Re: [PATCH 3/3] xfs: add a test that mkfs round up realtime subvolume sizes to the zone size

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

On Mon, Dec 15, 2025 at 10:50:29AM +0100, Christoph Hellwig wrote:
> Make sure mkfs doesn't create unmountable file systems.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  tests/xfs/653     | 33 +++++++++++++++++++++++++++++++++
>  tests/xfs/653.out |  2 ++
>  2 files changed, 35 insertions(+)
>  create mode 100755 tests/xfs/653
>  create mode 100644 tests/xfs/653.out
> 
> diff --git a/tests/xfs/653 b/tests/xfs/653
> new file mode 100755
> index 000000000000..07d9125c2ff0
> --- /dev/null
> +++ b/tests/xfs/653
> @@ -0,0 +1,33 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0-or-later
> +# Copyright (c) 2025 Christoph Hellwig.
> +#
> +# FS QA Test No. 653
> +#
> +# Tests that mkfs for a zoned file system rounds realtime subvolume sizes up to
> +# the zone size to create mountable file systems.

What size rt volume does this create?  It looks like you're specifying
an rt zone size of ... (1GB + 52K)?  And testing that mkfs rounds the
rt volume size down to some multiple of that?  Or is it rounding the
*zone* size down to 1G?

<confused>

--D

> +. ./common/preamble
> +_begin_fstest auto quick realtime growfs zone
> +
> +. ./common/filter
> +. ./common/zoned
> +
> +_require_realtime
> +_require_scratch
> +_require_scratch_size $((2 * 1024 * 1024)) # 1GiB in kiB units
> +
> +fsbsize=4096
> +unaligned_size=$((((1 * 1024 * 1024 * 1024) + (fsbsize * 13)) / fsbsize))
> +
> +# Manual mkfs and mount to not inject an existing RT device
> +echo "Try to format file system"
> +_try_mkfs_dev -b size=4k -r zoned=1,size=${unaligned_size}b $SCRATCH_DEV \
> +		>> $seqres.full 2>&1 ||\
> +	_notrun "cannot mkfs zoned filesystem"
> +_mount $SCRATCH_DEV $SCRATCH_MNT
> +umount $SCRATCH_MNT
> +
> +# success, all done
> +status=0
> +exit
> diff --git a/tests/xfs/653.out b/tests/xfs/653.out
> new file mode 100644
> index 000000000000..2cba5cdf1171
> --- /dev/null
> +++ b/tests/xfs/653.out
> @@ -0,0 +1,2 @@
> +QA output created by 653
> +Try to format file system
> -- 
> 2.47.3
> 
>