[PATCH, RFC] nvme: Do not test the read-ahead flag in cmd_flags

[Christoph Hellwig]

On Wed, Sep 14, 2016 at 08:43:48AM -0600, Jens Axboe wrote:
>> It's indeed a bug, but the questions is if why we shouldn't pass
>> REQ_RAHEAD down to the request layer.  It's a useful attribute,
>> and NVMe devices could make use of it.
>
> Indeed, seems a shame to lose this hint.

It currently doesn't work.  But it would be useful to actually pass
it through.  That being said we currently have a complete mess with
the common vs request only flags, both about their placement in the
enum and inclusion in the common mask.  Making it worse it seems
like REQ_NOMERGE actually is used in both currently and not actually
expecting propagation.