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

[Jaegeuk Kim]

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@xxxxxxxxxx>
> > ---
> >  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.

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