[PATCH v4 06/11] generic: Add atomic write multi-fsblock O_[D]SYNC tests

[Ojaswin Mujoo <ojaswin@linux.ibm.com>]

This adds various atomic write multi-fsblock stresst tests
with mixed mappings and O_SYNC, to ensure the data and metadata
is atomically persisted even if there is a shutdown.

Suggested-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
---
 tests/generic/1228     | 137 +++++++++++++++++++++++++++++++++++++++++
 tests/generic/1228.out |   2 +
 2 files changed, 139 insertions(+)
 create mode 100755 tests/generic/1228
 create mode 100644 tests/generic/1228.out

diff --git a/tests/generic/1228 b/tests/generic/1228
new file mode 100755
index 00000000..888599ce
--- /dev/null
+++ b/tests/generic/1228
@@ -0,0 +1,137 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2025 IBM Corporation. All Rights Reserved.
+#
+# FS QA Test 1228
+#
+# Atomic write multi-fsblock data integrity tests with mixed mappings
+# and O_SYNC
+#
+. ./common/preamble
+. ./common/atomicwrites
+_begin_fstest auto quick rw atomicwrites
+
+_require_scratch_write_atomic_multi_fsblock
+_require_atomic_write_test_commands
+_require_scratch_shutdown
+_require_xfs_io_command "truncate"
+
+_scratch_mkfs >> $seqres.full
+_scratch_mount >> $seqres.full
+
+check_data_integrity() {
+	actual=$(_hexdump $testfile)
+	if [[ "$expected" != "$actual" ]]
+	then
+		echo "Integrity check failed"
+		echo "Integrity check failed" >> $seqres.full
+		echo "# Expected file contents:" >> $seqres.full
+		echo "$expected" >> $seqres.full
+		echo "# Actual file contents:" >> $seqres.full
+		echo "$actual" >> $seqres.full
+
+		_fail "Data integrity check failed. The atomic write was torn."
+	fi
+}
+
+prep_mixed_mapping() {
+	$XFS_IO_PROG -c "truncate 0" $testfile >> $seqres.full
+	local off=0
+	local mapping=""
+
+	local operations=("W" "H" "U")
+	local num_blocks=$((awu_max / blksz))
+	for ((i=0; i<num_blocks; i++)); do
+		local index=$((RANDOM % ${#operations[@]}))
+		local map="${operations[$index]}"
+		local mapping="${mapping}${map}"
+
+		case "$map" in
+			"W")
+				$XFS_IO_PROG -dc "pwrite -S 0x61 -b $blksz $off $blksz" $testfile > /dev/null
+				;;
+			"H")
+				# No operation needed for hole
+				;;
+			"U")
+				$XFS_IO_PROG -c "falloc $off $blksz" $testfile >> /dev/null
+				;;
+		esac
+		off=$((off + blksz))
+	done
+
+	echo "+ + Mixed mapping prep done. Full mapping pattern: $mapping" >> $seqres.full
+
+	sync $testfile
+}
+
+verify_atomic_write() {
+	test $bytes_written -eq $awu_max || _fail "atomic write len=$awu_max assertion failed"
+	check_data_integrity
+}
+
+mixed_mapping_test() {
+	prep_mixed_mapping
+
+	echo -"+ + Performing O_DSYNC atomic write from 0 to $awu_max" >> $seqres.full
+	if [[ "$1" == "shutdown" ]]
+	then
+		bytes_written=$($XFS_IO_PROG -x -dc \
+				"pwrite -DA -V1 -b $awu_max 0 $awu_max" \
+				-c "shutdown" $testfile | grep wrote | \
+				awk -F'[/ ]' '{print $2}')
+		_scratch_cycle_mount >>$seqres.full 2>&1 || _fail "remount failed"
+	else
+		bytes_written=$($XFS_IO_PROG -dc \
+				"pwrite -DA -V1 -b $awu_max 0 $awu_max" $testfile | \
+				grep wrote | awk -F'[/ ]' '{print $2}')
+	fi
+
+	verify_atomic_write
+}
+
+testfile=$SCRATCH_MNT/testfile
+touch $testfile
+
+awu_max=$(_get_atomic_write_unit_max $testfile)
+blksz=$(_get_block_size $SCRATCH_MNT)
+
+# Create an expected pattern to compare with
+$XFS_IO_PROG -tc "pwrite -b $awu_max 0 $awu_max" $testfile >> $seqres.full
+expected=$(_hexdump $testfile)
+echo "# Expected file contents:" >> $seqres.full
+echo "$expected" >> $seqres.full
+echo >> $seqres.full
+
+echo "# Test 1: Do O_DSYNC atomic write on random mixed mapping:" >> $seqres.full
+echo >> $seqres.full
+for ((iteration=1; iteration<=10; iteration++)); do
+	echo "=== Mixed Mapping Test Iteration $iteration ===" >> $seqres.full
+
+	echo "+ Testing without shutdown..." >> $seqres.full
+	mixed_mapping_test
+	echo "Passed!" >> $seqres.full
+
+	echo "+ Testing with sudden shutdown..." >> $seqres.full
+	mixed_mapping_test "shutdown"
+	echo "Passed!" >> $seqres.full
+
+	echo "Iteration $iteration completed: OK" >> $seqres.full
+	echo >> $seqres.full
+done
+echo "# Test 1: Do O_SYNC atomic write on random mixed mapping (10 iterations): OK" >> $seqres.full
+
+
+echo >> $seqres.full
+echo "# Test 2: Do extending O_SYNC atomic writes: " >> $seqres.full
+bytes_written=$($XFS_IO_PROG -x -dstc "pwrite -A -V1 -b $awu_max 0 $awu_max" \
+		-c "shutdown" $testfile | grep wrote | awk -F'[/ ]' '{print $2}')
+_scratch_cycle_mount >>$seqres.full 2>&1 || _fail "remount failed"
+verify_atomic_write
+echo "# Test 2: Do extending O_SYNC atomic writes: OK" >> $seqres.full
+
+# success, all done
+echo "Silence is golden"
+status=0
+exit
+
diff --git a/tests/generic/1228.out b/tests/generic/1228.out
new file mode 100644
index 00000000..1baffa91
--- /dev/null
+++ b/tests/generic/1228.out
@@ -0,0 +1,2 @@
+QA output created by 1228
+Silence is golden
-- 
2.49.0