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

[Chao Yu]

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@xxxxxxxxxx>
> 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.

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@xxxxxxxxxx>
> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
> ---
>  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);
>