From: Filipe Manana <fdmanana@suse.com>
Date: Fri, 8 May 2020 11:02:07 +0100
Git-commit: 89490303a4294238b84c83541c140e540faa17ba
Patch-mainline: 5.8-rc1
References: bsc#1176019
Subject: [PATCH] btrfs: scrub, only lookup for csums if we are dealing with a
 data extent

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>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/scrub.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 2486f58d8205..0f7740970553 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -3343,13 +3343,14 @@ 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,
-- 
2.26.2