f2fs: keep dirty inodes selectively for checkpoint

This is to avoid no free segment bug during checkpoint caused by a number of
dirty inodes.

The case was reported by Chao like this.
1. mount with lazytime option
2. fill 4k file until disk is full
3. sync filesystem
4. read all files in the image
5. umount

In this case, we actually don't need to flush dirty inode to inode page during
checkpoint.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index 489fa0d..db33b56 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -778,7 +778,7 @@ static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	up_write(&F2FS_I(old_inode)->i_sem);
 
 	old_inode->i_ctime = current_time(old_inode);
-	f2fs_mark_inode_dirty_sync(old_inode);
+	f2fs_mark_inode_dirty_sync(old_inode, false);
 
 	f2fs_delete_entry(old_entry, old_page, old_dir, NULL);
 
@@ -938,7 +938,7 @@ static int f2fs_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
 		f2fs_i_links_write(old_dir, old_nlink > 0);
 		up_write(&F2FS_I(old_dir)->i_sem);
 	}
-	f2fs_mark_inode_dirty_sync(old_dir);
+	f2fs_mark_inode_dirty_sync(old_dir, false);
 
 	/* update directory entry info of new dir inode */
 	f2fs_set_link(new_dir, new_entry, new_page, old_inode);
@@ -953,7 +953,7 @@ static int f2fs_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
 		f2fs_i_links_write(new_dir, new_nlink > 0);
 		up_write(&F2FS_I(new_dir)->i_sem);
 	}
-	f2fs_mark_inode_dirty_sync(new_dir);
+	f2fs_mark_inode_dirty_sync(new_dir, false);
 
 	f2fs_unlock_op(sbi);