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

[Boris Burkov <boris@bur.io>]

On Tue, Mar 15, 2022 at 02:16:30AM +0000, Eric Biggers wrote:
> 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.
> 

Thanks for catching these oversights, will fix them. The nocheck thing
was left over from mixing/copy-pasting with btrfs/290 during this test's
evolution. Works fine without it on ext4 and btrfs.

> - Eric