Re: [PATCH 3/3] fstests: btrfs: testcase for sysfs policy syntax verification

[Dave Chinner <david@fromorbit.com>]

On Wed, Jan 29, 2025 at 11:19:54PM +0800, Anand Jain wrote:
> Checks if the sysfs attribute sanitizes arguments and verifies
> input syntax.
> 
> Signed-off-by: Anand Jain <anand.jain@oracle.com>
> ---
>  tests/btrfs/329     | 92 +++++++++++++++++++++++++++++++++++++++++++++
>  tests/btrfs/329.out |  2 +
>  2 files changed, 94 insertions(+)
>  create mode 100755 tests/btrfs/329
>  create mode 100644 tests/btrfs/329.out
> 
> diff --git a/tests/btrfs/329 b/tests/btrfs/329
> new file mode 100755
> index 000000000000..9f63ab951eac
> --- /dev/null
> +++ b/tests/btrfs/329
> @@ -0,0 +1,92 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2025 Oracle.  All Rights Reserved.
> +#
> +# FS QA Test 329
> +#
> +# Verify sysfs knob input syntax.
> +#
> +. ./common/preamble
> +_begin_fstest auto quick
> +
> +. ./common/filter
> +
> +# Modify as appropriate.
> +_require_scratch
> +_require_fs_sysfs read_policy
> +
> +_scratch_mkfs > /dev/null 2>&1 || _fail "mkfs failed"
> +_scratch_mount
> +
> +set_sysfs_policy()
> +{
> +	local attr=$1
> +	shift
> +	local policy=$@
> +
> +	_set_fs_sysfs_attr $SCRATCH_DEV $attr ${policy}
> +	_get_fs_sysfs_attr $SCRATCH_DEV $attr | grep -q "[${policy}]"
> +	if [[ $? != 0 ]]; then
> +		echo "Setting sysfs $attr $policy failed"
> +	fi
> +}
> +
> +set_sysfs_policy_must_fail()
> +{
> +	local attr=$1
> +	shift
> +	local policy=$@
> +
> +	_set_fs_sysfs_attr $SCRATCH_DEV $attr ${policy} | _filter_sysfs_error \
> +			| _expect_error_invalid_argument | tee -a $seqres.full

This "catch an exact error or output a different error then use
golden image match failure on secondary error to mark the test as
failed" semantic is .... overly complex.

The output on failure of _filter_sysfs_error will be "Invalid
input". If there's some other failure or it succeeds, the output
will indicate the failure that occurred (i.e. missing line means no
error, different error will output directly by the filter). The
golden image matching will still fail the test.

IOWs, _expect_error_invalid_argument and the output to seqres.full
can go away if the test.out file has a matching error for each
call to set_sysfs_policy_must_fail(). i.e it looks like:

QA output created by 329
Invalid input
Invalid input
Invalid input
Invalid input
Invalid input
Invalid input
.....
Invalid input

-Dave.
-- 
Dave Chinner
david@fromorbit.com