Driver Core: block: add nodename support for block drivers.

This adds support for block drivers to report their requested nodename
to userspace.  It also updates a number of block drivers to provide the
needed subdirectory and device name to be used for them.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jan Blunck <jblunck@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

block/genhd.c

@@ -996,10 +996,20 @@ struct class block_class = {
 	.name		= "block",
 };
 
+static char *block_nodename(struct device *dev)
+{
+	struct gendisk *disk = dev_to_disk(dev);
+
+	if (disk->nodename)
+		return disk->nodename(disk);
+	return NULL;
+}
+
 static struct device_type disk_type = {
 	.name		= "disk",
 	.groups		= disk_attr_groups,
 	.release	= disk_release,
+	.nodename	= block_nodename,
 };
 
 #ifdef CONFIG_PROC_FS

drivers/block/pktcdvd.c

@@ -2855,6 +2855,11 @@ static struct block_device_operations pktcdvd_ops = {
 	.media_changed =	pkt_media_changed,
 };
 
+static char *pktcdvd_nodename(struct gendisk *gd)
+{
+	return kasprintf(GFP_KERNEL, "pktcdvd/%s", gd->disk_name);
+}
+
 /*
  * Set up mapping from pktcdvd device to CD-ROM device.
  */
@@ -2907,6 +2912,7 @@ static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev)
 	disk->fops = &pktcdvd_ops;
 	disk->flags = GENHD_FL_REMOVABLE;
 	strcpy(disk->disk_name, pd->name);
+	disk->nodename = pktcdvd_nodename;
 	disk->private_data = pd;
 	disk->queue = blk_alloc_queue(GFP_KERNEL);
 	if (!disk->queue)
@@ -3062,6 +3068,7 @@ static const struct file_operations pkt_ctl_fops = {
 static struct miscdevice pkt_misc = {
 	.minor 		= MISC_DYNAMIC_MINOR,
 	.name  		= DRIVER_NAME,
+	.name  		= "pktcdvd/control",
 	.fops  		= &pkt_ctl_fops
 };
 

include/linux/genhd.h

@@ -142,7 +142,7 @@ struct gendisk {
                                          * disks that can't be partitioned. */
 
 	char disk_name[DISK_NAME_LEN];	/* name of major driver */
-
+	char *(*nodename)(struct gendisk *gd);
 	/* Array of pointers to partitions indexed by partno.
 	 * Protected with matching bdev lock but stat and other
 	 * non-critical accesses use RCU.  Always access through