Re: [PATCH v4] xfs: test reproducible builds

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

On Tue, Dec 16, 2025 at 09:02:33AM +0100, Luca Di Maio wrote:
> With the addition of the `-p` populate option, SOURCE_DATE_EPOCH and
> DETERMINISTIC_SEED support, it is possible to create fully reproducible
> pre-populated filesystems. We should test them here.
> 
> v1 -> v2:
> - Changed test group from parent to mkfs
> - Fixed PROTO_DIR to point to a new dir
> - Populate PROTO_DIR with relevant file types
> - Move from md5sum to sha256sum
> v2 -> v3
> - Properly check if mkfs.xfs supports SOURCE_DATE_EPOCH and
>   DETERMINISTIC_SEED
> - use fsstress program to generate the PROTO_DIR content
> - simplify test output
> v3 -> v4
> - Add _cleanup function
> 
> Signed-off-by: Luca Di Maio <luca.dimaio1@gmail.com>
> ---
>  tests/xfs/841     | 171 ++++++++++++++++++++++++++++++++++++++++++++++
>  tests/xfs/841.out |   3 +
>  2 files changed, 174 insertions(+)
>  create mode 100755 tests/xfs/841
>  create mode 100644 tests/xfs/841.out
> 
> diff --git a/tests/xfs/841 b/tests/xfs/841
> new file mode 100755
> index 00000000..a75f5879
> --- /dev/null
> +++ b/tests/xfs/841
> @@ -0,0 +1,171 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2025 Chainguard, Inc. All Rights Reserved.
> +#
> +# FS QA Test No. 841
> +#
> +# Test that XFS filesystems created with reproducibility options produce
> +# identical images across multiple runs. This verifies that the combination
> +# of SOURCE_DATE_EPOCH, DETERMINISTIC_SEED, and -m uuid= options result in
> +# bit-for-bit reproducible filesystem images.
> +
> +. ./common/preamble
> +_begin_fstest auto quick mkfs
> +
> +# Image file settings
> +IMG_SIZE="512M"
> +IMG_FILE="$TEST_DIR/xfs_reproducible_test.img"
> +PROTO_DIR="$TEST_DIR/proto"
> +
> +# Fixed values for reproducibility
> +FIXED_UUID="12345678-1234-1234-1234-123456789abc"
> +FIXED_EPOCH="1234567890"
> +
> +_cleanup() {
> +	rm -r -f "$PROTO_DIR" "$IMG_FILE"
> +}

The start of this function needs to copy the code from the _cleanup
function in common/preable, as Dave said elsewhere.  Otherwise this
looks ok to me.

--D