[PATCH 2/2] nvme: use driver pdu command for passthrough

[Keith Busch]

On Wed, Mar 17, 2021 at 03:16:59PM +0530, Kanchan Joshi wrote:
> On Tue, Mar 16, 2021 at 10:48 PM Keith Busch <kbusch at kernel.org> wrote:
> > @@ -595,7 +598,7 @@ static inline void nvme_init_request(struct request *req,
> >
> >         req->cmd_flags |= REQ_FAILFAST_DRIVER;
> >         nvme_clear_nvme_request(req);
> > -       nvme_req(req)->cmd = cmd;
> > +       memcpy(nvme_req(req)->cmd, cmd, sizeof(*cmd));
> >  }
> I am wondering if this memcpy() is fine. The "nvme_req(req)->cmd" is a
> pointer which may not have storage assigned to it?

The nvme drivers set it via blk_mq_op's .init_request(). This happens
before the request_queue is initialized, so the command pointer should
always be initialized before execution can reach this part of the code.