!4369 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/4A7AT3IUGL7457RSHJRTGRIINJGDPVWR/ 
 
https://gitee.com/src-openeuler/kernel/issues/I8RRAT 
 
Link:https://gitee.com/openeuler/kernel/pulls/4369

 

Reviewed-by: Liu YongQiang <liuyongqiang13@huawei.com>
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>