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.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt
index 51afba1..a2046a7 100644
--- a/Documentation/filesystems/f2fs.txt
+++ b/Documentation/filesystems/f2fs.txt
@@ -126,6 +126,11 @@
to eliminate redundant command issues. If the underlying
device handles the cache_flush command relatively slowly,
recommend to enable this option.
+nobarrier This option can be used if underlying storage guarantees
+ its cached data should be written to the novolatile area.
+ If this option is set, no cache_flush commands are issued
+ but f2fs still guarantees the write ordering of all the
+ data writes.
================================================================================
DEBUGFS ENTRIES
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 @@
/* 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 @@
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..93593ce 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -52,6 +52,7 @@
Opt_inline_xattr,
Opt_inline_data,
Opt_flush_merge,
+ Opt_nobarrier,
Opt_err,
};
@@ -69,6 +70,7 @@
{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 @@
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 @@
seq_puts(seq, ",inline_data");
if (!f2fs_readonly(sbi->sb) && test_opt(sbi, FLUSH_MERGE))
seq_puts(seq, ",flush_merge");
+ if (test_opt(sbi, NOBARRIER))
+ seq_puts(seq, ",nobarrier");
seq_printf(seq, ",active_logs=%u", sbi->active_logs);
return 0;