should be a directory dentry.
+ * @new_name: a pointer to a string containing the target name.
+ *
+ * This function renames a file/directory in debugfs.  The target must not
+ * exist for rename to succeed.
+ *
+ * This function will return a pointer to old_dentry (which is updated to
+ * reflect renaming) if it succeeds. If an error occurs, %NULL will be
+ * returned.
+ *
+ * If debugfs is not enabled in the kernel, the value -%ENODEV will be
+ * returned.
+ */
+struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
+		struct dentry *new_dir, const char *new_name)
+{
+	int error;
+	struct dentry *dentry = NULL, *trap;
+	const char *old_name;
+
+	trap = lock_rename(new_dir, old_dir);
+	/* Source or destination directories don't exist? */
+	if (!old_dir->d_inode || !new_dir->d_inode)
+		goto exit;
+	/* Source does not exist, cyclic rename, or mountpoint? */
+	if (!old_dentry->d_inode || old_dentry == trap ||
+	    d_mountpoint(old_dentry))
+		goto exit;
+	dentry = lookup_one_len(new_name, new_dir, strlen(new_name));
+	/* Lookup failed, cyclic rename or target exists? */
+	if (IS_ERR(dentry) || dentry == trap || dentry->d_inode)
+		goto exit;
+
+	old_name = fsnotify_oldname_init(old_dentry->d_name.name);
+
+	error = simple_rename(old_dir->d_inode, old_dentry, new_dir->d_inode,
+		dentry);
+	if (error) {
+		fsnotify_oldname_free(old_name);
+		goto exit;
+	}
+	d_move(old_dentry, dentry);
+	fsnotify_move(old_dir->d_inode, new_dir->d_inode, old_name,
+		old_dentry->d_name.name, S_ISDIR(old_dentry->d_inode->i_mode),
+		NULL, old_dentry->d_inode);
+	fsnotify_oldname_free(old_name);
+	unlock_rename(new_dir, old_dir);
+	dput(dentry);
+	return old_dentry;
+exit:
+	if (dentry && !IS_ERR(dentry))
+		dput(dentry);
+	unlock_rename(new_dir, old_dir);
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(debugfs_rename);
+
 static decl_subsys(debug, NULL, NULL);
 
 static int __init debugfs_init(void)
diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
index 606128f5c92..02ca6f1e55d 100644
--- a/fs/ecryptfs/main.c
+++ b/fs/ecryptfs/main.c
@@ -840,8 +840,6 @@ static int __init ecryptfs_init(void)
 		goto out;
 	}
 	kobj_set_kset_s(&ecryptfs_subsys, fs_subsys);
-	sysfs_attr_version.attr.owner = THIS_MODULE;
-	sysfs_attr_version_str.attr.owner = THIS_MODULE;
 	rc = do_sysfs_registration();
 	if (rc) {
 		printk(KERN_ERR "sysfs registration failed\n");
diff --git a/fs/ocfs2/cluster/masklog.c b/fs/ocfs2/cluster/masklog.c
index 2b205f5d579..e9e042b93db 100644
--- a/fs/ocfs2/cluster/masklog.c
+++ b/fs/ocfs2/cluster/masklog.c
@@ -74,7 +74,6 @@ struct mlog_attribute {
 #define define_mask(_name) {			\
 	.attr = {				\
 		.name = #_name,			\
-		.owner = THIS_MODULE,		\
 		.mode = S_IRUGO | S_IWUSR,	\
 	},					\
 	.mask = ML_##_name,			\
diff --git a/fs/partitions/check.c b/fs/partitions/check.c
index 9a3a058f355..98e0b85a9bb 100644
--- a/fs/partitions/check.c
+++ b/fs/partitions/check.c
@@ -397,7 +397,6 @@ void add_partition(struct gendisk *disk, int part, sector_t start, sector_t len,
 		static struct attribute addpartattr = {
 			.name = "whole_disk",
 			.mode = S_IRUSR | S_IRGRP | S_IROTH,
-			.owner = THIS_MODULE,
 		};
 
 		sysfs_create_file(&p->kobj, &addpartattr);
diff --git a/fs/sysfs/bin.c b/fs/sysfs/bin.c
index d3b9f5f07db..135353f8a29 100644
--- a/fs/sysfs/bin.c
+++ b/fs/sysfs/bin.c
@@ -20,29 +20,41 @@
 
 #include "sysfs.h"
 
+struct bin_buffer {
+	struct mutex	mutex;
+	void		*buffer;
+	int		mmapped;
+};
+
 static int
 fill_read(struct dentry *dentry, char *buffer, loff_t off, size_t count)
 {
-	struct bin_attribute * attr = to_bin_attr(dentry);
-	struct kobject * kobj = to_kobj(dentry->d_parent);
+	struct sysfs_dirent *attr_sd = dentry->d_fsdata;
+	struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr;
+	struct kobject *kobj = attr_sd->s_parent->s_elem.dir.kobj;
+	int rc;
+
+	/* need attr_sd for attr, its parent for kobj */
+	if (!sysfs_get_active_two(attr_sd))
+		return -ENODEV;
 
-	if (!attr->read)
-		return -EIO;
+	rc = -EIO;
+	if (attr->read)
+		rc = attr->read(kobj, attr, buffer, off, count);
 
-	return attr->read(kobj, buffer, off, count);
+	sysfs_put_active_two(attr_sd);
+
+	return rc;
 }
 
 static ssize_t
-read(struct file * file, char __user * userbuf, size_t count, loff_t * off)
+read(struct file *file, char __user *userbuf, size_t bytes, loff_t *off)
 {
-	char *buffer = file->private_data;
+	struct bin_buffer *bb = file->private_data;
 	struct dentry *dentry = file->f_path.dentry;
 	int size = dentry->d_inode->i_size;
 	loff_t offs = *off;
-	int ret;
-
-	if (count > PAGE_SIZE)
-		count = PAGE_SIZE;
+	int count = min_t(size_t, bytes, PAGE_SIZE);
 
 	if (size) {
 		if (offs > size)
@@ -51,43 +63,56 @@ read(struct file * file, char __user * userbuf, size_t count, loff_t * off)
 			count = size - offs;
 	}
 
-	ret = fill_read(dentry, buffer, offs, count);
-	if (ret < 0) 
-		return ret;
-	count = ret;
+	mutex_lock(&bb->mutex);
+
+	count = fill_read(dentry, bb->buffer, offs, count);
+	if (count < 0)
+		goto out_unlock;
 
-	if (copy_to_user(userbuf, buffer, count))
-		return -EFAULT;
+	if (copy_to_user(userbuf, bb->buffer, count)) {
+		count = -EFAULT;
+		goto out_unlock;
+	}
 
-	pr_debug("offs = %lld, *off = %lld, count = %zd\n", offs, *off, count);
+	pr_debug("offs = %lld, *off = %lld, count = %d\n", offs, *off, count);
 
 	*off = offs + count;
 
+ out_unlock:
+	mutex_unlock(&bb->mutex);
 	return count;
 }
 
 static int
 flush_write(struct dentry *dentry, char *buffer, loff_t offset, size_t count)
 {
-	struct bin_attribute *attr = to_bin_attr(dentry);
-	struct kobject *kobj = to_kobj(dentry->d_parent);
+	struct sysfs_dirent *attr_sd = dentry->d_fsdata;
+	struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr;
+	struct kobject *kobj = attr_sd->s_parent->s_elem.dir.kobj;
+	int rc;
+
+	/* need attr_sd for attr, its parent for kobj */
+	if (!sysfs_get_active_two(attr_sd))
+		return -ENODEV;
+
+	rc = -EIO;
+	if (attr->write)
+		rc = attr->write(kobj, attr, buffer, offset, count);
 
-	if (!attr->write)
-		return -EIO;
+	sysfs_put_active_two(attr_sd);
 
-	return attr->write(kobj, buffer, offset, count);
+	return rc;
 }
 
-static ssize_t write(struct file * file, const char __user * userbuf,
-		     size_t count, loff_t * off)
+static ssize_t write(struct file *file, const char __user *userbuf,
+		     size_t bytes, loff_t *off)
 {
-	char *buffer = file->private_data;
+	struct bin_buffer *bb = file->private_data;
 	struct dentry *dentry = file->f_path.dentry;
 	int size = dentry->d_inode->i_size;
 	loff_t offs = *off;
+	int count = min_t(size_t, bytes, PAGE_SIZE);
 
-	if (count > PAGE_SIZE)
-		count = PAGE_SIZE;
 	if (size) {
 		if (offs > size)
 			return 0;
@@ -95,72 +120,100 @@ static ssize_t write(struct file * file, const char __user * userbuf,
 			count = size - offs;
 	}
 
-	if (copy_from_user(buffer, userbuf, count))
-		return -EFAULT;
+	mutex_lock(&bb->mutex);
 
-	count = flush_write(dentry, buffer, offs, count);
+	if (copy_from_user(bb->buffer, userbuf, count)) {
+		count = -EFAULT;
+		goto out_unlock;
+	}
+
+	count = flush_write(dentry, bb->buffer, offs, count);
 	if (count > 0)
 		*off = offs + count;
+
+ out_unlock:
+	mutex_unlock(&bb->mutex);
 	return count;
 }
 
 static int mmap(struct file *file, struct vm_area_struct *vma)
 {
-	struct dentry *dentry = file->f_path.dentry;
-	struct bin_attribute *attr = to_bin_attr(dentry);
-	struct kobject *kobj = to_kobj(dentry->d_parent);
+	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_elem.bin_attr.bin_attr;
+	struct kobject *kobj = attr_sd->s_parent->s_elem.dir.kobj;
+	int rc;
+
+	mutex_lock(&bb->mutex);
+
+	/* need attr_sd for attr, its parent for kobj */
+	if (!sysfs_get_active_two(attr_sd))
+		return -ENODEV;
 
-	if (!attr->mmap)
-		return -EINVAL;
+	rc = -EINVAL;
+	if (attr->mmap)
+		rc = attr->mmap(kobj, attr, vma);
 
-	return attr->mmap(kobj, attr, vma);
+	if (rc == 0 && !bb->mmapped)
+		bb->mmapped = 1;
+	else
+		sysfs_put_active_two(attr_sd);
+
+	mutex_unlock(&bb->mutex);
+
+	return rc;
 }
 
 static int open(struct inode * inode, struct file * file)
 {
-	struct kobject *kobj = sysfs_get_kobject(file->f_path.dentry->d_parent);
-	struct bin_attribute * attr = to_bin_attr(file->f_path.dentry);
-	int error = -EINVAL;
-
-	if (!kobj || !attr)
-		goto Done;
+	struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
+	struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr;
+	struct bin_buffer *bb = NULL;
+	int error;
 
-	/* Grab the module reference for this attribute if we have one */
-	error = -ENODEV;
-	if (!try_module_get(attr->attr.owner)) 
-		goto Done;
+	/* need attr_sd for attr */
+	if (!sysfs_get_active(attr_sd))
+		return -ENODEV;
 
 	error = -EACCES;
 	if ((file->f_mode & FMODE_WRITE) && !(attr->write || attr->mmap))
-		goto Error;
+		goto err_out;
 	if ((file->f_mode & FMODE_READ) && !(attr->read || attr->mmap))
-		goto Error;
+		goto err_out;
 
 	error = -ENOMEM;
-	file->private_data = kmalloc(PAGE_SIZE, GFP_KERNEL);
-	if (!file->private_data)
-		goto Error;
-
-	error = 0;
-    goto Done;
-
- Error:
-	module_put(attr->attr.owner);
- Done:
-	if (error)
-		kobject_put(kobj);
+	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);
+	file->private_data = bb;
+
+	/* open succeeded, put active reference and pin attr_sd */
+	sysfs_put_active(attr_sd);
+	sysfs_get(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 kobject * kobj = to_kobj(file->f_path.dentry->d_parent);
-	struct bin_attribute * attr = to_bin_attr(file->f_path.dentry);
-	u8 * buffer = file->private_data;
-
-	kobject_put(kobj);
-	module_put(attr->attr.owner);
-	kfree(buffer);
+	struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
+	struct bin_buffer *bb = file->private_data;
+
+	if (bb->mmapped)
+		sysfs_put_active_two(attr_sd);
+	sysfs_put(attr_sd);
+	kfree(bb->buffer);
+	kfree(bb);
 	return 0;
 }
 
@@ -181,9 +234,9 @@ const struct file_operations bin_fops = {
 
 int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr)
 {
-	BUG_ON(!kobj || !kobj->dentry || !attr);
+	BUG_ON(!kobj || !kobj->sd || !attr);
 
-	return sysfs_add_file(kobj->dentry, &attr->attr, SYSFS_KOBJ_BIN_ATTR);
+	return sysfs_add_file(kobj->sd, &attr->attr, SYSFS_KOBJ_BIN_ATTR);
 }
 
 
@@ -195,7 +248,7 @@ int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr)
 
 void sysfs_remove_bin_file(struct kobject * kobj, struct bin_attribute * attr)
 {
-	if (sysfs_hash_and_remove(kobj->dentry, attr->attr.name) < 0) {
+	if (sysfs_hash_and_remove(kobj->sd, attr->attr.name) < 0) {
 		printk(KERN_ERR "%s: "
 			"bad dentry or inode or no such file: \"%s\"\n",
 			__FUNCTION__, attr->attr.name);
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index c4342a01997..aee966c44aa 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -9,21 +9,337 @@
 #include <linux/module.h>
 #include <linux/kobject.h>
 #include <linux/namei.h>
+#include <linux/idr.h>
+#include <linux/completion.h>
 #include <asm/semaphore.h>
 #include "sysfs.h"
 
