tree 0cc16f1a1baa738e97fab5df5f3607a92a4f6cba
parent 9cf3c3898a274ca637b88ad01b0830550ee2d318
author Jaegeuk Kim <jaegeuk.kim@samsung.com> 1393813720 +0900
committer Jaegeuk Kim <jaegeuk.kim@samsung.com> 1393813720 +0900

f2fs: fix to write node pages with WRITE_SYNC

This patch fixes performance regression of dbench reported by
Alex <hbx7d@yandex.com>.

This issue was revealed by Phoronix tests results:
http://www.phoronix.com/scan.php?page=article&item=linux_314_ssdfs&num=2

It turns out that we need to assign WRITE_SYNC to the node writes, if
fsync is triggered.

The performance numbers are like below, which is measured by Alex.
1. 355MB/s       ext4
2. 225MB/s       f2fs : WRITE for node writes
3. 525MB/s       f2fs : WRITE_SYNC for node writes

Reported-And-Tested-by: Alex <hbx7d@yandex.com>.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>