driver core: remove CONFIG_SYSFS_DEPRECATED_V2 but keep it for block devices

This patch removes the old CONFIG_SYSFS_DEPRECATED_V2 config option,
but it keeps the logic around to handle block devices in the old manner
as some people like to run new kernel versions on old (pre 2007/2008)
distros.

Signed-off-by: Kay Sievers <[e-mail]>
Cc: Jens Axboe <[e-mail]>
Cc: Stephen Hemminger <[e-mail]>
Cc: "Eric W. Biederman" <[e-mail]>
Cc: Alan Stern <[e-mail]>
Cc: "James E.J. Bottomley" <[e-mail]>
Cc: Andrew Morton <[e-mail]>
Cc: Alexey Kuznetsov <[e-mail]>
Cc: Randy Dunlap <[e-mail]>
Cc: Tejun Heo <[e-mail]>
Cc: "David S. Miller" <[e-mail]>
Cc: Jaroslav Kysela <[e-mail]>
Cc: Takashi Iwai <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: David Howells <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/base/bus.c

···
 	}
 }
 
-#ifdef CONFIG_SYSFS_DEPRECATED
-static int make_deprecated_bus_links(struct device *dev)
-{
-	return sysfs_create_link(&dev->kobj,
-				 &dev->bus->p->subsys.kobj, "bus");
-}
-
-static void remove_deprecated_bus_links(struct device *dev)
-{
-	sysfs_remove_link(&dev->kobj, "bus");
-}
-#else
-static inline int make_deprecated_bus_links(struct device *dev) { return 0; }
-static inline void remove_deprecated_bus_links(struct device *dev) { }
-#endif
-
 /**
  * bus_add_device - add device to bus
  * @dev: device being added
···
 				&dev->bus->p->subsys.kobj, "subsystem");
 		if (error)
 			goto out_subsys;
-		error = make_deprecated_bus_links(dev);
-		if (error)
-			goto out_deprecated;
 		klist_add_tail(&dev->p->knode_bus, &bus->p->klist_devices);
 	}
 	return 0;
 
-out_deprecated:
-	sysfs_remove_link(&dev->kobj, "subsystem");
 out_subsys:
 	sysfs_remove_link(&bus->p->devices_kset->kobj, dev_name(dev));
 out_id:
···
 {
 	if (dev->bus) {
 		sysfs_remove_link(&dev->kobj, "subsystem");
-		remove_deprecated_bus_links(dev);
 		sysfs_remove_link(&dev->bus->p->devices_kset->kobj,
 				  dev_name(dev));
 		device_remove_attrs(dev->bus, dev);

drivers/base/class.c

···
 	class_unregister(cls);
 }
 
-#ifdef CONFIG_SYSFS_DEPRECATED
-char *make_class_name(const char *name, struct kobject *kobj)
-{
-	char *class_name;
-	int size;
-
-	size = strlen(name) + strlen(kobject_name(kobj)) + 2;
-
-	class_name = kmalloc(size, GFP_KERNEL);
-	if (!class_name)
-		return NULL;
-
-	strcpy(class_name, name);
-	strcat(class_name, ":");
-	strcat(class_name, kobject_name(kobj));
-	return class_name;
-}
-#endif
-
 /**
  * class_dev_iter_init - initialize class device iterator
  * @iter: class iterator to initialize

drivers/base/core.c

···
 	if (dev->driver)
 		add_uevent_var(env, "DRIVER=%s", dev->driver->name);
 
-#ifdef CONFIG_SYSFS_DEPRECATED
-	if (dev->class) {
-		struct device *parent = dev->parent;
-
-		/* find first bus device in parent chain */
-		while (parent && !parent->bus)
-			parent = parent->parent;
-		if (parent && parent->bus) {
-			const char *path;
-
-			path = kobject_get_path(&parent->kobj, GFP_KERNEL);
-			if (path) {
-				add_uevent_var(env, "PHYSDEVPATH=%s", path);
-				kfree(path);
-			}
-
-			add_uevent_var(env, "PHYSDEVBUS=%s", parent->bus->name);
-
-			if (parent->driver)
-				add_uevent_var(env, "PHYSDEVDRIVER=%s",
-					       parent->driver->name);
-		}
-	} else if (dev->bus) {
-		add_uevent_var(env, "PHYSDEVBUS=%s", dev->bus->name);
-
-		if (dev->driver)
-			add_uevent_var(env, "PHYSDEVDRIVER=%s",
-				       dev->driver->name);
-	}
-#endif
-
 	/* have the bus specific function add its stuff */
 	if (dev->bus && dev->bus->uevent) {
 		retval = dev->bus->uevent(dev, env);
···
 	set_dev_node(dev, -1);
 }
 
