Re: [PATCH v2] fstests: btrfs/246: add test case to make sure btrfs can create compressed inline extent

[Qu Wenruo <wqu@suse.com>]

On 2021/8/29 下午9:42, Eryu Guan wrote:
> On Thu, Aug 26, 2021 at 01:34:32PM +0800, Qu Wenruo wrote:
>> Btrfs has the ability to inline small file extents into its metadata,
>> and such inlined extents can be further compressed if needed.
>>
>> The new test case is for a regression caused by commit f2165627319f
>> ("btrfs: compression: don't try to compress if we don't have enough
>> pages").
>>
>> That commit prevents btrfs from creating compressed inline extents, even
>> "-o compress,max_inline=2048" is specified, only uncompressed inline
>> extents can be created.
>>
>> The test case will make sure that the content of the small file is
>> consistent between cycle mount, then use "btrfs inspect dump-tree" to
>> verify the created extent is both inlined and compressed.
>>
>> Signed-off-by: Qu Wenruo <wqu@suse.com>
> 
> Is there a proposed fix available that could be referenced in the commit
> log?

The upstream commit is 4e9655763b82 ("Revert "btrfs: compression: don't 
try to compress if we don't have enough pages""), which is merged after 
I submitted the patch.

> 
>> ---
>> Changelog:
>> v2:
>> - Also output the sha256sum to make sure the content is consistent
>> ---
>>   tests/btrfs/246     | 53 +++++++++++++++++++++++++++++++++++++++++++++
>>   tests/btrfs/246.out |  5 +++++
>>   2 files changed, 58 insertions(+)
>>   create mode 100755 tests/btrfs/246
>>   create mode 100644 tests/btrfs/246.out
>>
>> diff --git a/tests/btrfs/246 b/tests/btrfs/246
>> new file mode 100755
>> index 00000000..e0d8016f
>> --- /dev/null
>> +++ b/tests/btrfs/246
>> @@ -0,0 +1,53 @@
>> +#! /bin/bash
>> +# SPDX-License-Identifier: GPL-2.0
>> +# Copyright (c) 2021 SUSE Linux Products GmbH.  All Rights Reserved.
>> +#
>> +# FS QA Test 246
>> +#
>> +# Make sure btrfs can create compressed inline extents
>> +#
>> +. ./common/preamble
>> +_begin_fstest auto quick compress
>> +
>> +# Override the default cleanup function.
>> +_cleanup()
>> +{
>> +	cd /
>> +	rm -r -f $tmp.*
>> +}
>> +
>> +# Import common functions.
>> +. ./common/filter
>> +# For __populate_find_inode()
>> +. ./common/populate
> 
> This function starts with double underscore, I take it as a 'private'
> function in common/populate. But all it does is returning the inode
> number of the given file, I think we could just open-code it in this
> test as
> 
> ino=$(stat -c %i $SCRATCH_MNT/foobar)
> 
> Otherwise test looks fine to me.

Mind me to send an update to include the fix in commit message and use 
the local ino helper?

Thanks,
Qu
> 
> Thanks,
> Eryu
> 
>> +
>> +# real QA test starts here
>> +
>> +# Modify as appropriate.
>> +_supported_fs btrfs
>> +_require_scratch
>> +
>> +_scratch_mkfs > /dev/null
>> +_scratch_mount -o compress,max_inline=2048
>> +
>> +# This should create compressed inline extent
>> +$XFS_IO_PROG -f -c "pwrite 0 2048" $SCRATCH_MNT/foobar > /dev/null
>> +ino=$(__populate_find_inode $SCRATCH_MNT/foobar)
>> +echo "sha256sum before mount cycle"
>> +sha256sum $SCRATCH_MNT/foobar | _filter_scratch
>> +_scratch_cycle_mount
>> +echo "sha256sum after mount cycle"
>> +sha256sum $SCRATCH_MNT/foobar | _filter_scratch
>> +_scratch_unmount
>> +
>> +$BTRFS_UTIL_PROG inspect dump-tree -t 5 $SCRATCH_DEV | \
>> +	grep "($ino EXTENT_DATA 0" -A2 > $tmp.dump-tree
>> +echo "dump tree result for ino $ino:" >> $seqres.full
>> +cat $tmp.dump-tree >> $seqres.full
>> +
>> +grep -q "inline extent" $tmp.dump-tree || echo "no inline extent found"
>> +grep -q "compression 1" $tmp.dump-tree || echo "no compressed extent found"
>> +
>> +# success, all done
>> +status=0
>> +exit
>> diff --git a/tests/btrfs/246.out b/tests/btrfs/246.out
>> new file mode 100644
>> index 00000000..3908cc50
>> --- /dev/null
>> +++ b/tests/btrfs/246.out
>> @@ -0,0 +1,5 @@
>> +QA output created by 246
>> +sha256sum before mount cycle
>> +0ca3bfdeda1ef5036bfa5dad078a9f15724e79cf296bd4388cf786bfaf4195d0  SCRATCH_MNT/foobar
>> +sha256sum after mount cycle
>> +0ca3bfdeda1ef5036bfa5dad078a9f15724e79cf296bd4388cf786bfaf4195d0  SCRATCH_MNT/foobar
>> -- 
>> 2.31.1
>