init android origin source code

1 files changed, 1049 insertions, 0 deletions

diff --git a/ANDROID_3.4.5/fs/sysfs/dir.c b/ANDROID_3.4.5/fs/sysfs/dir.c
new file mode 100644
index 00000000..35a36d39
--- /dev/null
+++ b/ANDROID_3.4.5/fs/sysfs/dir.c
@@ -0,0 +1,1049 @@
+/*
+ * fs/sysfs/dir.c - sysfs core and dir operation implementation
+ *
+ * Copyright (c) 2001-3 Patrick Mochel
+ * Copyright (c) 2007 SUSE Linux Products GmbH
+ * Copyright (c) 2007 Tejun Heo <teheo@suse.de>
+ *
+ * This file is released under the GPLv2.
+ *
+ * Please see Documentation/filesystems/sysfs.txt for more information.
+ */
+
+#undef DEBUG
+
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/module.h>
+#include <linux/kobject.h>
+#include <linux/namei.h>
+#include <linux/idr.h>
+#include <linux/completion.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/security.h>
+#include <linux/hash.h>
+#include "sysfs.h"
+
+DEFINE_MUTEX(sysfs_mutex);
+DEFINE_SPINLOCK(sysfs_assoc_lock);
+
+#define to_sysfs_dirent(X) rb_entry((X), struct sysfs_dirent, s_rb);
+
+static DEFINE_SPINLOCK(sysfs_ino_lock);
+static DEFINE_IDA(sysfs_ino_ida);
+
+/**
+ *	sysfs_name_hash
+ *	@ns:   Namespace tag to hash
+ *	@name: Null terminated string to hash
+ *
+ *	Returns 31 bit hash of ns + name (so it fits in an off_t )
+ */
+static unsigned int sysfs_name_hash(const void *ns, const char *name)
+{
+	unsigned long hash = init_name_hash();
+	unsigned int len = strlen(name);
+	while (len--)
+		hash = partial_name_hash(*name++, hash);
+	hash = ( end_name_hash(hash) ^ hash_ptr( (void *)ns, 31 ) );
+	hash &= 0x7fffffffU;
+	/* Reserve hash numbers 0, 1 and INT_MAX for magic directory entries */
+	if (hash < 1)
+		hash += 2;
+	if (hash >= INT_MAX)
+		hash = INT_MAX - 1;
+	return hash;
+}
+
+static int sysfs_name_compare(unsigned int hash, const void *ns,
+	const char *name, const struct sysfs_dirent *sd)
+{
+	if (hash != sd->s_hash)
+		return hash - sd->s_hash;
+	if (ns != sd->s_ns)
+		return ns - sd->s_ns;
+	return strcmp(name, sd->s_name);
+}
+
+static int sysfs_sd_compare(const struct sysfs_dirent *left,
+			    const struct sysfs_dirent *right)
+{
+	return sysfs_name_compare(left->s_hash, left->s_ns, left->s_name,
+				  right);
+}
+
+/**
+ *	sysfs_link_subling - link sysfs_dirent into sibling rbtree
+ *	@sd: sysfs_dirent of interest
+ *
+ *	Link @sd into its sibling rbtree which starts from
+ *	sd->s_parent->s_dir.children.
+ *
+ *	Locking:
+ *	mutex_lock(sysfs_mutex)
+ *
+ *	RETURNS:
+ *	0 on susccess -EEXIST on failure.
+ */
+static int sysfs_link_sibling(struct sysfs_dirent *sd)
+{
+	struct rb_node **node = &sd->s_parent->s_dir.children.rb_node;
+	struct rb_node *parent = NULL;
+
+	if (sysfs_type(sd) == SYSFS_DIR)
+		sd->s_parent->s_dir.subdirs++;
+
+	while (*node) {
+		struct sysfs_dirent *pos;
+		int result;
+
+		pos = to_sysfs_dirent(*node);
+		parent = *node;
+		result = sysfs_sd_compare(sd, pos);
+		if (result < 0)
+			node = &pos->s_rb.rb_left;
+		else if (result > 0)
+			node = &pos->s_rb.rb_right;
+		else
+			return -EEXIST;
+	}
+	/* add new node and rebalance the tree */
+	rb_link_node(&sd->s_rb, parent, node);
+	rb_insert_color(&sd->s_rb, &sd->s_parent->s_dir.children);
+	return 0;
+}
+
+/**
+ *	sysfs_unlink_sibling - unlink sysfs_dirent from sibling rbtree
+ *	@sd: sysfs_dirent of interest
+ *
+ *	Unlink @sd from its sibling rbtree which starts from
+ *	sd->s_parent->s_dir.children.
