[PATCH] f2fs: add sysfs entry to avoid FUA

[Jaegeuk Kim <jaegeuk@kernel.org>]

Some UFS storage gives slower performance on FUA than write+cache_flush.
Let's give a way to manage it.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 Documentation/ABI/testing/sysfs-fs-f2fs | 7 +++++++
 fs/f2fs/data.c                          | 2 ++
 fs/f2fs/f2fs.h                          | 1 +
 fs/f2fs/sysfs.c                         | 2 ++
 4 files changed, 12 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
index 9b583dd0298b..cd96b09d7182 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -434,6 +434,7 @@ Date:		April 2020
 Contact:	"Daeho Jeong" <daehojeong@google.com>
 Description:	Give a way to change iostat_period time. 3secs by default.
 		The new iostat trace gives stats gap given the period.
+
 What:		/sys/fs/f2fs/<disk>/max_io_bytes
 Date:		December 2020
 Contact:	"Jaegeuk Kim" <jaegeuk@kernel.org>
@@ -442,6 +443,12 @@ Description:	This gives a control to limit the bio size in f2fs.
 		whereas, if it has a certain bytes value, f2fs won't submit a
 		bio larger than that size.
 
+What:		/sys/fs/f2fs/<disk>/no_fua_dio
+Date:		May 2022
+Contact:	"Jaegeuk Kim" <jaegeuk@kernel.org>
+Description:	This gives a signal to iomap, which should not use FUA for
+		direct IOs. Default: 0.
+
 What:		/sys/fs/f2fs/<disk>/stat/sb_status
 Date:		December 2020
 Contact:	"Chao Yu" <yuchao0@huawei.com>
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index f5f2b7233982..23486486eab2 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -4153,6 +4153,8 @@ static int f2fs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
 	if ((inode->i_state & I_DIRTY_DATASYNC) ||
 	    offset + length > i_size_read(inode))
 		iomap->flags |= IOMAP_F_DIRTY;
+	if (F2FS_I_SB(inode)->no_fua_dio)
+		iomap->flags |= IOMAP_F_DIRTY;
 
 	return 0;
 }
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index e10838879538..c2400ea0080b 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1671,6 +1671,7 @@ struct f2fs_sb_info {
 	int dir_level;				/* directory level */
 	int readdir_ra;				/* readahead inode in readdir */
 	u64 max_io_bytes;			/* max io bytes to merge IOs */
+	int no_fua_dio;				/* avoid FUA in DIO */
 
 	block_t user_block_count;		/* # of user blocks */
 	block_t total_valid_block_count;	/* # of valid blocks */
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index 4c50aedd5144..24d628ca92cc 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -771,6 +771,7 @@ F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, iostat_period_ms, iostat_period_ms);
 #endif
 F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, readdir_ra, readdir_ra);
 F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, max_io_bytes, max_io_bytes);
+F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, no_fua_dio, no_fua_dio);
 F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, gc_pin_file_thresh, gc_pin_file_threshold);
 F2FS_RW_ATTR(F2FS_SBI, f2fs_super_block, extension_list, extension_list);
 #ifdef CONFIG_F2FS_FAULT_INJECTION
@@ -890,6 +891,7 @@ static struct attribute *f2fs_attrs[] = {
 #endif
 	ATTR_LIST(readdir_ra),
 	ATTR_LIST(max_io_bytes),
+	ATTR_LIST(no_fua_dio),
 	ATTR_LIST(gc_pin_file_thresh),
 	ATTR_LIST(extension_list),
 #ifdef CONFIG_F2FS_FAULT_INJECTION
-- 
2.36.1.124.g0e6072fb45-goog