-DECLARE_RWSEM(sysfs_rename_sem);
-spinlock_t sysfs_lock = SPIN_LOCK_UNLOCKED;
+DEFINE_MUTEX(sysfs_mutex);
+spinlock_t sysfs_assoc_lock = SPIN_LOCK_UNLOCKED;
+
+static spinlock_t sysfs_ino_lock = SPIN_LOCK_UNLOCKED;
+static DEFINE_IDA(sysfs_ino_ida);
+
+/**
+ *	sysfs_link_sibling - link sysfs_dirent into sibling list
+ *	@sd: sysfs_dirent of interest
+ *
+ *	Link @sd into its sibling list which starts from
+ *	sd->s_parent->s_children.
+ *
+ *	Locking:
+ *	mutex_lock(sysfs_mutex)
+ */
+void sysfs_link_sibling(struct sysfs_dirent *sd)
+{
+	struct sysfs_dirent *parent_sd = sd->s_parent;
+
+	BUG_ON(sd->s_sibling);
+	sd->s_sibling = parent_sd->s_children;
+	parent_sd->s_children = sd;
+}
+
+/**
+ *	sysfs_unlink_sibling - unlink sysfs_dirent from sibling list
+ *	@sd: sysfs_dirent of interest
+ *
+ *	Unlink @sd from its sibling list which starts from
+ *	sd->s_parent->s_children.
+ *
+ *	Locking:
+ *	mutex_lock(sysfs_mutex)
+ */
+void sysfs_unlink_sibling(struct sysfs_dirent *sd)
+{
+	struct sysfs_dirent **pos;
+
+	for (pos = &sd->s_parent->s_children; *pos; pos = &(*pos)->s_sibling) {
+		if (*pos == sd) {
+			*pos = sd->s_sibling;
+			sd->s_sibling = NULL;
+			break;
+		}
+	}
+}
+
+/**
+ *	sysfs_get_dentry - get dentry for the given sysfs_dirent
+ *	@sd: sysfs_dirent of interest
+ *
+ *	Get dentry for @sd.  Dentry is looked up if currently not
+ *	present.  This function climbs sysfs_dirent tree till it
+ *	reaches a sysfs_dirent with valid dentry attached and descends
+ *	down from there looking up dentry for each step.
+ *
+ *	LOCKING:
+ *	Kernel thread context (may sleep)
+ *
+ *	RETURNS:
+ *	Pointer to found dentry on success, ERR_PTR() value on error.
+ */
+struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd)
+{
+	struct sysfs_dirent *cur;
+	struct dentry *parent_dentry, *dentry;
+	int i, depth;
+
+	/* Find the first parent which has valid s_dentry and get the
+	 * dentry.
+	 */
+	mutex_lock(&sysfs_mutex);
+ restart0:
+	spin_lock(&sysfs_assoc_lock);
+ restart1:
+	spin_lock(&dcache_lock);
+
+	dentry = NULL;
+	depth = 0;
+	cur = sd;
+	while (!cur->s_dentry || !cur->s_dentry->d_inode) {
+		if (cur->s_flags & SYSFS_FLAG_REMOVED) {
+			dentry = ERR_PTR(-ENOENT);
+			depth = 0;
+			break;
+		}
+		cur = cur->s_parent;
+		depth++;
+	}
+	if (!IS_ERR(dentry))
+		dentry = dget_locked(cur->s_dentry);
+
+	spin_unlock(&dcache_lock);
+	spin_unlock(&sysfs_assoc_lock);
+
+	/* from the found dentry, look up depth times */
+	while (depth--) {
+		/* find and get depth'th ancestor */
+		for (cur = sd, i = 0; cur && i < depth; i++)
+			cur = cur->s_parent;
+
+		/* This can happen if tree structure was modified due
+		 * to move/rename.  Restart.
+		 */
+		if (i != depth) {
+			dput(dentry);
+			goto restart0;
+		}
+
+		sysfs_get(cur);
+
+		mutex_unlock(&sysfs_mutex);
+
+		/* look it up */
+		parent_dentry = dentry;
+		dentry = lookup_one_len_kern(cur->s_name, parent_dentry,
+					     strlen(cur->s_name));
+		dput(parent_dentry);
+
+		if (IS_ERR(dentry)) {
+			sysfs_put(cur);
+			return dentry;
+		}
+
+		mutex_lock(&sysfs_mutex);
+		spin_lock(&sysfs_assoc_lock);
+
+		/* This, again, can happen if tree structure has
+		 * changed and we looked up the wrong thing.  Restart.
+		 */
+		if (cur->s_dentry != dentry) {
+			dput(dentry);
+			sysfs_put(cur);
+			goto restart1;
+		}
+
+		spin_unlock(&sysfs_assoc_lock);
+
+		sysfs_put(cur);
+	}
+
+	mutex_unlock(&sysfs_mutex);
+	return dentry;
+}
+
+/**
+ *	sysfs_get_active - get an active reference to sysfs_dirent
+ *	@sd: sysfs_dirent to get an active reference to
+ *
+ *	Get an active reference of @sd.  This function is noop if @sd
+ *	is NULL.
+ *
+ *	RETURNS:
+ *	Pointer to @sd on success, NULL on failure.
+ */
+struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd)
+{
+	if (unlikely(!sd))
+		return NULL;
+
+	while (1) {
+		int v, t;
+
+		v = atomic_read(&sd->s_active);
+		if (unlikely(v < 0))
+			return NULL;
+
+		t = atomic_cmpxchg(&sd->s_active, v, v + 1);
+		if (likely(t == v))
+			return sd;
+		if (t < 0)
+			return NULL;
+
+		cpu_relax();
+	}
+}
+
+/**
+ *	sysfs_put_active - put an active reference to sysfs_dirent
+ *	@sd: sysfs_dirent to put an active reference to
+ *
+ *	Put an active reference to @sd.  This function is noop if @sd
+ *	is NULL.
+ */
+void sysfs_put_active(struct sysfs_dirent *sd)
+{
+	struct completion *cmpl;
+	int v;
+
+	if (unlikely(!sd))
+		return;
+
+	v = atomic_dec_return(&sd->s_active);
+	if (likely(v != SD_DEACTIVATED_BIAS))
+		return;
+
+	/* atomic_dec_return() is a mb(), we'll always see the updated
+	 * sd->s_sibling.
+	 */
+	cmpl = (void *)sd->s_sibling;
+	complete(cmpl);
+}
+
+/**
+ *	sysfs_get_active_two - get active references to sysfs_dirent and parent
+ *	@sd: sysfs_dirent of interest
+ *
+ *	Get active reference to @sd and its parent.  Parent's active
+ *	reference is grabbed first.  This function is noop if @sd is
+ *	NULL.
+ *
+ *	RETURNS:
+ *	Pointer to @sd on success, NULL on failure.
+ */
+struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd)
+{
+	if (sd) {
+		if (sd->s_parent && unlikely(!sysfs_get_active(sd->s_parent)))
+			return NULL;
+		if (unlikely(!sysfs_get_active(sd))) {
+			sysfs_put_active(sd->s_parent);
+			return NULL;
+		}
+	}
+	return sd;
+}
+
+/**
+ *	sysfs_put_active_two - put active references to sysfs_dirent and parent
+ *	@sd: sysfs_dirent of interest
+ *
+ *	Put active references to @sd and its parent.  This function is
+ *	noop if @sd is NULL.
+ */
+void sysfs_put_active_two(struct sysfs_dirent *sd)
+{
+	if (sd) {
+		sysfs_put_active(sd);
+		sysfs_put_active(sd->s_parent);
+	}
+}
+
+/**
+ *	sysfs_deactivate - deactivate sysfs_dirent
+ *	@sd: sysfs_dirent to deactivate
+ *
+ *	Deny new active references and drain existing ones.
+ */
+static void sysfs_deactivate(struct sysfs_dirent *sd)
+{
+	DECLARE_COMPLETION_ONSTACK(wait);
+	int v;
+
+	BUG_ON(sd->s_sibling || !(sd->s_flags & SYSFS_FLAG_REMOVED));
+	sd->s_sibling = (void *)&wait;
+
+	/* atomic_add_return() is a mb(), put_active() will always see
+	 * the updated sd->s_sibling.
+	 */
+	v = atomic_add_return(SD_DEACTIVATED_BIAS, &sd->s_active);
+
+	if (v != SD_DEACTIVATED_BIAS)
+		wait_for_completion(&wait);
+
+	sd->s_sibling = NULL;
+}
+
+static int sysfs_alloc_ino(ino_t *pino)
+{
+	int ino, rc;
+
+ retry:
+	spin_lock(&sysfs_ino_lock);
+	rc = ida_get_new_above(&sysfs_ino_ida, 2, &ino);
+	spin_unlock(&sysfs_ino_lock);
+
+	if (rc == -EAGAIN) {
+		if (ida_pre_get(&sysfs_ino_ida, GFP_KERNEL))
+			goto retry;
+		rc = -ENOMEM;
+	}
+
+	*pino = ino;
+	return rc;
+}
+
+static void sysfs_free_ino(ino_t ino)
+{
+	spin_lock(&sysfs_ino_lock);
+	ida_remove(&sysfs_ino_ida, ino);
+	spin_unlock(&sysfs_ino_lock);
+}
+
+void release_sysfs_dirent(struct sysfs_dirent * sd)
+{
+	struct sysfs_dirent *parent_sd;
+
+ repeat:
+	/* Moving/renaming is always done while holding reference.
+	 * sd->s_parent won't change beneath us.
+	 */
+	parent_sd = sd->s_parent;
+
+	if (sysfs_type(sd) == SYSFS_KOBJ_LINK)
+		sysfs_put(sd->s_elem.symlink.target_sd);
+	if (sysfs_type(sd) & SYSFS_COPY_NAME)
+		kfree(sd->s_name);
+	kfree(sd->s_iattr);
+	sysfs_free_ino(sd->s_ino);
+	kmem_cache_free(sysfs_dir_cachep, sd);
+
+	sd = parent_sd;
+	if (sd && atomic_dec_and_test(&sd->s_count))
+		goto repeat;
+}
 
 static void sysfs_d_iput(struct dentry * dentry, struct inode * inode)
 {
 	struct sysfs_dirent * sd = dentry->d_fsdata;
 
 	if (sd) {
-		/* sd->s_dentry is protected with sysfs_lock.  This
-		 * allows sysfs_drop_dentry() to dereference it.
+		/* sd->s_dentry is protected with sysfs_assoc_lock.
+		 * This allows sysfs_drop_dentry() to dereference it.
 		 */
-		spin_lock(&sysfs_lock);
+		spin_lock(&sysfs_assoc_lock);
 
 		/* The dentry might have been deleted or another
 		 * lookup could have happened updating sd->s_dentry to
@@ -32,7 +348,7 @@ static void sysfs_d_iput(struct dentry * dentry, struct inode * inode)
 		 */
 		if (sd->s_dentry == dentry)
 			sd->s_dentry = NULL;
-		spin_unlock(&sysfs_lock);
+		spin_unlock(&sysfs_assoc_lock);
 		sysfs_put(sd);
 	}
 	iput(inode);
@@ -42,260 +358,402 @@ static struct dentry_operations sysfs_dentry_ops = {
 	.d_iput		= sysfs_d_iput,
 };
 
-static unsigned int sysfs_inode_counter;
-ino_t sysfs_get_inum(void)
+struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type)
 {
-	if (unlikely(sysfs_inode_counter < 3))
-		sysfs_inode_counter = 3;
-	return sysfs_inode_counter++;
-}
+	char *dup_name = NULL;
+	struct sysfs_dirent *sd = NULL;
 
-/*
- * Allocates a new sysfs_dirent and links it to the parent sysfs_dirent
- */
-static struct sysfs_dirent * __sysfs_new_dirent(void * element)
-{
-	struct sysfs_dirent * sd;
+	if (type & SYSFS_COPY_NAME) {
+		name = dup_name = kstrdup(name, GFP_KERNEL);
+		if (!name)
+			goto err_out;
+	}
 
 	sd = kmem_cache_zalloc(sysfs_dir_cachep, GFP_KERNEL);
 	if (!sd)
-		return NULL;
+		goto err_out;
+
+	if (sysfs_alloc_ino(&sd->s_ino))
+		goto err_out;
 
-	sd->s_ino = sysfs_get_inum();
 	atomic_set(&sd->s_count, 1);
+	atomic_set(&sd->s_active, 0);
 	atomic_set(&sd->s_event, 1);
-	INIT_LIST_HEAD(&sd->s_children);
-	INIT_LIST_HEAD(&sd->s_sibling);
-	sd->s_element = element;
+
+	sd->s_name = name;
+	sd->s_mode = mode;
+	sd->s_flags = type;
 
 	return sd;
+
+ err_out:
+	kfree(dup_name);
+	kmem_cache_free(sysfs_dir_cachep, sd);
+	return NULL;
 }
 
-static void __sysfs_list_dirent(struct sysfs_dirent *parent_sd,
-			      struct sysfs_dirent *sd)
+/**
+ *	sysfs_attach_dentry - associate sysfs_dirent with dentry
+ *	@sd: target sysfs_dirent
+ *	@dentry: dentry to associate
+ *
+ *	Associate @sd with @dentry.  This is protected by
+ *	sysfs_assoc_lock to avoid race with sysfs_d_iput().
+ *
+ *	LOCKING:
+ *	mutex_lock(sysfs_mutex)
+ */
+static void sysfs_attach_dentry(struct sysfs_dirent *sd, struct dentry *dentry)
 {
-	if (sd)
-		list_add(&sd->s_sibling, &parent_sd->s_children);
+	dentry->d_op = &sysfs_dentry_ops;
+	dentry->d_fsdata = sysfs_get(sd);
+
+	/* protect sd->s_dentry against sysfs_d_iput */
+	spin_lock(&sysfs_assoc_lock);
+	sd->s_dentry = dentry;
+	spin_unlock(&sysfs_assoc_lock);
+
+	d_rehash(dentry);
 }
 
-static struct sysfs_dirent * sysfs_new_dirent(struct sysfs_dirent *parent_sd,
-						void * element)
+static int sysfs_ilookup_test(struct inode *inode, void *arg)
 {
-	struct sysfs_dirent *sd;
-	sd = __sysfs_new_dirent(element);
-	__sysfs_list_dirent(parent_sd, sd);
-	return sd;
+	struct sysfs_dirent *sd = arg;
+	return inode->i_ino == sd->s_ino;
 }
 
-/*
+/**
+ *	sysfs_addrm_start - prepare for sysfs_dirent add/remove
+ *	@acxt: pointer to sysfs_addrm_cxt to be used
+ *	@parent_sd: parent sysfs_dirent
  *
- * Return -EEXIST if there is already a sysfs element with the same name for
- * the same parent.
+ *	This function is called when the caller is about to add or
+ *	remove sysfs_dirent under @parent_sd.  This function acquires
+ *	sysfs_mutex, grabs inode for @parent_sd if available and lock
+ *	i_mutex of it.  @acxt is used to keep and pass context to
+ *	other addrm functions.
  *
- * called with parent inode's i_mutex held
+ *	LOCKING:
+ *	Kernel thread context (may sleep).  sysfs_mutex is locked on
+ *	return.  i_mutex of parent inode is locked on return if
+ *	available.
  */
-int sysfs_dirent_exist(struct sysfs_dirent *parent_sd,
-			  const unsigned char *new)
+void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
+		       struct sysfs_dirent *parent_sd)
 {
-	struct sysfs_dirent * sd;
+	struct inode *inode;
 
