Re: [PATCH] f2fs: enable atgc if atgc_age_threshold from user is less than elapsed_time

[Chao Yu]

On 2024/5/30 17:49, Zhiguo Niu wrote:
> On Mon, May 27, 2024 at 12:07 PM Zhiguo Niu <niuzhiguo84@xxxxxxxxx> wrote:
> > On Mon, May 27, 2024 at 11:49 AM Chao Yu <chao@xxxxxxxxxx> wrote:
> > > On 2024/5/20 19:36, Zhiguo Niu wrote:
> > > > Now atgc can be enabled based on the following conditions:
> > > > -ATGC mount option is set
> > > > -elapsed_time is more than atgc_age_threshold already
> > > > but these conditions are check when umounted->mounted device again.
> > > > If the device has not be umounted->mounted for a long time, atgc can
> > > > not work even the above conditions met.
> > >
> > > Zhiguo, I didn't get it, can you please explain more about this issue?
> > >
> > > Thanks,
> > Hi Chao,
> >
> > At present, the point of atgc enale is checked during the mount
> > process. What I mean is that if a device has not been rebooted
> > (re-mounted) for a long time, even if the above two conditions are
> > met(ATGC mount option is set, and the device has been powered on long
> > enough， more than atgc default threshold ), atgc cannot be dynamically
> > enabled.
> >
> > If the user is used to not restarting the phone after turning it on,
> > it will be difficult to use atgc.
> > thanks!
> Hi Chao,
> Do you have any suggestions or comments on this?

Zhiguo,

I remember that atgc can not be enabled at runtime due to some reasons, but
I need some time to recall and check the details...

Thanks,

> thanks！
>
> > > > It is better to enable atgc dynamiclly when user change atgc_age_threshold
> > > > meanwhile this vale is less than elapsed_time and ATGC mount option is on.
> > > >
> > > > Signed-off-by: Zhiguo Niu <zhiguo.niu@xxxxxxxxxx>
> > > > ---
> > > >    fs/f2fs/f2fs.h    |  1 +
> > > >    fs/f2fs/segment.c |  9 ++++-----
> > > >    fs/f2fs/sysfs.c   | 16 ++++++++++++++++
> > > >    3 files changed, 21 insertions(+), 5 deletions(-)
> > > >
> > > > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> > > > index 1974b6a..e441d2d 100644
> > > > --- a/fs/f2fs/f2fs.h
> > > > +++ b/fs/f2fs/f2fs.h
> > > > @@ -3694,6 +3694,7 @@ void f2fs_clear_prefree_segments(struct f2fs_sb_info *sbi,
> > > >    int f2fs_init_inmem_curseg(struct f2fs_sb_info *sbi);
> > > >    void f2fs_save_inmem_curseg(struct f2fs_sb_info *sbi);
> > > >    void f2fs_restore_inmem_curseg(struct f2fs_sb_info *sbi);
> > > > +int f2fs_init_atgc_curseg(struct f2fs_sb_info *sbi);
> > > >    int f2fs_allocate_segment_for_resize(struct f2fs_sb_info *sbi, int type,
> > > >                                        unsigned int start, unsigned int end);
> > > >    int f2fs_allocate_new_section(struct f2fs_sb_info *sbi, int type, bool force);
> > > > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> > > > index 71dc8042..44923d4 100644
> > > > --- a/fs/f2fs/segment.c
> > > > +++ b/fs/f2fs/segment.c
> > > > @@ -2931,14 +2931,11 @@ static int get_atssr_segment(struct f2fs_sb_info *sbi, int type,
> > > >        return ret;
> > > >    }
> > > >
> > > > -static int __f2fs_init_atgc_curseg(struct f2fs_sb_info *sbi)
> > > > +int f2fs_init_atgc_curseg(struct f2fs_sb_info *sbi)
> > > >    {
> > > >        struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_ALL_DATA_ATGC);
> > > >        int ret = 0;
> > > >
> > > > -     if (!sbi->am.atgc_enabled)
> > > > -             return 0;
> > > > -
> > > >        f2fs_down_read(&SM_I(sbi)->curseg_lock);
> > > >
> > > >        mutex_lock(&curseg->curseg_mutex);
> > > > @@ -2955,7 +2952,9 @@ static int __f2fs_init_atgc_curseg(struct f2fs_sb_info *sbi)
> > > >    }
> > > >    int f2fs_init_inmem_curseg(struct f2fs_sb_info *sbi)
> > > >    {
> > > > -     return __f2fs_init_atgc_curseg(sbi);
> > > > +     if (!sbi->am.atgc_enabled)
> > > > +             return 0;
> > > > +     return f2fs_init_atgc_curseg(sbi);
> > > >    }
> > > >
> > > >    static void __f2fs_save_inmem_curseg(struct f2fs_sb_info *sbi, int type)
> > > > diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
> > > > index 09d3ecf..72676c5 100644
> > > > --- a/fs/f2fs/sysfs.c
> > > > +++ b/fs/f2fs/sysfs.c
> > > > @@ -673,6 +673,22 @@ static ssize_t __sbi_store(struct f2fs_attr *a,
> > > >                return count;
> > > >        }
> > > >
> > > > +     if (!strcmp(a->attr.name, "atgc_age_threshold")) {
> > > > +             if (t < 0)
> > > > +                     return -EINVAL;
> > > > +             sbi->am.age_threshold = t;
> > > > +             if (sbi->am.atgc_enabled)
> > > > +                     return count;
> > > > +
> > > > +             if (test_opt(sbi, ATGC) &&
> > > > +                     le64_to_cpu(sbi->ckpt->elapsed_time) >= t) {
> > > > +                     if (f2fs_init_atgc_curseg(sbi))
> > > > +                             return -EINVAL;
> > > > +                     sbi->am.atgc_enabled = true;
> > > > +             }
> > > > +             return count;
> > > > +     }
> > > > +
> > > >        if (!strcmp(a->attr.name, "gc_segment_mode")) {
> > > >                if (t < MAX_GC_MODE)
> > > >                        sbi->gc_segment_mode = t;