uce: pagecache reading scenario support kernel recovery

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I44REB


CVE: NA

---------------------------

Support pagecache reading triggered by user-mode file access scenario
to kernel recovery.

At the same time, in this patch, we solved the problem of process D
state caused by waiting for PG_writeback in memory_failure() (the
background writeback thread timed out while writing back to the disk on
the page with hardware error). In this case, our processing method is
panic system to avoid the business interruption for a long time caused
by the business process in D state.

Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Signed-off-by: Chen Huang <chenhuang5@huawei.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>