+ *
+ *	Locking:
+ *	mutex_lock(sysfs_mutex)
+ */
+static void sysfs_unlink_sibling(struct sysfs_dirent *sd)
+{
+	if (sysfs_type(sd) == SYSFS_DIR)
+		sd->s_parent->s_dir.subdirs--;
+
+	rb_erase(&sd->s_rb, &sd->s_parent->s_dir.children);
+}
+
+/**
+ *	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)) {
+			rwsem_acquire_read(&sd->dep_map, 0, 1, _RET_IP_);
+			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)
+{
+	int v;
+
+	if (unlikely(!sd))
+		return;
+
+	rwsem_release(&sd->dep_map, 1, _RET_IP_);
+	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->u.completion.
+	 */
+	complete(sd->u.completion);
+}
+
+/**
+ *	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_flags & SYSFS_FLAG_REMOVED));
+
+	if (!(sysfs_type(sd) & SYSFS_ACTIVE_REF))
+		return;
+
+	sd->u.completion = (void *)&wait;
+
+	rwsem_acquire(&sd->dep_map, 0, 0, _RET_IP_);
+	/* atomic_add_return() is a mb(), put_active() will always see
+	 * the updated sd->u.completion.
+	 */
+	v = atomic_add_return(SD_DEACTIVATED_BIAS, &sd->s_active);
+
+	if (v != SD_DEACTIVATED_BIAS) {
+		lock_contended(&sd->dep_map, _RET_IP_);
+		wait_for_completion(&wait);
+	}
+
+	lock_acquired(&sd->dep_map, _RET_IP_);
+	rwsem_release(&sd->dep_map, 1, _RET_IP_);
+}
+
+static int sysfs_alloc_ino(unsigned int *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(unsigned int 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_symlink.target_sd);
+	if (sysfs_type(sd) & SYSFS_COPY_NAME)
+		kfree(sd->s_name);
+	if (sd->s_iattr && sd->s_iattr->ia_secdata)
+		security_release_secctx(sd->s_iattr->ia_secdata,
+					sd->s_iattr->ia_secdata_len);
+	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 int sysfs_dentry_delete(const struct dentry *dentry)
+{
+	struct sysfs_dirent *sd = dentry->d_fsdata;
+	return !!(sd->s_flags & SYSFS_FLAG_REMOVED);
+}
+
+static int sysfs_dentry_revalidate(struct dentry *dentry, struct nameidata *nd)
+{
+	struct sysfs_dirent *sd;
+	int is_dir;
+
+	if (nd->flags & LOOKUP_RCU)
+		return -ECHILD;
+
+	sd = dentry->d_fsdata;
+	mutex_lock(&sysfs_mutex);
+
+	/* The sysfs dirent has been deleted */
+	if (sd->s_flags & SYSFS_FLAG_REMOVED)
+		goto out_bad;
+
+	/* The sysfs dirent has been moved? */
+	if (dentry->d_parent->d_fsdata != sd->s_parent)
+		goto out_bad;
+
+	/* The sysfs dirent has been renamed */
+	if (strcmp(dentry->d_name.name, sd->s_name) != 0)
+		goto out_bad;
+
+	mutex_unlock(&sysfs_mutex);
+out_valid:
+	return 1;
+out_bad:
+	/* Remove the dentry from the dcache hashes.
+	 * If this is a deleted dentry we use d_drop instead of d_delete
+	 * so sysfs doesn't need to cope with negative dentries.
+	 *
+	 * If this is a dentry that has simply been renamed we
+	 * use d_drop to remove it from the dcache lookup on its
+	 * old parent.  If this dentry persists later when a lookup
+	 * is performed at its new name the dentry will be readded
+	 * to the dcache hashes.
+	 */
+	is_dir = (sysfs_type(sd) == SYSFS_DIR);
+	mutex_unlock(&sysfs_mutex);
+	if (is_dir) {
+		/* If we have submounts we must allow the vfs caches
+		 * to lie about the state of the filesystem to prevent
+		 * leaks and other nasty things.
