[PATCH 4/4] Btrfs: scrub, only lookup for ccums if we are dealing with a data extent

[fdmanana@kernel.org]

From: Filipe Manana <fdmanana@suse.com>

When scrubbing a stripe, whenever we find an extent we lookup for its
checksums in the checksum tree. However we do it even for metadata extents
which don't have checksum items stored in the checksum tree, that is
only for data extents.

So make the lookup for checksums only if we are processing with a data
extent.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
---
 fs/btrfs/scrub.c | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 2486f58d8205..c3b670858f8a 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -3343,13 +3343,16 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
 						   &extent_dev,
 						   &extent_mirror_num);
 
-			ret = btrfs_lookup_csums_range(csum_root,
-						       extent_logical,
-						       extent_logical +
-						       extent_len - 1,
-						       &sctx->csum_list, 1);
-			if (ret)
-				goto out;
+			if (flags & BTRFS_EXTENT_FLAG_DATA) {
+				ret = btrfs_lookup_csums_range(csum_root,
+							       extent_logical,
+							       extent_logical +
+							       extent_len - 1,
+							       &sctx->csum_list,
+							       1);
+				if (ret)
+					goto out;
+			}
 
 			ret = scrub_extent(sctx, map, extent_logical, extent_len,
 					   extent_physical, extent_dev, flags,
-- 
2.11.0