From: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>

We brute force all possible blocksize & clustersize combinations on
a bigalloc filesystem for stressing atomic write using fio data crc
verifier. We run nproc * $LOAD_FACTOR threads in parallel writing to
a single $SCRATCH_MNT/test-file. With atomic writes this test ensures
that we never see the mix of data contents from different threads on
a given bsrange.

Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
---
 tests/ext4/061     | 130 +++++++++++++++++++++++++++++++++++++++++++++
 tests/ext4/061.out |   2 +
 2 files changed, 132 insertions(+)
 create mode 100755 tests/ext4/061
 create mode 100644 tests/ext4/061.out

diff --git a/tests/ext4/061 b/tests/ext4/061
new file mode 100755
index 00000000..a0e49249
--- /dev/null
+++ b/tests/ext4/061
@@ -0,0 +1,130 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2025 IBM Corporation. All Rights Reserved.
+#
+# FS QA Test 061
+#
+# Brute force all possible blocksize clustersize combination on a bigalloc
+# filesystem for stressing atomic write using fio data crc verifier. We run
+# nproc * 2 * $LOAD_FACTOR threads in parallel writing to a single
+# $SCRATCH_MNT/test-file. With fio aio-dio atomic write this test ensures that
+# we should never see the mix of data contents from different threads for any
+# given fio blocksize.
+#
+
+. ./common/preamble
+. ./common/atomicwrites
+
+_begin_fstest auto rw stress atomicwrites
+
+_require_scratch_write_atomic
+_require_aiodio
+
+FIO_LOAD=$(($(nproc) * 2 * LOAD_FACTOR))
+SIZE=$((100*1024*1024))
+fiobsize=4096
+
+# Calculate fsblocksize as per bdev atomic write units.
+bdev_awu_min=$(_get_atomic_write_unit_min $SCRATCH_DEV)
+bdev_awu_max=$(_get_atomic_write_unit_max $SCRATCH_DEV)
+fsblocksize=$(_max 4096 "$bdev_awu_min")
+
+function create_fio_configs()
+{
+	create_fio_aw_config
+	create_fio_verify_config
+}
+
+function create_fio_verify_config()
+{
+cat >$fio_verify_config <<EOF
+	[aio-dio-aw-verify]
+	direct=1
+	ioengine=libaio
+	rw=randwrite
+	bs=$fiobsize
+	fallocate=native
+	filename=$SCRATCH_MNT/test-file
+	size=$SIZE
+	iodepth=$FIO_LOAD
+	numjobs=$FIO_LOAD
+	atomic=1
+	group_reporting=1
+
+	verify_only=1
+	verify_state_save=0
+	verify=crc32c
+	verify_fatal=1
+	verify_write_sequence=0
+EOF
+}
+
+function create_fio_aw_config()
+{
+cat >$fio_aw_config <<EOF
+	[aio-dio-aw]
+	direct=1
+	ioengine=libaio
+	rw=randwrite
+	bs=$fiobsize
+	fallocate=native
+	filename=$SCRATCH_MNT/test-file
+	size=$SIZE
+	iodepth=$FIO_LOAD
+	numjobs=$FIO_LOAD
+	group_reporting=1
+	atomic=1
+
+	verify_state_save=0
+	verify=crc32c
+	do_verify=0
+
+EOF
+}
+
+# Let's create a sample fio config to check whether fio supports all options.
+fio_aw_config=$tmp.aw.fio
+fio_verify_config=$tmp.verify.fio
+fio_out=$tmp.fio.out
+
+create_fio_configs
+_require_fio $fio_aw_config
+
+for ((fsblocksize=$fsblocksize; fsblocksize <= $(_get_page_size); fsblocksize = $fsblocksize << 1)); do
+	# cluster sizes above 16 x blocksize are experimental so avoid them
+	# Also, cap cluster size at 128kb to keep it reasonable for large
+	# blocks size
+	fs_max_clustersize=$(_min $((16 * fsblocksize)) "$bdev_awu_max" $((128 * 1024)))
+
+	for ((fsclustersize=$fsblocksize; fsclustersize <= $fs_max_clustersize; fsclustersize = $fsclustersize << 1)); do
+		for ((fiobsize = $fsblocksize; fiobsize <= $fsclustersize; fiobsize = $fiobsize << 1)); do
+			MKFS_OPTIONS="-O bigalloc -b $fsblocksize -C $fsclustersize"
+			_scratch_mkfs_ext4  >> $seqres.full 2>&1 || continue
+			if _try_scratch_mount >> $seqres.full 2>&1; then
+				echo "== FIO test for fsblocksize=$fsblocksize fsclustersize=$fsclustersize fiobsize=$fiobsize ==" >> $seqres.full
+
+				touch $SCRATCH_MNT/f1
+				create_fio_configs
+
+				cat $fio_aw_config >> $seqres.full
+				echo >> $seqres.full
+				cat $fio_verify_config >> $seqres.full
+
+				$FIO_PROG $fio_aw_config >> $seqres.full
+				ret1=$?
+
+				$FIO_PROG $fio_verify_config >> $seqres.full
+				ret2=$?
+
+				_scratch_unmount
+
+				[[ $ret1 -eq 0 && $ret2 -eq 0 ]] || _fail "fio with atomic write failed"
+			fi
+		done
+	done
+done
+
+# success, all done
+echo Silence is golden
+status=0
+exit
diff --git a/tests/ext4/061.out b/tests/ext4/061.out
new file mode 100644
index 00000000..273be9e0
--- /dev/null
+++ b/tests/ext4/061.out
@@ -0,0 +1,2 @@
+QA output created by 061
+Silence is golden
-- 
2.49.0