Re: [f2fs-dev] [PATCH] f2fs: don't clear CP_QUOTA_NEED_FSCK_FLAG

From: Jaegeuk Kim
Date: Wed Feb 20 2019 - 02:09:08 EST


On 02/18, Chao Yu wrote:
> On 2019/2/16 12:55, Jaegeuk Kim wrote:
> > On 02/13, Chao Yu wrote:
> >> On 2019/2/12 10:33, Jaegeuk Kim wrote:
> >>> If we met this once, let fsck.f2fs clear this only.
> >>> Note that, this addresses all the subtle fault injection test.
> >>>
> >>> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
> >>> ---
> >>> fs/f2fs/checkpoint.c | 2 --
> >>> 1 file changed, 2 deletions(-)
> >>>
> >>> diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
> >>> index 03fea4efd64b..10a3ada28715 100644
> >>> --- a/fs/f2fs/checkpoint.c
> >>> +++ b/fs/f2fs/checkpoint.c
> >>> @@ -1267,8 +1267,6 @@ static void update_ckpt_flags(struct f2fs_sb_info *sbi, struct cp_control *cpc)
> >>>
> >>> if (is_sbi_flag_set(sbi, SBI_QUOTA_SKIP_FLUSH))
> >>> __set_ckpt_flags(ckpt, CP_QUOTA_NEED_FSCK_FLAG);
> >>> - else
> >>> - __clear_ckpt_flags(ckpt, CP_QUOTA_NEED_FSCK_FLAG);
> >>
> >> I didn't get it, previously, if we didn't persist all quota file's data in
> >> checkpoint, then we will tag CP_QUOTA_NEED_FSCK_FLAG in CP area, but in current
> >> checkpoint, we have persisted all quota file's data, quota files are consistent
> >> with all other files in filesystem, why we can't remove this NEED_FSCK flag..?
> >
> > I said it's subtle. So, I guessed 1) set CP_QUOTA_NEED_FSCK_FLAG, 2) clear
>
> I know it's subtle... and I agreed we can fix it like this in upstream
> first, but in our product, it's not rare that we hit the
> QUOTA_SKIP_FLUSH(its value is 4) case, later we may encounter long latency
> caused by quota repairing of fsck.
>
> > SBI_QUOTA_SKIP_FLUSH by checkpoint, 3) clear CP_QUOTA_NEED_FSCK_FLAG by another
> > checkpoint?
>
> But later if QUOTA_NEED_REPAIR is set, we will set QUOTA_NEED_FSCK_FLAG
> again, right?
>
> if (is_sbi_flag_set(sbi, SBI_QUOTA_NEED_REPAIR))
> __set_ckpt_flags(ckpt, CP_QUOTA_NEED_FSCK_FLAG);
>
>
> So in order to figure out whether this is caused by out-of-order execution
> of below assignments:
>
> if (is_sbi_flag_set(sbi, SBI_QUOTA_SKIP_FLUSH))
> __set_ckpt_flags(ckpt, CP_QUOTA_NEED_FSCK_FLAG);
> else
> __clear_ckpt_flags(ckpt, CP_QUOTA_NEED_FSCK_FLAG); --- clear flag later
>
> if (is_sbi_flag_set(sbi, SBI_QUOTA_NEED_REPAIR))
> __set_ckpt_flags(ckpt, CP_QUOTA_NEED_FSCK_FLAG); --- set flag first
>
>
> Could you have a try:
>
> if (is_sbi_flag_set(sbi, SBI_QUOTA_NEED_REPAIR) ||
> is_sbi_flag_set(sbi, SBI_QUOTA_SKIP_FLUSH))
> __set_ckpt_flags(ckpt, CP_QUOTA_NEED_FSCK_FLAG);
> else
> __clear_ckpt_flags(ckpt, CP_QUOTA_NEED_FSCK_FLAG);

What does this mean? I'm in doubt we have a missing case where we clear this
flag, CP_QUOTA_NEED_FSCK_FLAG.

>
> Thanks,
>
> >
> >>
> >> Thanks,
> >>
> >>>
> >>> if (is_sbi_flag_set(sbi, SBI_QUOTA_NEED_REPAIR))
> >>> __set_ckpt_flags(ckpt, CP_QUOTA_NEED_FSCK_FLAG);
> >>>
> >
> > .
> >