Re: [PATCH V4] f2fs: show more discard status by sysfs

[Chao Yu <chao@kernel.org>]

On 2023/12/19 10:21, Zhiguo Niu wrote:
> The current pending_discard attr just only shows the discard_cmd_cnt
> information. More discard status can be shown so that we can check
> them through sysfs when needed.
> 
> Signed-off-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
> ---
> changes of v2: Improve the patch according to Chao's suggestions.
> changes of v3: Add a blank line for easy reading.
> changes of v4: Split to three entries
> ---
> ---
>   Documentation/ABI/testing/sysfs-fs-f2fs | 15 +++++++++++++++
>   fs/f2fs/sysfs.c                         | 33 +++++++++++++++++++++++++++++++++
>   2 files changed, 48 insertions(+)
> 
> diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
> index 4f1d4e6..606a298 100644
> --- a/Documentation/ABI/testing/sysfs-fs-f2fs
> +++ b/Documentation/ABI/testing/sysfs-fs-f2fs
> @@ -159,6 +159,21 @@ Date:		November 2021
>   Contact:	"Jaegeuk Kim" <jaegeuk@kernel.org>
>   Description:	Shows the number of pending discard commands in the queue.
>   
> +What:           /sys/fs/f2fs/<disk>/issued_discard

Add them to /sys/fs/f2fs/<disk>/stat/?

Thanks,

> +Date:           December 2023
> +Contact:        "Zhiguo Niu" <zhiguo.niu@unisoc.com>
> +Description:    Shows the number of issued discard.
> +
> +What:           /sys/fs/f2fs/<disk>/queued_discard
> +Date:           December 2023
> +Contact:        "Zhiguo Niu" <zhiguo.niu@unisoc.com>
> +Description:    Shows the number of queued discard.
> +
> +What:           /sys/fs/f2fs/<disk>/undiscard_blks
> +Date:           December 2023
> +Contact:        "Zhiguo Niu" <zhiguo.niu@unisoc.com>
> +Description:    Shows the total number of undiscard blocks.
> +
>   What:		/sys/fs/f2fs/<disk>/max_victim_search
>   Date:		January 2014
>   Contact:	"Jaegeuk Kim" <jaegeuk.kim@samsung.com>
> diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
> index 7099ffa..666efdd 100644
> --- a/fs/f2fs/sysfs.c
> +++ b/fs/f2fs/sysfs.c
> @@ -143,6 +143,33 @@ static ssize_t pending_discard_show(struct f2fs_attr *a,
>   				&SM_I(sbi)->dcc_info->discard_cmd_cnt));
>   }
>   
> +static ssize_t issued_discard_show(struct f2fs_attr *a,
> +		struct f2fs_sb_info *sbi, char *buf)
> +{
> +	if (!SM_I(sbi)->dcc_info)
> +		return -EINVAL;
> +	return sysfs_emit(buf, "%llu\n", (unsigned long long)atomic_read(
> +				&SM_I(sbi)->dcc_info->issued_discard));
> +}
> +
> +static ssize_t queued_discard_show(struct f2fs_attr *a,
> +		struct f2fs_sb_info *sbi, char *buf)
> +{
> +	if (!SM_I(sbi)->dcc_info)
> +		return -EINVAL;
> +	return sysfs_emit(buf, "%llu\n", (unsigned long long)atomic_read(
> +				&SM_I(sbi)->dcc_info->queued_discard));
> +}
> +
> +static ssize_t undiscard_blks_show(struct f2fs_attr *a,
> +		struct f2fs_sb_info *sbi, char *buf)
> +{
> +	if (!SM_I(sbi)->dcc_info)
> +		return -EINVAL;
> +	return sysfs_emit(buf, "%u\n",
> +				SM_I(sbi)->dcc_info->undiscard_blks);
> +}
> +
>   static ssize_t gc_mode_show(struct f2fs_attr *a,
>   		struct f2fs_sb_info *sbi, char *buf)
>   {
> @@ -1025,6 +1052,9 @@ static ssize_t f2fs_sb_feature_show(struct f2fs_attr *a,
>   F2FS_GENERAL_RO_ATTR(mounted_time_sec);
>   F2FS_GENERAL_RO_ATTR(main_blkaddr);
>   F2FS_GENERAL_RO_ATTR(pending_discard);
> +F2FS_GENERAL_RO_ATTR(issued_discard);
> +F2FS_GENERAL_RO_ATTR(queued_discard);
> +F2FS_GENERAL_RO_ATTR(undiscard_blks);
>   F2FS_GENERAL_RO_ATTR(gc_mode);
>   #ifdef CONFIG_F2FS_STAT_FS
>   F2FS_GENERAL_RO_ATTR(moved_blocks_background);
> @@ -1084,6 +1114,9 @@ static ssize_t f2fs_sb_feature_show(struct f2fs_attr *a,
>   	ATTR_LIST(max_ordered_discard),
>   	ATTR_LIST(discard_io_aware),
>   	ATTR_LIST(pending_discard),
> +	ATTR_LIST(issued_discard),
> +	ATTR_LIST(queued_discard),
> +	ATTR_LIST(undiscard_blks),
>   	ATTR_LIST(gc_mode),
>   	ATTR_LIST(ipu_policy),
>   	ATTR_LIST(min_ipu_util),