Re: [f2fs-dev] [PATCH] f2fs: fix quota info to adjust recovered data

[Jaegeuk Kim <jaegeuk@kernel.org>]

On 09/18, Chao Yu wrote:
> On 2018/9/18 10:05, Jaegeuk Kim wrote:
> > On 09/18, Chao Yu wrote:
> >> On 2018/9/18 9:19, Jaegeuk Kim wrote:
> >>> On 09/13, Chao Yu wrote:
> >>>> On 2018/9/13 3:54, Jaegeuk Kim wrote:
> >>>>> On 09/12, Chao Yu wrote:
> >>>>>> On 2018/9/12 9:40, Chao Yu wrote:
> >>>>>>> On 2018/9/12 9:25, Jaegeuk Kim wrote:
> >>>>>>>> On 09/12, Chao Yu wrote:
> >>>>>>>>> On 2018/9/12 8:27, Jaegeuk Kim wrote:
> >>>>>>>>>> On 09/11, Jaegeuk Kim wrote:
> >>>>>>>>>>> On 09/12, Chao Yu wrote:
> >>>>>>>>>>>> On 2018/9/12 4:15, Jaegeuk Kim wrote:
> >>>>>>>>>>>>> fsck.f2fs is able to recover the quota structure, since roll-forward recovery
> >>>>>>>>>>>>> can recover it based on previous user information.
> >>>>>>>>>>>>
> >>>>>>>>>>>> I didn't get it, both fsck and kernel recover quota file based all inodes'
> >>>>>>>>>>>> uid/gid/prjid, if {x}id didn't change, wouldn't those two recovery result be the
> >>>>>>>>>>>> same?
> >>>>>>>>>>>
> >>>>>>>>>>> I thought that, but had to add this, since I was encountering quota errors right
> >>>>>>>>>>> after getting some files recovered. And, I thought it'd make it more safe to do
> >>>>>>>>>>> fsck after roll-forward recovery.
> >>>>>>>>>>>
> >>>>>>>>>>> Anyway, let me test again without this patch for a while.
> >>>>>>>>>>
> >>>>>>>>>> Hmm, I just got a fsck failure right after some files recovered.
> >>>>>>>>>
> >>>>>>>>> To make sure, do you test with "f2fs: guarantee journalled quota data by
> >>>>>>>>> checkpoint"? if not, I think there is no guarantee that f2fs can recover
> >>>>>>>>> quote info into correct quote file, because, in last checkpoint, quota file
> >>>>>>>>> may was corrupted/inconsistent. Right?
> >>>>>>>
> >>>>>>> Oh, I forget to mention that, I add a patch to fsck to let it noticing
> >>>>>>> CP_QUOTA_NEED_FSCK_FLAG flag, and by default, fsck will fix corrupted quote
> >>>>>>> file if the flag is set, but w/o this flag, quota file is still corrupted
> >>>>>>> detected by fsck, I guess there is bug in v8.
> >>>>>>
> >>>>>> In v8, there are two cases we didn't guarantee quota file's consistence:
> >>>>>> 1. flush time in block_operation exceed a threshold.
> >>>>>> 2. dquot subsystem error occurs.
> >>>>>>
> >>>>>> For above case, fsck should repair the quota file by default.
> >>>>>
> >>>>> Okay, I got another failure and it seems CP_QUOTA_NEED_FSCK_FLAG was not set
> >>>>> during the recovery. So, we have something missing in the recovery in terms
> >>>>> of quota updates.
> >>>>
> >>>> Yeah, I checked the code, just found one suspected place:
> >>>>
> >>>> find_fsync_dnodes()
> >>>>  - f2fs_recover_inode_page
> >>>>   - inc_valid_node_count
> >>>>    - dquot_reserve_block  dquot info is not initialized now
> >>>>  - add_fsync_inode
> >>>>   - dquot_initialize
> >>>>
> >>>> I think we should reserve block for inode block after dquot_initialize(), can
> >>>> you confirm this?
> >>>
> >>> Let me test this.
> >>>
> >>> >From b90260bc577fe87570b1ef7b134554a8295b1f6c Mon Sep 17 00:00:00 2001
> >>> From: Jaegeuk Kim <jaegeuk@kernel.org>
> >>> Date: Mon, 17 Sep 2018 18:14:41 -0700
> >>> Subject: [PATCH] f2fs: count inode block for recovered files
> >>>
> >>> If a new file is recovered, we missed to reserve its inode block.
> >>
> >> I remember, in order to keep line with other filesystem, unlike on-disk, we
> >> have to keep backward compatibilty, in memory we don't account block number
> >> for f2fs' inode block, but only account inode number for it, so here like
> >> we did in inc_valid_node_count(), we don't need to do this.
> > 
> > Okay, I just hit the error again w/o your patch. Another one coming to my mind
> > is that caused by uid/gid change during recovery. Let me try out your patch.
> 
> I guess we should update dquot and inode's uid/gid atomically under
> lock_op() in f2fs_setattr() to prevent corruption on sys quota file.
> 
> v9 can pass all xfstest cases and por_fsstress case w/ sys quota file
> enabled, but w/ normal quota file, I got one regression reported by
> generic/232, I fixed in v10, will do some tests and release it later.
> 
> Note that, my fsck can fix corrupted quota file automatically once
> CP_QUOTA_NEED_FSCK_FLAG is set.

I hit failures again with your v9 w/ sysfile quota and modified fsck to detect
CP_QUOTA_NEED_FSCK_FLAG to fix the partition. Note that, if I set NEED_FSCK
flag in roll-forward recovery, everything is fine.

> 
> Thanks,
> 
> > 
> >>
> >> Can you test v9 first? I didn't encounter quota corruption with your
> >> testcase right now. Will check it in cell phone environment.
> >>
> >>>
> >>> Signed-off-by: Chao Yu <yuchao0@huawei.com>
> >>> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
> >>> ---
> >>>  fs/f2fs/recovery.c | 5 +++++
> >>>  1 file changed, 5 insertions(+)
> >>>
> >>> diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
> >>> index 56d34193a74b..bff5cf730e13 100644
> >>> --- a/fs/f2fs/recovery.c
> >>> +++ b/fs/f2fs/recovery.c
> >>> @@ -84,6 +84,11 @@ static struct fsync_inode_entry *add_fsync_inode(struct f2fs_sb_info *sbi,
> >>>  		err = dquot_alloc_inode(inode);
> >>>  		if (err)
> >>>  			goto err_out;
> >>> +		err = dquot_reserve_block(inode, 1);
> >>> +		if (err) {
> >>> +			dquot_drop(inode);
> >>> +			goto err_out;
> >>> +		}
> >>>  	}
> >>>  
> >>>  	entry = f2fs_kmem_cache_alloc(fsync_entry_slab, GFP_F2FS_ZERO);
> >>>
> > 
> > .
> >