f2fs: give an option to enable in-place-updates during fsync to users
If user wrote F2FS_IPU_FSYNC:4 in /sys/fs/f2fs/ipu_policy, f2fs_sync_file
only starts to try in-place-updates.
And, if the number of dirty pages is over /sys/fs/f2fs/min_fsync_blocks, it
keeps out-of-order manner. Otherwise, it triggers in-place-updates.
This may be used by storage showing very high random write performance.
For example, it can be used when,
Seq. writes (Data) + wait + Seq. writes (Node)
is pretty much slower than,
Rand. writes (Data)
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index ad7e9b3..8efa170 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -386,6 +386,7 @@
unsigned int ipu_policy; /* in-place-update policy */
unsigned int min_ipu_util; /* in-place-update threshold */
+ unsigned int min_fsync_blocks; /* threshold for fsync */
/* for flush command control */
struct flush_cmd_control *cmd_control_info;