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

[Chao Yu <chao@kernel.org>]

On 2022/11/12 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()?

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)));