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driver core: fix namespace issue with devices assigned to classes

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- uses a kset in "struct class" to keep track of all directories
    belonging to this class
  - merges with the /sys/devices/virtual logic.
  - removes the namespace-dir if the last member of that class
    leaves the directory.

There may be locking or refcounting fixes left, I stopped when it seemed
to work with network and sound modules. :)

From: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Kay Sievers
2007-03-14 03:25:56 +01:00
committed by Greg Kroah-Hartman
parent 00ed8e3dda
commit 864062457a
6 changed files with 89 additions and 28 deletions
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82
drivers/base/core.c
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@@ -477,34 +477,58 @@ static struct kobject * get_device_parent(struct device *dev,
return NULL;
}
#else
static struct kobject * virtual_device_parent(struct device *dev)
static struct kobject *virtual_device_parent(struct device *dev)
{
if (!dev->class)
return ERR_PTR(-ENODEV);
static struct kobject *virtual_dir = NULL;
if (!dev->class->virtual_dir) {
static struct kobject *virtual_dir = NULL;
if (!virtual_dir)
virtual_dir = kobject_add_dir(&devices_subsys.kset.kobj, "virtual");
if (!virtual_dir)
virtual_dir = kobject_add_dir(&devices_subsys.kset.kobj, "virtual");
dev->class->virtual_dir = kobject_add_dir(virtual_dir, dev->class->name);
}
return dev->class->virtual_dir;
return virtual_dir;
}
static struct kobject * get_device_parent(struct device *dev,
struct device *parent)
{
/* if this is a class device, and has no parent, create one */
if ((dev->class) && (parent == NULL)) {
return virtual_device_parent(dev);
} else if (parent)
if (dev->class) {
struct kobject *kobj = NULL;
struct kobject *parent_kobj;
struct kobject *k;
/*
* If we have no parent, we live in "virtual".
* Class-devices with a bus-device as parent, live
* in a class-directory to prevent namespace collisions.
*/
if (parent == NULL)
parent_kobj = virtual_device_parent(dev);
else if (parent->class)
return &parent->kobj;
else
parent_kobj = &parent->kobj;
/* find our class-directory at the parent and reference it */
spin_lock(&dev->class->class_dirs.list_lock);
list_for_each_entry(k, &dev->class->class_dirs.list, entry)
if (k->parent == parent_kobj) {
kobj = kobject_get(k);
break;
}
spin_unlock(&dev->class->class_dirs.list_lock);
if (kobj)
return kobj;
/* or create a new class-directory at the parent device */
return kobject_kset_add_dir(&dev->class->class_dirs,
parent_kobj, dev->class->name);
}
if (parent)
return &parent->kobj;
return NULL;
}
#endif
static int setup_parent(struct device *dev, struct device *parent)
{
struct kobject *kobj;
@@ -541,7 +565,6 @@ int device_add(struct device *dev)
pr_debug("DEV: registering device: ID = '%s'\n", dev->bus_id);
parent = get_device(dev->parent);
error = setup_parent(dev, parent);
if (error)
goto Error;
@@ -787,6 +810,31 @@ void device_del(struct device * dev)
/* remove the device from the class list */
list_del_init(&dev->node);
up(&dev->class->sem);
/* If we live in a parent class-directory, unreference it */
if (dev->kobj.parent->kset == &dev->class->class_dirs) {
struct device *d;
int other = 0;
/*
* if we are the last child of our class, delete
* our class-directory at this parent
*/
down(&dev->class->sem);
list_for_each_entry(d, &dev->class->devices, node) {
if (d == dev)
continue;
if (d->kobj.parent == dev->kobj.parent) {
other = 1;
break;
}
}
if (!other)
kobject_del(dev->kobj.parent);
kobject_put(dev->kobj.parent);
up(&dev->class->sem);
}
}
device_remove_file(dev, &dev->uevent_attr);
device_remove_groups(dev);