From 2252b62a56601c9e31396da230b4ce792f167fb4 Mon Sep 17 00:00:00 2001
From: Younger Liu <liuyiyang@hisense.com>
Date: Thu, 23 Jan 2014 15:53:47 -0800
Subject: [PATCH] logfs: check for the return value after calling
 find_or_create_page()
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In get_mapping_page(), after calling find_or_create_page(), the return
value should be checked.

 This patch has been provided:
http://www.spinics.net/lists/linux-fsdevel/msg66948.html but not been
applied now.

Signed-off-by: Younger Liu <liuyiyang@hisense.com>
Cc: Younger Liu <younger.liucn@gmail.com>
Cc: Vyacheslav Dubeyko <slava@dubeyko.com>
Reviewed-by: Prasad Joshi <prasadjoshi.linux@gmail.com>
Cc: Jörn Engel <joern@logfs.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 fs/logfs/segment.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/logfs/segment.c b/fs/logfs/segment.c
index d448a77..7f9b096 100644
--- a/fs/logfs/segment.c
+++ b/fs/logfs/segment.c
@@ -62,7 +62,8 @@ static struct page *get_mapping_page(struct super_block *sb, pgoff_t index,
 		page = read_cache_page(mapping, index, filler, sb);
 	else {
 		page = find_or_create_page(mapping, index, GFP_NOFS);
-		unlock_page(page);
+		if (page)
+			unlock_page(page);
 	}
 	return page;
 }
-- 
2.7.4