btrfs-progs: tests: add 020-extent-ref-cases

In order to confirm that btrfsck supports to check a variety of
refs, add the
following cases:
* keyed_block_ref
* keyed_data_ref
* shared_block_ref
* shared_data_ref
* no_inline_ref (a extent item without inline ref)
* no_skinny_ref

Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>

tests/fsck-tests/020-extent-ref-cases/test.sh

@@ -0,0 +1,23 @@
+#!/bin/bash
+# In order to confirm that btrfsck supports to check a variety of refs, add the
+# following cases:
+#
+# * keyed_block_ref
+# * keyed_data_ref
+# * shared_block_ref
+# * shared_data_ref
+# * no_inline_ref (a extent item without inline ref)
+# * no_skinny_ref
+
+source $TOP/tests/common
+
+check_prereq btrfs
+
+for img in *.img
+do
+	image=$(extract_image $img)
+	run_check_stdout $TOP/btrfs check "$image" 2>&1 |
+		grep -q "Errors found in extent allocation tree or chunk allocation" &&
+		_fail "unexpected error occurred when checking $img"
+	rm -f "$image"
+done