RE: [f2fs-dev] [PATCH 01/11] f2fs: add nobarrier mount option

From: Chao Yu
Date: Tue Jul 29 2014 - 07:29:28 EST


Hi Jaegeuk,

> -----Original Message-----
> From: Jaegeuk Kim [mailto:jaegeuk@xxxxxxxxxx]
> Sent: Saturday, July 26, 2014 6:47 AM
> To: linux-kernel@xxxxxxxxxxxxxxx; linux-fsdevel@xxxxxxxxxxxxxxx;
> linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx
> Cc: Jaegeuk Kim
> Subject: [f2fs-dev] [PATCH 01/11] f2fs: add nobarrier mount option
>
> This patch adds a mount option, nobarrier, in f2fs.
> The assumption in here is that file system keeps the IO ordering, but
> doesn't care about cache flushes inside the storages.

Looks good to me.
But it's better to add some description in f2fs document.

>
> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>

Reviewed-by: Chao Yu <chao2.yu@xxxxxxxxxxx>

> ---
> fs/f2fs/data.c | 5 ++++-
> fs/f2fs/f2fs.h | 1 +
> fs/f2fs/segment.c | 3 +++
> fs/f2fs/super.c | 7 +++++++
> 4 files changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index c77c667..482313d 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -139,7 +139,10 @@ void f2fs_submit_merged_bio(struct f2fs_sb_info *sbi,
> /* change META to META_FLUSH in the checkpoint procedure */
> if (type >= META_FLUSH) {
> io->fio.type = META_FLUSH;
> - io->fio.rw = WRITE_FLUSH_FUA | REQ_META | REQ_PRIO;
> + if (test_opt(sbi, NOBARRIER))
> + io->fio.rw = WRITE_FLUSH | REQ_META | REQ_PRIO;
> + else
> + io->fio.rw = WRITE_FLUSH_FUA | REQ_META | REQ_PRIO;
> }
> __submit_merged_bio(io);
> up_write(&io->io_rwsem);
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 8f507d4..e999eec 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -41,6 +41,7 @@
> #define F2FS_MOUNT_INLINE_XATTR 0x00000080
> #define F2FS_MOUNT_INLINE_DATA 0x00000100
> #define F2FS_MOUNT_FLUSH_MERGE 0x00000200
> +#define F2FS_MOUNT_NOBARRIER 0x00000400
>
> #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/segment.c b/fs/f2fs/segment.c
> index 8a6e57d..9fce0f47 100644
> --- a/fs/f2fs/segment.c
> +++ b/fs/f2fs/segment.c
> @@ -239,6 +239,9 @@ int f2fs_issue_flush(struct f2fs_sb_info *sbi)
> struct flush_cmd_control *fcc = SM_I(sbi)->cmd_control_info;
> struct flush_cmd cmd;
>
> + if (test_opt(sbi, NOBARRIER))
> + return 0;
> +
> if (!test_opt(sbi, FLUSH_MERGE))
> return blkdev_issue_flush(sbi->sb->s_bdev, GFP_KERNEL, NULL);
>
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index 34649aa..eec89a2 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -52,6 +52,7 @@ enum {
> Opt_inline_xattr,
> Opt_inline_data,
> Opt_flush_merge,
> + Opt_nobarrier,
> Opt_err,
> };
>
> @@ -69,6 +70,7 @@ static match_table_t f2fs_tokens = {
> {Opt_inline_xattr, "inline_xattr"},
> {Opt_inline_data, "inline_data"},
> {Opt_flush_merge, "flush_merge"},
> + {Opt_nobarrier, "nobarrier"},
> {Opt_err, NULL},
> };
>
> @@ -339,6 +341,9 @@ static int parse_options(struct super_block *sb, char *options)
> case Opt_flush_merge:
> set_opt(sbi, FLUSH_MERGE);
> break;
> + case Opt_nobarrier:
> + set_opt(sbi, NOBARRIER);
> + break;
> default:
> f2fs_msg(sb, KERN_ERR,
> "Unrecognized mount option \"%s\" or missing value",
> @@ -544,6 +549,8 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
> seq_puts(seq, ",inline_data");
> if (!f2fs_readonly(sbi->sb) && test_opt(sbi, FLUSH_MERGE))
> seq_puts(seq, ",flush_merge");
> + if (!f2fs_readonly(sbi->sb) && test_opt(sbi, NOBARRIER))
> + seq_puts(seq, ",nobarrier");
> seq_printf(seq, ",active_logs=%u", sbi->active_logs);
>
> return 0;
> --
> 1.8.5.2 (Apple Git-48)
>
>
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