+		 */
+		if (have_submounts(dentry))
+			goto out_valid;
+		shrink_dcache_parent(dentry);
+	}
+	d_drop(dentry);
+	return 0;
+}
+
+static void sysfs_dentry_iput(struct dentry *dentry, struct inode *inode)
+{
+	struct sysfs_dirent * sd = dentry->d_fsdata;
+
+	sysfs_put(sd);
+	iput(inode);
+}
+
+static const struct dentry_operations sysfs_dentry_ops = {
+	.d_revalidate	= sysfs_dentry_revalidate,
+	.d_delete	= sysfs_dentry_delete,
+	.d_iput		= sysfs_dentry_iput,
+};
+
+struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type)
+{
+	char *dup_name = NULL;
+	struct sysfs_dirent *sd;
+
+	if (type & SYSFS_COPY_NAME) {
+		name = dup_name = kstrdup(name, GFP_KERNEL);
+		if (!name)
+			return NULL;
+	}
+
+	sd = kmem_cache_zalloc(sysfs_dir_cachep, GFP_KERNEL);
+	if (!sd)
+		goto err_out1;
+
+	if (sysfs_alloc_ino(&sd->s_ino))
+		goto err_out2;
+
+	atomic_set(&sd->s_count, 1);
+	atomic_set(&sd->s_active, 0);
+
+	sd->s_name = name;
+	sd->s_mode = mode;
+	sd->s_flags = type;
+
+	return sd;
+
+ err_out2:
+	kmem_cache_free(sysfs_dir_cachep, sd);
+ err_out1:
+	kfree(dup_name);
+	return NULL;
+}
+
+/**
+ *	sysfs_addrm_start - prepare for sysfs_dirent add/remove
+ *	@acxt: pointer to sysfs_addrm_cxt to be used
+ *	@parent_sd: parent sysfs_dirent
+ *
+ *	This function is called when the caller is about to add or
+ *	remove sysfs_dirent under @parent_sd.  This function acquires
+ *	sysfs_mutex.  @acxt is used to keep and pass context to
+ *	other addrm functions.
+ *
+ *	LOCKING:
+ *	Kernel thread context (may sleep).  sysfs_mutex is locked on
+ *	return.
+ */
+void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
+		       struct sysfs_dirent *parent_sd)
+{
+	memset(acxt, 0, sizeof(*acxt));
+	acxt->parent_sd = parent_sd;
+
+	mutex_lock(&sysfs_mutex);
+}
+
+/**
+ *	__sysfs_add_one - add sysfs_dirent to parent without warning
+ *	@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 and link into the
+ *	children list of the parent.
+ *
+ *	This function should be called between calls to
+ *	sysfs_addrm_start() and sysfs_addrm_finish() and should be
+ *	passed the same @acxt as passed to sysfs_addrm_start().
+ *
+ *	LOCKING:
+ *	Determined by sysfs_addrm_start().
+ *
+ *	RETURNS:
+ *	0 on success, -EEXIST if entry with the given name already
+ *	exists.
+ */
+int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
+{
+	struct sysfs_inode_attrs *ps_iattr;
+	int ret;
+
+	if (!!sysfs_ns_type(acxt->parent_sd) != !!sd->s_ns) {
+		WARN(1, KERN_WARNING "sysfs: ns %s in '%s' for '%s'\n",
+			sysfs_ns_type(acxt->parent_sd)? "required": "invalid",
+			acxt->parent_sd->s_name, sd->s_name);
+		return -EINVAL;
+	}
+
+	sd->s_hash = sysfs_name_hash(sd->s_ns, sd->s_name);
+	sd->s_parent = sysfs_get(acxt->parent_sd);
+
+	ret = sysfs_link_sibling(sd);
+	if (ret)
+		return ret;
+
+	/* Update timestamps on the parent */
+	ps_iattr = acxt->parent_sd->s_iattr;
+	if (ps_iattr) {
+		struct iattr *ps_iattrs = &ps_iattr->ia_iattr;
+		ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME;
+	}
+
+	return 0;
+}
+
+/**
+ *	sysfs_pathname - return full path to sysfs dirent
+ *	@sd: sysfs_dirent whose path we want
+ *	@path: caller allocated buffer
+ *
+ *	Gives the name "/" to the sysfs_root entry; any path returned
+ *	is relative to wherever sysfs is mounted.
