[PATCH] Btrfs: fix csum search offset/length calculation in log tree

[Filipe David Borba Manana <fdmanana@gmail.com>]

We were setting the csums search offset and length to the right values if
the extent is compressed, but later on right before doing the csums lookup
we were overriding these two parameters regardless of compression being
set or not for the extent.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
---
 fs/btrfs/tree-log.c |   14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 2ff031a..d75303e 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -3458,11 +3458,6 @@ static int log_one_extent(struct btrfs_trans_handle *trans,
 	if (skip_csum)
 		return 0;
 
-	if (em->compress_type) {
-		csum_offset = 0;
-		csum_len = block_len;
-	}
-
 	/*
 	 * First check and see if our csums are on our outstanding ordered
 	 * extents.
@@ -3546,8 +3541,13 @@ unlocked:
 	if (!mod_len || ret)
 		return ret;
 
-	csum_offset = mod_start - em->start;
-	csum_len = mod_len;
+	if (em->compress_type) {
+		csum_offset = 0;
+		csum_len = block_len;
+	} else {
+		csum_offset = mod_start - em->start;
+		csum_len = mod_len;
+	}
 
 	/* block start is already adjusted for the file extent offset. */
 	ret = btrfs_lookup_csums_range(log->fs_info->csum_root,
-- 
1.7.9.5