-#ifdef CONFIG_SYSFS_DEPRECATED
-static struct kobject *get_device_parent(struct device *dev,
-					 struct device *parent)
-{
-	/* class devices without a parent live in /sys/class/<classname>/ */
-	if (dev->class && (!parent || parent->class != dev->class))
-		return &dev->class->p->class_subsys.kobj;
-	/* all other devices keep their parent */
-	else if (parent)
-		return &parent->kobj;
-
-	return NULL;
-}
-
-static inline void cleanup_device_parent(struct device *dev) {}
-static inline void cleanup_glue_dir(struct device *dev,
-				    struct kobject *glue_dir) {}
-#else
 static struct kobject *virtual_device_parent(struct device *dev)
 {
 	static struct kobject *virtual_dir = NULL;
···
 		struct kobject *parent_kobj;
 		struct kobject *k;
 
+#ifdef CONFIG_SYSFS_DEPRECATED
+		/* block disks show up in /sys/block */
+		if (dev->class == &block_class) {
+			if (parent && parent->class == &block_class)
+				return &parent->kobj;
+			return &block_class.p->class_subsys.kobj;
+		}
+#endif
 		/*
 		 * If we have no parent, we live in "virtual".
 		 * Class-devices with a non class-device as parent, live
···
 {
 	cleanup_glue_dir(dev, dev->kobj.parent);
 }
-#endif
 
 static void setup_parent(struct device *dev, struct device *parent)
 {
···
 	if (error)
 		goto out;
 
-#ifdef CONFIG_SYSFS_DEPRECATED
-	/* stacked class devices need a symlink in the class directory */
-	if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
-	    device_is_not_partition(dev)) {
-		error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
-					  &dev->kobj, dev_name(dev));
-		if (error)
-			goto out_subsys;
-	}
-
-	if (dev->parent && device_is_not_partition(dev)) {
-		struct device *parent = dev->parent;
-		char *class_name;
-
-		/*
-		 * stacked class devices have the 'device' link
-		 * pointing to the bus device instead of the parent
-		 */
-		while (parent->class && !parent->bus && parent->parent)
-			parent = parent->parent;
-
-		error = sysfs_create_link(&dev->kobj,
-					  &parent->kobj,
-					  "device");
-		if (error)
-			goto out_busid;
-
-		class_name = make_class_name(dev->class->name,
-						&dev->kobj);
-		if (class_name)
-			error = sysfs_create_link(&dev->parent->kobj,
-						&dev->kobj, class_name);
-		kfree(class_name);
-		if (error)
-			goto out_device;
-	}
-	return 0;
-
-out_device:
-	if (dev->parent && device_is_not_partition(dev))
-		sysfs_remove_link(&dev->kobj, "device");
-out_busid:
-	if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
-	    device_is_not_partition(dev))
-		sysfs_delete_link(&dev->class->p->class_subsys.kobj, &dev->kobj,
-				  dev_name(dev));
-#else
-	/* link in the class directory pointing to the device */
-	error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
-				  &dev->kobj, dev_name(dev));
-	if (error)
-		goto out_subsys;
-
 	if (dev->parent && device_is_not_partition(dev)) {
 		error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
 					  "device");
 		if (error)
-			goto out_busid;
+			goto out_subsys;
 	}
+
+#ifdef CONFIG_SYSFS_DEPRECATED
+	/* /sys/block has directories and does not need symlinks */
+	if (dev->class == &block_class)
+		return 0;
+#endif
+
+	/* link in the class directory pointing to the device */
+	error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
+				  &dev->kobj, dev_name(dev));
+	if (error)
+		goto out_device;
+
 	return 0;
 
-out_busid:
-	sysfs_delete_link(&dev->class->p->class_subsys.kobj, &dev->kobj, dev_name(dev));
-#endif
+out_device:
+	sysfs_remove_link(&dev->kobj, "device");
 
 out_subsys:
 	sysfs_remove_link(&dev->kobj, "subsystem");
···
 	if (!dev->class)
 		return;
 
