btrfs-progs: tests: test full 64bit timestamp conversion on ext4

Verify that [acm]time are copied from the ext4 source without loss of ns
precision.

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

tests/convert-tests/019-ext4-copy-timestamps/test.sh

@@ -0,0 +1,38 @@
+#!/bin/bash
+# Check if [acm]time values are copied from ext4 with full precision
+
+source "$TEST_TOP/common"
+source "$TEST_TOP/common.convert"
+
+setup_root_helper
+prepare_test_dev
+check_prereq btrfs-convert
+check_global_prereq mke2fs
+
+convert_test_prep_fs ext4 mke2fs -t ext4 -b 4096
+run_check $SUDO_HELPER touch "$TEST_MNT/file"
+# Read time values
+run_check stat "$TEST_MNT/file"
+atime=$(run_check_stdout stat --format=%x "$TEST_MNT/file")
+mtime=$(run_check_stdout stat --format=%y "$TEST_MNT/file")
+ctime=$(run_check_stdout stat --format=%z "$TEST_MNT/file")
+run_check_umount_test_dev
+
+convert_test_do_convert
+
+run_check_mount_test_dev
+run_check stat "$TEST_MNT/file"
+# Verify
+time=$(run_check_stdout stat --format=%x "$TEST_MNT/file")
+if [ "$time" != "$atime" ]; then
+	_fail "atime on converted inode does not match"
+fi
+time=$(run_check_stdout stat --format=%y "$TEST_MNT/file")
+if [ "$time" != "$mtime" ]; then
+	_fail "mtime on converted inoded does not match"
+fi
+time=$(run_check_stdout stat --format=%z "$TEST_MNT/file")
+if [ "$time" != "$mtime" ]; then
+	_fail "ctime on converted inoded does not match"
+fi
+run_check_umount_test_dev