Re: [PATCH 2/6] f2fs: support goingdown for fs shutdown

[Jaegeuk Kim <jaegeuk@kernel.org>]

On Thu, Jan 08, 2015 at 01:54:20PM -0600, Eric Sandeen wrote:
> On 1/8/15 12:10 PM, Jaegeuk Kim wrote:
> > This patch add an ioctl to shutdown f2fs, which stops all the further block
> > writes after this point.
> 
> would it make sense to just re-use the xfs ioctl nr, if the semantics are
> the same?

The semantics are not same for now.
In order to reuse xfs ioctl, it needs to support options for flushing logs.

Thanks,

> 
> That way any test using it will "just work" on f2fs...
> 
> -Eric
> 
> > Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
> > ---
> >  fs/f2fs/f2fs.h |  1 +
> >  fs/f2fs/file.c | 14 ++++++++++++++
> >  2 files changed, 15 insertions(+)
> > 
> > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> > index ba30218..febad35 100644
> > --- a/fs/f2fs/f2fs.h
> > +++ b/fs/f2fs/f2fs.h
> > @@ -209,6 +209,7 @@ static inline bool __has_cursum_space(struct f2fs_summary_block *sum, int size,
> >  #define F2FS_IOC_START_VOLATILE_WRITE	_IO(F2FS_IOCTL_MAGIC, 3)
> >  #define F2FS_IOC_RELEASE_VOLATILE_WRITE	_IO(F2FS_IOCTL_MAGIC, 4)
> >  #define F2FS_IOC_ABORT_VOLATILE_WRITE	_IO(F2FS_IOCTL_MAGIC, 5)
> > +#define F2FS_IOC_GOINGDOWN		_IO(F2FS_IOCTL_MAGIC, 6)
> >  
> >  #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
> >  /*
> > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> > index 5df3367..de2f669 100644
> > --- a/fs/f2fs/file.c
> > +++ b/fs/f2fs/file.c
> > @@ -1020,6 +1020,18 @@ static int f2fs_ioc_abort_volatile_write(struct file *filp)
> >  	return ret;
> >  }
> >  
> > +static int f2fs_ioc_goingdown(struct file *filp)
> > +{
> > +	struct inode *inode = file_inode(filp);
> > +	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> > +
> > +	if (!capable(CAP_SYS_ADMIN))
> > +		return -EPERM;
> > +
> > +	f2fs_stop_checkpoint(sbi);
> > +	return 0;
> > +}
> > +
> >  static int f2fs_ioc_fitrim(struct file *filp, unsigned long arg)
> >  {
> >  	struct inode *inode = file_inode(filp);
> > @@ -1067,6 +1079,8 @@ long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
> >  		return f2fs_ioc_release_volatile_write(filp);
> >  	case F2FS_IOC_ABORT_VOLATILE_WRITE:
> >  		return f2fs_ioc_abort_volatile_write(filp);
> > +	case F2FS_IOC_GOINGDOWN:
> > +		return f2fs_ioc_goingdown(filp);
> >  	case FITRIM:
> >  		return f2fs_ioc_fitrim(filp, arg);
> >  	default:
> >