Re: [PATCH 1/2] f2fs/006: add testcase to check out-of-space case

[Chao Yu <chao@kernel.org>]

On 2024/10/23 10:37, Zorro Lang wrote:
> On Tue, Oct 15, 2024 at 10:51:05AM +0800, Chao Yu wrote:
>> This is a regression test to check whether f2fs handles dirty
>> data correctly when checkpoint is disabled, if lfs mode is on,
>> it will trigger OPU for all overwritten data, this will cost
>> free segments, so f2fs must account overwritten data as OPU
>> data when calculating free space, otherwise, it may run out
>> of free segments in f2fs' allocation function, resulting in
>> panic.
>>
>> Cc: Jaegeuk Kim <jaegeuk@kernel.org>
>> Signed-off-by: Chao Yu <chao@kernel.org>
>> ---
>>   tests/f2fs/006     | 52 ++++++++++++++++++++++++++++++++++++++++++++++
>>   tests/f2fs/006.out |  6 ++++++
>>   2 files changed, 58 insertions(+)
>>   create mode 100755 tests/f2fs/006
>>   create mode 100644 tests/f2fs/006.out
>>
>> diff --git a/tests/f2fs/006 b/tests/f2fs/006
>> new file mode 100755
>> index 00000000..b359ef8f
>> --- /dev/null
>> +++ b/tests/f2fs/006
>> @@ -0,0 +1,52 @@
>> +#! /bin/bash
>> +# SPDX-License-Identifier: GPL-2.0
>> +# Copyright (c) 2024 Oppo.  All Rights Reserved.
>> +#
>> +# FS QA Test No. f2fs/006
>> +#
>> +# This is a regression test to check whether f2fs handles dirty
>> +# data correctly when checkpoint is disabled, if lfs mode is on,
>> +# it will trigger OPU for all overwritten data, this will cost
>> +# free segments, so f2fs must account overwritten data as OPU
>> +# data when calculating free space, otherwise, it may run out
>> +# of free segments in f2fs' allocation function, resulting in
>> +# panic.
>> +#
>> +. ./common/preamble
>> +_begin_fstest auto quick
>> +
>> +_cleanup()
>> +{
>> +	rm -f $img
>> +	_scratch_unmount >> $seqres.full
>> +	cd /
>> +	rm -r -f $tmp.*
>> +}
>> +
>> +_require_scratch
>> +_scratch_mkfs >> $seqres.full
>> +_scratch_mount >> $seqres.full
>> +
>> +img=$SCRATCH_MNT/f2fs.img
>> +mnt=$SCRATCH_MNT/f2fs.mnt
>> +testfile=$mnt/testfile
>> +
>> +mkdir $mnt
>> +dd if=/dev/zero of=$img bs=1M count=100 2>/dev/null
>> +$MKFS_F2FS_PROG -f $img >/dev/null 2>&1
>> +sync
>> +
>> +# use mode=lfs to let f2fs always triggers OPU
>> +mount -t $FSTYP -o loop,mode=lfs,checkpoint=disable:10%,noinline_dentry $img $mnt
> 
> Hi Chao,
> 
> Is the loop device necessary? What if use SCRATCH_DEV and SCRATCH_MNT directly?

Hi Zorro,

It uses loop device to limit image size, so that we can speed
up padding steps of the test since it depends on ENOSPC state.

Or maybe we can mkfs.f2fs $SCRATCH_DEV w/ specified sector size?
Any suggestion?

Thanks,

> 
> Thanks,
> Zorro
> 
>> +
>> +dd if=/dev/zero of=$testfile bs=1M count=50 2>/dev/null
>> +
>> +# it may run out of free space of f2fs and hang kernel
>> +dd if=/dev/zero of=$testfile bs=1M count=50 conv=notrunc conv=fsync
>> +dd if=/dev/zero of=$testfile bs=1M count=50 conv=notrunc conv=fsync
>> +
>> +mount -o remount,checkpoint=enable $mnt
>> +umount $mnt
>> +
>> +status=0
>> +exit
>> diff --git a/tests/f2fs/006.out b/tests/f2fs/006.out
>> new file mode 100644
>> index 00000000..a2c7ba48
>> --- /dev/null
>> +++ b/tests/f2fs/006.out
>> @@ -0,0 +1,6 @@
>> +QA output created by 006
>> +50+0 records in
>> +50+0 records out
>> +dd: error writing '/mnt/scratch_f2fs/f2fs.mnt/testfile': No space left on device
>> +3+0 records in
>> +2+0 records out
>> -- 
>> 2.40.1
>>
>