Re: [PATCH] fstests: btrfs: add a test case to verify fsverity on compressed files

[Eric Biggers <ebiggers@kernel.org>]

On Sat, Oct 10, 2026 at 01:55:08PM +1030, Qu Wenruo wrote:
> There is a bug report that with the recently enabled large folios
> support, compressed files on btrfs can give random but reproducible
> warnings about file corruption.
> 
> It turns out to be a bug in the verification range, where blocks not
> included in the read range are passed to be verified.
> 
> Add a new regression test case for it, the workload is pretty simple:
> 
> - Create a 64M file with compressed file extents
> - Enable fsverity digest on that file
> - Drop page cache
> - Read that file
> - Verify there is no "FILE CORRUPTED!" warning
> 
> Signed-off-by: Qu Wenruo <wqu@suse.com>
> ---
>  tests/btrfs/359     | 45 +++++++++++++++++++++++++++++++++++++++++++++
>  tests/btrfs/359.out |  6 ++++++
>  2 files changed, 51 insertions(+)
>  create mode 100755 tests/btrfs/359
>  create mode 100644 tests/btrfs/359.out
> 
> diff --git a/tests/btrfs/359 b/tests/btrfs/359
> new file mode 100755
> index 00000000..2047d965
> --- /dev/null
> +++ b/tests/btrfs/359
> @@ -0,0 +1,45 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2026 SUSE S.A.  All Rights Reserved.
> +#
> +# FS QA Test 359
> +#
> +# Test if btrfs handles fsverity read correctly without corruption warning
> +#
> +. ./common/preamble
> +_begin_fstest auto quick verity compress
> +
> +_fixed_by_kernel_commit xxxxxxxxxxxx \
> +	"btrfs: fix the fsverity callback where unexpected range is verified"
> +
> +. ./common/filter
> +. ./common/verity
> +
> +_require_scratch_verity

Missing _require_check_dmesg?

Also, sourcing common/verity adds nodatasum to the mount options.
Doesn't that disable compression too?

- Eric