[PATCH 1/7] f2fs: avoid needless lock for node pages when fsyncing a file

From: Jaegeuk Kim
Date: Mon Apr 25 2016 - 20:08:48 EST


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

Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
---
fs/f2fs/node.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

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:
--
2.6.3