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: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 36eedfdeb..c60114d 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -390,22 +390,23 @@
}
#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 @@
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 @@
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 (error)
- goto out;
- error = sysfs_create_link(&new_parent->kobj, &dev->kobj, class_name);
- if (error)
- sysfs_remove_link(&dev->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);
+ if (error)
+ sysfs_remove_link(&dev->kobj, "device");
+ }
+ else
+ error = 0;
out:
kfree(class_name);
return error;
@@ -993,25 +1006,28 @@
/**
* 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;
@@ -1020,7 +1036,8 @@
dev->parent = new_parent;
if (old_parent)
klist_remove(&dev->knode_parent);
- klist_add_tail(&dev->knode_parent, &new_parent->klist_children);
+ if (new_parent)
+ klist_add_tail(&dev->knode_parent, &new_parent->klist_children);
if (!dev->class)
goto out_put;
error = device_move_class_links(dev, old_parent, new_parent);
@@ -1028,7 +1045,8 @@
/* 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)) {
- klist_remove(&dev->knode_parent);
+ if (new_parent)
+ klist_remove(&dev->knode_parent);
if (old_parent)
klist_add_tail(&dev->knode_parent,
&old_parent->klist_children);