-	list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
-		if (sd->s_element) {
-			const unsigned char *existing = sysfs_get_name(sd);
-			if (strcmp(existing, new))
-				continue;
-			else
-				return -EEXIST;
-		}
-	}
+	memset(acxt, 0, sizeof(*acxt));
+	acxt->parent_sd = parent_sd;
 
-	return 0;
+	/* Lookup parent inode.  inode initialization and I_NEW
+	 * clearing are protected by sysfs_mutex.  By grabbing it and
+	 * looking up with _nowait variant, inode state can be
+	 * determined reliably.
+	 */
+	mutex_lock(&sysfs_mutex);
+
+	inode = ilookup5_nowait(sysfs_sb, parent_sd->s_ino, sysfs_ilookup_test,
+				parent_sd);
+
+	if (inode && !(inode->i_state & I_NEW)) {
+		/* parent inode available */
+		acxt->parent_inode = inode;
+
+		/* sysfs_mutex is below i_mutex in lock hierarchy.
+		 * First, trylock i_mutex.  If fails, unlock
+		 * sysfs_mutex and lock them in order.
+		 */
+		if (!mutex_trylock(&inode->i_mutex)) {
+			mutex_unlock(&sysfs_mutex);
+			mutex_lock(&inode->i_mutex);
+			mutex_lock(&sysfs_mutex);
+		}
+	} else
+		iput(inode);
 }
 
+/**
+ *	sysfs_add_one - add sysfs_dirent to parent
+ *	@acxt: addrm context to use
+ *	@sd: sysfs_dirent to be added
+ *
+ *	Get @acxt->parent_sd and set sd->s_parent to it and increment
+ *	nlink of parent inode if @sd is a directory.  @sd is NOT
+ *	linked into the children list of the parent.  The caller
+ *	should invoke sysfs_link_sibling() after this function
+ *	completes if @sd needs to be on the children list.
+ *
+ *	This function should be called between calls to
+ *	sysfs_addrm_start() and sysfs_addrm_finish() and should be
+ *	passed the same @acxt as passed to sysfs_addrm_start().
+ *
+ *	LOCKING:
+ *	Determined by sysfs_addrm_start().
+ */
+void sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
+{
+	sd->s_parent = sysfs_get(acxt->parent_sd);
+
+	if (sysfs_type(sd) == SYSFS_DIR && acxt->parent_inode)
+		inc_nlink(acxt->parent_inode);
+
+	acxt->cnt++;
+}
 
-static struct sysfs_dirent *
-__sysfs_make_dirent(struct dentry *dentry, void *element, mode_t mode, int type)
+/**
+ *	sysfs_remove_one - remove sysfs_dirent from parent
+ *	@acxt: addrm context to use
+ *	@sd: sysfs_dirent to be added
+ *
+ *	Mark @sd removed and drop nlink of parent inode if @sd is a
+ *	directory.  @sd is NOT unlinked from the children list of the
+ *	parent.  The caller is repsonsible for removing @sd from the
+ *	children list before calling this function.
+ *
+ *	This function should be called between calls to
+ *	sysfs_addrm_start() and sysfs_addrm_finish() and should be
+ *	passed the same @acxt as passed to sysfs_addrm_start().
+ *
+ *	LOCKING:
+ *	Determined by sysfs_addrm_start().
+ */
+void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
 {
-	struct sysfs_dirent * sd;
+	BUG_ON(sd->s_sibling || (sd->s_flags & SYSFS_FLAG_REMOVED));
 
-	sd = __sysfs_new_dirent(element);
-	if (!sd)
-		goto out;
+	sd->s_flags |= SYSFS_FLAG_REMOVED;
+	sd->s_sibling = acxt->removed;
+	acxt->removed = sd;
 
-	sd->s_mode = mode;
-	sd->s_type = type;
-	sd->s_dentry = dentry;
-	if (dentry) {
-		dentry->d_fsdata = sysfs_get(sd);
-		dentry->d_op = &sysfs_dentry_ops;
-	}
+	if (sysfs_type(sd) == SYSFS_DIR && acxt->parent_inode)
+		drop_nlink(acxt->parent_inode);
 
-out:
-	return sd;
+	acxt->cnt++;
 }
 
-int sysfs_make_dirent(struct sysfs_dirent * parent_sd, struct dentry * dentry,
-			void * element, umode_t mode, int type)
+/**
+ *	sysfs_drop_dentry - drop dentry for the specified sysfs_dirent
+ *	@sd: target sysfs_dirent
+ *
+ *	Drop dentry for @sd.  @sd must have been unlinked from its
+ *	parent on entry to this function such that it can't be looked
+ *	up anymore.
+ *
+ *	@sd->s_dentry which is protected with sysfs_assoc_lock points
+ *	to the currently associated dentry but we're not holding a
+ *	reference to it and racing with dput().  Grab dcache_lock and
+ *	verify dentry before dropping it.  If @sd->s_dentry is NULL or
+ *	dput() beats us, no need to bother.
+ */
+static void sysfs_drop_dentry(struct sysfs_dirent *sd)
 {
-	struct sysfs_dirent *sd;
+	struct dentry *dentry = NULL;
+	struct inode *inode;
+
+	/* We're not holding a reference to ->s_dentry dentry but the
+	 * field will stay valid as long as sysfs_assoc_lock is held.
+	 */
+	spin_lock(&sysfs_assoc_lock);
+	spin_lock(&dcache_lock);
+
+	/* drop dentry if it's there and dput() didn't kill it yet */
+	if (sd->s_dentry && sd->s_dentry->d_inode) {
+		dentry = dget_locked(sd->s_dentry);
+		spin_lock(&dentry->d_lock);
+		__d_drop(dentry);
+		spin_unlock(&dentry->d_lock);
+	}
 
-	sd = __sysfs_make_dirent(dentry, element, mode, type);
-	__sysfs_list_dirent(parent_sd, sd);
+	spin_unlock(&dcache_lock);
+	spin_unlock(&sysfs_assoc_lock);
 
-	return sd ? 0 : -ENOMEM;
+	/* dentries for shadowed inodes are pinned, unpin */
+	if (dentry && sysfs_is_shadowed_inode(dentry->d_inode))
+		dput(dentry);
+	dput(dentry);
+
+	/* adjust nlink and update timestamp */
+	inode = ilookup(sysfs_sb, sd->s_ino);
+	if (inode) {
+		mutex_lock(&inode->i_mutex);
+
+		inode->i_ctime = CURRENT_TIME;
+		drop_nlink(inode);
+		if (sysfs_type(sd) == SYSFS_DIR)
+			drop_nlink(inode);
+
+		mutex_unlock(&inode->i_mutex);
+		iput(inode);
+	}
 }
 
-static int init_dir(struct inode * inode)
+/**
+ *	sysfs_addrm_finish - finish up sysfs_dirent add/remove
+ *	@acxt: addrm context to finish up
+ *
+ *	Finish up sysfs_dirent add/remove.  Resources acquired by
+ *	sysfs_addrm_start() are released and removed sysfs_dirents are
+ *	cleaned up.  Timestamps on the parent inode are updated.
+ *
+ *	LOCKING:
+ *	All mutexes acquired by sysfs_addrm_start() are released.
+ *
+ *	RETURNS:
+ *	Number of added/removed sysfs_dirents since sysfs_addrm_start().
+ */
+int sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt)
 {
-	inode->i_op = &sysfs_dir_inode_operations;
-	inode->i_fop = &sysfs_dir_operations;
+	/* release resources acquired by sysfs_addrm_start() */
+	mutex_unlock(&sysfs_mutex);
+	if (acxt->parent_inode) {
+		struct inode *inode = acxt->parent_inode;
 
-	/* directory inodes start off with i_nlink == 2 (for "." entry) */
-	inc_nlink(inode);
-	return 0;
+		/* if added/removed, update timestamps on the parent */
+		if (acxt->cnt)
+			inode->i_ctime = inode->i_mtime = CURRENT_TIME;
+
+		mutex_unlock(&inode->i_mutex);
+		iput(inode);
+	}
+
+	/* kill removed sysfs_dirents */
+	while (acxt->removed) {
+		struct sysfs_dirent *sd = acxt->removed;
+
+		acxt->removed = sd->s_sibling;
+		sd->s_sibling = NULL;
+
+		sysfs_drop_dentry(sd);
+		sysfs_deactivate(sd);
+		sysfs_put(sd);
+	}
+
+	return acxt->cnt;
 }
 
-static int init_file(struct inode * inode)
+/**
+ *	sysfs_find_dirent - find sysfs_dirent with the given name
+ *	@parent_sd: sysfs_dirent to search under
+ *	@name: name to look for
+ *
+ *	Look for sysfs_dirent with name @name under @parent_sd.
+ *
+ *	LOCKING:
+ *	mutex_lock(sysfs_mutex)
+ *
+ *	RETURNS:
+ *	Pointer to sysfs_dirent if found, NULL if not.
+ */
+struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd,
+				       const unsigned char *name)
 {
-	inode->i_size = PAGE_SIZE;
-	inode->i_fop = &sysfs_file_operations;
-	return 0;
+	struct sysfs_dirent *sd;
+
+	for (sd = parent_sd->s_children; sd; sd = sd->s_sibling)
+		if (sysfs_type(sd) && !strcmp(sd->s_name, name))
+			return sd;
+	return NULL;
 }
 
-static int init_symlink(struct inode * inode)
+/**
+ *	sysfs_get_dirent - find and get sysfs_dirent with the given name
+ *	@parent_sd: sysfs_dirent to search under
+ *	@name: name to look for
+ *
+ *	Look for sysfs_dirent with name @name under @parent_sd and get
+ *	it if found.
+ *
+ *	LOCKING:
+ *	Kernel thread context (may sleep).  Grabs sysfs_mutex.
+ *
+ *	RETURNS:
+ *	Pointer to sysfs_dirent if found, NULL if not.
+ */
+struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
+				      const unsigned char *name)
 {
-	inode->i_op = &sysfs_symlink_inode_operations;
-	return 0;
+	struct sysfs_dirent *sd;
+
+	mutex_lock(&sysfs_mutex);
+	sd = sysfs_find_dirent(parent_sd, name);
+	sysfs_get(sd);
+	mutex_unlock(&sysfs_mutex);
+
+	return sd;
 }
 
-static int create_dir(struct kobject * k, struct dentry * p,
-		      const char * n, struct dentry ** d)
+static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd,
+		      const char *name, struct sysfs_dirent **p_sd)
 {
-	int error;
 	umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;
+	struct sysfs_addrm_cxt acxt;
+	struct sysfs_dirent *sd;
 
-	mutex_lock(&p->d_inode->i_mutex);
-	*d = lookup_one_len(n, p, strlen(n));
-	if (!IS_ERR(*d)) {
- 		if (sysfs_dirent_exist(p->d_fsdata, n))
-  			error = -EEXIST;
-  		else
-			error = sysfs_make_dirent(p->d_fsdata, *d, k, mode,
-								SYSFS_DIR);
-		if (!error) {
-			error = sysfs_create(*d, mode, init_dir);
-			if (!error) {
-				inc_nlink(p->d_inode);
-				(*d)->d_op = &sysfs_dentry_ops;
-				d_rehash(*d);
-			}
-		}
-		if (error && (error != -EEXIST)) {
-			struct sysfs_dirent *sd = (*d)->d_fsdata;
-			if (sd) {
- 				list_del_init(&sd->s_sibling);
-				sysfs_put(sd);
-			}
-			d_drop(*d);
-		}
-		dput(*d);
-	} else
-		error = PTR_ERR(*d);
-	mutex_unlock(&p->d_inode->i_mutex);
-	return error;
-}
+	/* allocate */
+	sd = sysfs_new_dirent(name, mode, SYSFS_DIR);
+	if (!sd)
+		return -ENOMEM;
+	sd->s_elem.dir.kobj = kobj;
 
+	/* link in */
+	sysfs_addrm_start(&acxt, parent_sd);
+	if (!sysfs_find_dirent(parent_sd, name)) {
+		sysfs_add_one(&acxt, sd);
+		sysfs_link_sibling(sd);
+	}
+	if (sysfs_addrm_finish(&acxt)) {
+		*p_sd = sd;
+		return 0;
+	}
 
-int sysfs_create_subdir(struct kobject * k, const char * n, struct dentry ** d)
+	sysfs_put(sd);
+	return -EEXIST;
+}
+
+int sysfs_create_subdir(struct kobject *kobj, const char *name,
+			struct sysfs_dirent **p_sd)
 {
-	return create_dir(k,k->dentry,n,d);
+	return create_dir(kobj, kobj->sd, name, p_sd);
 }
 
 /**
  *	sysfs_create_dir - create a directory for an object.
  *	@kobj:		object we're creating directory for. 
- *	@shadow_parent:	parent parent object.
+ *	@shadow_parent:	parent object.
  */
-
-int sysfs_create_dir(struct kobject * kobj, struct dentry *shadow_parent)
+int sysfs_create_dir(struct kobject *kobj,
+		     struct sysfs_dirent *shadow_parent_sd)
 {
-	struct dentry * dentry = NULL;
-	struct dentry * parent;
+	struct sysfs_dirent *parent_sd, *sd;
 	int error = 0;
 
 	BUG_ON(!kobj);
 
-	if (shadow_parent)
-		parent = shadow_parent;
+	if (shadow_parent_sd)
+		parent_sd = shadow_parent_sd;
 	else if (kobj->parent)
-		parent = kobj->parent->dentry;
+		parent_sd = kobj->parent->sd;
 	else if (sysfs_mount && sysfs_mount->mnt_sb)
-		parent = sysfs_mount->mnt_sb->s_root;
+		parent_sd = sysfs_mount->mnt_sb->s_root->d_fsdata;
 	else
 		return -EFAULT;
 
-	error = create_dir(kobj,parent,kobject_name(kobj),&dentry);
+	error = create_dir(kobj, parent_sd, kobject_name(kobj), &sd);
 	if (!error)
-		kobj->dentry = dentry;
+		kobj->sd = sd;
 	return error;
 }
 
-/* attaches attribute's sysfs_dirent to the dentry corresponding to the
- * attribute file
- */
-static int sysfs_attach_attr(struct sysfs_dirent * sd, struct dentry * dentry)
+static int sysfs_count_nlink(struct sysfs_dirent *sd)
 {
-	struct attribute * attr = NULL;
-	struct bin_attribute * bin_attr = NULL;
-	int (* init) (struct inode *) = NULL;
-	int error = 0;
-
-        if (sd->s_type & SYSFS_KOBJ_BIN_ATTR) {
-                bin_attr = sd->s_element;
-                attr = &bin_attr->attr;
-        } else {
-                attr = sd->s_element;
-                init = init_file;
-        }
+	struct sysfs_dirent *child;
+	int nr = 0;
 
