Re: [PATCH 1/3] f2fs: fix to alloc_mode changed after remount on a small volume device

Yuwei Guan
2022-11-15T06:01:50Z

On 2022/11/15 9:23, Chao Yu wrote:
> On 2022/11/15 0:13, Yuwei Guan wrote:
>>
>> On 2022/11/14 22:42, Chao Yu wrote:
>>> On 2022/11/12 16:32, Yuwei Guan wrote:
>>>> The commit 84b89e5d943d8 ("f2fs: add auto tuning for small
>>>> devices") add
>>>> tuning for small volume device, now support to tune alloce_mode to
>>>> 'reuse'
>>>> if it's small size. But the alloc_mode will change to 'default'
>>>> when do
>>>> remount on this small size dievce.
>>>>
>>>> The commit 4cac90d5491c9 ("f2fs: relocate readdir_ra configure
>>>> initialization") relocates readdir_ra variable to tuning process.
>>>>
>>>> This patch fo fix alloc_mode changed when do remount for a small
>>>> volume
>>>> device.
>>>>
>>>> For a small device,
>>>> - alloc_mode will keep 'reuse', if no alloc_mode option in remount
>>>>    command,
>>>> - alloc_mode will be set as remount command, if it has 'alloc_mode='.
>>>>
>>>> Signed-off-by: Yuwei Guan <Yuwei.Guan@zeekrlife.com>
>>>> ---
>>>>   fs/f2fs/super.c | 37 ++++++++++++++++++++-----------------
>>>>   1 file changed, 20 insertions(+), 17 deletions(-)
>>>>
>>>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
>>>> index 3834ead04620..2f36824ff84b 100644
>>>> --- a/fs/f2fs/super.c
>>>> +++ b/fs/f2fs/super.c
>>>> @@ -2190,6 +2190,23 @@ static void f2fs_enable_checkpoint(struct
>>>> f2fs_sb_info *sbi)
>>>>       f2fs_flush_ckpt_thread(sbi);
>>>>   }
>>>>   +static void f2fs_tuning_parameters(struct f2fs_sb_info *sbi,
>>>> bool is_remount)
>>>> +{
>>>> +    struct f2fs_sm_info *sm_i = SM_I(sbi);
>>>> +
>>>> +    /* adjust parameters according to the volume size */
>>>> +    if (sm_i->main_segments <= SMALL_VOLUME_SEGMENTS) {
>>>> +        F2FS_OPTION(sbi).alloc_mode = ALLOC_MODE_REUSE;
>>>
>>> How about moving above logic into default_options()?
>>>
>> Hi Chao,
>>
>> 'sm_i->main_segments' init in func 'f2fs_build_segment_manager()',
>>
>> when do fill super process, so it cannot move into default_options().
>
> How about checking le32_to_cpu(raw_super->segment_count_main) directly?
>
Hi Chao,

Thanks a lot for it, I will update with v1 patch.

> Thanks,
>
>>
>>> Thanks,
>>>
>>>> +        if (f2fs_block_unit_discard(sbi))
>>>> +            sm_i->dcc_info->discard_granularity = 1;
>>>> +        sm_i->ipu_policy = 1 << F2FS_IPU_FORCE |
>>>> +                    1 << F2FS_IPU_HONOR_OPU_WRITE;
>>>> +    }
>>>> +
>>>> +    if (!is_remount)
>>>> +        sbi->readdir_ra = 1;
>>>> +}
>>>> +
>>>>   static int f2fs_remount(struct super_block *sb, int *flags, char
>>>> *data)
>>>>   {
>>>>       struct f2fs_sb_info *sbi = F2FS_SB(sb);
>>>> @@ -2248,6 +2265,8 @@ static int f2fs_remount(struct super_block
>>>> *sb, int *flags, char *data)
>>>>         default_options(sbi);
>>>>   +    f2fs_tuning_parameters(sbi, true);
>>>> +
>>>>       /* parse mount options */
>>>>       err = parse_options(sb, data, true);
>>>>       if (err)
>>>> @@ -4054,22 +4073,6 @@ static int f2fs_setup_casefold(struct
>>>> f2fs_sb_info *sbi)
>>>>       return 0;
>>>>   }
>>>>   -static void f2fs_tuning_parameters(struct f2fs_sb_info *sbi)
>>>> -{
>>>> -    struct f2fs_sm_info *sm_i = SM_I(sbi);
>>>> -
>>>> -    /* adjust parameters according to the volume size */
>>>> -    if (sm_i->main_segments <= SMALL_VOLUME_SEGMENTS) {
>>>> -        F2FS_OPTION(sbi).alloc_mode = ALLOC_MODE_REUSE;
>>>> -        if (f2fs_block_unit_discard(sbi))
>>>> -            sm_i->dcc_info->discard_granularity = 1;
>>>> -        sm_i->ipu_policy = 1 << F2FS_IPU_FORCE |
>>>> -                    1 << F2FS_IPU_HONOR_OPU_WRITE;
>>>> -    }
>>>> -
>>>> -    sbi->readdir_ra = 1;
>>>> -}
>>>> -
>>>>   static int f2fs_fill_super(struct super_block *sb, void *data,
>>>> int silent)
>>>>   {
>>>>       struct f2fs_sb_info *sbi;
>>>> @@ -4475,7 +4478,7 @@ static int f2fs_fill_super(struct super_block
>>>> *sb, void *data, int silent)
>>>>         f2fs_join_shrinker(sbi);
>>>>   -    f2fs_tuning_parameters(sbi);
>>>> +    f2fs_tuning_parameters(sbi, false);
>>>>         f2fs_notice(sbi, "Mounted with checkpoint version = %llx",
>>>>               cur_cp_version(F2FS_CKPT(sbi)));