f2fs: cache more dentry pages

While traversing dir entries in dentry page, it's better to refresh current
accessed page in lru list by using FGP_ACCESSED flag, otherwise, such page
may has less chance to survive during memory reclaim, result in causing
additional IO when revisiting dentry page.

Signed-off-by: zangyangyang1 <[email protected]>
Reviewed-by: Chao Yu <[email protected]>
Signed-off-by: Jaegeuk Kim <[email protected]>

Author: zangyangyang666

fs/f2fs/data.c

@@ -1280,7 +1280,7 @@ struct page *f2fs_find_data_page(struct inode *inode, pgoff_t index,
 	struct address_space *mapping = inode->i_mapping;
 	struct page *page;
 
-	page = find_get_page(mapping, index);
+	page = find_get_page_flags(mapping, index, FGP_ACCESSED);
 	if (page && PageUptodate(page))
 		return page;
 	f2fs_put_page(page, 0);