-	dentry->d_fsdata = sysfs_get(sd);
-	/* protect sd->s_dentry against sysfs_d_iput */
-	spin_lock(&sysfs_lock);
-	sd->s_dentry = dentry;
-	spin_unlock(&sysfs_lock);
-	error = sysfs_create(dentry, (attr->mode & S_IALLUGO) | S_IFREG, init);
-	if (error) {
-		sysfs_put(sd);
-		return error;
-	}
-
-        if (bin_attr) {
-		dentry->d_inode->i_size = bin_attr->size;
-		dentry->d_inode->i_fop = &bin_fops;
-	}
-	dentry->d_op = &sysfs_dentry_ops;
-	d_rehash(dentry);
-
-	return 0;
-}
-
-static int sysfs_attach_link(struct sysfs_dirent * sd, struct dentry * dentry)
-{
-	int err = 0;
-
-	dentry->d_fsdata = sysfs_get(sd);
-	/* protect sd->s_dentry against sysfs_d_iput */
-	spin_lock(&sysfs_lock);
-	sd->s_dentry = dentry;
-	spin_unlock(&sysfs_lock);
-	err = sysfs_create(dentry, S_IFLNK|S_IRWXUGO, init_symlink);
-	if (!err) {
-		dentry->d_op = &sysfs_dentry_ops;
-		d_rehash(dentry);
-	} else
-		sysfs_put(sd);
-
-	return err;
+	for (child = sd->s_children; child; child = child->s_sibling)
+		if (sysfs_type(child) == SYSFS_DIR)
+			nr++;
+	return nr + 2;
 }
 
 static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
@@ -303,24 +761,60 @@ static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
 {
 	struct sysfs_dirent * parent_sd = dentry->d_parent->d_fsdata;
 	struct sysfs_dirent * sd;
-	int err = 0;
+	struct bin_attribute *bin_attr;
+	struct inode *inode;
+	int found = 0;
 
-	list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
-		if (sd->s_type & SYSFS_NOT_PINNED) {
-			const unsigned char * name = sysfs_get_name(sd);
+	for (sd = parent_sd->s_children; sd; sd = sd->s_sibling) {
+		if (sysfs_type(sd) &&
+		    !strcmp(sd->s_name, dentry->d_name.name)) {
+			found = 1;
+			break;
+		}
+	}
 
-			if (strcmp(name, dentry->d_name.name))
-				continue;
+	/* no such entry */
+	if (!found)
+		return NULL;
 
-			if (sd->s_type & SYSFS_KOBJ_LINK)
-				err = sysfs_attach_link(sd, dentry);
-			else
-				err = sysfs_attach_attr(sd, dentry);
+	/* attach dentry and inode */
+	inode = sysfs_get_inode(sd);
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+
+	mutex_lock(&sysfs_mutex);
+
+	if (inode->i_state & I_NEW) {
+		/* initialize inode according to type */
+		switch (sysfs_type(sd)) {
+		case SYSFS_DIR:
+			inode->i_op = &sysfs_dir_inode_operations;
+			inode->i_fop = &sysfs_dir_operations;
+			inode->i_nlink = sysfs_count_nlink(sd);
+			break;
+		case SYSFS_KOBJ_ATTR:
+			inode->i_size = PAGE_SIZE;
+			inode->i_fop = &sysfs_file_operations;
+			break;
+		case SYSFS_KOBJ_BIN_ATTR:
+			bin_attr = sd->s_elem.bin_attr.bin_attr;
+			inode->i_size = bin_attr->size;
+			inode->i_fop = &bin_fops;
 			break;
+		case SYSFS_KOBJ_LINK:
+			inode->i_op = &sysfs_symlink_inode_operations;
+			break;
+		default:
+			BUG();
 		}
 	}
 
-	return ERR_PTR(err);
+	sysfs_instantiate(dentry, inode);
+	sysfs_attach_dentry(sd, dentry);
+
+	mutex_unlock(&sysfs_mutex);
+
+	return NULL;
 }
 
 const struct inode_operations sysfs_dir_inode_operations = {
@@ -328,58 +822,46 @@ const struct inode_operations sysfs_dir_inode_operations = {
 	.setattr	= sysfs_setattr,
 };
 
-static void remove_dir(struct dentry * d)
+static void remove_dir(struct sysfs_dirent *sd)
 {
-	struct dentry * parent = dget(d->d_parent);
-	struct sysfs_dirent * sd;
-
-	mutex_lock(&parent->d_inode->i_mutex);
-	d_delete(d);
-	sd = d->d_fsdata;
- 	list_del_init(&sd->s_sibling);
-	sysfs_put(sd);
-	if (d->d_inode)
-		simple_rmdir(parent->d_inode,d);
-
-	pr_debug(" o %s removing done (%d)\n",d->d_name.name,
-		 atomic_read(&d->d_count));
+	struct sysfs_addrm_cxt acxt;
 
-	mutex_unlock(&parent->d_inode->i_mutex);
-	dput(parent);
+	sysfs_addrm_start(&acxt, sd->s_parent);
+	sysfs_unlink_sibling(sd);
+	sysfs_remove_one(&acxt, sd);
+	sysfs_addrm_finish(&acxt);
 }
 
-void sysfs_remove_subdir(struct dentry * d)
+void sysfs_remove_subdir(struct sysfs_dirent *sd)
 {
-	remove_dir(d);
+	remove_dir(sd);
 }
 
 
-static void __sysfs_remove_dir(struct dentry *dentry)
+static void __sysfs_remove_dir(struct sysfs_dirent *dir_sd)
 {
-	struct sysfs_dirent * parent_sd;
-	struct sysfs_dirent * sd, * tmp;
+	struct sysfs_addrm_cxt acxt;
+	struct sysfs_dirent **pos;
 
-	dget(dentry);
-	if (!dentry)
+	if (!dir_sd)
 		return;
 
-	pr_debug("sysfs %s: removing dir\n",dentry->d_name.name);
-	mutex_lock(&dentry->d_inode->i_mutex);
-	parent_sd = dentry->d_fsdata;
-	list_for_each_entry_safe(sd, tmp, &parent_sd->s_children, s_sibling) {
-		if (!sd->s_element || !(sd->s_type & SYSFS_NOT_PINNED))
-			continue;
-		list_del_init(&sd->s_sibling);
-		sysfs_drop_dentry(sd, dentry);
-		sysfs_put(sd);
+	pr_debug("sysfs %s: removing dir\n", dir_sd->s_name);
+	sysfs_addrm_start(&acxt, dir_sd);
+	pos = &dir_sd->s_children;
+	while (*pos) {
+		struct sysfs_dirent *sd = *pos;
+
+		if (sysfs_type(sd) && sysfs_type(sd) != SYSFS_DIR) {
+			*pos = sd->s_sibling;
+			sd->s_sibling = NULL;
+			sysfs_remove_one(&acxt, sd);
+		} else
+			pos = &(*pos)->s_sibling;
 	}
-	mutex_unlock(&dentry->d_inode->i_mutex);
+	sysfs_addrm_finish(&acxt);
 
-	remove_dir(dentry);
-	/**
-	 * Drop reference from dget() on entrance.
-	 */
-	dput(dentry);
+	remove_dir(dir_sd);
 }
 
 /**
@@ -393,102 +875,166 @@ static void __sysfs_remove_dir(struct dentry *dentry)
 
 void sysfs_remove_dir(struct kobject * kobj)
 {
-	__sysfs_remove_dir(kobj->dentry);
-	kobj->dentry = NULL;
+	struct sysfs_dirent *sd = kobj->sd;
+
+	spin_lock(&sysfs_assoc_lock);
+	kobj->sd = NULL;
+	spin_unlock(&sysfs_assoc_lock);
+
+	__sysfs_remove_dir(sd);
 }
 
-int sysfs_rename_dir(struct kobject * kobj, struct dentry *new_parent,
+int sysfs_rename_dir(struct kobject *kobj, struct sysfs_dirent *new_parent_sd,
 		     const char *new_name)
 {
-	int error = 0;
-	struct dentry * new_dentry;
+	struct sysfs_dirent *sd = kobj->sd;
+	struct dentry *new_parent = NULL;
+	struct dentry *old_dentry = NULL, *new_dentry = NULL;
+	const char *dup_name = NULL;
+	int error;
 
-	if (!new_parent)
-		return -EFAULT;
+	/* get dentries */
+	old_dentry = sysfs_get_dentry(sd);
+	if (IS_ERR(old_dentry)) {
+		error = PTR_ERR(old_dentry);
+		goto out_dput;
+	}
 
-	down_write(&sysfs_rename_sem);
+	new_parent = sysfs_get_dentry(new_parent_sd);
+	if (IS_ERR(new_parent)) {
+		error = PTR_ERR(new_parent);
+		goto out_dput;
+	}
+
+	/* lock new_parent and get dentry for new name */
 	mutex_lock(&new_parent->d_inode->i_mutex);
 
 	new_dentry = lookup_one_len(new_name, new_parent, strlen(new_name));
-	if (!IS_ERR(new_dentry)) {
-		/* By allowing two different directories with the
-		 * same d_parent we allow this routine to move
-		 * between different shadows of the same directory
-		 */
-		if (kobj->dentry->d_parent->d_inode != new_parent->d_inode)
-			return -EINVAL;
-		else if (new_dentry->d_parent->d_inode != new_parent->d_inode)
-			error = -EINVAL;
-		else if (new_dentry == kobj->dentry)
-			error = -EINVAL;
-		else if (!new_dentry->d_inode) {
-			error = kobject_set_name(kobj, "%s", new_name);
-			if (!error) {
-				struct sysfs_dirent *sd, *parent_sd;
-
-				d_add(new_dentry, NULL);
-				d_move(kobj->dentry, new_dentry);
-
-				sd = kobj->dentry->d_fsdata;
-				parent_sd = new_parent->d_fsdata;
-
-				list_del_init(&sd->s_sibling);
-				list_add(&sd->s_sibling, &parent_sd->s_children);
-			}
-			else
-				d_drop(new_dentry);
-		} else
-			error = -EEXIST;
-		dput(new_dentry);
+	if (IS_ERR(new_dentry)) {
+		error = PTR_ERR(new_dentry);
+		goto out_unlock;
 	}
-	mutex_unlock(&new_parent->d_inode->i_mutex);
-	up_write(&sysfs_rename_sem);
 
+	/* By allowing two different directories with the same
+	 * d_parent we allow this routine to move between different
+	 * shadows of the same directory
+	 */
+	error = -EINVAL;
+	if (old_dentry->d_parent->d_inode != new_parent->d_inode ||
+	    new_dentry->d_parent->d_inode != new_parent->d_inode ||
+	    old_dentry == new_dentry)
+		goto out_unlock;
+
+	error = -EEXIST;
+	if (new_dentry->d_inode)
+		goto out_unlock;
+
+	/* rename kobject and sysfs_dirent */
+	error = -ENOMEM;
+	new_name = dup_name = kstrdup(new_name, GFP_KERNEL);
+	if (!new_name)
+		goto out_drop;
+
+	error = kobject_set_name(kobj, "%s", new_name);
+	if (error)
+		goto out_drop;
+
+	dup_name = sd->s_name;
+	sd->s_name = new_name;
+
+	/* move under the new parent */
+	d_add(new_dentry, NULL);
+	d_move(sd->s_dentry, new_dentry);
+
+	mutex_lock(&sysfs_mutex);
+
+	sysfs_unlink_sibling(sd);
+	sysfs_get(new_parent_sd);
+	sysfs_put(sd->s_parent);
+	sd->s_parent = new_parent_sd;
+	sysfs_link_sibling(sd);
+
+	mutex_unlock(&sysfs_mutex);
+
+	error = 0;
+	goto out_unlock;
+
+ out_drop:
+	d_drop(new_dentry);
+ out_unlock:
+	mutex_unlock(&new_parent->d_inode->i_mutex);
+ out_dput:
+	kfree(dup_name);
+	dput(new_parent);
+	dput(old_dentry);
+	dput(new_dentry);
 	return error;
 }
 
-int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent)
+int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent_kobj)
 {
-	struct dentry *old_parent_dentry, *new_parent_dentry, *new_dentry;
-	struct sysfs_dirent *new_parent_sd, *sd;
+	struct sysfs_dirent *sd = kobj->sd;
+	struct sysfs_dirent *new_parent_sd;
+	struct dentry *old_parent, *new_parent = NULL;
+	struct dentry *old_dentry = NULL, *new_dentry = NULL;
 	int error;
 
-	old_parent_dentry = kobj->parent ?
-		kobj->parent->dentry : sysfs_mount->mnt_sb->s_root;
-	new_parent_dentry = new_parent ?
-		new_parent->dentry : sysfs_mount->mnt_sb->s_root;
+	BUG_ON(!sd->s_parent);
+	new_parent_sd = new_parent_kobj->sd ? new_parent_kobj->sd : &sysfs_root;
+
+	/* get dentries */
+	old_dentry = sysfs_get_dentry(sd);
+	if (IS_ERR(old_dentry)) {
+		error = PTR_ERR(old_dentry);
+		goto out_dput;
+	}
+	old_parent = sd->s_parent->s_dentry;
+
+	new_parent = sysfs_get_dentry(new_parent_sd);
+	if (IS_ERR(new_parent)) {
+		error = PTR_ERR(new_parent);
+		goto out_dput;
+	}
 
-	if (old_parent_dentry->d_inode == new_parent_dentry->d_inode)
-		return 0;	/* nothing to move */
+	if (old_parent->d_inode == new_parent->d_inode) {
+		error = 0;
+		goto out_dput;	/* nothing to move */
+	}
 again:
-	mutex_lock(&old_parent_dentry->d_inode->i_mutex);
-	if (!mutex_trylock(&new_parent_dentry->d_inode->i_mutex)) {
-		mutex_unlock(&old_parent_dentry->d_inode->i_mutex);
+	mutex_lock(&old_parent->d_inode->i_mutex);
+	if (!mutex_trylock(&new_parent->d_inode->i_mutex)) {
+		mutex_unlock(&old_parent->d_inode->i_mutex);
 		goto again;
 	}
 
