1 files changed, 36 insertions, 15 deletions

diff --git a/block/genhd.c b/block/genhd.c
index c13cc77291af..e0ce23ac2ece 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -190,7 +190,6 @@ void add_disk(struct gendisk *disk)
 			    disk->minors, NULL, exact_match, exact_lock, disk);
 	register_disk(disk);
 	blk_register_queue(disk);
-	blk_register_filter(disk);
 
 	bdi = &disk->queue->backing_dev_info;
 	bdi_register_dev(bdi, MKDEV(disk->major, disk->first_minor));
@@ -203,7 +202,6 @@ EXPORT_SYMBOL(del_gendisk);	/* in partitions/check.c */
 
 void unlink_gendisk(struct gendisk *disk)
 {
-	blk_unregister_filter(disk);
 	sysfs_remove_link(&disk->dev.kobj, "bdi");
 	bdi_unregister(&disk->queue->backing_dev_info);
 	blk_unregister_queue(disk);
@@ -293,27 +291,30 @@ void __init printk_all_partitions(void)
 /* iterator */
 static int find_start(struct device *dev, void *data)
 {
-	loff_t k = *(loff_t *)data;
+	loff_t *k = data;
 
 	if (dev->type != &disk_type)
 		return 0;
-	if (!k--)
+	if (!*k)
 		return 1;
+	(*k)--;
 	return 0;
 }
 
 static void *part_start(struct seq_file *part, loff_t *pos)
 {
 	struct device *dev;
-	loff_t n = *pos;
+	loff_t k = *pos;
 
-	if (!n)
-		seq_puts(part, "major minor  #blocks  name\n\n");
+	if (!k)
+		part->private = (void *)1LU;	/* tell show to print header */
 
 	mutex_lock(&block_class_lock);
-	dev = class_find_device(&block_class, NULL, (void *)pos, find_start);
-	if (dev)
+	dev = class_find_device(&block_class, NULL, &k, find_start);
+	if (dev) {
+		put_device(dev);
 		return dev_to_disk(dev);
+	}
 	return NULL;
 }
 
@@ -330,8 +331,10 @@ static void *part_next(struct seq_file *part, void *v, loff_t *pos)
 	struct device *dev;
 	++*pos;
 	dev = class_find_device(&block_class, &gp->dev, NULL, find_next);
-	if (dev)
+	if (dev) {
+		put_device(dev);
 		return dev_to_disk(dev);
+	}
 	return NULL;
 }
 
@@ -346,6 +349,17 @@ static int show_partition(struct seq_file *part, void *v)
 	int n;
 	char buf[BDEVNAME_SIZE];
 
+	/*
+	 * Print header if start told us to do.  This is to preserve
+	 * the original behavior of not printing header if no
+	 * partition exists.  This hackery will be removed later with
+	 * class iteration clean up.
+	 */
+	if (part->private) {
+		seq_puts(part, "major minor  #blocks  name\n\n");
+		part->private = NULL;
+	}
+
 	/* Don't show non-partitionable removeable devices or empty devices */
 	if (!get_capacity(sgp) ||
 			(sgp->minors == 1 && (sgp->flags & GENHD_FL_REMOVABLE)))
@@ -568,11 +582,14 @@ static struct device_type disk_type = {
 static void *diskstats_start(struct seq_file *part, loff_t *pos)
 {
 	struct device *dev;
+	loff_t k = *pos;
 
 	mutex_lock(&block_class_lock);
-	dev = class_find_device(&block_class, NULL, (void *)pos, find_start);
-	if (dev)
+	dev = class_find_device(&block_class, NULL, &k, find_start);
+	if (dev) {
+		put_device(dev);
 		return dev_to_disk(dev);
+	}
 	return NULL;
 }
 
@@ -583,8 +600,10 @@ static void *diskstats_next(struct seq_file *part, void *v, loff_t *pos)
 
 	++*pos;
 	dev = class_find_device(&block_class, &gp->dev, NULL, find_next);
-	if (dev)
+	if (dev) {
+		put_device(dev);
 		return dev_to_disk(dev);
+	}
 	return NULL;
 }
 
@@ -712,10 +731,12 @@ dev_t blk_lookup_devt(const char *name, int part)
 	mutex_lock(&block_class_lock);
 	find.name = name;
 	find.part = part;
-	dev = class_find_device(&block_class, NULL, (void *)&find, match_id);
-	if (dev)
+	dev = class_find_device(&block_class, NULL, &find, match_id);
+	if (dev) {
+		put_device(dev);
 		devt = MKDEV(MAJOR(dev->devt),
 			     MINOR(dev->devt) + part);
+	}
 	mutex_unlock(&block_class_lock);
 
 	return devt;