+ *
+ *	XXX: does no error checking on @path size
+ */
+static char *sysfs_pathname(struct sysfs_dirent *sd, char *path)
+{
+	if (sd->s_parent) {
+		sysfs_pathname(sd->s_parent, path);
+		strcat(path, "/");
+	}
+	strcat(path, sd->s_name);
+	return path;
+}
+
+/**
+ *	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 and link into the
+ *	children list of the parent.
+ *
+ *	This function should be called between calls to
+ *	sysfs_addrm_start() and sysfs_addrm_finish() and should be
+ *	passed the same @acxt as passed to sysfs_addrm_start().
+ *
+ *	LOCKING:
+ *	Determined by sysfs_addrm_start().
+ *
+ *	RETURNS:
+ *	0 on success, -EEXIST if entry with the given name already
+ *	exists.
+ */
+int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
+{
+	int ret;
+
+	ret = __sysfs_add_one(acxt, sd);
+	if (ret == -EEXIST) {
+		char *path = kzalloc(PATH_MAX, GFP_KERNEL);
+		WARN(1, KERN_WARNING
+		     "sysfs: cannot create duplicate filename '%s'\n",
+		     (path == NULL) ? sd->s_name :
+		     strcat(strcat(sysfs_pathname(acxt->parent_sd, path), "/"),
+		            sd->s_name));
+		kfree(path);
+	}
+
+	return ret;
+}
+
+/**
+ *	sysfs_remove_one - remove sysfs_dirent from parent
+ *	@acxt: addrm context to use
+ *	@sd: sysfs_dirent to be removed
+ *
+ *	Mark @sd removed and drop nlink of parent inode if @sd is a
+ *	directory.  @sd is unlinked from 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_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
+{
+	struct sysfs_inode_attrs *ps_iattr;
+
+	BUG_ON(sd->s_flags & SYSFS_FLAG_REMOVED);
+
+	sysfs_unlink_sibling(sd);
+
+	/* Update timestamps on the parent */
+	ps_iattr = acxt->parent_sd->s_iattr;
+	if (ps_iattr) {
+		struct iattr *ps_iattrs = &ps_iattr->ia_iattr;
+		ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME;
+	}
+
+	sd->s_flags |= SYSFS_FLAG_REMOVED;
+	sd->u.removed_list = acxt->removed;
+	acxt->removed = sd;
+}
+
+/**
+ *	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.
+ *
+ *	LOCKING:
+ *	sysfs_mutex is released.
+ */
+void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt)
+{
+	/* release resources acquired by sysfs_addrm_start() */
+	mutex_unlock(&sysfs_mutex);
+
+	/* kill removed sysfs_dirents */
+	while (acxt->removed) {
+		struct sysfs_dirent *sd = acxt->removed;
+
+		acxt->removed = sd->u.removed_list;
+
+		sysfs_deactivate(sd);
+		unmap_bin_file(sd);
+		sysfs_put(sd);
+	}
+}
+
+/**
+ *	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 void *ns,
+				       const unsigned char *name)
+{
+	struct rb_node *node = parent_sd->s_dir.children.rb_node;
+	unsigned int hash;
+
+	if (!!sysfs_ns_type(parent_sd) != !!ns) {
+		WARN(1, KERN_WARNING "sysfs: ns %s in '%s' for '%s'\n",
+			sysfs_ns_type(parent_sd)? "required": "invalid",
+			parent_sd->s_name, name);
+		return NULL;
+	}
+
+	hash = sysfs_name_hash(ns, name);
+	while (node) {
+		struct sysfs_dirent *sd;
+		int result;
+
+		sd = to_sysfs_dirent(node);
+		result = sysfs_name_compare(hash, ns, name, sd);
+		if (result < 0)
+			node = node->rb_left;
+		else if (result > 0)
+			node = node->rb_right;
+		else
+			return sd;
+	}
+	return NULL;
+}
+
+/**
