Re: [PATCH] f2fs: show more discard stat by sysfs

[Chao Yu]

On 2023/11/24 9:08, Zhiguo Niu wrote:
> The current pending_discard attr just only shows the discard_cmd_cnt
> information, which is not very meaningful. More discard information
> can be shown so that we can check them through sysfs when needed.

What about adding this entry to /sys/fs/f2fs/<dev>/stat/?

> Signed-off-by: Zhiguo Niu <zhiguo.niu@xxxxxxxxxx>
> ---
>   fs/f2fs/sysfs.c | 21 +++++++++++++++------
>   1 file changed, 15 insertions(+), 6 deletions(-)
>
> diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
> index 417fae96..f98e680 100644
> --- a/fs/f2fs/sysfs.c
> +++ b/fs/f2fs/sysfs.c
> @@ -134,13 +134,22 @@ static ssize_t cp_status_show(struct f2fs_attr *a,
>   	return sysfs_emit(buf, "%x\n", le32_to_cpu(F2FS_CKPT(sbi)->ckpt_flags));
>   }
>   
> -static ssize_t pending_discard_show(struct f2fs_attr *a,
> +static ssize_t discard_stat_show(struct f2fs_attr *a,
>   		struct f2fs_sb_info *sbi, char *buf)
>   {
> -	if (!SM_I(sbi)->dcc_info)
> +	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
> +
> +	if (!dcc)
>   		return -EINVAL;
> -	return sysfs_emit(buf, "%llu\n", (unsigned long long)atomic_read(
> -				&SM_I(sbi)->dcc_info->discard_cmd_cnt));

It's better to keep the old one for any potential user.

> +
> +	return sysfs_emit(buf, "%llu, %llu, %llu, %u\n",
> +			(unsigned long long)atomic_read(
> +				&dcc->discard_cmd_cnt),
> +			(unsigned long long)atomic_read(
> +				&dcc->issued_discard),
> +			(unsigned long long)atomic_read(
> +				&dcc->queued_discard),
> +			dcc->undiscard_blks);
>   }
>   
>   static ssize_t gc_mode_show(struct f2fs_attr *a,
> @@ -1016,7 +1025,7 @@ static ssize_t f2fs_sb_feature_show(struct f2fs_attr *a,
>   F2FS_GENERAL_RO_ATTR(encoding);
>   F2FS_GENERAL_RO_ATTR(mounted_time_sec);
>   F2FS_GENERAL_RO_ATTR(main_blkaddr);
> -F2FS_GENERAL_RO_ATTR(pending_discard);
> +F2FS_GENERAL_RO_ATTR(discard_stat);

It needs to adjust Documentation/ABI/testing/sysfs-fs-f2fs.

Thanks,

>   F2FS_GENERAL_RO_ATTR(gc_mode);
>   #ifdef CONFIG_F2FS_STAT_FS
>   F2FS_GENERAL_RO_ATTR(moved_blocks_background);
> @@ -1074,7 +1083,7 @@ static ssize_t f2fs_sb_feature_show(struct f2fs_attr *a,
>   	ATTR_LIST(discard_urgent_util),
>   	ATTR_LIST(discard_granularity),
>   	ATTR_LIST(max_ordered_discard),
> -	ATTR_LIST(pending_discard),
> +	ATTR_LIST(discard_stat),
>   	ATTR_LIST(gc_mode),
>   	ATTR_LIST(ipu_policy),
>   	ATTR_LIST(min_ipu_util),