Re: [f2fs-dev] [PATCH 3/3 v2] f2fs: clean up /sys/fs/f2fs/<disk>/features

[Eric Biggers]

On Sat, Jun 05, 2021 at 10:36:10PM -0700, Jaegeuk Kim wrote:
> Let's create /sys/fs/f2fs/<disk>/feature_list/ to meet sysfs rule.
> 
> Note that there are three feature list entries:
> 1) /sys/fs/f2fs/features
>   : shows runtime features supported by in-kernel f2fs along with Kconfig.
>     - ref. F2FS_FEATURE_RO_ATTR()
> 
> 2) /sys/fs/f2fs/$s_id/features <deprecated>
>   : shows on-disk features enabled by mkfs.f2fs, used for old kernels. This
>     won't add new feature anymore, and thus, users should check entries in 3)
>     instead of this 2).
> 
> 3) /sys/fs/f2fs/$s_id/feature_list
>   : shows on-disk features enabled by mkfs.f2fs per instance, which follows
>     sysfs entry rule where each entry should expose single value.
>     This list covers old feature list provided by 2) and beyond. Therefore,
>     please add new on-disk feature in this list only.
>     - ref. F2FS_SB_FEATURE_RO_ATTR()
> 
> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
> ---
> 
> change log from v1:
>  - adjust Eric's comment
> 
>  Documentation/ABI/testing/sysfs-fs-f2fs |  29 +++-
>  fs/f2fs/f2fs.h                          |   3 +
>  fs/f2fs/sysfs.c                         | 196 ++++++++++++++++--------
>  3 files changed, 163 insertions(+), 65 deletions(-)

Reviewed-by: Eric Biggers <ebiggers@xxxxxxxxxx>

- Eric