Re: [PATCH V3] f2fs: show more discard status by sysfs

[Zhiguo Niu]

On Tue, Dec 19, 2023 at 1:45 AM Jaegeuk Kim <jaegeuk@xxxxxxxxxx> wrote:
>
> On 12/18, 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@xxxxxxxxxx>
> > ---
> > changes of v2: Improve the patch according to Chao's suggestions.
> > changes of v3: Add a blank line for easy reading.
> > ---
> > ---
> >  Documentation/ABI/testing/sysfs-fs-f2fs |  6 ++++++
> >  fs/f2fs/sysfs.c                         | 19 +++++++++++++++++++
> >  2 files changed, 25 insertions(+)
> >
> > diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
> > index 36c3cb5..c6970e5 100644
> > --- a/Documentation/ABI/testing/sysfs-fs-f2fs
> > +++ b/Documentation/ABI/testing/sysfs-fs-f2fs
> > @@ -498,6 +498,12 @@ Description:     Show status of f2fs checkpoint in real time.
> >               CP_RESIZEFS_FLAG                0x00004000
> >               =============================== ==============================
> >
> > +What:                /sys/fs/f2fs/<disk>/stat/discard_status
> > +Date:                November 2023
> > +Contact:     "Zhiguo Niu" <zhiguo.niu@xxxxxxxxxx>
> > +Description: Show status of f2fs discard in real time, including
> > +             "issued discard","queued discard" and "undiscard blocks".
> > +
> >  What:                /sys/fs/f2fs/<disk>/ckpt_thread_ioprio
> >  Date:                January 2021
> >  Contact:     "Daeho Jeong" <daehojeong@xxxxxxxxxx>
> > diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
> > index 417fae96..312a4dc 100644
> > --- a/fs/f2fs/sysfs.c
> > +++ b/fs/f2fs/sysfs.c
> > @@ -134,6 +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 discard_status_show(struct f2fs_attr *a,
> > +             struct f2fs_sb_info *sbi, char *buf)
> > +{
> > +     struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
> > +
> > +     if (!dcc)
> > +             return -EINVAL;
> > +
> > +     return sysfs_emit(buf, "%llu, %llu, %u\n",
> > +                     (unsigned long long)atomic_read(
> > +                             &dcc->issued_discard),
> > +                     (unsigned long long)atomic_read(
> > +                             &dcc->queued_discard),
> > +                     dcc->undiscard_blks);
>
> We cannot do this since it needs one value per one entry.
OK, I will split this into three entry. thanks
>
> > +}
> > +
> >  static ssize_t pending_discard_show(struct f2fs_attr *a,
> >               struct f2fs_sb_info *sbi, char *buf)
> >  {
> > @@ -1197,9 +1213,12 @@ static ssize_t f2fs_sb_feature_show(struct f2fs_attr *a,
> >
> >  F2FS_GENERAL_RO_ATTR(sb_status);
> >  F2FS_GENERAL_RO_ATTR(cp_status);
> > +F2FS_GENERAL_RO_ATTR(discard_status);
> > +
> >  static struct attribute *f2fs_stat_attrs[] = {
> >       ATTR_LIST(sb_status),
> >       ATTR_LIST(cp_status),
> > +     ATTR_LIST(discard_status),
> >       NULL,
> >  };
> >  ATTRIBUTE_GROUPS(f2fs_stat);
> > --
> > 1.9.1