From b9df537e5fcd7df6cae6ffa3906657c71e79b71f Mon Sep 17 00:00:00 2001
From: Mike Snitzer <snitzer@redhat.com>
Date: Fri, 13 Nov 2020 14:52:28 -0800
Subject: [PATCH] dm writecache: remove BUG() and fail gracefully instead

commit 857c4c0a8b2888d806f4308c58f59a6a81a1dee9 upstream.

Building on arch/s390/ results in this build error:

cc1: some warnings being treated as errors
../drivers/md/dm-writecache.c: In function 'persistent_memory_claim':
../drivers/md/dm-writecache.c:323:1: error: no return statement in function returning non-void [-Werror=return-type]

Fix this by replacing the BUG() with an -EOPNOTSUPP return.

Fixes: 48debafe4f2f ("dm: add writecache target")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/md/dm-writecache.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c
index 27ec6c537d95..08ae59a6e873 100644
--- a/drivers/md/dm-writecache.c
+++ b/drivers/md/dm-writecache.c
@@ -316,7 +316,7 @@ err1:
 #else
 static int persistent_memory_claim(struct dm_writecache *wc)
 {
-	BUG();
+	return -EOPNOTSUPP;
 }
 #endif