Re: [PATCH v2] fstests: btrfs: add a regression test for incorrect inode incompressible flag

[Qu Wenruo <wqu@suse.com>]

在 2026/2/9 20:24, Filipe Manana 写道:
> On Mon, Feb 9, 2026 at 9:50 AM Qu Wenruo <wqu@suse.com> wrote:
>>
>> [BUG]
>> Since kernel commit 59615e2c1f63 ("btrfs: reject single block sized
>> compression early"), a single block write at file offset 0, which can
>> not be inlined due the inode size, will mark the inode incompressible.
>>
>> [REGRESSION TEST]
>> The new regression test will do:
>>
>> - Create and mount the fs with compression,max_inline=2k
>>
>> - Do the following operations:
>>    * Truncate the inode to 2 * blocksize
>>      This will rule out any future inlined writes.
>>
>>    * Buffered write [0, 2K)
>>      Which will not be inlined.
>>
>>    * Sync
>>      For affected kernels, this will set the inode with NOCOMPRESS
>>      and reject all future compression on that inode.
>>
>>    * Buffered write [1M, 2M)
>>      For affected kernels, the range will not be compressed due
>>      to the NOCOMPRESS inode flag.
>>
>> - Unmount the fs
>>
>> - Make sure that:
>>    * The inode has no NOCOMPRESS flag
>>    * File extent at file offset 1M is being compressed
>>
>> Reviewed-by: Filipe Manana <fdmanana@suse.com>
>> Signed-off-by: Qu Wenruo <wqu@suse.com>
>> ---
>> Changelog:
>> v2:
>> - Remove an unnessary sentence
>>    Which is confusing because I missed the "and" to connect the two
>>    sentences, and it's not needed after the first paragraph anyway.
>>
>> - Use full "btrfs inspect-internal" group name instead
>>
>> - Add missing punctures
>> ---
>>   tests/btrfs/343     | 47 +++++++++++++++++++++++++++++++++++++++++++++
>>   tests/btrfs/343.out |  2 ++
>>   2 files changed, 49 insertions(+)
>>   create mode 100755 tests/btrfs/343
>>   create mode 100644 tests/btrfs/343.out
>>
>> diff --git a/tests/btrfs/343 b/tests/btrfs/343
>> new file mode 100755
>> index 00000000..78079eff
>> --- /dev/null
>> +++ b/tests/btrfs/343
>> @@ -0,0 +1,47 @@
>> +#! /bin/bash
>> +# SPDX-License-Identifier: GPL-2.0
>> +# Copyright (c) 2026 SUSE S.A.  All Rights Reserved.
>> +#
>> +# FS QA Test 343
>> +#
>> +# A regression test to make sure a single-block write at file offset 0 won't
>> +# incorrectly mark the inode incompressible.
>> +#
>> +. ./common/preamble
>> +_begin_fstest auto quick compress
>> +
>> +_require_scratch
> 
> Still missing a:
> 
> _require_btrfs_command inspect-internal dump-tree
> 
> As noted in the review of the first version.
> Otherwise it looks good, thanks.

Facepalm, I forgot to commit...