CVE-2021-47498

In the Linux kernel, the following vulnerability has been resolved: dm rq:
don’t queue request to blk-mq during DM suspend DM uses blk-mq’s
quiesce/unquiesce to stop/start device mapper queue. But blk-mq’s unquiesce
may come from outside events, such as elevator switch, updating nr_requests
or others, and request may come during suspend, so simply ask for blk-mq to
requeue it. Fixes one kernel panic issue when running updating nr_requests
and dm-mpath suspend/resume stress test.