Re: [f2fs-dev] [PATCH] f2fs: add an ioctl() to explicitly trigger fsck later

[Chao Yu <yuchao0@huawei.com>]

On 2018/12/1 4:36, Jaegeuk Kim wrote:
> On 11/30, Chao Yu wrote:
>> On 2018/11/29 9:52, Jaegeuk Kim wrote:
>>> This adds an option in ioctl(F2FS_IOC_SHUTDOWN) in order to trigger fsck by
>>> setting a NEED_FSCK flag.
>>>
>>> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
>>> ---
>>>  fs/f2fs/f2fs.h | 1 +
>>>  fs/f2fs/file.c | 7 +++++++
>>>  2 files changed, 8 insertions(+)
>>>
>>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
>>> index aa500239baf2..7cec897146a3 100644
>>> --- a/fs/f2fs/f2fs.h
>>> +++ b/fs/f2fs/f2fs.h
>>> @@ -417,6 +417,7 @@ static inline bool __has_cursum_space(struct f2fs_journal *journal,
>>>  #define F2FS_GOING_DOWN_METASYNC	0x1	/* going down with metadata */
>>>  #define F2FS_GOING_DOWN_NOSYNC		0x2	/* going down */
>>>  #define F2FS_GOING_DOWN_METAFLUSH	0x3	/* going down with meta flush */
>>> +#define F2FS_GOING_DOWN_NEED_FSCK	0x4	/* going down to trigger fsck */
>>
>> Why not add a new ioctl interface for this? F2FS_GOING_DOWN_ prefix implies
>> filesystem will shutdown, IMO, we'd better to keep all sub-interfaces being
>> consistent in f2fs_ioc_shutdown().
> 
> I'm thinking to use this for QA as device shutdown tests.
> 
>>
>>>  
>>>  #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
>>>  /*
>>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
>>> index ff82350a2c55..ca9bdbb8651b 100644
>>> --- a/fs/f2fs/file.c
>>> +++ b/fs/f2fs/file.c
>>> @@ -1966,6 +1966,13 @@ static int f2fs_ioc_shutdown(struct file *filp, unsigned long arg)
>>>  		f2fs_stop_checkpoint(sbi, false);
>>>  		set_sbi_flag(sbi, SBI_IS_SHUTDOWN);
>>>  		break;
>>> +	case F2FS_GOING_DOWN_NEED_FSCK:
>>> +		set_sbi_flag(sbi, SBI_NEED_FSCK);
>>> +		/* do checkpoint only */
>>> +		ret = f2fs_sync_fs(sb, 1);
>>> +		if (ret)
>>> +			goto out;
>>
>> In large-sized image, it may take long time to trigger full scan during
>> boot, so I'd like to ask how often we set this flag?
> 
> Based on the use of shutdown ioctl, I'll use this for testing purpose, so it
> won't be used for regular cases.

How about adding some commit messages or comments on
F2FS_GOING_DOWN_NEED_FSCK marco definition to give a bit hint for f2fs
developers to know the usage of the interface?

Thanks,

> 
>>
>> Thanks,
>>
>>> +		break;
>>>  	default:
>>>  		ret = -EINVAL;
>>>  		goto out;
>>>
> 
> .
>