!4019 mm/filemap: avoid buffered read/write race to read inconsistent data

Merge Pull Request from: @ci-robot 
 
PR sync from: Baokun Li <libaokun1@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/UI4IK5BXOOKYIVD74QR36OY27BRM5MWV/ 
 
https://gitee.com/src-openeuler/kernel/issues/I8RRAT 
 
Link:https://gitee.com/openeuler/kernel/pulls/4019

 

Reviewed-by: zhangyi (F) <yi.zhang@huawei.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com>