Commit c744aeae authored by Cornelia Huck's avatar Cornelia Huck Committed by Greg Kroah-Hartman
Browse files

driver core: Allow device_move(dev, NULL). 



If we allow NULL as the new parent in device_move(), we need to make sure
that the device is placed into the same place as it would if it was
newly registered:

- Consider the device virtual tree. In order to be able to reuse code,
  setup_parent() has been tweaked a bit.
- kobject_move() can fall back to the kset's kobject.
- sysfs_move_dir() uses the sysfs root dir as fallback.

Signed-off-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 717e48c2

drivers/base/core.c

+47 −29
Original line number Diff line number Diff line
@@ -390,22 +390,23 @@ void device_initialize(struct device *dev) 
}



#ifdef CONFIG_SYSFS_DEPRECATED

static int setup_parent(struct device *dev, struct device *parent)

static struct kobject * get_device_parent(struct device *dev,

					  struct device *parent)

{

	/* Set the parent to the class, not the parent device */

	/* this keeps sysfs from having a symlink to make old udevs happy */

	if (dev->class)

		dev->kobj.parent = &dev->class->subsys.kset.kobj;

		return &dev->class->subsys.kset.kobj;

	else if (parent)

		dev->kobj.parent = &parent->kobj;

		return &parent->kobj;



	return 0;

	return NULL;

}

#else

static int virtual_device_parent(struct device *dev)

static struct kobject * virtual_device_parent(struct device *dev)

{

	if (!dev->class)

		return -ENODEV;

		return ERR_PTR(-ENODEV);



	if (!dev->class->virtual_dir) {

		static struct kobject *virtual_dir = NULL;
@@ -415,25 +416,31 @@ static int virtual_device_parent(struct device *dev) 
		dev->class->virtual_dir = kobject_add_dir(virtual_dir, dev->class->name);

	}



	dev->kobj.parent = dev->class->virtual_dir;

	return 0;

	return dev->class->virtual_dir;

}



static int setup_parent(struct device *dev, struct device *parent)

static struct kobject * get_device_parent(struct device *dev,

					  struct device *parent)

{

	int error;



	/* if this is a class device, and has no parent, create one */

	if ((dev->class) && (parent == NULL)) {

		error = virtual_device_parent(dev);

		if (error)

			return error;

		return virtual_device_parent(dev);

	} else if (parent)

		dev->kobj.parent = &parent->kobj;

		return &parent->kobj;

	return NULL;

}



#endif

static int setup_parent(struct device *dev, struct device *parent)

{

	struct kobject *kobj;

	kobj = get_device_parent(dev, parent);

	if (IS_ERR(kobj))

		return PTR_ERR(kobj);

	if (kobj)

		dev->kobj.parent = kobj;

	return 0;

}

#endif



/**

 *	device_add - add device to device hierarchy.
@@ -976,12 +983,18 @@ static int device_move_class_links(struct device *dev, 
		sysfs_remove_link(&dev->kobj, "device");

		sysfs_remove_link(&old_parent->kobj, class_name);

	}

	error = sysfs_create_link(&dev->kobj, &new_parent->kobj, "device");

	if (new_parent) {

		error = sysfs_create_link(&dev->kobj, &new_parent->kobj,

					  "device");

		if (error)

			goto out;

	error = sysfs_create_link(&new_parent->kobj, &dev->kobj, class_name);

		error = sysfs_create_link(&new_parent->kobj, &dev->kobj,

					  class_name);

		if (error)

			sysfs_remove_link(&dev->kobj, "device");

	}

	else

		error = 0;

out:

	kfree(class_name);

	return error;
@@ -993,25 +1006,28 @@ out: 
/**

 * device_move - moves a device to a new parent

 * @dev: the pointer to the struct device to be moved

 * @new_parent: the new parent of the device

 * @new_parent: the new parent of the device (can by NULL)

 */

int device_move(struct device *dev, struct device *new_parent)

{

	int error;

	struct device *old_parent;

	struct kobject *new_parent_kobj;



	dev = get_device(dev);

	if (!dev)

		return -EINVAL;



	new_parent = get_device(new_parent);

	if (!new_parent) {

		error = -EINVAL;

	new_parent_kobj = get_device_parent (dev, new_parent);

	if (IS_ERR(new_parent_kobj)) {

		error = PTR_ERR(new_parent_kobj);

		put_device(new_parent);

		goto out;

	}

	pr_debug("DEVICE: moving '%s' to '%s'\n", dev->bus_id,

		new_parent->bus_id);

	error = kobject_move(&dev->kobj, &new_parent->kobj);

		 new_parent ? new_parent->bus_id : "<NULL>");

	error = kobject_move(&dev->kobj, new_parent_kobj);

	if (error) {

		put_device(new_parent);

		goto out;
@@ -1020,6 +1036,7 @@ int device_move(struct device *dev, struct device *new_parent) 
	dev->parent = new_parent;

	if (old_parent)

		klist_remove(&dev->knode_parent);

	if (new_parent)

		klist_add_tail(&dev->knode_parent, &new_parent->klist_children);

	if (!dev->class)

		goto out_put;
@@ -1028,6 +1045,7 @@ int device_move(struct device *dev, struct device *new_parent) 
		/* We ignore errors on cleanup since we're hosed anyway... */

		device_move_class_links(dev, new_parent, old_parent);

		if (!kobject_move(&dev->kobj, &old_parent->kobj)) {

			if (new_parent)

				klist_remove(&dev->knode_parent);

			if (old_parent)

				klist_add_tail(&dev->knode_parent,

fs/sysfs/dir.c

+2 −4
Original line number Diff line number Diff line
@@ -378,12 +378,10 @@ int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent) 
	struct sysfs_dirent *new_parent_sd, *sd;

	int error;



	if (!new_parent)

		return -EINVAL;



	old_parent_dentry = kobj->parent ?

		kobj->parent->dentry : sysfs_mount->mnt_sb->s_root;

	new_parent_dentry = new_parent->dentry;

	new_parent_dentry = new_parent ?

		new_parent->dentry : sysfs_mount->mnt_sb->s_root;



again:

	mutex_lock(&old_parent_dentry->d_inode->i_mutex);

lib/kobject.c

+3 −3
Original line number Diff line number Diff line
@@ -314,7 +314,7 @@ int kobject_rename(struct kobject * kobj, const char *new_name) 
/**

 *	kobject_move - move object to another parent

 *	@kobj:	object in question.

 *	@new_parent: object's new parent

 *	@new_parent: object's new parent (can be NULL)

 */



int kobject_move(struct kobject *kobj, struct kobject *new_parent)
@@ -330,8 +330,8 @@ int kobject_move(struct kobject *kobj, struct kobject *new_parent) 
		return -EINVAL;

	new_parent = kobject_get(new_parent);

	if (!new_parent) {

		error = -EINVAL;

		goto out;

		if (kobj->kset)

			new_parent = kobject_get(&kobj->kset->kobj);

	}

	/* old object path */

	devpath = kobject_get_path(kobj, GFP_KERNEL);

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