[PATCH] generic: Add integrity tests with synchronous directio

["Ritesh Harjani (IBM)" <ritesh.list@gmail.com>]

This test covers data & metadata integrity check with directio with
o_sync flag and checks the file contents & size after sudden fileystem
shutdown once the directio write is completed. ext4 directio after iomap
conversion was broken in the sense that if the FS crashes after
synchronous directio write, it's file size is not properly updated.
This test adds a testcase to cover such scenario.

Man page of open says that -
O_SYNC provides synchronized I/O file integrity completion, meaning write
operations will flush data and all associated metadata to the underlying
hardware

Reported-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
---
 tests/generic/471     | 45 +++++++++++++++++++++++++++++++++++++++++++
 tests/generic/471.out |  8 ++++++++
 2 files changed, 53 insertions(+)
 create mode 100755 tests/generic/471
 create mode 100644 tests/generic/471.out

diff --git a/tests/generic/471 b/tests/generic/471
new file mode 100755
index 00000000..6c31cff8
--- /dev/null
+++ b/tests/generic/471
@@ -0,0 +1,45 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2023 IBM Corporation.  All Rights Reserved.
+#
+# FS QA Test 471
+#
+# Integrity test with DIRECT_IO & O_SYNC with sudden shutdown
+#
+. ./common/preamble
+_begin_fstest auto quick shutdown
+
+# Override the default cleanup function.
+_cleanup()
+{
+	cd /
+	rm -r -f $tmp.*
+}
+
+# Import common functions.
+. ./common/filter
+
+# real QA test starts here
+
+# Modify as appropriate.
+_supported_fs generic
+_require_scratch
+_require_scratch_shutdown
+
+_scratch_mkfs > $seqres.full 2>&1
+_scratch_mount
+
+echo "Create a 1M file using O_DIRECT & O_SYNC"
+xfs_io -fsd -c "pwrite -S 0x5a 0 1M" $SCRATCH_MNT/testfile > /dev/null 2>&1
+
+echo "Shutdown the fs suddenly"
+_scratch_shutdown
+
+echo "Cycle mount"
+_scratch_cycle_mount
+
+echo "File contents after cycle mount"
+_hexdump $SCRATCH_MNT/testfile
+
+status=0
+exit
diff --git a/tests/generic/471.out b/tests/generic/471.out
new file mode 100644
index 00000000..ae279b79
--- /dev/null
+++ b/tests/generic/471.out
@@ -0,0 +1,8 @@
+QA output created by 471
+Create a 1M file using O_DIRECT & O_SYNC
+Shutdown the fs suddenly
+Cycle mount
+File contents after cycle mount
+000000 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a  >ZZZZZZZZZZZZZZZZ<
+*
+100000
-- 
2.41.0