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

[Chao Yu <chao@kernel.org>]

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?

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)));