From fe8cf654b1ccf7f0b49cc0de9e6ad8a56529e384 Mon Sep 17 00:00:00 2001
From: Zhao Lei <zhaolei@cn.fujitsu.com>
Date: Wed, 22 Jul 2015 13:14:47 +0800
Subject: [PATCH] btrfs: Load only necessary csums into list in scrub

We need not load csum of whole strip in scrub because strip is trimed
before use, it is to say, what we really need to calculate csum is
data between [extent_logical, extent_len).

This patch changed to use above segment for btrfs_lookup_csums_range()
in scrub_stripe()

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
---
 fs/btrfs/scrub.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 185595a7be10..b03dd10e1d25 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -3254,9 +3254,11 @@ again:
 						   &extent_dev,
 						   &extent_mirror_num);
 
-			ret = btrfs_lookup_csums_range(csum_root, logical,
-						logical + map->stripe_len - 1,
-						&sctx->csum_list, 1);
+			ret = btrfs_lookup_csums_range(csum_root,
+						       extent_logical,
+						       extent_logical +
+						       extent_len - 1,
+						       &sctx->csum_list, 1);
 			if (ret)
 				goto out;
 
-- 
2.34.1