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

[Chao Yu <yuchao0@huawei.com>]

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().

>  
>  #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?

Thanks,

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