From 5d2b42ede71c9da0bf4248fd2d409918fb065b5f Mon Sep 17 00:00:00 2001
From: Shuoran Liu <liushuoran@huawei.com>
Date: Thu, 25 Aug 2016 20:42:09 +0800
Subject: [PATCH] f2fs: fix a bug when using namehash to locate dentry bucket

In the following scenario,

1) we don't have the key and doing a lookup for encrypted file,
2) and the encrypted filename is big name

we should use fname->hash as name hash value instead of what is
calculated by fname->disk_name. Because in such case,
fname->disk_name is empty.

Signed-off-by: Shuoran Liu <liushuoran@huawei.com>
Acked-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 fs/f2fs/dir.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index 9054aeac8015..b3e6f7feadc9 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -172,7 +172,10 @@ static struct f2fs_dir_entry *find_in_level(struct inode *dir,
 	int max_slots;
 	f2fs_hash_t namehash;
 
-	namehash = f2fs_dentry_hash(&name);
+	if(fname->hash)
+		namehash = cpu_to_le32(fname->hash);
+	else
+		namehash = f2fs_dentry_hash(&name);
 
 	nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
 	nblock = bucket_blocks(level);