1 files changed, 73 insertions, 432 deletions

diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 59734ba1ee6..0b45ff42f37 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -1,482 +1,123 @@
 /*
- * dir.c - Operations for sysfs directories.
+ * 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/slab.h>
 #include "sysfs.h"
 
-DECLARE_RWSEM(sysfs_rename_sem);
+DEFINE_SPINLOCK(sysfs_symlink_target_lock);
 
-static void sysfs_d_iput(struct dentry * dentry, struct inode * inode)
+void sysfs_warn_dup(struct kernfs_node *parent, const char *name)
 {
-	struct sysfs_dirent * sd = dentry->d_fsdata;
+	char *buf, *path = NULL;
 
-	if (sd) {
-		BUG_ON(sd->s_dentry != dentry);
-		sd->s_dentry = NULL;
-		sysfs_put(sd);
-	}
-	iput(inode);
-}
+	buf = kzalloc(PATH_MAX, GFP_KERNEL);
+	if (buf)
+		path = kernfs_path(parent, buf, PATH_MAX);
 
-static struct dentry_operations sysfs_dentry_ops = {
-	.d_iput		= sysfs_d_iput,
-};
+	WARN(1, KERN_WARNING "sysfs: cannot create duplicate filename '%s/%s'\n",
+	     path, name);
 
-/*
- * Allocates a new sysfs_dirent and links it to the parent sysfs_dirent
- */
-static struct sysfs_dirent * sysfs_new_dirent(struct sysfs_dirent * parent_sd,
-						void * element)
-{
-	struct sysfs_dirent * sd;
-
-	sd = kmem_cache_alloc(sysfs_dir_cachep, GFP_KERNEL);
-	if (!sd)
-		return NULL;
-
-	memset(sd, 0, sizeof(*sd));
-	atomic_set(&sd->s_count, 1);
-	INIT_LIST_HEAD(&sd->s_children);
-	list_add(&sd->s_sibling, &parent_sd->s_children);
-	sd->s_element = element;
-
-	return sd;
-}
-
-int sysfs_make_dirent(struct sysfs_dirent * parent_sd, struct dentry * dentry,
-			void * element, umode_t mode, int type)
-{
-	struct sysfs_dirent * sd;
-
-	sd = sysfs_new_dirent(parent_sd, element);
-	if (!sd)
-		return -ENOMEM;
-
-	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;
-	}
-
-	return 0;
-}
-
-static int init_dir(struct inode * inode)
-{
-	inode->i_op = &sysfs_dir_inode_operations;
-	inode->i_fop = &sysfs_dir_operations;
-
-	/* directory inodes start off with i_nlink == 2 (for "." entry) */
-	inode->i_nlink++;
-	return 0;
-}
-
-static int init_file(struct inode * inode)
-{
-	inode->i_size = PAGE_SIZE;
-	inode->i_fop = &sysfs_file_operations;
-	return 0;
-}
-
-static int init_symlink(struct inode * inode)
-{
-	inode->i_op = &sysfs_symlink_inode_operations;
-	return 0;
-}
-
-static int create_dir(struct kobject * k, struct dentry * p,
-		      const char * n, struct dentry ** d)
-{
-	int error;
-	umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;
-
-	down(&p->d_inode->i_sem);
-	*d = lookup_one_len(n, p, strlen(n));
-	if (!IS_ERR(*d)) {
-		error = sysfs_make_dirent(p->d_fsdata, *d, k, mode, SYSFS_DIR);
-		if (!error) {
-			error = sysfs_create(*d, mode, init_dir);
-			if (!error) {
-				p->d_inode->i_nlink++;
-				(*d)->d_op = &sysfs_dentry_ops;
-				d_rehash(*d);
-			}
-		}
-		if (error && (error != -EEXIST)) {
-			sysfs_put((*d)->d_fsdata);
-			d_drop(*d);
-		}
-		dput(*d);
-	} else
-		error = PTR_ERR(*d);
-	up(&p->d_inode->i_sem);
-	return error;
-}
-
-
-int sysfs_create_subdir(struct kobject * k, const char * n, struct dentry ** d)
-{
-	return create_dir(k,k->dentry,n,d);
+	kfree(buf);
 }
 
 /**
- *	sysfs_create_dir - create a directory for an object.
- *	@parent:	parent parent object.
- *	@kobj:		object we're creating directory for. 
+ * sysfs_create_dir_ns - create a directory for an object with a namespace tag
+ * @kobj: object we're creating directory for
+ * @ns: the namespace tag to use
  */
-
-int sysfs_create_dir(struct kobject * kobj)
+int sysfs_create_dir_ns(struct kobject *kobj, const void *ns)
 {
-	struct dentry * dentry = NULL;
-	struct dentry * parent;
-	int error = 0;
+	struct kernfs_node *parent, *kn;
 
 	BUG_ON(!kobj);
 
 	if (kobj->parent)
-		parent = kobj->parent->dentry;
-	else if (sysfs_mount && sysfs_mount->mnt_sb)
-		parent = sysfs_mount->mnt_sb->s_root;
+		parent = kobj->parent->sd;
 	else
-		return -EFAULT;
-
-	error = create_dir(kobj,parent,kobject_name(kobj),&dentry);
-	if (!error)
-		kobj->dentry = dentry;
-	return error;
-}
+		parent = sysfs_root_kn;
 
