From ac6a2b36f9fcfbe4865550afb6d333dec6b57578 Mon Sep 17 00:00:00 2001
From: Miao Xie <miaox@cn.fujitsu.com>
Date: Wed, 5 Dec 2012 10:56:13 +0000
Subject: [PATCH] Btrfs: fix wrong return value of btrfs_truncate_page()

ret variant may be set to 0 if we read page successfully, but it might be
released before we lock it again. On this case, if we fail to allocate a
new page, we will return 0, it is wrong, fix it.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
---
 fs/btrfs/inode.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index bf609581c5d0..0446cbe8bcaf 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -3521,11 +3521,11 @@ int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len,
 	if (ret)
 		goto out;
 
-	ret = -ENOMEM;
 again:
 	page = find_or_create_page(mapping, index, mask);
 	if (!page) {
 		btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
+		ret = -ENOMEM;
 		goto out;
 	}
 
@@ -3574,7 +3574,6 @@ int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len,
 		goto out_unlock;
 	}
 
-	ret = 0;
 	if (offset != PAGE_CACHE_SIZE) {
 		if (!len)
 			len = PAGE_CACHE_SIZE - offset;
-- 
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