From: Zhaolei <zhaolei@cn.fujitsu.com>
Date: Wed, 5 Aug 2015 10:00:02 +0000 (+0800)
Subject: btrfs: Error handle for get_ref_objectid_v0() in relocate_block_group()
X-Git-Tag: v4.3-rc1~16^2~31
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=4b3576e450a1539492e26e2d7b1e2e69578c032e;p=profile%2Fcommon%2Fplatform%2Fkernel%2Flinux-artik7.git

btrfs: Error handle for get_ref_objectid_v0() in relocate_block_group()

We need error checking code for get_ref_objectid_v0() in
relocate_block_group(), to avoid unpredictable result, especially
for accessing uninitialized value(when function failed) after
this line.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
---

diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 52fe55a..1659c94 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -3976,6 +3976,10 @@ restart:
 			       sizeof(struct btrfs_extent_item_v0));
 			ret = get_ref_objectid_v0(rc, path, &key, &ref_owner,
 						  &path_change);
+			if (ret < 0) {
+				err = ret;
+				break;
+			}
 			if (ref_owner < BTRFS_FIRST_FREE_OBJECTID)
 				flags = BTRFS_EXTENT_FLAG_TREE_BLOCK;
 			else