From: Leonardo Potenza <lpotenza@inwind.it>

Add a check for the class_register() return value.

Signed-off-by: Leonardo Potenza <lpotenza@inwind.it>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 block/genhd.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff -puN block/genhd.c~block-genhdc-check-class_register-return-value block/genhd.c
--- a/block/genhd.c~block-genhdc-check-class_register-return-value
+++ a/block/genhd.c
@@ -360,7 +360,12 @@ static struct kobject *base_probe(dev_t 
 
 static int __init genhd_device_init(void)
 {
-	class_register(&block_class);
+	int ret;
+
+	ret = class_register(&block_class);
+	if (ret != 0)
+		return ret;
+
 	bdev_map = kobj_map_init(base_probe, &block_class_lock);
 	blk_dev_init();
 
_