-/* 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)
-{
-	struct attribute * attr = NULL;
-	struct bin_attribute * bin_attr = NULL;
-	int (* init) (struct inode *) = NULL;
-	int error = 0;
+	if (!parent)
+		return -ENOENT;
 
-        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;
-        }
-
-	dentry->d_fsdata = sysfs_get(sd);
-	sd->s_dentry = dentry;
-	error = sysfs_create(dentry, (attr->mode & S_IALLUGO) | S_IFREG, init);
-	if (error) {
-		sysfs_put(sd);
-		return error;
+	kn = kernfs_create_dir_ns(parent, kobject_name(kobj),
+				  S_IRWXU | S_IRUGO | S_IXUGO, kobj, ns);
+	if (IS_ERR(kn)) {
+		if (PTR_ERR(kn) == -EEXIST)
+			sysfs_warn_dup(parent, kobject_name(kobj));
+		return PTR_ERR(kn);
 	}
 
-        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);
-
+	kobj->sd = kn;
 	return 0;
 }
 
-static int sysfs_attach_link(struct sysfs_dirent * sd, struct dentry * dentry)
-{
-	int err = 0;
-
-	dentry->d_fsdata = sysfs_get(sd);
-	sd->s_dentry = dentry;
-	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;
-}
-
-static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
-				struct nameidata *nd)
-{
-	struct sysfs_dirent * parent_sd = dentry->d_parent->d_fsdata;
-	struct sysfs_dirent * sd;
-	int err = 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);
-
-			if (strcmp(name, dentry->d_name.name))
-				continue;
-
-			if (sd->s_type & SYSFS_KOBJ_LINK)
-				err = sysfs_attach_link(sd, dentry);
-			else
-				err = sysfs_attach_attr(sd, dentry);
-			break;
-		}
-	}
-
-	return ERR_PTR(err);
-}
-
-struct inode_operations sysfs_dir_inode_operations = {
-	.lookup		= sysfs_lookup,
-	.setattr	= sysfs_setattr,
-};
-
-static void remove_dir(struct dentry * d)
-{
-	struct dentry * parent = dget(d->d_parent);
-	struct sysfs_dirent * sd;
-
-	down(&parent->d_inode->i_sem);
-	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));
-
-	up(&parent->d_inode->i_sem);
-	dput(parent);
-}
-
-void sysfs_remove_subdir(struct dentry * d)
-{
-	remove_dir(d);
-}
-
-
 /**
  *	sysfs_remove_dir - remove an object's directory.
- *	@kobj:	object. 
+ *	@kobj:	object.
  *
- *	The only thing special about this is that we remove any files in 
+ *	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 dentry * dentry = dget(kobj->dentry);
-	struct sysfs_dirent * parent_sd;
-	struct sysfs_dirent * sd, * tmp;
-
-	if (!dentry)
-		return;
-
-	pr_debug("sysfs %s: removing dir\n",dentry->d_name.name);
-	down(&dentry->d_inode->i_sem);
-	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);
-	}
-	up(&dentry->d_inode->i_sem);
-
-	remove_dir(dentry);
-	/**
-	 * Drop reference from dget() on entrance.
+void sysfs_remove_dir(struct kobject *kobj)
+{
+	struct kernfs_node *kn = kobj->sd;
+
+	/*
+	 * In general, kboject owner is responsible for ensuring removal
+	 * doesn't race with other operations and sysfs doesn't provide any
+	 * protection; however, when @kobj is used as a symlink target, the
+	 * symlinking entity usually doesn't own @kobj and thus has no
+	 * control over removal.  @kobj->sd may be removed anytime
+	 * and symlink code may end up dereferencing an already freed node.
+	 *
+	 * sysfs_symlink_target_lock synchronizes @kobj->sd
+	 * disassociation against symlink operations so that symlink code
+	 * can safely dereference @kobj->sd.
 	 */
-	dput(dentry);
-}
-
-int sysfs_rename_dir(struct kobject * kobj, const char *new_name)
-{
-	int error = 0;
-	struct dentry * new_dentry, * parent;
-
-	if (!strcmp(kobject_name(kobj), new_name))
-		return -EINVAL;
-
-	if (!kobj->parent)
-		return -EINVAL;
-
-	down_write(&sysfs_rename_sem);
-	parent = kobj->parent->dentry;
-
-	down(&parent->d_inode->i_sem);
+	spin_lock(&sysfs_symlink_target_lock);
+	kobj->sd = NULL;
+	spin_unlock(&sysfs_symlink_target_lock);
 
