[PATCH] f2fs: add a way to turn off ipu bio cache

[Jaegeuk Kim]

Setting 0x40 in /sys/fs/f2fs/dev/ipu_policy gives a way to turn off
bio cache, which is useufl to check whether block layer using hardware
encryption engine merges IOs correctly.

Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
---
 Documentation/filesystems/f2fs.txt | 1 +
 fs/f2fs/segment.c                  | 2 +-
 fs/f2fs/segment.h                  | 1 +
 3 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt
index 41b5aa94b30f..cd93bcc34726 100644
--- a/Documentation/filesystems/f2fs.txt
+++ b/Documentation/filesystems/f2fs.txt
@@ -335,6 +335,7 @@ Files in /sys/fs/f2fs/<devname>
                                0x01: F2FS_IPU_FORCE, 0x02: F2FS_IPU_SSR,
                                0x04: F2FS_IPU_UTIL,  0x08: F2FS_IPU_SSR_UTIL,
                                0x10: F2FS_IPU_FSYNC.
+			       0x40: F2FS_IPU_NOCACHE disables bio caches.
 
  min_ipu_util                 This parameter controls the threshold to trigger
                               in-place-updates. The number indicates percentage
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index a9519532c029..311fe4937f6a 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -3289,7 +3289,7 @@ int f2fs_inplace_write_data(struct f2fs_io_info *fio)
 
 	stat_inc_inplace_blocks(fio->sbi);
 
-	if (fio->bio)
+	if (fio->bio && !(SM_I(sbi)->ipu_policy & (1 << F2FS_IPU_NOCACHE)))
 		err = f2fs_merge_page_bio(fio);
 	else
 		err = f2fs_submit_page_bio(fio);
diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index a1b3951367cd..02e620470eef 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -623,6 +623,7 @@ enum {
 	F2FS_IPU_SSR_UTIL,
 	F2FS_IPU_FSYNC,
 	F2FS_IPU_ASYNC,
+	F2FS_IPU_NOCACHE,
 };
 
 static inline unsigned int curseg_segno(struct f2fs_sb_info *sbi,
-- 
2.24.0.525.g8f36a354ae-goog