-#ifdef CONFIG_SYSFS_DEPRECATED
-	if (dev->parent && device_is_not_partition(dev)) {
-		char *class_name;
-
-		class_name = make_class_name(dev->class->name, &dev->kobj);
-		if (class_name) {
-			sysfs_remove_link(&dev->parent->kobj, class_name);
-			kfree(class_name);
-		}
-		sysfs_remove_link(&dev->kobj, "device");
-	}
-
-	if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
-	    device_is_not_partition(dev))
-		sysfs_delete_link(&dev->class->p->class_subsys.kobj, &dev->kobj,
-				  dev_name(dev));
-#else
 	if (dev->parent && device_is_not_partition(dev))
 		sysfs_remove_link(&dev->kobj, "device");
-
-	sysfs_delete_link(&dev->class->p->class_subsys.kobj, &dev->kobj, dev_name(dev));
-#endif
-
 	sysfs_remove_link(&dev->kobj, "subsystem");
+#ifdef CONFIG_SYSFS_DEPRECATED
+	if (dev->class == &block_class)
+		return;
+#endif
+	sysfs_delete_link(&dev->class->p->class_subsys.kobj, &dev->kobj, dev_name(dev));
 }
 
 /**
···
 	pr_debug("device: '%s': %s: renaming to '%s'\n", dev_name(dev),
 		 __func__, new_name);
 
-#ifdef CONFIG_SYSFS_DEPRECATED
-	if ((dev->class) && (dev->parent))
-		old_class_name = make_class_name(dev->class->name, &dev->kobj);
-#endif
-
 	old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
 	if (!old_device_name) {
 		error = -ENOMEM;
 		goto out;
 	}
 
-#ifndef CONFIG_SYSFS_DEPRECATED
 	if (dev->class) {
 		error = sysfs_rename_link(&dev->class->p->class_subsys.kobj,
 			&dev->kobj, old_device_name, new_name);
 		if (error)
 			goto out;
 	}
-#endif
+
 	error = kobject_rename(&dev->kobj, new_name);
 	if (error)
 		goto out;
-
-#ifdef CONFIG_SYSFS_DEPRECATED
-	if (old_class_name) {
-		new_class_name = make_class_name(dev->class->name, &dev->kobj);
-		if (new_class_name) {
-			error = sysfs_rename_link(&dev->parent->kobj,
-						  &dev->kobj,
-						  old_class_name,
-						  new_class_name);
-		}
-	}
-#endif
 
 out:
 	put_device(dev);
···
 				   struct device *new_parent)
 {
 	int error = 0;
-#ifdef CONFIG_SYSFS_DEPRECATED
-	char *class_name;
 
-	class_name = make_class_name(dev->class->name, &dev->kobj);
-	if (!class_name) {
-		error = -ENOMEM;
-		goto out;
-	}
-	if (old_parent) {
-		sysfs_remove_link(&dev->kobj, "device");
-		sysfs_remove_link(&old_parent->kobj, class_name);
-	}
-	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;
-#else
 	if (old_parent)
 		sysfs_remove_link(&dev->kobj, "device");
 	if (new_parent)
 		error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
 					  "device");
 	return error;
-#endif
 }
 
 /**

drivers/scsi/hosts.c

···
 
 	device_initialize(&shost->shost_gendev);
 	dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
-#ifndef CONFIG_SYSFS_DEPRECATED
 	shost->shost_gendev.bus = &scsi_bus_type;
-#endif
 	shost->shost_gendev.type = &scsi_host_type;
 
 	device_initialize(&shost->shost_dev);

drivers/scsi/scsi_scan.c

···
 	starget->reap_ref = 1;
 	dev->parent = get_device(parent);
 	dev_set_name(dev, "target%d:%d:%d", shost->host_no, channel, id);
-#ifndef CONFIG_SYSFS_DEPRECATED
 	dev->bus = &scsi_bus_type;
-#endif
 	dev->type = &scsi_target_type;
 	starget->id = id;
 	starget->channel = channel;

include/sound/core.h

···
 	int free_on_last_close;		/* free in context of file_release */
 	wait_queue_head_t shutdown_sleep;
 	struct device *dev;		/* device assigned to this card */
-#ifndef CONFIG_SYSFS_DEPRECATED
 	struct device *card_dev;	/* cardX object for sysfs */
-#endif
 
