btrfs-progs: fsck-tests: a new test case for missing root orphan item

The new image is created by:

- Make btrfs_delete_subvolume() to commit transaction
  So that we're sure the orphan item is committed to disk after removing
  the subvolume.

- Remove the orphan item from tree root

Then use this image to make sure btrfs check can detect such problem.
Repair is not yet supported.

Reviewed-by: Boris Burkov <[email protected]>
Signed-off-by: Qu Wenruo <[email protected]>

Author: adam900710

tests/fsck-tests/066-missing-root-orphan-item/default.img.xz

@@ -0,0 +1,14 @@
+#!/bin/bash
+#
+# Verify that check can report missing orphan root itemm as an error
+
+source "$TEST_TOP/common" || exit
+
+check_prereq btrfs
+
+check_image() {
+	run_mustfail "missing root orphan item not reported as an error" \
+		"$TOP/btrfs" check "$1"
+}
+
+check_all_images