[PATCH] NVMe: Fix obtaining command result

[Keith Busch]

On Sat, 23 May 2015, Christoph Hellwig wrote:
> On Fri, May 22, 2015 at 12:28:31PM -0600, Keith Busch wrote:
>> Replaces req->sense_len usage, which is not owned by the LLD, to
>> req->special to contain the command result for driver created commands,
>> and sets the result unconditionally on completion.
>
> Thanks Keith,
>
> sorry for the mess, after porting this from my series to use replace
> the BLOCK_PC specific fields to mainline I only tested this on Qemu
> which only has a single queue.  I'll make sure to always do final
> testing on real hardware as well.

No problem, it's a good enhancement overall and caught early enough,
so no a big deal. Break and fix cycles are better than doing nothing. :)

BTW, the qemu nvme block device *should* be multi-queue capable if you
allocate multiple CPUs (-smp <cpus>) to your guest. It works in my tree
at least, so I hope it works in qemu mainline. Maybe I'll have time this
week to look at that.