[PATCH] nvme-core: introduce the preferential local retry mechanism

[Chao Leng]

On 2020/7/28 19:20, Christoph Hellwig wrote:
> If the callers asks for failfast, the caller will get failfast,
> period.
> 
If user issue cmd through ioctrl, nvme core will set cmd_flags:
REQ_FAILFAST_DRIVER, and then in some scenarios which need retry io
after a defined time, we will return io error, this is not what we
expected. So we need introduce the preferential local retry mechanism.