scsi: RDMA/srp: Use scsi_cmd_to_rq() instead of scsi_cmnd.request

Prepare for removal of the request pointer by using scsi_cmd_to_rq()
instead. This patch does not change any functionality.

Link: https://lore.kernel.org/r/20210809230355.8186-10-bvanassche@acm.org
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/infiniband/ulp/srp/ib_srp.c

@@ -1280,7 +1280,7 @@ static bool srp_terminate_cmd(struct scsi_cmnd *scmnd, void *context_ptr,
 {
 	struct srp_terminate_context *context = context_ptr;
 	struct srp_target_port *target = context->srp_target;
-	u32 tag = blk_mq_unique_tag(scmnd->request);
+	u32 tag = blk_mq_unique_tag(scsi_cmd_to_rq(scmnd));
 	struct srp_rdma_ch *ch = &target->ch[blk_mq_unique_tag_to_hwq(tag)];
 	struct srp_request *req = scsi_cmd_priv(scmnd);
 
@@ -2152,6 +2152,7 @@ static void srp_handle_qp_err(struct ib_cq *cq, struct ib_wc *wc,
 
 static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd)
 {
+	struct request *rq = scsi_cmd_to_rq(scmnd);
 	struct srp_target_port *target = host_to_target(shost);
 	struct srp_rdma_ch *ch;
 	struct srp_request *req = scsi_cmd_priv(scmnd);
@@ -2166,8 +2167,8 @@ static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd)
 	if (unlikely(scmnd->result))
 		goto err;
 
-	WARN_ON_ONCE(scmnd->request->tag < 0);
-	tag = blk_mq_unique_tag(scmnd->request);
+	WARN_ON_ONCE(rq->tag < 0);
+	tag = blk_mq_unique_tag(rq);
 	ch = &target->ch[blk_mq_unique_tag_to_hwq(tag)];
 
 	spin_lock_irqsave(&ch->lock, flags);
@@ -2791,7 +2792,7 @@ static int srp_abort(struct scsi_cmnd *scmnd)
 
 	if (!req)
 		return SUCCESS;
-	tag = blk_mq_unique_tag(scmnd->request);
+	tag = blk_mq_unique_tag(scsi_cmd_to_rq(scmnd));
 	ch_idx = blk_mq_unique_tag_to_hwq(tag);
 	if (WARN_ON_ONCE(ch_idx >= target->ch_count))
 		return SUCCESS;