f2fs: try grabbing node page lock aggressively in sync scenario

In synchronous scenario, like in checkpoint(), we are going to flush
dirty node pages to device synchronously, we can easily failed
writebacking node page due to trylock_page() failure, especially in
condition of intensive lock competition, which can cause long latency
of checkpoint(). So let's use lock_page() in synchronous scenario to
avoid this issue.

Signed-off-by: Yunlei He <heyunlei@huawei.com>
Signed-off-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 6f21319d08d34d8fe0b20739eefb04dc689c6045..82664733f7702d1b4efbfc3266f97f6c78598827 100644 (file)
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1638,7 +1638,9 @@ next_step:
                                                !is_cold_node(page)))
                                continue;
 lock_node:
-                       if (!trylock_page(page))
+                       if (wbc->sync_mode == WB_SYNC_ALL)
+                               lock_page(page);
+                       else if (!trylock_page(page))
                                continue;
 
                        if (unlikely(page->mapping != NODE_MAPPING(sbi))) {