From 294462a5c6c4fb9a6ced9cb5a368ff335f1b656e Mon Sep 17 00:00:00 2001
From: Akinobu Mita <akinobu.mita@gmail.com>
Date: Tue, 17 Jul 2007 04:03:45 -0700
Subject: [PATCH] unregister_blkdev(): do WARN_ON on failure

When unregister_blkdev() has failed, something wrong happened.  This patch
adds WARN_ON to notify of such badness.

Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 block/genhd.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/block/genhd.c b/block/genhd.c
index b321cadd6e65..7f71b2c472b8 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -120,9 +120,10 @@ int unregister_blkdev(unsigned int major, const char *name)
 	for (n = &major_names[index]; *n; n = &(*n)->next)
 		if ((*n)->major == major)
 			break;
-	if (!*n || strcmp((*n)->name, name))
+	if (!*n || strcmp((*n)->name, name)) {
+		WARN_ON(1);
 		ret = -EINVAL;
-	else {
+	} else {
 		p = *n;
 		*n = p->next;
 	}