 #ifdef CONFIG_PM
 	unsigned int power_state;	/* power state */
···
 /* return a device pointer linked to each sound device as a parent */
 static inline struct device *snd_card_get_device_link(struct snd_card *card)
 {
-#ifdef CONFIG_SYSFS_DEPRECATED
-	return card ? card->dev : NULL;
-#else
 	return card ? card->card_dev : NULL;
-#endif
 }
 
 /* sound.c */

init/Kconfig

···
 	bool
 
 config SYSFS_DEPRECATED
-	bool
-
-config SYSFS_DEPRECATED_V2
 	bool "enable deprecated sysfs features to support old userspace tools"
 	depends on SYSFS
 	default n
-	select SYSFS_DEPRECATED
 	help
-	  This option switches the layout of sysfs to the deprecated
-	  version. Do not use it on recent distributions.
+	  This option switches the layout of the "block" class devices, to not
+	  show up in /sys/class/block/, but only in /sys/block/.
 
-	  The current sysfs layout features a unified device tree at
-	  /sys/devices/, which is able to express a hierarchy between
-	  class devices. If the deprecated option is set to Y, the
-	  unified device tree is split into a bus device tree at
-	  /sys/devices/ and several individual class device trees at
-	  /sys/class/. The class and bus devices will be connected by
-	  "<subsystem>:<name>" and the "device" links. The "block"
-	  class devices, will not show up in /sys/class/block/. Some
-	  subsystems will suppress the creation of some devices which
-	  depend on the unified device tree.
+	  This option allows new kernels to run on old distributions and tools,
+	  which might get confused by /sys/class/block/. Since 2007/2008 all
+	  major distributions and tools handle this just fine.
 
-	  This option is not a pure compatibility option that can
-	  be safely enabled on newer distributions. It will change the
-	  layout of sysfs to the non-extensible deprecated version,
-	  and disable some features, which can not be exported without
-	  confusing older userspace tools. Since 2007/2008 all major
-	  distributions do not enable this option, and ship no tools which
-	  depend on the deprecated layout or this option.
+	  Recent distributions and userspace tools after 2009/2010 depend on
+	  the existence of /sys/class/block/, and will not work with this
+	  option enabled.
 
-	  If you are using a new kernel on an older distribution, or use
-	  older userspace tools, you might need to say Y here. Do not say Y,
-	  if the original kernel, that came with your distribution, has
-	  this option set to N.
+	  Only if you are using a new kernel on an old distribution, you might
+	  need to say Y here. Never say Y, if the original kernel, that came
+	  with your distribution, has not set this option.
 
 config RELAY
 	bool "Kernel->user space relay support (formerly relayfs)"

sound/core/init.c

···
 		snd_printk(KERN_ERR "not all devices for card %i can be disconnected\n", card->number);
 
 	snd_info_card_disconnect(card);
-#ifndef CONFIG_SYSFS_DEPRECATED
 	if (card->card_dev) {
 		device_unregister(card->card_dev);
 		card->card_dev = NULL;
 	}
-#endif
 #ifdef CONFIG_PM
 	wake_up(&card->power_sleep);
 #endif
···
 }
 EXPORT_SYMBOL(snd_card_set_id);
 
-#ifndef CONFIG_SYSFS_DEPRECATED
 static ssize_t
 card_id_show_attr(struct device *dev,
 		  struct device_attribute *attr, char *buf)
···
 
 static struct device_attribute card_number_attrs =
 	__ATTR(number, S_IRUGO, card_number_show_attr, NULL);
-#endif /* CONFIG_SYSFS_DEPRECATED */
 
 /**
  *  snd_card_register - register the soundcard
···
 
 	if (snd_BUG_ON(!card))
 		return -EINVAL;
-#ifndef CONFIG_SYSFS_DEPRECATED
+
 	if (!card->card_dev) {
 		card->card_dev = device_create(sound_class, card->dev,
 					       MKDEV(0, 0), card,
···
 		if (IS_ERR(card->card_dev))
 			card->card_dev = NULL;
 	}
-#endif
+
 	if ((err = snd_device_register_all(card)) < 0)
 		return err;
 	mutex_lock(&snd_card_mutex);
···
 	if (snd_mixer_oss_notify_callback)
 		snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
 #endif
-#ifndef CONFIG_SYSFS_DEPRECATED
 	if (card->card_dev) {
 		err = device_create_file(card->card_dev, &card_id_attrs);
 		if (err < 0)
···
 		if (err < 0)
 			return err;
 	}
-#endif
+
 	return 0;
 }