+ *	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 void *ns,
+				      const unsigned char *name)
+{
+	struct sysfs_dirent *sd;
+
+	mutex_lock(&sysfs_mutex);
+	sd = sysfs_find_dirent(parent_sd, ns, name);
+	sysfs_get(sd);
+	mutex_unlock(&sysfs_mutex);
+
+	return sd;
+}
+EXPORT_SYMBOL_GPL(sysfs_get_dirent);
+
+static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd,
+	enum kobj_ns_type type, const void *ns, const char *name,
+	struct sysfs_dirent **p_sd)
+{
+	umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;
+	struct sysfs_addrm_cxt acxt;
+	struct sysfs_dirent *sd;
+	int rc;
+
+	/* allocate */
+	sd = sysfs_new_dirent(name, mode, SYSFS_DIR);
+	if (!sd)
+		return -ENOMEM;
+
+	sd->s_flags |= (type << SYSFS_NS_TYPE_SHIFT);
+	sd->s_ns = ns;
+	sd->s_dir.kobj = kobj;
+
+	/* link in */
+	sysfs_addrm_start(&acxt, parent_sd);
+	rc = sysfs_add_one(&acxt, sd);
+	sysfs_addrm_finish(&acxt);
+
+	if (rc == 0)
+		*p_sd = sd;
+	else
+		sysfs_put(sd);
+
+	return rc;
+}
+
+int sysfs_create_subdir(struct kobject *kobj, const char *name,
+			struct sysfs_dirent **p_sd)
+{
+	return create_dir(kobj, kobj->sd,
+			  KOBJ_NS_TYPE_NONE, NULL, name, p_sd);
+}
+
+/**
+ *	sysfs_read_ns_type: return associated ns_type
+ *	@kobj: the kobject being queried
+ *
+ *	Each kobject can be tagged with exactly one namespace type
+ *	(i.e. network or user).  Return the ns_type associated with
+ *	this object if any
+ */
+static enum kobj_ns_type sysfs_read_ns_type(struct kobject *kobj)
+{
+	const struct kobj_ns_type_operations *ops;
+	enum kobj_ns_type type;
+
+	ops = kobj_child_ns_ops(kobj);
+	if (!ops)
+		return KOBJ_NS_TYPE_NONE;
+
+	type = ops->type;
+	BUG_ON(type <= KOBJ_NS_TYPE_NONE);
+	BUG_ON(type >= KOBJ_NS_TYPES);
+	BUG_ON(!kobj_ns_type_registered(type));
+
+	return type;
+}
+
+/**
+ *	sysfs_create_dir - create a directory for an object.
+ *	@kobj:		object we're creating directory for. 
+ */
+int sysfs_create_dir(struct kobject * kobj)
+{
+	enum kobj_ns_type type;
+	struct sysfs_dirent *parent_sd, *sd;
+	const void *ns = NULL;
+	int error = 0;
+
+	BUG_ON(!kobj);
+
+	if (kobj->parent)
+		parent_sd = kobj->parent->sd;
+	else
+		parent_sd = &sysfs_root;
+
+	if (!parent_sd)
+		return -ENOENT;
+
+	if (sysfs_ns_type(parent_sd))
+		ns = kobj->ktype->namespace(kobj);
+	type = sysfs_read_ns_type(kobj);
+
+	error = create_dir(kobj, parent_sd, type, ns, kobject_name(kobj), &sd);
+	if (!error)
+		kobj->sd = sd;
+	return error;
+}
+
+static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
+				struct nameidata *nd)
+{
+	struct dentry *ret = NULL;
+	struct dentry *parent = dentry->d_parent;
+	struct sysfs_dirent *parent_sd = parent->d_fsdata;
+	struct sysfs_dirent *sd;
+	struct inode *inode;
+	enum kobj_ns_type type;
+	const void *ns;
+
+	mutex_lock(&sysfs_mutex);
+
+	type = sysfs_ns_type(parent_sd);
+	ns = sysfs_info(dir->i_sb)->ns[type];
+
+	sd = sysfs_find_dirent(parent_sd, ns, dentry->d_name.name);
+
+	/* no such entry */
+	if (!sd) {
+		ret = ERR_PTR(-ENOENT);
+		goto out_unlock;
+	}
+
+	/* attach dentry and inode */
+	inode = sysfs_get_inode(dir->i_sb, sd);
+	if (!inode) {
+		ret = ERR_PTR(-ENOMEM);
+		goto out_unlock;
+	}
+
+	/* instantiate and hash dentry */
