RE: [PATCH 7/8] f2fs: introduce new option for controlling data flush

[Chao Yu <chao2.yu@samsung.com>]

Hi Jaegeuk,

> -----Original Message-----
> From: Jaegeuk Kim [mailto:jaegeuk@kernel.org]
> Sent: Wednesday, December 16, 2015 6:03 AM
> To: Chao Yu
> Cc: linux-f2fs-devel@lists.sourceforge.net; linux-kernel@vger.kernel.org
> Subject: Re: [PATCH 7/8] f2fs: introduce new option for controlling data flush
> 
> Hi,
> 
> On Tue, Dec 15, 2015 at 01:35:21PM +0800, Chao Yu wrote:
> > Add a new option 'data_flush' to enable/disable data flush functionality
> > in checkpoint.
> >
> > Signed-off-by: Chao Yu <chao2.yu@samsung.com>
> > ---
> >  Documentation/filesystems/f2fs.txt | 2 ++
> >  fs/f2fs/checkpoint.c               | 2 +-
> >  fs/f2fs/f2fs.h                     | 1 +
> >  fs/f2fs/super.c                    | 7 +++++++
> >  4 files changed, 11 insertions(+), 1 deletion(-)
> >
> > diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt
> > index 8088bd9..727373e 100644
> > --- a/Documentation/filesystems/f2fs.txt
> > +++ b/Documentation/filesystems/f2fs.txt
> > @@ -151,6 +151,8 @@ noextent_cache         Disable an extent cache based on rb-tree explicitly,
> see
> >                         the above extent_cache mount option.
> >  noinline_data          Disable the inline data feature, inline data feature is
> >                         enabled by default.
> > +data_flush             Enable data flushing during checkpoint in order to
> > +                       persist data of regular and symlink.
> >
> >  ================================================================================
> >  DEBUGFS ENTRIES
> > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
> > index a73909c..2fdf271 100644
> > --- a/fs/f2fs/checkpoint.c
> > +++ b/fs/f2fs/checkpoint.c
> > @@ -855,7 +855,7 @@ static int block_operations(struct f2fs_sb_info *sbi)
> >
> >  retry_flush_datas:
> >  	/* write all the dirty data pages */
> > -	if (get_pages(sbi, F2FS_DIRTY_DATAS)) {
> > +	if (test_opt(sbi, DATA_FLUSH) && get_pages(sbi, F2FS_DIRTY_DATAS)) {
> >  		sync_dirty_inodes(sbi, FILE_INODE);
> >  		if (unlikely(f2fs_cp_error(sbi))) {
> >  			err = -EIO;
> > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> > index 4d44732..ee1f0a8 100644
> > --- a/fs/f2fs/f2fs.h
> > +++ b/fs/f2fs/f2fs.h
> > @@ -54,6 +54,7 @@
> >  #define F2FS_MOUNT_FASTBOOT		0x00001000
> >  #define F2FS_MOUNT_EXTENT_CACHE		0x00002000
> >  #define F2FS_MOUNT_FORCE_FG_GC		0x00004000
> > +#define F2FS_MOUNT_DATA_FLUSH		0x00008000
> >
> >  #define clear_opt(sbi, option)	(sbi->mount_opt.opt &= ~F2FS_MOUNT_##option)
> >  #define set_opt(sbi, option)	(sbi->mount_opt.opt |= F2FS_MOUNT_##option)
> > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> > index 051bce6..694e092 100644
> > --- a/fs/f2fs/super.c
> > +++ b/fs/f2fs/super.c
> > @@ -67,6 +67,7 @@ enum {
> >  	Opt_extent_cache,
> >  	Opt_noextent_cache,
> >  	Opt_noinline_data,
> > +	Opt_data_flush,
> 
> Need Opt_nodata_flush too.

We need this unless we set data_flush as a default option. Is that right?

Thanks,

> 
> Thanks,
> 
> >  	Opt_nodiscard,
> >  	Opt_err,
> >  };
> > @@ -92,6 +93,7 @@ static match_table_t f2fs_tokens = {
> >  	{Opt_extent_cache, "extent_cache"},
> >  	{Opt_noextent_cache, "noextent_cache"},
> >  	{Opt_noinline_data, "noinline_data"},
> > +	{Opt_data_flush, "data_flush"},
> >  	{Opt_nodiscard, "nodiscard"},
> >  	{Opt_err, NULL},
> >  };
> > @@ -411,6 +413,9 @@ static int parse_options(struct super_block *sb, char *options)
> >  		case Opt_noinline_data:
> >  			clear_opt(sbi, INLINE_DATA);
> >  			break;
> > +		case Opt_data_flush:
> > +			clear_opt(sbi, DATA_FLUSH);
> > +			break;
> >  		default:
> >  			f2fs_msg(sb, KERN_ERR,
> >  				"Unrecognized mount option \"%s\" or missing value",
> > @@ -694,6 +699,8 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
> >  		seq_puts(seq, ",extent_cache");
> >  	else
> >  		seq_puts(seq, ",noextent_cache");
> > +	if (test_opt(sbi, DATA_FLUSH))
> > +		seq_puts(seq, ",data_flush");
> >  	seq_printf(seq, ",active_logs=%u", sbi->active_logs);
> >
> >  	return 0;
> > --
> > 2.6.3
> >