Commit 86406245 authored by Kay Sievers's avatar Kay Sievers Committed by Greg Kroah-Hartman
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driver core: fix namespace issue with devices assigned to classes 



  - 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: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 00ed8e3d

drivers/base/class.c

+1 −1
Original line number Diff line number Diff line
@@ -145,6 +145,7 @@ int class_register(struct class * cls) 
	INIT_LIST_HEAD(&cls->children);

	INIT_LIST_HEAD(&cls->devices);

	INIT_LIST_HEAD(&cls->interfaces);

	kset_init(&cls->class_dirs);

	init_MUTEX(&cls->sem);

	error = kobject_set_name(&cls->subsys.kset.kobj, "%s", cls->name);

	if (error)
@@ -163,7 +164,6 @@ int class_register(struct class * cls) 
void class_unregister(struct class * cls)

{

	pr_debug("device class '%s': unregistering\n", cls->name);

	kobject_unregister(cls->virtual_dir);

	remove_class_attrs(cls);

	subsystem_unregister(&cls->subsys);

}

drivers/base/core.c

+65 −17
Original line number Diff line number Diff line
@@ -479,32 +479,56 @@ static struct kobject * get_device_parent(struct device *dev, 
#else

static struct kobject *virtual_device_parent(struct device *dev)

{

	if (!dev->class)

		return ERR_PTR(-ENODEV);



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

	static struct kobject *virtual_dir = NULL;



	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;

	return NULL;

		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);

include/linux/device.h

+1 −2
Original line number Diff line number Diff line
@@ -181,10 +181,9 @@ struct class { 
	struct list_head	children;

	struct list_head	devices;

	struct list_head	interfaces;

	struct kset		class_dirs;

	struct semaphore	sem;	/* locks both the children and interfaces lists */



	struct kobject		*virtual_dir;



	struct class_attribute		* class_attrs;

	struct class_device_attribute	* class_dev_attrs;

	struct device_attribute		* dev_attrs;

include/linux/kobject.h

+2 −0
Original line number Diff line number Diff line
@@ -89,6 +89,8 @@ extern void kobject_unregister(struct kobject *); 
extern struct kobject * kobject_get(struct kobject *);

extern void kobject_put(struct kobject *);



extern struct kobject *kobject_kset_add_dir(struct kset *kset,

					    struct kobject *, const char *);

extern struct kobject *kobject_add_dir(struct kobject *, const char *);



extern char * kobject_get_path(struct kobject *, gfp_t);

lib/kobject.c

+10 −2
Original line number Diff line number Diff line
@@ -488,13 +488,15 @@ static struct kobj_type dir_ktype = { 
};



/**

 *	kobject_add_dir - add sub directory of object.

 *	kobject__kset_add_dir - add sub directory of object.

 *	@kset:		kset the directory is belongs to.

 *	@parent:	object in which a directory is created.

 *	@name:	directory name.

 *

 *	Add a plain directory object as child of given object.

 */

struct kobject *kobject_add_dir(struct kobject *parent, const char *name)

struct kobject *kobject_kset_add_dir(struct kset *kset,

				     struct kobject *parent, const char *name)

{

	struct kobject *k;

	int ret;
@@ -506,6 +508,7 @@ struct kobject *kobject_add_dir(struct kobject *parent, const char *name) 
	if (!k)

		return NULL;



	k->kset = kset;

	k->parent = parent;

	k->ktype = &dir_ktype;

	kobject_set_name(k, name);
@@ -520,6 +523,11 @@ struct kobject *kobject_add_dir(struct kobject *parent, const char *name) 
	return k;

}



struct kobject *kobject_add_dir(struct kobject *parent, const char *name)

{

	return kobject_kset_add_dir(NULL, parent, name);

}



/**

 *	kset_init - initialize a kset for use

 *	@k:	kset

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