Driver core: convert block from raw kobjects to core devices

This moves the block devices to /sys/class/block. It will create a
flat list of all block devices, with the disks and partitions in one
directory. For compatibility /sys/block is created and contains symlinks
to the disks.

  /sys/class/block
  |-- sda -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda
  |-- sda1 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda1
  |-- sda10 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda10
  |-- sda5 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda5
  |-- sda6 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda6
  |-- sda7 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda7
  |-- sda8 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda8
  |-- sda9 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda9
  `-- sr0 -> ../../devices/pci0000:00/0000:00:1f.2/host1/target1:0:0/1:0:0:0/block/sr0

  /sys/block/
  |-- sda -> ../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda
  `-- sr0 -> ../devices/pci0000:00/0000:00:1f.2/host1/target1:0:0/1:0:0:0/block/sr0

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 19 insertions, 8 deletions

diff --git a/drivers/base/class.c b/drivers/base/class.c
index ba6745b0fd2f..624b3316e938 100644
--- a/drivers/base/class.c
+++ b/drivers/base/class.c
@@ -17,6 +17,7 @@
 #include <linux/kdev_t.h>
 #include <linux/err.h>
 #include <linux/slab.h>
+#include <linux/genhd.h>
 #include "base.h"
 
 #define to_class_attr(_attr) container_of(_attr, struct class_attribute, attr)
@@ -149,7 +150,13 @@ int class_register(struct class * cls)
 	if (error)
 		return error;
 
+#ifdef CONFIG_SYSFS_DEPRECATED
+	/* let the block class directory show up in the root of sysfs */
+	if (cls != &block_class)
+		cls->subsys.kobj.kset = class_kset;
+#else
 	cls->subsys.kobj.kset = class_kset;
+#endif
 	cls->subsys.kobj.ktype = &class_ktype;
 
 	error = kset_register(&cls->subsys);
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 13cae18936c5..06e8738ab263 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -671,14 +671,15 @@ static int device_add_class_symlinks(struct device *dev)
 
 #ifdef CONFIG_SYSFS_DEPRECATED
 	/* stacked class devices need a symlink in the class directory */
-	if (dev->kobj.parent != &dev->class->subsys.kobj) {
+	if (dev->kobj.parent != &dev->class->subsys.kobj &&
+	    dev->type != &part_type) {
 		error = sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj,
 					  dev->bus_id);
 		if (error)
 			goto out_subsys;
 	}
 
-	if (dev->parent) {
+	if (dev->parent && dev->type != &part_type) {
 		struct device *parent = dev->parent;
 		char *class_name;
 
@@ -707,10 +708,11 @@ static int device_add_class_symlinks(struct device *dev)
 	return 0;
 
 out_device:
-	if (dev->parent)
+	if (dev->parent && dev->type != &part_type)
 		sysfs_remove_link(&dev->kobj, "device");
 out_busid:
-	if (dev->kobj.parent != &dev->class->subsys.kobj)
+	if (dev->kobj.parent != &dev->class->subsys.kobj &&
+	    dev->type != &part_type)
 		sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
 #else
 	/* link in the class directory pointing to the device */
@@ -719,7 +721,7 @@ out_busid:
 	if (error)
 		goto out_subsys;
 
-	if (dev->parent) {
+	if (dev->parent && dev->type != &part_type) {
 		error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
 					  "device");
 		if (error)
@@ -743,7 +745,7 @@ static void device_remove_class_symlinks(struct device *dev)
 		return;
 
 #ifdef CONFIG_SYSFS_DEPRECATED
-	if (dev->parent) {
+	if (dev->parent && dev->type != &part_type) {
 		char *class_name;
 
 		class_name = make_class_name(dev->class->name, &dev->kobj);
@@ -754,10 +756,11 @@ static void device_remove_class_symlinks(struct device *dev)
 		sysfs_remove_link(&dev->kobj, "device");
 	}
 
-	if (dev->kobj.parent != &dev->class->subsys.kobj)
+	if (dev->kobj.parent != &dev->class->subsys.kobj &&
+	    dev->type != &part_type)
 		sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
 #else
-	if (dev->parent)
+	if (dev->parent && dev->type != &part_type)
 		sysfs_remove_link(&dev->kobj, "device");
 
 	sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
@@ -925,6 +928,7 @@ struct device * get_device(struct device * dev)
  */
 void put_device(struct device * dev)
 {
+	/* might_sleep(); */
 	if (dev)
 		kobject_put(&dev->kobj);
 }