btrfs-progs: tests: add crafted image to test needs_recovery

Image of ext4 with needs_recovery incompat bit set. This bit cannot be
set by regular tune2fs so was created on an empty 4M image by patched
tune2fs that set the bit unconditionally (the image still passed e2fsck,
with journal recovery).

Issue: #348
Signed-off-by: David Sterba <dsterba@suse.com>

tests/convert-tests/020-refuse-needs-recovery/test.sh

@@ -0,0 +1,27 @@
+#!/bin/bash
+# Crafted image with needs_recovery incompat bit feature set, convert must
+# refuse to convert such image
+
+source "$TEST_TOP/common"
+
+check_prereq btrfs-convert
+check_prereq btrfs
+
+setup_root_helper
+prepare_test_dev
+
+# Override common function
+check_image() {
+	local features
+
+	TEST_DEV="$1"
+	features=$(run_check_stdout dumpe2fs "$TEST_DEV" | grep 'Filesystem features')
+	if ! echo "$features" | grep -q 'needs_recovery'; then
+		_fail "image does not have the needs_recovery bit set"
+	fi
+	run_mustfail "convert worked on unclean image" \
+		"$TOP/btrfs-convert" "$TEST_DEV"
+	rm -f "$TEST_DEV"
+}
+
+check_all_images