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

[Keith Busch]

On Wed, Jul 29, 2020 at 10:06:43AM +0800, Chao Leng wrote:
> 
> 
> 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.

Userspace owns error handling with ioctl passthrough commands. The
interface exists for unfiltered access to the device; the driver will
return status exactly as the device provided it. If userspace wants to
retry an error'ed passthrough, it is free to do so.