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

[Chao Yu <yuchao0@huawei.com>]

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.

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);
>>>
> 
> .
>