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>

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 185595a7be10c5fb40ad8a963b6600f43fbd6784..b03dd10e1d25873551e39dcd523043f433498b3e 100644 (file)
--- 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;