nvme: submit internal commands through the block layer

[Christoph Hellwig]

On Tue, May 26, 2015 at 12:08:15PM +0300, Dan Carpenter wrote:
> drivers/block/nvme-core.c
>    853		 */
>    854		if (ns && ns->ms && !blk_integrity_rq(req)) {
>                     ^^
> Patch adds a new check.

Correctly so ..

>    912		nvme_set_info(cmd, iod, req_completion);
>    913		spin_lock_irq(&nvmeq->q_lock);
>    914		if (req->cmd_type == REQ_TYPE_DRV_PRIV)
>    915			nvme_submit_priv(nvmeq, req, iod);
>    916		else if (req->cmd_flags & REQ_DISCARD)
>    917			nvme_submit_discard(nvmeq, ns, req, iod);
>                                                    ^^
> Dereferenced inside function.
> 
>    918		else if (req->cmd_flags & REQ_FLUSH)
>    919			nvme_submit_flush(nvmeq, ns, req->tag);

We'll only get REQ_TYPE_DRV_PRIV requests through the passthrough
interface, so this is unrechable.