-	new_parent_sd = new_parent_dentry->d_fsdata;
-	sd = kobj->dentry->d_fsdata;
-
-	new_dentry = lookup_one_len(kobj->name, new_parent_dentry,
-				    strlen(kobj->name));
+	new_dentry = lookup_one_len(kobj->name, new_parent, strlen(kobj->name));
 	if (IS_ERR(new_dentry)) {
 		error = PTR_ERR(new_dentry);
-		goto out;
+		goto out_unlock;
 	} else
 		error = 0;
 	d_add(new_dentry, NULL);
-	d_move(kobj->dentry, new_dentry);
+	d_move(sd->s_dentry, new_dentry);
 	dput(new_dentry);
 
 	/* Remove from old parent's list and insert into new parent's list. */
-	list_del_init(&sd->s_sibling);
-	list_add(&sd->s_sibling, &new_parent_sd->s_children);
+	mutex_lock(&sysfs_mutex);
+
+	sysfs_unlink_sibling(sd);
+	sysfs_get(new_parent_sd);
+	sysfs_put(sd->s_parent);
+	sd->s_parent = new_parent_sd;
+	sysfs_link_sibling(sd);
 
-out:
-	mutex_unlock(&new_parent_dentry->d_inode->i_mutex);
-	mutex_unlock(&old_parent_dentry->d_inode->i_mutex);
+	mutex_unlock(&sysfs_mutex);
 
+ out_unlock:
+	mutex_unlock(&new_parent->d_inode->i_mutex);
+	mutex_unlock(&old_parent->d_inode->i_mutex);
+ out_dput:
+	dput(new_parent);
+	dput(old_dentry);
+	dput(new_dentry);
 	return error;
 }
 
@@ -496,23 +1042,27 @@ static int sysfs_dir_open(struct inode *inode, struct file *file)
 {
 	struct dentry * dentry = file->f_path.dentry;
 	struct sysfs_dirent * parent_sd = dentry->d_fsdata;
+	struct sysfs_dirent * sd;
 
-	mutex_lock(&dentry->d_inode->i_mutex);
-	file->private_data = sysfs_new_dirent(parent_sd, NULL);
-	mutex_unlock(&dentry->d_inode->i_mutex);
-
-	return file->private_data ? 0 : -ENOMEM;
+	sd = sysfs_new_dirent("_DIR_", 0, 0);
+	if (sd) {
+		mutex_lock(&sysfs_mutex);
+		sd->s_parent = sysfs_get(parent_sd);
+		sysfs_link_sibling(sd);
+		mutex_unlock(&sysfs_mutex);
+	}
 
+	file->private_data = sd;
+	return sd ? 0 : -ENOMEM;
 }
 
 static int sysfs_dir_close(struct inode *inode, struct file *file)
 {
-	struct dentry * dentry = file->f_path.dentry;
 	struct sysfs_dirent * cursor = file->private_data;
 
-	mutex_lock(&dentry->d_inode->i_mutex);
-	list_del_init(&cursor->s_sibling);
-	mutex_unlock(&dentry->d_inode->i_mutex);
+	mutex_lock(&sysfs_mutex);
+	sysfs_unlink_sibling(cursor);
+	mutex_unlock(&sysfs_mutex);
 
 	release_sysfs_dirent(cursor);
 
@@ -530,7 +1080,7 @@ static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
 	struct dentry *dentry = filp->f_path.dentry;
 	struct sysfs_dirent * parent_sd = dentry->d_fsdata;
 	struct sysfs_dirent *cursor = filp->private_data;
-	struct list_head *p, *q = &cursor->s_sibling;
+	struct sysfs_dirent **pos;
 	ino_t ino;
 	int i = filp->f_pos;
 
@@ -543,38 +1093,52 @@ static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
 			i++;
 			/* fallthrough */
 		case 1:
-			ino = parent_ino(dentry);
+			if (parent_sd->s_parent)
+				ino = parent_sd->s_parent->s_ino;
+			else
+				ino = parent_sd->s_ino;
 			if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
 				break;
 			filp->f_pos++;
 			i++;
 			/* fallthrough */
 		default:
+			mutex_lock(&sysfs_mutex);
+
+			pos = &parent_sd->s_children;
+			while (*pos != cursor)
+				pos = &(*pos)->s_sibling;
+
+			/* unlink cursor */
+			*pos = cursor->s_sibling;
+
 			if (filp->f_pos == 2)
-				list_move(q, &parent_sd->s_children);
+				pos = &parent_sd->s_children;
 
-			for (p=q->next; p!= &parent_sd->s_children; p=p->next) {
-				struct sysfs_dirent *next;
+			for ( ; *pos; pos = &(*pos)->s_sibling) {
+				struct sysfs_dirent *next = *pos;
 				const char * name;
 				int len;
 
-				next = list_entry(p, struct sysfs_dirent,
-						   s_sibling);
-				if (!next->s_element)
+				if (!sysfs_type(next))
 					continue;
 
-				name = sysfs_get_name(next);
+				name = next->s_name;
 				len = strlen(name);
 				ino = next->s_ino;
 
 				if (filldir(dirent, name, len, filp->f_pos, ino,
 						 dt_type(next)) < 0)
-					return 0;
+					break;
 
-				list_move(q, p);
-				p = q;
 				filp->f_pos++;
 			}
+
+			/* put cursor back in */
+			cursor->s_sibling = *pos;
+			*pos = cursor;
+
+			mutex_unlock(&sysfs_mutex);
 	}
 	return 0;
 }
@@ -583,7 +1147,6 @@ static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin)
 {
 	struct dentry * dentry = file->f_path.dentry;
 
-	mutex_lock(&dentry->d_inode->i_mutex);
 	switch (origin) {
 		case 1:
 			offset += file->f_pos;
@@ -591,31 +1154,35 @@ static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin)
 			if (offset >= 0)
 				break;
 		default:
-			mutex_unlock(&file->f_path.dentry->d_inode->i_mutex);
 			return -EINVAL;
 	}
 	if (offset != file->f_pos) {
+		mutex_lock(&sysfs_mutex);
+
 		file->f_pos = offset;
 		if (file->f_pos >= 2) {
 			struct sysfs_dirent *sd = dentry->d_fsdata;
 			struct sysfs_dirent *cursor = file->private_data;
-			struct list_head *p;
+			struct sysfs_dirent **pos;
 			loff_t n = file->f_pos - 2;
 
-			list_del(&cursor->s_sibling);
-			p = sd->s_children.next;
-			while (n && p != &sd->s_children) {
-				struct sysfs_dirent *next;
-				next = list_entry(p, struct sysfs_dirent,
-						   s_sibling);
-				if (next->s_element)
+			sysfs_unlink_sibling(cursor);
+
+			pos = &sd->s_children;
+			while (n && *pos) {
+				struct sysfs_dirent *next = *pos;
+				if (sysfs_type(next))
 					n--;
-				p = p->next;
+				pos = &(*pos)->s_sibling;
 			}
-			list_add_tail(&cursor->s_sibling, p);
+
+			cursor->s_sibling = *pos;
+			*pos = cursor;
 		}
+
+		mutex_unlock(&sysfs_mutex);
 	}
-	mutex_unlock(&dentry->d_inode->i_mutex);
+
 	return offset;
 }
 
@@ -628,12 +1195,20 @@ static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin)
 int sysfs_make_shadowed_dir(struct kobject *kobj,
 	void * (*follow_link)(struct dentry *, struct nameidata *))
 {
+	struct dentry *dentry;
 	struct inode *inode;
 	struct inode_operations *i_op;
 
-	inode = kobj->dentry->d_inode;
-	if (inode->i_op != &sysfs_dir_inode_operations)
+	/* get dentry for @kobj->sd, dentry of a shadowed dir is pinned */
+	dentry = sysfs_get_dentry(kobj->sd);
+	if (IS_ERR(dentry))
+		return PTR_ERR(dentry);
+
+	inode = dentry->d_inode;
+	if (inode->i_op != &sysfs_dir_inode_operations) {
+		dput(dentry);
 		return -EINVAL;
+	}
 
 	i_op = kmalloc(sizeof(*i_op), GFP_KERNEL);
 	if (!i_op)
@@ -658,54 +1233,72 @@ int sysfs_make_shadowed_dir(struct kobject *kobj,
  *	directory.
  */
 
-struct dentry *sysfs_create_shadow_dir(struct kobject *kobj)
+struct sysfs_dirent *sysfs_create_shadow_dir(struct kobject *kobj)
 {
-	struct sysfs_dirent *sd;
-	struct dentry *parent, *dir, *shadow;
+	struct sysfs_dirent *parent_sd = kobj->sd->s_parent;
+	struct dentry *dir, *parent, *shadow;
 	struct inode *inode;
+	struct sysfs_dirent *sd;
+	struct sysfs_addrm_cxt acxt;
 
-	dir = kobj->dentry;
-	inode = dir->d_inode;
+	dir = sysfs_get_dentry(kobj->sd);
+	if (IS_ERR(dir)) {
+		sd = (void *)dir;
+		goto out;
+	}
 	parent = dir->d_parent;
-	shadow = ERR_PTR(-EINVAL);
+
+	inode = dir->d_inode;
+	sd = ERR_PTR(-EINVAL);
 	if (!sysfs_is_shadowed_inode(inode))
-		goto out;
+		goto out_dput;
 
 	shadow = d_alloc(parent, &dir->d_name);
 	if (!shadow)
 		goto nomem;
 
-	sd = __sysfs_make_dirent(shadow, kobj, inode->i_mode, SYSFS_DIR);
+	sd = sysfs_new_dirent("_SHADOW_", inode->i_mode, SYSFS_DIR);
 	if (!sd)
 		goto nomem;
+	sd->s_elem.dir.kobj = kobj;
 
+	sysfs_addrm_start(&acxt, parent_sd);
+
+	/* add but don't link into children list */
+	sysfs_add_one(&acxt, sd);
+
+	/* attach and instantiate dentry */
+	sysfs_attach_dentry(sd, shadow);
 	d_instantiate(shadow, igrab(inode));
-	inc_nlink(inode);
-	inc_nlink(parent->d_inode);
-	shadow->d_op = &sysfs_dentry_ops;
+	inc_nlink(inode);	/* tj: synchronization? */
+
+	sysfs_addrm_finish(&acxt);
 
 	dget(shadow);		/* Extra count - pin the dentry in core */
 
-out:
-	return shadow;
-nomem:
+	goto out_dput;
+
+ nomem:
 	dput(shadow);
-	shadow = ERR_PTR(-ENOMEM);
-	goto out;
+	sd = ERR_PTR(-ENOMEM);
+ out_dput:
+	dput(dir);
+ out:
+	return sd;
 }
 
 /**
  *	sysfs_remove_shadow_dir - remove an object's directory.
- *	@shadow: dentry of shadow directory
+ *	@shadow_sd: sysfs_dirent of shadow directory
  *
  *	The only thing special about this is that we remove any files in
  *	the directory before we remove the directory, and we've inlined
  *	what used to be sysfs_rmdir() below, instead of calling separately.
  */
 
-void sysfs_remove_shadow_dir(struct dentry *shadow)
+void sysfs_remove_shadow_dir(struct sysfs_dirent *shadow_sd)
 {
-	__sysfs_remove_dir(shadow);
+	__sysfs_remove_dir(shadow_sd);
 }
 
 const struct file_operations sysfs_dir_operations = {
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index b502c7197ec..cc497994b2a 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -50,29 +50,15 @@ static struct sysfs_ops subsys_sysfs_ops = {
 	.store	= subsys_attr_store,
 };
 
-/**
- *	add_to_collection - add buffer to a collection
- *	@buffer:	buffer to be added
- *	@node:		inode of set to add to
- */
-
-static inline void
-add_to_collection(struct sysfs_buffer *buffer, struct inode *node)
-{
-	struct sysfs_buffer_collection *set = node->i_private;
-
-	mutex_lock(&node->i_mutex);
-	list_add(&buffer->associates, &set->associates);
-	mutex_unlock(&node->i_mutex);
-}
-
-static inline void
-remove_from_collection(struct sysfs_buffer *buffer, struct inode *node)
-{
-	mutex_lock(&node->i_mutex);
-	list_del(&buffer->associates);
-	mutex_unlock(&node->i_mutex);
-}
+struct sysfs_buffer {
+	size_t			count;
+	loff_t			pos;
+	char			* page;
+	struct sysfs_ops	* ops;
+	struct semaphore	sem;
+	int			needs_read_fill;
+	int			event;
+};
 
 /**
  *	fill_read_buffer - allocate and fill buffer from object.
@@ -87,9 +73,8 @@ remove_from_collection(struct sysfs_buffer *buffer, struct inode *node)
  */
 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_dirent *attr_sd = dentry->d_fsdata;
+	struct kobject *kobj = attr_sd->s_parent->s_elem.dir.kobj;
 	struct sysfs_ops * ops = buffer->ops;
 	int ret = 0;
 	ssize_t count;
@@ -99,8 +84,15 @@ static int fill_read_buffer(struct dentry * dentry, struct sysfs_buffer * buffer
 	if (!buffer->page)
 		return -ENOMEM;
 
-	buffer->event = atomic_read(&sd->s_event);
-	count = ops->show(kobj,attr,buffer->page);
+	/* need attr_sd for attr and ops, its parent for kobj */
+	if (!sysfs_get_active_two(attr_sd))
+		return -ENODEV;
+
+	buffer->event = atomic_read(&attr_sd->s_event);
+	count = ops->show(kobj, attr_sd->s_elem.attr.attr, buffer->page);
+
+	sysfs_put_active_two(attr_sd);
+
 	BUG_ON(count > (ssize_t)PAGE_SIZE);
 	if (count >= 0) {
 		buffer->needs_read_fill = 0;
@@ -138,10 +130,7 @@ sysfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos)
 
 	down(&buffer->sem);
 	if (buffer->needs_read_fill) {
-		if (buffer->orphaned)
-			retval = -ENODEV;
-		else
-			retval = fill_read_buffer(file->f_path.dentry,buffer);
+		retval = fill_read_buffer(file->f_path.dentry,buffer);
 		if (retval)
 			goto out;
 	}
@@ -196,14 +185,23 @@ fill_write_buffer(struct sysfs_buffer * buffer, const char __user * buf, size_t
  *	passing the buffer that we acquired in fill_write_buffer().
  */
 
-static int 
+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_dirent *attr_sd = dentry->d_fsdata;
+	struct kobject *kobj = attr_sd->s_parent->s_elem.dir.kobj;
 	struct sysfs_ops * ops = buffer->ops;
+	int rc;
+
+	/* need attr_sd for attr and ops, its parent for kobj */
+	if (!sysfs_get_active_two(attr_sd))
+		return -ENODEV;
+
+	rc = ops->store(kobj, attr_sd->s_elem.attr.attr, buffer->page, count);
 
-	return ops->store(kobj,attr,buffer->page,count);
+	sysfs_put_active_two(attr_sd);
+
+	return rc;
 }
 
