f2fs: recover wrong pino after checkpoint during fsync

If a file is linked, f2fs loose its parent inode number so that fsync calls
for the linked file should do checkpoint all the time.
But, if we can recover its parent inode number after the checkpoint, we can
adjust roll-forward mechanism for the further fsync calls, which is able to
improve the fsync performance significatly.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

fs/f2fs/segment.c

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index b15debc..0e1a60a 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -796,7 +796,7 @@
 
 		if (S_ISDIR(inode->i_mode))
 			return CURSEG_HOT_DATA;
-		else if (is_cold_data(page) || is_cold_file(inode))
+		else if (is_cold_data(page) || file_is_cold(inode))
 			return CURSEG_COLD_DATA;
 		else
 			return CURSEG_WARM_DATA;