-	new_dentry = lookup_one_len(new_name, parent, strlen(new_name));
-	if (!IS_ERR(new_dentry)) {
-  		if (!new_dentry->d_inode) {
-			error = kobject_set_name(kobj, "%s", new_name);
-			if (!error) {
-				d_add(new_dentry, NULL);
-				d_move(kobj->dentry, new_dentry);
-			}
-			else
-				d_drop(new_dentry);
-		} else
-			error = -EEXIST;
-		dput(new_dentry);
+	if (kn) {
+		WARN_ON_ONCE(kernfs_type(kn) != KERNFS_DIR);
+		kernfs_remove(kn);
 	}
-	up(&parent->d_inode->i_sem);	
-	up_write(&sysfs_rename_sem);
-
-	return error;
-}
-
-static int sysfs_dir_open(struct inode *inode, struct file *file)
-{
-	struct dentry * dentry = file->f_dentry;
-	struct sysfs_dirent * parent_sd = dentry->d_fsdata;
-
-	down(&dentry->d_inode->i_sem);
-	file->private_data = sysfs_new_dirent(parent_sd, NULL);
-	up(&dentry->d_inode->i_sem);
-
-	return file->private_data ? 0 : -ENOMEM;
-
-}
-
-static int sysfs_dir_close(struct inode *inode, struct file *file)
-{
-	struct dentry * dentry = file->f_dentry;
-	struct sysfs_dirent * cursor = file->private_data;
-
-	down(&dentry->d_inode->i_sem);
-	list_del_init(&cursor->s_sibling);
-	up(&dentry->d_inode->i_sem);
-
-	release_sysfs_dirent(cursor);
-
-	return 0;
 }
 
-/* Relationship between s_mode and the DT_xxx types */
-static inline unsigned char dt_type(struct sysfs_dirent *sd)
+int sysfs_rename_dir_ns(struct kobject *kobj, const char *new_name,
+			const void *new_ns)
 {
-	return (sd->s_mode >> 12) & 15;
-}
-
-static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
-{
-	struct dentry *dentry = filp->f_dentry;
-	struct sysfs_dirent * parent_sd = dentry->d_fsdata;
-	struct sysfs_dirent *cursor = filp->private_data;
-	struct list_head *p, *q = &cursor->s_sibling;
-	ino_t ino;
-	int i = filp->f_pos;
-
-	switch (i) {
-		case 0:
-			ino = dentry->d_inode->i_ino;
-			if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
-				break;
-			filp->f_pos++;
-			i++;
-			/* fallthrough */
-		case 1:
-			ino = parent_ino(dentry);
-			if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
-				break;
-			filp->f_pos++;
-			i++;
-			/* fallthrough */
-		default:
-			if (filp->f_pos == 2) {
-				list_del(q);
-				list_add(q, &parent_sd->s_children);
-			}
-			for (p=q->next; p!= &parent_sd->s_children; p=p->next) {
-				struct sysfs_dirent *next;
-				const char * name;
-				int len;
-
-				next = list_entry(p, struct sysfs_dirent,
-						   s_sibling);
-				if (!next->s_element)
-					continue;
-
-				name = sysfs_get_name(next);
-				len = strlen(name);
-				if (next->s_dentry)
-					ino = next->s_dentry->d_inode->i_ino;
-				else
-					ino = iunique(sysfs_sb, 2);
-
-				if (filldir(dirent, name, len, filp->f_pos, ino,
-						 dt_type(next)) < 0)
-					return 0;
+	struct kernfs_node *parent;
+	int ret;
 
-				list_del(q);
-				list_add(q, p);
-				p = q;
-				filp->f_pos++;
-			}
-	}
-	return 0;
+	parent = kernfs_get_parent(kobj->sd);
+	ret = kernfs_rename_ns(kobj->sd, parent, new_name, new_ns);
+	kernfs_put(parent);
+	return ret;
 }
 
-static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin)
+int sysfs_move_dir_ns(struct kobject *kobj, struct kobject *new_parent_kobj,
+		      const void *new_ns)
 {
-	struct dentry * dentry = file->f_dentry;
+	struct kernfs_node *kn = kobj->sd;
+	struct kernfs_node *new_parent;
 
-	down(&dentry->d_inode->i_sem);
-	switch (origin) {
-		case 1:
-			offset += file->f_pos;
-		case 0:
-			if (offset >= 0)
-				break;
-		default:
-			up(&file->f_dentry->d_inode->i_sem);
-			return -EINVAL;
-	}
-	if (offset != file->f_pos) {
-		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;
-			loff_t n = file->f_pos - 2;
+	new_parent = new_parent_kobj && new_parent_kobj->sd ?
+		new_parent_kobj->sd : sysfs_root_kn;
 
-			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)
-					n--;
-				p = p->next;
-			}
-			list_add_tail(&cursor->s_sibling, p);
-		}
-	}
-	up(&dentry->d_inode->i_sem);
-	return offset;
+	return kernfs_rename_ns(kn, new_parent, kn->name, new_ns);
 }
-
-struct file_operations sysfs_dir_operations = {
-	.open		= sysfs_dir_open,
-	.release	= sysfs_dir_close,
-	.llseek		= sysfs_dir_lseek,
-	.read		= generic_read_dir,
-	.readdir	= sysfs_readdir,
-};
-
-EXPORT_SYMBOL_GPL(sysfs_create_dir);
-EXPORT_SYMBOL_GPL(sysfs_remove_dir);
-EXPORT_SYMBOL_GPL(sysfs_rename_dir);
-