 
@@ -231,37 +229,26 @@ sysfs_write_file(struct file *file, const char __user *buf, size_t count, loff_t
 	ssize_t len;
 
 	down(&buffer->sem);
-	if (buffer->orphaned) {
-		len = -ENODEV;
-		goto out;
-	}
 	len = fill_write_buffer(buffer, buf, count);
 	if (len > 0)
 		len = flush_write_buffer(file->f_path.dentry, buffer, len);
 	if (len > 0)
 		*ppos += len;
-out:
 	up(&buffer->sem);
 	return len;
 }
 
 static int sysfs_open_file(struct inode *inode, struct file *file)
 {
-	struct kobject *kobj = sysfs_get_kobject(file->f_path.dentry->d_parent);
-	struct attribute * attr = to_attr(file->f_path.dentry);
-	struct sysfs_buffer_collection *set;
+	struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
+	struct kobject *kobj = attr_sd->s_parent->s_elem.dir.kobj;
 	struct sysfs_buffer * buffer;
 	struct sysfs_ops * ops = NULL;
-	int error = 0;
-
-	if (!kobj || !attr)
-		goto Einval;
+	int error;
 
-	/* Grab the module reference for this attribute if we have one */
-	if (!try_module_get(attr->owner)) {
-		error = -ENODEV;
-		goto Done;
-	}
+	/* need attr_sd for attr and ops, its parent for kobj */
+	if (!sysfs_get_active_two(attr_sd))
+		return -ENODEV;
 
 	/* if the kobject has no ktype, then we assume that it is a subsystem
 	 * itself, and use ops for it.
@@ -273,33 +260,21 @@ static int sysfs_open_file(struct inode *inode, struct file *file)
 	else
 		ops = &subsys_sysfs_ops;
 
+	error = -EACCES;
+
 	/* No sysfs operations, either from having no subsystem,
 	 * or the subsystem have no operations.
 	 */
 	if (!ops)
-		goto Eaccess;
-
-	/* make sure we have a collection to add our buffers to */
-	mutex_lock(&inode->i_mutex);
-	if (!(set = inode->i_private)) {
-		if (!(set = inode->i_private = kmalloc(sizeof(struct sysfs_buffer_collection), GFP_KERNEL))) {
-			error = -ENOMEM;
-			goto Done;
-		} else {
-			INIT_LIST_HEAD(&set->associates);
-		}
-	}
-	mutex_unlock(&inode->i_mutex);
+		goto err_out;
 
 	/* 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) {
-
 		if (!(inode->i_mode & S_IWUGO) || !ops->store)
-			goto Eaccess;
-
+			goto err_out;
 	}
 
 	/* File needs read support.
@@ -308,48 +283,38 @@ static int sysfs_open_file(struct inode *inode, struct file *file)
 	 */
 	if (file->f_mode & FMODE_READ) {
 		if (!(inode->i_mode & S_IRUGO) || !ops->show)
-			goto Eaccess;
+			goto err_out;
 	}
 
 	/* No error? Great, allocate a buffer for the file, and store it
 	 * it in file->private_data for easy access.
 	 */
+	error = -ENOMEM;
 	buffer = kzalloc(sizeof(struct sysfs_buffer), GFP_KERNEL);
-	if (buffer) {
-		INIT_LIST_HEAD(&buffer->associates);
-		init_MUTEX(&buffer->sem);
-		buffer->needs_read_fill = 1;
-		buffer->ops = ops;
-		add_to_collection(buffer, inode);
-		file->private_data = buffer;
-	} else
-		error = -ENOMEM;
-	goto Done;
-
- Einval:
-	error = -EINVAL;
-	goto Done;
- Eaccess:
-	error = -EACCES;
-	module_put(attr->owner);
- Done:
-	if (error)
-		kobject_put(kobj);
+	if (!buffer)
+		goto err_out;
+
+	init_MUTEX(&buffer->sem);
+	buffer->needs_read_fill = 1;
+	buffer->ops = ops;
+	file->private_data = buffer;
+
+	/* open succeeded, put active references and pin attr_sd */
+	sysfs_put_active_two(attr_sd);
+	sysfs_get(attr_sd);
+	return 0;
+
+ err_out:
+	sysfs_put_active_two(attr_sd);
 	return error;
 }
 
 static int sysfs_release(struct inode * inode, struct file * filp)
 {
-	struct kobject * kobj = to_kobj(filp->f_path.dentry->d_parent);
-	struct attribute * attr = to_attr(filp->f_path.dentry);
-	struct module * owner = attr->owner;
-	struct sysfs_buffer * buffer = filp->private_data;
+	struct sysfs_dirent *attr_sd = filp->f_path.dentry->d_fsdata;
+	struct sysfs_buffer *buffer = filp->private_data;
 
-	if (buffer)
-		remove_from_collection(buffer, inode);
-	kobject_put(kobj);
-	/* After this point, attr should not be accessed. */
-	module_put(owner);
+	sysfs_put(attr_sd);
 
 	if (buffer) {
 		if (buffer->page)
@@ -376,57 +341,43 @@ static int sysfs_release(struct inode * inode, struct file * filp)
 static unsigned int sysfs_poll(struct file *filp, poll_table *wait)
 {
 	struct sysfs_buffer * buffer = filp->private_data;
-	struct kobject * kobj = to_kobj(filp->f_path.dentry->d_parent);
-	struct sysfs_dirent * sd = filp->f_path.dentry->d_fsdata;
-	int res = 0;
+	struct sysfs_dirent *attr_sd = filp->f_path.dentry->d_fsdata;
+	struct kobject *kobj = attr_sd->s_parent->s_elem.dir.kobj;
+
+	/* need parent for the kobj, grab both */
+	if (!sysfs_get_active_two(attr_sd))
+		goto trigger;
 
 	poll_wait(filp, &kobj->poll, wait);
 
-	if (buffer->event != atomic_read(&sd->s_event)) {
-		res = POLLERR|POLLPRI;
-		buffer->needs_read_fill = 1;
-	}
+	sysfs_put_active_two(attr_sd);
 
-	return res;
-}
+	if (buffer->event != atomic_read(&attr_sd->s_event))
+		goto trigger;
 
+	return 0;
 
-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;
+ trigger:
+	buffer->needs_read_fill = 1;
+	return POLLERR|POLLPRI;
 }
 
-void sysfs_notify(struct kobject * k, char *dir, char *attr)
+void sysfs_notify(struct kobject *k, char *dir, char *attr)
 {
-	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);
+	struct sysfs_dirent *sd = k->sd;
+
+	mutex_lock(&sysfs_mutex);
+
+	if (sd && dir)
+		sd = sysfs_find_dirent(sd, dir);
+	if (sd && attr)
+		sd = sysfs_find_dirent(sd, attr);
+	if (sd) {
+		atomic_inc(&sd->s_event);
 		wake_up_interruptible(&k->poll);
-		dput(de);
 	}
+
+	mutex_unlock(&sysfs_mutex);
 }
 EXPORT_SYMBOL_GPL(sysfs_notify);
 
@@ -440,19 +391,30 @@ const struct file_operations sysfs_file_operations = {
 };
 
 
-int sysfs_add_file(struct dentry * dir, const struct attribute * attr, int type)
+int sysfs_add_file(struct sysfs_dirent *dir_sd, 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;
+	struct sysfs_addrm_cxt acxt;
+	struct sysfs_dirent *sd;
 
-	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);
+	sd = sysfs_new_dirent(attr->name, mode, type);
+	if (!sd)
+		return -ENOMEM;
+	sd->s_elem.attr.attr = (void *)attr;
 
-	return error;
+	sysfs_addrm_start(&acxt, dir_sd);
+
+	if (!sysfs_find_dirent(dir_sd, attr->name)) {
+		sysfs_add_one(&acxt, sd);
+		sysfs_link_sibling(sd);
+	}
+
+	if (sysfs_addrm_finish(&acxt))
+		return 0;
+
+	sysfs_put(sd);
+	return -EEXIST;
 }
 
 
@@ -464,9 +426,9 @@ int sysfs_add_file(struct dentry * dir, const struct attribute * attr, int type)
 
 int sysfs_create_file(struct kobject * kobj, const struct attribute * attr)
 {
-	BUG_ON(!kobj || !kobj->dentry || !attr);
+	BUG_ON(!kobj || !kobj->sd || !attr);
 
-	return sysfs_add_file(kobj->dentry, attr, SYSFS_KOBJ_ATTR);
+	return sysfs_add_file(kobj->sd, attr, SYSFS_KOBJ_ATTR);
 
 }
 
@@ -480,16 +442,16 @@ int sysfs_create_file(struct kobject * kobj, const struct attribute * attr)
 int sysfs_add_file_to_group(struct kobject *kobj,
 		const struct attribute *attr, const char *group)
 {
-	struct dentry *dir;
+	struct sysfs_dirent *dir_sd;
 	int error;
 
-	dir = lookup_one_len(group, kobj->dentry, strlen(group));
-	if (IS_ERR(dir))
-		error = PTR_ERR(dir);
-	else {
-		error = sysfs_add_file(dir, attr, SYSFS_KOBJ_ATTR);
-		dput(dir);
-	}
+	dir_sd = sysfs_get_dirent(kobj->sd, group);
+	if (!dir_sd)
+		return -ENOENT;
+
+	error = sysfs_add_file(dir_sd, attr, SYSFS_KOBJ_ATTR);
+	sysfs_put(dir_sd);
+
 	return error;
 }
 EXPORT_SYMBOL_GPL(sysfs_add_file_to_group);
@@ -502,30 +464,31 @@ EXPORT_SYMBOL_GPL(sysfs_add_file_to_group);
  */
 int sysfs_update_file(struct kobject * kobj, const struct attribute * attr)
 {
-	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);
-			res = 0;
-		} else
-			d_drop(victim);
-		
-		/**
-		 * Drop the reference acquired from lookup_one_len() above.
-		 */
-		dput(victim);
+	struct sysfs_dirent *victim_sd = NULL;
+	struct dentry *victim = NULL;
+	int rc;
+
+	rc = -ENOENT;
+	victim_sd = sysfs_get_dirent(kobj->sd, attr->name);
+	if (!victim_sd)
+		goto out;
+
+	victim = sysfs_get_dentry(victim_sd);
+	if (IS_ERR(victim)) {
+		rc = PTR_ERR(victim);
+		victim = NULL;
+		goto out;
 	}
-	mutex_unlock(&dir->d_inode->i_mutex);
 
-	return res;
+	mutex_lock(&victim->d_inode->i_mutex);
+	victim->d_inode->i_mtime = CURRENT_TIME;
+	fsnotify_modify(victim);
+	mutex_unlock(&victim->d_inode->i_mutex);
+	rc = 0;
+ out:
+	dput(victim);
+	sysfs_put(victim_sd);
+	return rc;
 }
 
 
@@ -538,30 +501,34 @@ int sysfs_update_file(struct kobject * kobj, const struct attribute * attr)
  */
 int sysfs_chmod_file(struct kobject *kobj, struct attribute *attr, mode_t mode)
 {
-	struct dentry *dir = kobj->dentry;
-	struct dentry *victim;
+	struct sysfs_dirent *victim_sd = NULL;
+	struct dentry *victim = NULL;
 	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);
+	int rc;
+
+	rc = -ENOENT;
+	victim_sd = sysfs_get_dirent(kobj->sd, attr->name);
+	if (!victim_sd)
+		goto out;
+
+	victim = sysfs_get_dentry(victim_sd);
+	if (IS_ERR(victim)) {
+		rc = PTR_ERR(victim);
+		victim = NULL;
+		goto out;
 	}
-	mutex_unlock(&dir->d_inode->i_mutex);
 
-	return res;
+	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;
+	rc = notify_change(victim, &newattrs);
+	mutex_unlock(&inode->i_mutex);
+ out:
+	dput(victim);
+	sysfs_put(victim_sd);
+	return rc;
 }
 EXPORT_SYMBOL_GPL(sysfs_chmod_file);
 
@@ -576,7 +543,7 @@ EXPORT_SYMBOL_GPL(sysfs_chmod_file);
 
 void sysfs_remove_file(struct kobject * kobj, const struct attribute * attr)
 {
-	sysfs_hash_and_remove(kobj->dentry, attr->name);
+	sysfs_hash_and_remove(kobj->sd, attr->name);
 }
 
 
@@ -589,12 +556,12 @@ void sysfs_remove_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;
+	struct sysfs_dirent *dir_sd;
 
-	dir = lookup_one_len(group, kobj->dentry, strlen(group));
-	if (!IS_ERR(dir)) {
-		sysfs_hash_and_remove(dir, attr->name);
-		dput(dir);
+	dir_sd = sysfs_get_dirent(kobj->sd, group);
+	if (dir_sd) {
+		sysfs_hash_and_remove(dir_sd, attr->name);
+		sysfs_put(dir_sd);
 	}
 }
 EXPORT_SYMBOL_GPL(sysfs_remove_file_from_group);
diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c
index 52eed2a7a5e..f318b73c790 100644
--- a/fs/sysfs/group.c
+++ b/fs/sysfs/group.c
@@ -18,26 +18,25 @@
 #include "sysfs.h"
 
 
-static void remove_files(struct dentry * dir, 
-			 const struct attribute_group * grp)
+static void remove_files(struct sysfs_dirent *dir_sd,
+			 const struct attribute_group *grp)
 {
 	struct attribute *const* attr;
 
 	for (attr = grp->attrs; *attr; attr++)
-		sysfs_hash_and_remove(dir,(*attr)->name);
+		sysfs_hash_and_remove(dir_sd, (*attr)->name);
 }
 
-static int create_files(struct dentry * dir,
-			const struct attribute_group * grp)
+static int create_files(struct sysfs_dirent *dir_sd,
+			const struct attribute_group *grp)
 {
 	struct attribute *const* attr;
 	int error = 0;
 
-	for (attr = grp->attrs; *attr && !error; attr++) {
-		error = sysfs_add_file(dir, *attr, SYSFS_KOBJ_ATTR);
-	}
+	for (attr = grp->attrs; *attr && !error; attr++)
+		error = sysfs_add_file(dir_sd, *attr, SYSFS_KOBJ_ATTR);
 	if (error)
-		remove_files(dir,grp);
+		remove_files(dir_sd, grp);
 	return error;
 }
 
@@ -45,44 +44,44 @@ static int create_files(struct dentry * dir,
 int sysfs_create_group(struct kobject * kobj, 
 		       const struct attribute_group * grp)
 {
-	struct dentry * dir;
+	struct sysfs_dirent *sd;
 	int error;
 