+	ret = d_find_alias(inode);
+	if (!ret) {
+		d_set_d_op(dentry, &sysfs_dentry_ops);
+		dentry->d_fsdata = sysfs_get(sd);
+		d_add(dentry, inode);
+	} else {
+		d_move(ret, dentry);
+		iput(inode);
+	}
+
+ out_unlock:
+	mutex_unlock(&sysfs_mutex);
+	return ret;
+}
+
+const struct inode_operations sysfs_dir_inode_operations = {
+	.lookup		= sysfs_lookup,
+	.permission	= sysfs_permission,
+	.setattr	= sysfs_setattr,
+	.getattr	= sysfs_getattr,
+	.setxattr	= sysfs_setxattr,
+};
+
+static void remove_dir(struct sysfs_dirent *sd)
+{
+	struct sysfs_addrm_cxt acxt;
+
+	sysfs_addrm_start(&acxt, sd->s_parent);
+	sysfs_remove_one(&acxt, sd);
+	sysfs_addrm_finish(&acxt);
+}
+
+void sysfs_remove_subdir(struct sysfs_dirent *sd)
+{
+	remove_dir(sd);
+}
+
+
+static void __sysfs_remove_dir(struct sysfs_dirent *dir_sd)
+{
+	struct sysfs_addrm_cxt acxt;
+	struct rb_node *pos;
+
+	if (!dir_sd)
+		return;
+
+	pr_debug("sysfs %s: removing dir\n", dir_sd->s_name);
+	sysfs_addrm_start(&acxt, dir_sd);
+	pos = rb_first(&dir_sd->s_dir.children);
+	while (pos) {
+		struct sysfs_dirent *sd = to_sysfs_dirent(pos);
+		pos = rb_next(pos);
+		if (sysfs_type(sd) != SYSFS_DIR)
+			sysfs_remove_one(&acxt, sd);
+	}
+	sysfs_addrm_finish(&acxt);
+
+	remove_dir(dir_sd);
+}
+
+/**
+ *	sysfs_remove_dir - remove an object's directory.
+ *	@kobj:	object.
+ *
+ *	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_dir(struct kobject * kobj)
+{
+	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(struct sysfs_dirent *sd,
+	struct sysfs_dirent *new_parent_sd, const void *new_ns,
+	const char *new_name)
+{
+	const char *dup_name = NULL;
+	int error;
+
+	mutex_lock(&sysfs_mutex);
+
+	error = 0;
+	if ((sd->s_parent == new_parent_sd) && (sd->s_ns == new_ns) &&
+	    (strcmp(sd->s_name, new_name) == 0))
+		goto out;	/* nothing to rename */
+
+	error = -EEXIST;
+	if (sysfs_find_dirent(new_parent_sd, new_ns, new_name))
+		goto out;
+
+	/* rename sysfs_dirent */
+	if (strcmp(sd->s_name, new_name) != 0) {
+		error = -ENOMEM;
+		new_name = dup_name = kstrdup(new_name, GFP_KERNEL);
+		if (!new_name)
+			goto out;
+
+		dup_name = sd->s_name;
+		sd->s_name = new_name;
+	}
+
+	/* Move to the appropriate place in the appropriate directories rbtree. */
+	sysfs_unlink_sibling(sd);
+	sysfs_get(new_parent_sd);
+	sysfs_put(sd->s_parent);
+	sd->s_ns = new_ns;
+	sd->s_hash = sysfs_name_hash(sd->s_ns, sd->s_name);
+	sd->s_parent = new_parent_sd;
+	sysfs_link_sibling(sd);
+
+	error = 0;
+ out:
+	mutex_unlock(&sysfs_mutex);
+	kfree(dup_name);
+	return error;
+}
+
+int sysfs_rename_dir(struct kobject *kobj, const char *new_name)
+{
+	struct sysfs_dirent *parent_sd = kobj->sd->s_parent;
+	const void *new_ns = NULL;
+
+	if (sysfs_ns_type(parent_sd))
+		new_ns = kobj->ktype->namespace(kobj);
+
+	return sysfs_rename(kobj->sd, parent_sd, new_ns, new_name);
+}
+
+int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent_kobj)
+{
+	struct sysfs_dirent *sd = kobj->sd;
+	struct sysfs_dirent *new_parent_sd;
+	const void *new_ns = NULL;
+
+	BUG_ON(!sd->s_parent);
+	if (sysfs_ns_type(sd->s_parent))
+		new_ns = kobj->ktype->namespace(kobj);
+	new_parent_sd = new_parent_kobj && new_parent_kobj->sd ?
