From df9ed23918560fa31d495a651e9fea2f14cf65f2 Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Fri, 21 Aug 2009 17:40:08 -0700
Subject: [PATCH] --- yaml --- r: 156993 b: refs/heads/master c:
 8e9d78edea3ce5c0036f85b93091483f2f15443a h: refs/heads/master i:   156991:
 3cba487d3a3bd91990d6ed2e0e823e8db62a3592 v: v3

---
 [refs]            | 2 +-
 trunk/fs/buffer.c | 7 +++++--
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/[refs] b/[refs]
index aedf29d115d1..5c7db219b492 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 4dfd79e7b42bff334128907e28c3b41f1ef1cec8
+refs/heads/master: 8e9d78edea3ce5c0036f85b93091483f2f15443a
diff --git a/trunk/fs/buffer.c b/trunk/fs/buffer.c
index a3ef091a45bd..28f320fac4d4 100644
--- a/trunk/fs/buffer.c
+++ b/trunk/fs/buffer.c
@@ -1165,8 +1165,11 @@ void mark_buffer_dirty(struct buffer_head *bh)
 
 	if (!test_set_buffer_dirty(bh)) {
 		struct page *page = bh->b_page;
-		if (!TestSetPageDirty(page))
-			__set_page_dirty(page, page_mapping(page), 0);
+		if (!TestSetPageDirty(page)) {
+			struct address_space *mapping = page_mapping(page);
+			if (mapping)
+				__set_page_dirty(page, mapping, 0);
+		}
 	}
 }