Re: [PATCH v6 4/4] generic: test fs-verity EFBIG scenarios

[Eric Biggers <ebiggers@kernel.org>]

On Mon, Feb 14, 2022 at 04:09:58PM -0800, Boris Burkov wrote:
> diff --git a/tests/generic/690 b/tests/generic/690
> new file mode 100755
> index 00000000..77906dd8
> --- /dev/null
> +++ b/tests/generic/690
> @@ -0,0 +1,66 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2021 Facebook, Inc.  All Rights Reserved.
> +#
> +# FS QA Test 690
> +#
> +# fs-verity requires the filesystem to decide how it stores the Merkle tree,
> +# which can be quite large.
> +# It is convenient to treat the Merkle tree as past EOF, and ext4, f2fs, and
> +# btrfs do so in at least some fashion. This leads to an edge case where a
> +# large file can be under the file system file size limit, but trigger EFBIG
> +# on enabling fs-verity. Test enabling verity on some large files to exercise
> +# EFBIG logic for filesystems with fs-verity specific limits.
> +#
> +. ./common/preamble
> +_begin_fstest auto quick verity
> +
> +
> +# Import common functions.
> +. ./common/filter
> +. ./common/verity
> +
> +# real QA test starts here
> +_supported_fs generic
> +_require_test
> +_require_math
> +_require_scratch_verity
> +_require_fsverity_max_file_size_limit
> +_require_scratch_nocheck

Why is _require_scratch_nocheck() needed?  _require_scratch_verity() already
does _require_scratch(), and I don't see why skipping fsck would be needed.

> +# have to go back by 4096 from max to not hit the fsverity MAX_LEVELS check.
> +truncate -s $max_sz $fsv_file

The above comment should be removed.

- Eric