From: Jaegeuk Kim <jaegeuk@kernel.org>
Date: Wed, 13 Apr 2016 23:14:38 +0000 (-0700)
Subject: f2fs: avoid needless lock for node pages when fsyncing a file
X-Git-Tag: v4.7-rc1~84^2~58
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=eca76e783cf5970db36edfda7e66487d897ea222;p=platform%2Fkernel%2Flinux-exynos.git

f2fs: avoid needless lock for node pages when fsyncing a file

When fsync is called, sync_node_pages finds a proper direct node pages to flush.
But, it locks unrelated direct node pages together unnecessarily.

Acked-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---

diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 095fc2c..cccee50 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1272,10 +1272,14 @@ next_step:
 			 * we should not skip writing node pages.
 			 */
 lock_node:
-			if (ino && ino_of_node(page) == ino)
-				lock_page(page);
-			else if (!trylock_page(page))
+			if (ino) {
+				if (ino_of_node(page) == ino)
+					lock_page(page);
+				else
+					continue;
+			} else if (!trylock_page(page)) {
 				continue;
+			}
 
 			if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
 continue_unlock: