On 2019/2/20 15:25, Chao Yu wrote: > On 2019/2/20 15:08, Jaegeuk Kim wrote: >> 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 <jaeg...@kernel.org> >>>>>> --- >>>>>> 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 > > Cpu pipeline / compiler can make code out-of-order execution, which means: > > a = 1; > b = 2; > > may actually be executed as the order of: > > b = 2; > a = 1; > > So I doubt that below two line codes can be executed out-of-order: > > else > __clear_ckpt_flags(ckpt, CP_QUOTA_NEED_FSCK_FLAG); --- clear flag later > > if () > __set_ckpt_flags(ckpt, CP_QUOTA_NEED_FSCK_FLAG); --- set flag first > >> flag, CP_QUOTA_NEED_FSCK_FLAG. > > Agreed, I've checked each operation in f2fs_quota_operations yesterday, and > didn't find any missing places yet...
Oh, I mean the place where set SBI_QUOTA_NEED_REPAIR, I also doubt we missed to set the flag. Thanks, > > Thanks, > >> >>> >>> Thanks, >>> >>>> >>>>> >>>>> Thanks, >>>>> >>>>>> >>>>>> if (is_sbi_flag_set(sbi, SBI_QUOTA_NEED_REPAIR)) >>>>>> __set_ckpt_flags(ckpt, CP_QUOTA_NEED_FSCK_FLAG); >>>>>> >>>> >>>> . >>>> >> >> . >> > > > > _______________________________________________ > Linux-f2fs-devel mailing list > Linux-f2fs-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel > > . > _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
