Re: [RFC 04/12] generic/767: Add atomic write test using fio crc check verifier

["Darrick J. Wong" <djwong@kernel.org>]

On Wed, Jun 11, 2025 at 03:04:47PM +0530, Ojaswin Mujoo wrote:
> From: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
> 
> This adds atomic write test using fio based on it's crc check verifier.
> fio adds a crc for each data block. If the underlying device supports atomic
> write then it is guaranteed that we will never have a mix data from two
> threads writing on the same physical block.
> 
> Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
> Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
> ---
>  tests/generic/767     | 84 +++++++++++++++++++++++++++++++++++++++++++
>  tests/generic/767.out |  2 ++
>  2 files changed, 86 insertions(+)
>  create mode 100755 tests/generic/767
>  create mode 100644 tests/generic/767.out
> 
> diff --git a/tests/generic/767 b/tests/generic/767
> new file mode 100755
> index 00000000..4f80e7b6
> --- /dev/null
> +++ b/tests/generic/767
> @@ -0,0 +1,84 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2025 IBM Corporation. All Rights Reserved.
> +#
> +# FS QA Test 767
> +#
> +# Validate FS atomic write using fio crc check verifier.
> +#
> +. ./common/preamble
> +. ./common/atomicwrites
> +
> +_begin_fstest auto aio rw atomicwrites
> +
> +_require_scratch_write_atomic
> +_require_odirect
> +_require_aio
> +
> +function max()
> +{
> +	if (( $1 > $2 )); then
> +		echo "$1"
> +	else
> +		echo "$2"
> +	fi
> +}
> +
> +function min()
> +{
> +	if (( $1 > $2 )); then
> +		echo "$2"
> +	else
> +		echo "$1"
> +	fi
> +}

Should these be common/rc helpers?

Or, since bash is ... uh fun with arguments...

_min() {
	local ret

	for arg in "$@"; do
		if [ -z "$ret" ] || (( $arg < $ret )); then
			ret="$arg"
		fi
	done
	echo $ret
}

and then you can pass as many arguments as you like.  The only downside
is that you can pass stringly typed crap "_min cow frog" and it still
returns "cow".  As if.

> +_scratch_mkfs >> $seqres.full 2>&1
> +_scratch_mount
> +
> +touch "$SCRATCH_MNT/f1"
> +awu_min_write=$(_get_atomic_write_unit_min "$SCRATCH_MNT/f1")
> +awu_max_write=$(_get_atomic_write_unit_max "$SCRATCH_MNT/f1")
> +blocksize=$(max "$awu_min_write" "$((awu_max_write/2))")
> +
> +# XFS can have high awu_max_write due to software fallback. Cap it at 64k
> +blocksize=$(min "$blocksize" "65536")
> +
> +fio_config=$tmp.fio
> +fio_out=$tmp.fio.out
> +
> +FIO_LOAD=$(($(nproc) * 2 * LOAD_FACTOR))

What program is nproc?

--D

> +SIZE=$((100 * 1024 * 1024))
> +
> +cat >$fio_config <<EOF
> +[aio-dio-aw-verify]
> +direct=1
> +ioengine=libaio
> +rw=randwrite
> +bs=$blocksize
> +fallocate=native
> +filename=$SCRATCH_MNT/test-file
> +size=$SIZE
> +iodepth=$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
> +EOF
> +
> +_require_fio $fio_config
> +
> +cat $fio_config >> $seqres.full
> +$FIO_PROG $fio_config --output=$fio_out
> +cat $fio_out >> $seqres.full
> +
> +# success, all done
> +echo Silence is golden
> +status=0
> +exit
> diff --git a/tests/generic/767.out b/tests/generic/767.out
> new file mode 100644
> index 00000000..2bf7f989
> --- /dev/null
> +++ b/tests/generic/767.out
> @@ -0,0 +1,2 @@
> +QA output created by 767
> +Silence is golden
> -- 
> 2.49.0
> 
>