btrfs-progs: misc-tests: add a basic resume test using error injection

The new test case does:

- Make sure the build has error injection support
  This is done by checking "btrfs --version" output.

- Inject error at the last commit transaction of new data csum
  generation

- Resume the csum conversion and make sure it works

Signed-off-by: Qu Wenruo <wqu@suse.com>

tests/common

@@ -406,6 +406,13 @@ check_regular_build()
 	fi
 }
 
+check_injection()
+{
+	if ! _test_config "INJECT"; then
+		_not_run "This test requires error injection support (make D=1)"
+	fi
+}
+
 check_prereq()
 {
 	# Internal tools for testing, not shipped with the package

tests/misc-tests/065-csum-conversion-inject/test.sh

@@ -0,0 +1,45 @@
+#!/bin/bash
+# Verify the csum conversion can still resume after an interruption
+
+source "$TEST_TOP/common" || exit
+source "$TEST_TOP/common.convert" || exit
+
+check_experimental_build
+check_injection
+setup_root_helper
+prepare_test_dev
+
+test_resume_data_csum_generation()
+{
+	local new_csum="$1"
+	local tmp=$(_mktemp "csum-convert")
+
+	# Error at the end of the data csum generation.
+	export INJECT="0x4de02239"
+	run_mustfail_stdout "error injection not working" \
+		"$TOP/btrfstune" --csum "$new_csum" "$TEST_DEV" &> $tmp
+	cat "$tmp" >> "$RESULTS"
+	if ! grep -q "$INJECT" "$tmp"; then
+		rm -f -- "$tmp"
+		_fail "csum conversion failed to unexpected reason"
+	fi
+	rm -f -- "$tmp"
+	unset INJECT
+	run_check "$TOP/btrfstune" --csum "$new_csum" "$TEST_DEV"
+	run_check "$TOP/btrfs" check --check-data-csum "$TEST_DEV"
+}
+
+check_injection
+
+run_check_mkfs_test_dev --csum crc32c
+
+# We only mount the filesystem once to populate its contents, later one we
+# would never mount the fs (to reduce the dependency on kernel features).
+run_check_mount_test_dev
+populate_fs
+run_check_umount_test_dev
+
+test_resume_data_csum_generation xxhash
+test_resume_data_csum_generation blake2
+test_resume_data_csum_generation sha256
+test_resume_data_csum_generation crc32c