+		new_parent_kobj->sd : &sysfs_root;
+
+	return sysfs_rename(sd, new_parent_sd, new_ns, sd->s_name);
+}
+
+/* Relationship between s_mode and the DT_xxx types */
+static inline unsigned char dt_type(struct sysfs_dirent *sd)
+{
+	return (sd->s_mode >> 12) & 15;
+}
+
+static int sysfs_dir_release(struct inode *inode, struct file *filp)
+{
+	sysfs_put(filp->private_data);
+	return 0;
+}
+
+static struct sysfs_dirent *sysfs_dir_pos(const void *ns,
+	struct sysfs_dirent *parent_sd,	loff_t hash, struct sysfs_dirent *pos)
+{
+	if (pos) {
+		int valid = !(pos->s_flags & SYSFS_FLAG_REMOVED) &&
+			pos->s_parent == parent_sd &&
+			hash == pos->s_hash;
+		sysfs_put(pos);
+		if (!valid)
+			pos = NULL;
+	}
+	if (!pos && (hash > 1) && (hash < INT_MAX)) {
+		struct rb_node *node = parent_sd->s_dir.children.rb_node;
+		while (node) {
+			pos = to_sysfs_dirent(node);
+
+			if (hash < pos->s_hash)
+				node = node->rb_left;
+			else if (hash > pos->s_hash)
+				node = node->rb_right;
+			else
+				break;
+		}
+	}
+	/* Skip over entries in the wrong namespace */
+	while (pos && pos->s_ns != ns) {
+		struct rb_node *node = rb_next(&pos->s_rb);
+		if (!node)
+			pos = NULL;
+		else
+			pos = to_sysfs_dirent(node);
+	}
+	return pos;
+}
+
+static struct sysfs_dirent *sysfs_dir_next_pos(const void *ns,
+	struct sysfs_dirent *parent_sd,	ino_t ino, struct sysfs_dirent *pos)
+{
+	pos = sysfs_dir_pos(ns, parent_sd, ino, pos);
+	if (pos) do {
+		struct rb_node *node = rb_next(&pos->s_rb);
+		if (!node)
+			pos = NULL;
+		else
+			pos = to_sysfs_dirent(node);
+	} while (pos && pos->s_ns != ns);
+	return pos;
+}
+
+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 *pos = filp->private_data;
+	enum kobj_ns_type type;
+	const void *ns;
+	ino_t ino;
+
+	type = sysfs_ns_type(parent_sd);
+	ns = sysfs_info(dentry->d_sb)->ns[type];
+
+	if (filp->f_pos == 0) {
+		ino = parent_sd->s_ino;
+		if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) == 0)
+			filp->f_pos++;
+	}
+	if (filp->f_pos == 1) {
+		if (parent_sd->s_parent)
+			ino = parent_sd->s_parent->s_ino;
+		else
+			ino = parent_sd->s_ino;
+		if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) == 0)
+			filp->f_pos++;
+	}
+	mutex_lock(&sysfs_mutex);
+	for (pos = sysfs_dir_pos(ns, parent_sd, filp->f_pos, pos);
+	     pos;
+	     pos = sysfs_dir_next_pos(ns, parent_sd, filp->f_pos, pos)) {
+		const char * name;
+		unsigned int type;
+		int len, ret;
+
+		name = pos->s_name;
+		len = strlen(name);
+		ino = pos->s_ino;
+		type = dt_type(pos);
+		filp->f_pos = pos->s_hash;
+		filp->private_data = sysfs_get(pos);
+
+		mutex_unlock(&sysfs_mutex);
+		ret = filldir(dirent, name, len, filp->f_pos, ino, type);
+		mutex_lock(&sysfs_mutex);
+		if (ret < 0)
+			break;
+	}
+	mutex_unlock(&sysfs_mutex);
+	if ((filp->f_pos > 1) && !pos) { /* EOF */
+		filp->f_pos = INT_MAX;
+		filp->private_data = NULL;
+	}
+	return 0;
+}
+
+
+const struct file_operations sysfs_dir_operations = {
+	.read		= generic_read_dir,
+	.readdir	= sysfs_readdir,
+	.release	= sysfs_dir_release,
+	.llseek		= generic_file_llseek,
+};