[PATCH v5 14/16] btrfs-progs: lowmem: introduce repair_block_accounting()

[Su Yue <suy.fnst@cn.fujitsu.com>]

Introduce repair_block_accounting() which calls
btrfs_fix_block_accounting() to repair block group accouting.

Replace btrfs_fix_block_accounting() with the new function.

Note: This patch and next patches cause error in lowmem repair like:
"Error: Commit_root already set when starting transaction".
Such error will disappear after removing @trans finished.

Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com>
---
 check/mode-lowmem.c | 26 +++++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/check/mode-lowmem.c b/check/mode-lowmem.c
index babbe60fd92c..3e81fc16e564 100644
--- a/check/mode-lowmem.c
+++ b/check/mode-lowmem.c
@@ -537,6 +537,30 @@ static int end_avoid_extents_overwrite(struct btrfs_fs_info *fs_info)
 	return ret;
 }
 
+/*
+ * Wrapper function for btrfs_fix_block_accounting().
+ *
+ * Returns 0     on success.
+ * Returns != 0  on error.
+ */
+static int repair_block_accounting(struct btrfs_fs_info *fs_info)
+{
+	struct btrfs_trans_handle *trans = NULL;
+	struct btrfs_root *root = fs_info->extent_root;
+	int ret;
+
+	trans = btrfs_start_transaction(root, 1);
+	if (IS_ERR(trans)) {
+		ret = PTR_ERR(trans);
+		error("fail to start transaction %s", strerror(-ret));
+		return ret;
+	}
+
+	ret = btrfs_fix_block_accounting(trans, root);
+	btrfs_commit_transaction(trans, root);
+	return ret;
+}
+
 /*
  * This function only handles BACKREF_MISSING,
  * If corresponding extent item exists, increase the ref, else insert an extent
@@ -4991,7 +5015,7 @@ out:
 
 		reset_cached_block_groups(fs_info);
 		/* update block accounting */
-		ret = btrfs_fix_block_accounting(trans, root);
+		ret = repair_block_accounting(fs_info);
 		if (ret)
 			err |= ret;
 		else
-- 
2.17.0