-	BUG_ON(!kobj || !kobj->dentry);
+	BUG_ON(!kobj || !kobj->sd);
 
 	if (grp->name) {
-		error = sysfs_create_subdir(kobj,grp->name,&dir);
+		error = sysfs_create_subdir(kobj, grp->name, &sd);
 		if (error)
 			return error;
 	} else
-		dir = kobj->dentry;
-	dir = dget(dir);
-	if ((error = create_files(dir,grp))) {
+		sd = kobj->sd;
+	sysfs_get(sd);
+	error = create_files(sd, grp);
+	if (error) {
 		if (grp->name)
-			sysfs_remove_subdir(dir);
+			sysfs_remove_subdir(sd);
 	}
-	dput(dir);
+	sysfs_put(sd);
 	return error;
 }
 
 void sysfs_remove_group(struct kobject * kobj, 
 			const struct attribute_group * grp)
 {
-	struct dentry * dir;
+	struct sysfs_dirent *dir_sd = kobj->sd;
+	struct sysfs_dirent *sd;
 
 	if (grp->name) {
-		dir = lookup_one_len_kern(grp->name, kobj->dentry,
-				strlen(grp->name));
-		BUG_ON(IS_ERR(dir));
-	}
-	else
-		dir = dget(kobj->dentry);
+		sd = sysfs_get_dirent(dir_sd, grp->name);
+		BUG_ON(!sd);
+	} else
+		sd = sysfs_get(dir_sd);
 
-	remove_files(dir,grp);
+	remove_files(sd, grp);
 	if (grp->name)
-		sysfs_remove_subdir(dir);
-	/* release the ref. taken in this routine */
-	dput(dir);
+		sysfs_remove_subdir(sd);
+
+	sysfs_put(sd);
 }
 
 
diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c
index 5266eec15f6..3756e152285 100644
--- a/fs/sysfs/inode.c
+++ b/fs/sysfs/inode.c
@@ -133,187 +133,94 @@ static inline void set_inode_attr(struct inode * inode, struct iattr * iattr)
  */
 static struct lock_class_key sysfs_inode_imutex_key;
 
-struct inode * sysfs_new_inode(mode_t mode, struct sysfs_dirent * sd)
+void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode)
 {
-	struct inode * inode = new_inode(sysfs_sb);
-	if (inode) {
-		inode->i_blocks = 0;
-		inode->i_mapping->a_ops = &sysfs_aops;
-		inode->i_mapping->backing_dev_info = &sysfs_backing_dev_info;
-		inode->i_op = &sysfs_inode_operations;
-		inode->i_ino = sd->s_ino;
-		lockdep_set_class(&inode->i_mutex, &sysfs_inode_imutex_key);
-
-		if (sd->s_iattr) {
-			/* sysfs_dirent has non-default attributes
-			 * get them for the new inode from persistent copy
-			 * in sysfs_dirent
-			 */
-			set_inode_attr(inode, sd->s_iattr);
-		} else
-			set_default_inode_attr(inode, mode);
-	}
-	return inode;
-}
-
-int sysfs_create(struct dentry * dentry, int mode, int (*init)(struct inode *))
-{
-	int error = 0;
-	struct inode * inode = NULL;
-	if (dentry) {
-		if (!dentry->d_inode) {
-			struct sysfs_dirent * sd = dentry->d_fsdata;
-			if ((inode = sysfs_new_inode(mode, sd))) {
-				if (dentry->d_parent && dentry->d_parent->d_inode) {
-					struct inode *p_inode = dentry->d_parent->d_inode;
-					p_inode->i_mtime = p_inode->i_ctime = CURRENT_TIME;
-				}
-				goto Proceed;
-			}
-			else 
-				error = -ENOMEM;
-		} else
-			error = -EEXIST;
-	} else 
-		error = -ENOENT;
-	goto Done;
-
- Proceed:
-	if (init)
-		error = init(inode);
-	if (!error) {
-		d_instantiate(dentry, inode);
-		if (S_ISDIR(mode))
-			dget(dentry);  /* pin only directory dentry in core */
+	inode->i_blocks = 0;
+	inode->i_mapping->a_ops = &sysfs_aops;
+	inode->i_mapping->backing_dev_info = &sysfs_backing_dev_info;
+	inode->i_op = &sysfs_inode_operations;
+	inode->i_ino = sd->s_ino;
+	lockdep_set_class(&inode->i_mutex, &sysfs_inode_imutex_key);
+
+	if (sd->s_iattr) {
+		/* sysfs_dirent has non-default attributes
+		 * get them for the new inode from persistent copy
+		 * in sysfs_dirent
+		 */
+		set_inode_attr(inode, sd->s_iattr);
 	} else
-		iput(inode);
- Done:
-	return error;
+		set_default_inode_attr(inode, sd->s_mode);
 }
 
-/*
- * Get the name for corresponding element represented by the given sysfs_dirent
+/**
+ *	sysfs_get_inode - get inode for sysfs_dirent
+ *	@sd: sysfs_dirent to allocate inode for
+ *
+ *	Get inode for @sd.  If such inode doesn't exist, a new inode
+ *	is allocated and basics are initialized.  New inode is
+ *	returned locked.
+ *
+ *	LOCKING:
+ *	Kernel thread context (may sleep).
+ *
+ *	RETURNS:
+ *	Pointer to allocated inode on success, NULL on failure.
  */
-const unsigned char * sysfs_get_name(struct sysfs_dirent *sd)
+struct inode * sysfs_get_inode(struct sysfs_dirent *sd)
 {
-	struct attribute * attr;
-	struct bin_attribute * bin_attr;
-	struct sysfs_symlink  * sl;
-
-	BUG_ON(!sd || !sd->s_element);
-
-	switch (sd->s_type) {
-		case SYSFS_DIR:
-			/* Always have a dentry so use that */
-			return sd->s_dentry->d_name.name;
-
-		case SYSFS_KOBJ_ATTR:
-			attr = sd->s_element;
-			return attr->name;
-
-		case SYSFS_KOBJ_BIN_ATTR:
-			bin_attr = sd->s_element;
-			return bin_attr->attr.name;
+	struct inode *inode;
 
-		case SYSFS_KOBJ_LINK:
-			sl = sd->s_element;
-			return sl->link_name;
-	}
-	return NULL;
-}
+	inode = iget_locked(sysfs_sb, sd->s_ino);
+	if (inode && (inode->i_state & I_NEW))
+		sysfs_init_inode(sd, inode);
 
-static inline void orphan_all_buffers(struct inode *node)
-{
-	struct sysfs_buffer_collection *set;
-	struct sysfs_buffer *buf;
-
-	mutex_lock_nested(&node->i_mutex, I_MUTEX_CHILD);
-	set = node->i_private;
-	if (set) {
-		list_for_each_entry(buf, &set->associates, associates) {
-			down(&buf->sem);
-			buf->orphaned = 1;
-			up(&buf->sem);
-		}
-	}
-	mutex_unlock(&node->i_mutex);
+	return inode;
 }
 
-
-/*
- * Unhashes the dentry corresponding to given sysfs_dirent
- * Called with parent inode's i_mutex held.
+/**
+ *	sysfs_instantiate - instantiate dentry
+ *	@dentry: dentry to be instantiated
+ *	@inode: inode associated with @sd
+ *
+ *	Unlock @inode if locked and instantiate @dentry with @inode.
+ *
+ *	LOCKING:
+ *	None.
  */
-void sysfs_drop_dentry(struct sysfs_dirent * sd, struct dentry * parent)
+void sysfs_instantiate(struct dentry *dentry, struct inode *inode)
 {
-	struct dentry *dentry = NULL;
-	struct inode *inode;
+	BUG_ON(!dentry || dentry->d_inode);
 
-	/* We're not holding a reference to ->s_dentry dentry but the
-	 * field will stay valid as long as sysfs_lock is held.
-	 */
-	spin_lock(&sysfs_lock);
-	spin_lock(&dcache_lock);
-
-	/* dget dentry if it's still alive */
-	if (sd->s_dentry && sd->s_dentry->d_inode)
-		dentry = dget_locked(sd->s_dentry);
-
-	spin_unlock(&dcache_lock);
-	spin_unlock(&sysfs_lock);
-
-	/* drop dentry */
-	if (dentry) {
-		spin_lock(&dcache_lock);
-		spin_lock(&dentry->d_lock);
-		if (!d_unhashed(dentry) && dentry->d_inode) {
-			inode = dentry->d_inode;
-			spin_lock(&inode->i_lock);
-			__iget(inode);
-			spin_unlock(&inode->i_lock);
-			dget_locked(dentry);
-			__d_drop(dentry);
-			spin_unlock(&dentry->d_lock);
-			spin_unlock(&dcache_lock);
-			simple_unlink(parent->d_inode, dentry);
-			orphan_all_buffers(inode);
-			iput(inode);
-		} else {
-			spin_unlock(&dentry->d_lock);
-			spin_unlock(&dcache_lock);
-		}
+	if (inode->i_state & I_NEW)
+		unlock_new_inode(inode);
 
-		dput(dentry);
-	}
+	d_instantiate(dentry, inode);
 }
 
-int sysfs_hash_and_remove(struct dentry * dir, const char * name)
+int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name)
 {
-	struct sysfs_dirent * sd;
-	struct sysfs_dirent * parent_sd;
-	int found = 0;
+	struct sysfs_addrm_cxt acxt;
+	struct sysfs_dirent **pos, *sd;
 
-	if (!dir)
+	if (!dir_sd)
 		return -ENOENT;
 
-	if (dir->d_inode == NULL)
-		/* no inode means this hasn't been made visible yet */
-		return -ENOENT;
+	sysfs_addrm_start(&acxt, dir_sd);
+
+	for (pos = &dir_sd->s_children; *pos; pos = &(*pos)->s_sibling) {
+		sd = *pos;
 
-	parent_sd = dir->d_fsdata;
-	mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
-	list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
-		if (!sd->s_element)
+		if (!sysfs_type(sd))
 			continue;
-		if (!strcmp(sysfs_get_name(sd), name)) {
-			list_del_init(&sd->s_sibling);
-			sysfs_drop_dentry(sd, dir);
-			sysfs_put(sd);
-			found = 1;
+		if (!strcmp(sd->s_name, name)) {
+			*pos = sd->s_sibling;
+			sd->s_sibling = NULL;
+			sysfs_remove_one(&acxt, sd);
 			break;
 		}
 	}
-	mutex_unlock(&dir->d_inode->i_mutex);
 
-	return found ? 0 : -ENOENT;
+	if (sysfs_addrm_finish(&acxt))
+		return 0;
+	return -ENOENT;
 }
diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c
index 00ab9125d39..402cc356203 100644
--- a/fs/sysfs/mount.c
+++ b/fs/sysfs/mount.c
@@ -19,28 +19,18 @@ struct vfsmount *sysfs_mount;
 struct super_block * sysfs_sb = NULL;
 struct kmem_cache *sysfs_dir_cachep;
 
-static void sysfs_clear_inode(struct inode *inode);
-
 static const struct super_operations sysfs_ops = {
 	.statfs		= simple_statfs,
 	.drop_inode	= sysfs_delete_inode,
-	.clear_inode	= sysfs_clear_inode,
 };
 
-static struct sysfs_dirent sysfs_root = {
-	.s_sibling	= LIST_HEAD_INIT(sysfs_root.s_sibling),
-	.s_children	= LIST_HEAD_INIT(sysfs_root.s_children),
-	.s_element	= NULL,
-	.s_type		= SYSFS_ROOT,
-	.s_iattr	= NULL,
+struct sysfs_dirent sysfs_root = {
+	.s_count	= ATOMIC_INIT(1),
+	.s_flags	= SYSFS_ROOT,
+	.s_mode		= S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
 	.s_ino		= 1,
 };
 
-static void sysfs_clear_inode(struct inode *inode)
-{
-	kfree(inode->i_private);
-}
-
 static int sysfs_fill_super(struct super_block *sb, void *data, int silent)
 {
 	struct inode *inode;
@@ -53,24 +43,26 @@ static int sysfs_fill_super(struct super_block *sb, void *data, int silent)
 	sb->s_time_gran = 1;
 	sysfs_sb = sb;
 
-	inode = sysfs_new_inode(S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
-				 &sysfs_root);
-	if (inode) {
-		inode->i_op = &sysfs_dir_inode_operations;
-		inode->i_fop = &sysfs_dir_operations;
-		/* directory inodes start off with i_nlink == 2 (for "." entry) */
-		inc_nlink(inode);
-	} else {
+	inode = new_inode(sysfs_sb);
+	if (!inode) {
 		pr_debug("sysfs: could not get root inode\n");
 		return -ENOMEM;
 	}
 
+	sysfs_init_inode(&sysfs_root, inode);
+
+	inode->i_op = &sysfs_dir_inode_operations;
+	inode->i_fop = &sysfs_dir_operations;
+	/* directory inodes start off with i_nlink == 2 (for "." entry) */
+	inc_nlink(inode);
+
 	root = d_alloc_root(inode);
 	if (!root) {
 		pr_debug("%s: could not get root dentry!\n",__FUNCTION__);
 		iput(inode);
 		return -ENOMEM;
 	}
+	sysfs_root.s_dentry = root;
 	root->d_fsdata = &sysfs_root;
 	sb->s_root = root;
 	return 0;
diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c
index 7b9c5bfde92..2f86e042229 100644
--- a/fs/sysfs/symlink.c
+++ b/fs/sysfs/symlink.c
@@ -11,71 +11,39 @@
 
 #include "sysfs.h"
 
-static int object_depth(struct kobject * kobj)
+static int object_depth(struct sysfs_dirent *sd)
 {
-	struct kobject * p = kobj;
 	int depth = 0;
-	do { depth++; } while ((p = p->parent));
+
+	for (; sd->s_parent; sd = sd->s_parent)
+		depth++;
+
 	return depth;
 }
 
-static int object_path_length(struct kobject * kobj)
+static int object_path_length(struct sysfs_dirent * sd)
 {
-	struct kobject * p = kobj;
 	int length = 1;
-	do {
-		length += strlen(kobject_name(p)) + 1;
-		p = p->parent;
-	} while (p);
+
+	for (; sd->s_parent; sd = sd->s_parent)
+		length += strlen(sd->s_name) + 1;
+
 	return length;
 }
 
-static void fill_object_path(struct kobject * kobj, char * buffer, int length)
+static void fill_object_path(struct sysfs_dirent *sd, char *buffer, int length)
 {
-	struct kobject * p;
-
 	--length;
-	for (p = kobj; p; p = p->parent) {
-		int cur = strlen(kobject_name(p));
+	for (; sd->s_parent; sd = sd->s_parent) {
+		int cur = strlen(sd->s_name);
 
