[PATCH v2 11/13] ext4/062: Atomic writes test for bigalloc using fio crc verifier on multiple files

Ojaswin Mujoo
2025-06-26T11:59:37Z

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

Brute force all possible blocksize clustersize combination on a bigalloc
filesystem for stressing atomic write using fio data crc verifier. We run
multiple threads in parallel with each job writing to its own file. The
parallel jobs running on a constrained filesystem size ensure that we stress
the ext4 allocator to allocate contiguous extents.

Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
---
tests/ext4/062 | 121 +++++++++++++++++++++++++++++++++++++++++++++
tests/ext4/062.out | 2 +
2 files changed, 123 insertions(+)
create mode 100755 tests/ext4/062
create mode 100644 tests/ext4/062.out

diff --git a/tests/ext4/062 b/tests/ext4/062
new file mode 100755
index 00000000..d59701c8
--- /dev/null
+++ b/tests/ext4/062
@@ -0,0 +1,121 @@
+#! /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 * $LOAD_FACTOR threads in parallel writing to a single
+# $SCRATCH_MNT/test-file. We also create 8 such parallel jobs to run on
+# a constrained filesystem size to stress the ext4 allocator to allocate
+# contiguous extents.
+#
+
+. ./common/preamble
+. ./common/atomicwrites
+
+_begin_fstest auto rw stress atomicwrites
+
+_require_scratch_write_atomic
+_require_aiodio
+
+FSSIZE=$((360*1024*1024))
+FIO_LOAD=$(($(nproc) * LOAD_FACTOR))
+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 "$bdev_awu_min")
+
+function create_fio_config()
+{
+cat >$fio_config <<EOF
+ [global]
+ direct=1
+ ioengine=libaio
+ rw=randwrite
+ bs=$fiobsize
+ fallocate=truncate
+ size=$((FSSIZE / 12))
+ iodepth=$FIO_LOAD
+ numjobs=$FIO_LOAD
+ group_reporting=1
+ verify_state_save=0
+ verify=crc32c
+ verify_fatal=1
+ verify_dump=0
+ verify_backlog=1024
+ verify_async=4
+ verify_write_sequence=0
+ atomic=1
+
+ [job1]
+ filename=$SCRATCH_MNT/testfile-job1
+
+ [job2]
+ filename=$SCRATCH_MNT/testfile-job2
+
+ [job3]
+ filename=$SCRATCH_MNT/testfile-job3
+
+ [job4]
+ filename=$SCRATCH_MNT/testfile-job4
+
+ [job5]
+ filename=$SCRATCH_MNT/testfile-job5
+
+ [job6]
+ filename=$SCRATCH_MNT/testfile-job6
+
+ [job7]
+ filename=$SCRATCH_MNT/testfile-job7
+
+ [job8]
+ filename=$SCRATCH_MNT/testfile-job8
+
+EOF
+}
+
+# Let's create a sample fio config to check whether fio supports all options.
+fio_config=$tmp.fio
+fio_out=$tmp.fio.out
+
+create_fio_config
+_require_fio $fio_config
+
+for ((fsblocksize=$fsblocksize; fsblocksize <= $(_get_page_size); fsblocksize = $fsblocksize << 1)); do
+ # cluster sizes above 16 x blocksize are experimental so avoid them
+ # Also, cap cluster size at 128kb to keep it reasonable for large
+ # blocks size cases.
+ fs_max_clustersize=$(_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 $fsclustersize"
+ _scratch_mkfs_sized "$FSSIZE" >> $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_config
+
+ cat $fio_config >> $seqres.full
+
+ $FIO_PROG $fio_config --output=$fio_out
+ ret=$?
+ cat $fio_out >> $seqres.full
+
+ _scratch_unmount
+
+ [[ $ret -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/ext4/062.out b/tests/ext4/062.out
new file mode 100644
index 00000000..a1578f48
--- /dev/null
+++ b/tests/ext4/062.out
@@ -0,0 +1,2 @@
+QA output created by 062
+Silence is golden
--
2.49.0