 		/* back up enough to print this bus id with '/' */
 		length -= cur;
-		strncpy(buffer + length,kobject_name(p),cur);
+		strncpy(buffer + length, sd->s_name, cur);
 		*(buffer + --length) = '/';
 	}
 }
 
-static int sysfs_add_link(struct dentry * parent, const char * name, struct kobject * target)
-{
-	struct sysfs_dirent * parent_sd = parent->d_fsdata;
-	struct sysfs_symlink * sl;
-	int error = 0;
-
-	error = -ENOMEM;
-	sl = kmalloc(sizeof(*sl), GFP_KERNEL);
-	if (!sl)
-		goto exit1;
-
-	sl->link_name = kmalloc(strlen(name) + 1, GFP_KERNEL);
-	if (!sl->link_name)
-		goto exit2;
-
-	strcpy(sl->link_name, name);
-	sl->target_kobj = kobject_get(target);
-
-	error = sysfs_make_dirent(parent_sd, NULL, sl, S_IFLNK|S_IRWXUGO,
-				SYSFS_KOBJ_LINK);
-	if (!error)
-		return 0;
-
-	kobject_put(target);
-	kfree(sl->link_name);
-exit2:
-	kfree(sl);
-exit1:
-	return error;
-}
-
 /**
  *	sysfs_create_link - create symlink between two objects.
  *	@kobj:	object whose directory we're creating the link in.
@@ -84,24 +52,57 @@ exit1:
  */
 int sysfs_create_link(struct kobject * kobj, struct kobject * target, const char * name)
 {
-	struct dentry *dentry = NULL;
-	int error = -EEXIST;
+	struct sysfs_dirent *parent_sd = NULL;
+	struct sysfs_dirent *target_sd = NULL;
+	struct sysfs_dirent *sd = NULL;
+	struct sysfs_addrm_cxt acxt;
+	int error;
 
 	BUG_ON(!name);
 
 	if (!kobj) {
 		if (sysfs_mount && sysfs_mount->mnt_sb)
-			dentry = sysfs_mount->mnt_sb->s_root;
+			parent_sd = sysfs_mount->mnt_sb->s_root->d_fsdata;
 	} else
-		dentry = kobj->dentry;
+		parent_sd = kobj->sd;
+
+	error = -EFAULT;
+	if (!parent_sd)
+		goto out_put;
+
+	/* target->sd can go away beneath us but is protected with
+	 * sysfs_assoc_lock.  Fetch target_sd from it.
+	 */
+	spin_lock(&sysfs_assoc_lock);
+	if (target->sd)
+		target_sd = sysfs_get(target->sd);
+	spin_unlock(&sysfs_assoc_lock);
+
+	error = -ENOENT;
+	if (!target_sd)
+		goto out_put;
+
+	error = -ENOMEM;
+	sd = sysfs_new_dirent(name, S_IFLNK|S_IRWXUGO, SYSFS_KOBJ_LINK);
+	if (!sd)
+		goto out_put;
+	sd->s_elem.symlink.target_sd = target_sd;
 
-	if (!dentry)
-		return -EFAULT;
+	sysfs_addrm_start(&acxt, parent_sd);
 
-	mutex_lock(&dentry->d_inode->i_mutex);
-	if (!sysfs_dirent_exist(dentry->d_fsdata, name))
-		error = sysfs_add_link(dentry, name, target);
-	mutex_unlock(&dentry->d_inode->i_mutex);
+	if (!sysfs_find_dirent(parent_sd, name)) {
+		sysfs_add_one(&acxt, sd);
+		sysfs_link_sibling(sd);
+	}
+
+	if (sysfs_addrm_finish(&acxt))
+		return 0;
+
+	error = -EEXIST;
+	/* fall through */
+ out_put:
+	sysfs_put(target_sd);
+	sysfs_put(sd);
 	return error;
 }
 
@@ -114,17 +115,17 @@ int sysfs_create_link(struct kobject * kobj, struct kobject * target, const char
 
 void sysfs_remove_link(struct kobject * kobj, const char * name)
 {
-	sysfs_hash_and_remove(kobj->dentry,name);
+	sysfs_hash_and_remove(kobj->sd, name);
 }
 
-static int sysfs_get_target_path(struct kobject * kobj, struct kobject * target,
-				 char *path)
+static int sysfs_get_target_path(struct sysfs_dirent * parent_sd,
+				 struct sysfs_dirent * target_sd, char *path)
 {
 	char * s;
 	int depth, size;
 
-	depth = object_depth(kobj);
-	size = object_path_length(target) + depth * 3 - 1;
+	depth = object_depth(parent_sd);
+	size = object_path_length(target_sd) + depth * 3 - 1;
 	if (size > PATH_MAX)
 		return -ENAMETOOLONG;
 
@@ -133,7 +134,7 @@ static int sysfs_get_target_path(struct kobject * kobj, struct kobject * target,
 	for (s = path; depth--; s += 3)
 		strcpy(s,"../");
 
-	fill_object_path(target, path, size);
+	fill_object_path(target_sd, path, size);
 	pr_debug("%s: path = '%s'\n", __FUNCTION__, path);
 
 	return 0;
@@ -141,27 +142,16 @@ static int sysfs_get_target_path(struct kobject * kobj, struct kobject * target,
 
 static int sysfs_getlink(struct dentry *dentry, char * path)
 {
-	struct kobject *kobj, *target_kobj;
-	int error = 0;
+	struct sysfs_dirent *sd = dentry->d_fsdata;
+	struct sysfs_dirent *parent_sd = sd->s_parent;
+	struct sysfs_dirent *target_sd = sd->s_elem.symlink.target_sd;
+	int error;
 
-	kobj = sysfs_get_kobject(dentry->d_parent);
-	if (!kobj)
-		return -EINVAL;
+	mutex_lock(&sysfs_mutex);
+	error = sysfs_get_target_path(parent_sd, target_sd, path);
+	mutex_unlock(&sysfs_mutex);
 
-	target_kobj = sysfs_get_kobject(dentry);
-	if (!target_kobj) {
-		kobject_put(kobj);
-		return -EINVAL;
-	}
-
-	down_read(&sysfs_rename_sem);
-	error = sysfs_get_target_path(kobj, target_kobj, path);
-	up_read(&sysfs_rename_sem);
-	
-	kobject_put(kobj);
-	kobject_put(target_kobj);
 	return error;
-
 }
 
 static void *sysfs_follow_link(struct dentry *dentry, struct nameidata *nd)
diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
index 502c949c402..6a37f2386a8 100644
--- a/fs/sysfs/sysfs.h
+++ b/fs/sysfs/sysfs.h
@@ -1,9 +1,40 @@
+struct sysfs_elem_dir {
+	struct kobject		* kobj;
+};
+
+struct sysfs_elem_symlink {
+	struct sysfs_dirent	* target_sd;
+};
+
+struct sysfs_elem_attr {
+	struct attribute	* attr;
+};
+
+struct sysfs_elem_bin_attr {
+	struct bin_attribute	* bin_attr;
+};
+
+/*
+ * As long as s_count reference is held, the sysfs_dirent itself is
+ * accessible.  Dereferencing s_elem or any other outer entity
+ * requires s_active reference.
+ */
 struct sysfs_dirent {
 	atomic_t		s_count;
-	struct list_head	s_sibling;
-	struct list_head	s_children;
-	void 			* s_element;
-	int			s_type;
+	atomic_t		s_active;
+	struct sysfs_dirent	* s_parent;
+	struct sysfs_dirent	* s_sibling;
+	struct sysfs_dirent	* s_children;
+	const char		* s_name;
+
+	union {
+		struct sysfs_elem_dir		dir;
+		struct sysfs_elem_symlink	symlink;
+		struct sysfs_elem_attr		attr;
+		struct sysfs_elem_bin_attr	bin_attr;
+	}			s_elem;
+
+	unsigned int		s_flags;
 	umode_t			s_mode;
 	ino_t			s_ino;
 	struct dentry		* s_dentry;
@@ -11,30 +42,60 @@ struct sysfs_dirent {
 	atomic_t		s_event;
 };
 
+#define SD_DEACTIVATED_BIAS	INT_MIN
+
+struct sysfs_addrm_cxt {
+	struct sysfs_dirent	*parent_sd;
+	struct inode		*parent_inode;
+	struct sysfs_dirent	*removed;
+	int			cnt;
+};
+
 extern struct vfsmount * sysfs_mount;
+extern struct sysfs_dirent sysfs_root;
 extern struct kmem_cache *sysfs_dir_cachep;
 
-extern void sysfs_delete_inode(struct inode *inode);
-extern struct inode * sysfs_new_inode(mode_t mode, struct sysfs_dirent *);
-extern int sysfs_create(struct dentry *, int mode, int (*init)(struct inode *));
+extern struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd);
+extern void sysfs_link_sibling(struct sysfs_dirent *sd);
+extern void sysfs_unlink_sibling(struct sysfs_dirent *sd);
+extern struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd);
+extern void sysfs_put_active(struct sysfs_dirent *sd);
+extern struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd);
+extern void sysfs_put_active_two(struct sysfs_dirent *sd);
+extern void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
+			      struct sysfs_dirent *parent_sd);
+extern void sysfs_add_one(struct sysfs_addrm_cxt *acxt,
+			  struct sysfs_dirent *sd);
+extern void sysfs_remove_one(struct sysfs_addrm_cxt *acxt,
+			     struct sysfs_dirent *sd);
+extern int sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt);
 
-extern int sysfs_dirent_exist(struct sysfs_dirent *, const unsigned char *);
-extern int sysfs_make_dirent(struct sysfs_dirent *, struct dentry *, void *,
-				umode_t, int);
-
-extern int sysfs_add_file(struct dentry *, const struct attribute *, int);
-extern int sysfs_hash_and_remove(struct dentry * dir, const char * name);
+extern void sysfs_delete_inode(struct inode *inode);
+extern void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode);
+extern struct inode * sysfs_get_inode(struct sysfs_dirent *sd);
+extern void sysfs_instantiate(struct dentry *dentry, struct inode *inode);
+
+extern void release_sysfs_dirent(struct sysfs_dirent * sd);
+extern struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd,
+					      const unsigned char *name);
+extern struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
+					     const unsigned char *name);
+extern struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode,
+					     int type);
+
+extern int sysfs_add_file(struct sysfs_dirent *dir_sd,
+			  const struct attribute *attr, int type);
+extern int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name);
 extern struct sysfs_dirent *sysfs_find(struct sysfs_dirent *dir, const char * name);
 
-extern int sysfs_create_subdir(struct kobject *, const char *, struct dentry **);
-extern void sysfs_remove_subdir(struct dentry *);
+extern int sysfs_create_subdir(struct kobject *kobj, const char *name,
+			       struct sysfs_dirent **p_sd);
+extern void sysfs_remove_subdir(struct sysfs_dirent *sd);
 
-extern const unsigned char * sysfs_get_name(struct sysfs_dirent *sd);
-extern void sysfs_drop_dentry(struct sysfs_dirent *sd, struct dentry *parent);
 extern int sysfs_setattr(struct dentry *dentry, struct iattr *iattr);
 
-extern spinlock_t sysfs_lock;
-extern struct rw_semaphore sysfs_rename_sem;
+extern spinlock_t sysfs_assoc_lock;
+extern struct mutex sysfs_mutex;
 extern struct super_block * sysfs_sb;
 extern const struct file_operations sysfs_dir_operations;
 extern const struct file_operations sysfs_file_operations;
@@ -42,73 +103,9 @@ extern const struct file_operations bin_fops;
 extern const struct inode_operations sysfs_dir_inode_operations;
 extern const struct inode_operations sysfs_symlink_inode_operations;
 
-struct sysfs_symlink {
-	char * link_name;
-	struct kobject * target_kobj;
-};
-
-struct sysfs_buffer {
-	struct list_head		associates;
-	size_t				count;
-	loff_t				pos;
-	char				* page;
-	struct sysfs_ops		* ops;
-	struct semaphore		sem;
-	int				orphaned;
-	int				needs_read_fill;
-	int				event;
-};
-
-struct sysfs_buffer_collection {
-	struct list_head	associates;
-};
-
-static inline struct kobject * to_kobj(struct dentry * dentry)
-{
-	struct sysfs_dirent * sd = dentry->d_fsdata;
-	return ((struct kobject *) sd->s_element);
-}
-
-static inline struct attribute * to_attr(struct dentry * dentry)
+static inline unsigned int sysfs_type(struct sysfs_dirent *sd)
 {
-	struct sysfs_dirent * sd = dentry->d_fsdata;
-	return ((struct attribute *) sd->s_element);
-}
-
-static inline struct bin_attribute * to_bin_attr(struct dentry * dentry)
-{
-	struct sysfs_dirent * sd = dentry->d_fsdata;
-	return ((struct bin_attribute *) sd->s_element);
-}
-
-static inline struct kobject *sysfs_get_kobject(struct dentry *dentry)
-{
-	struct kobject * kobj = NULL;
-
-	spin_lock(&dcache_lock);
-	if (!d_unhashed(dentry)) {
-		struct sysfs_dirent * sd = dentry->d_fsdata;
-		if (sd->s_type & SYSFS_KOBJ_LINK) {
-			struct sysfs_symlink * sl = sd->s_element;
-			kobj = kobject_get(sl->target_kobj);
-		} else
-			kobj = kobject_get(sd->s_element);
-	}
-	spin_unlock(&dcache_lock);
-
-	return kobj;
-}
-
-static inline void release_sysfs_dirent(struct sysfs_dirent * sd)
-{
-	if (sd->s_type & SYSFS_KOBJ_LINK) {
-		struct sysfs_symlink * sl = sd->s_element;
-		kfree(sl->link_name);
-		kobject_put(sl->target_kobj);
-		kfree(sl);
-	}
-	kfree(sd->s_iattr);
-	kmem_cache_free(sysfs_dir_cachep, sd);
+	return sd->s_flags & SYSFS_TYPE_MASK;
 }
 
 static inline struct sysfs_dirent * sysfs_get(struct sysfs_dirent * sd)
@@ -122,7 +119,7 @@ static inline struct sysfs_dirent * sysfs_get(struct sysfs_dirent * sd)
 
 static inline void sysfs_put(struct sysfs_dirent * sd)
 {
-	if (atomic_dec_and_test(&sd->s_count))
+	if (sd && atomic_dec_and_test(&sd->s_count))
 		release_sysfs_dirent(sd);
 }