nvme: merge nvme_abort_req and nvme_timeout

BugLink: http://bugs.launchpad.net/bugs/1531539

We want to be able to return bettern error values frmo nvme_timeout, which
is significantly easier if the two functions are merged.  Also clean up and
reduce the printk spew so that we only get one message per abort.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
(cherry picked from commit 31c7c7d2)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

drivers/nvme/host/pci.c

@@ -1078,13 +1078,7 @@ static int adapter_delete_sq(struct nvme_dev *dev, u16 sqid)
 	return adapter_delete_queue(dev, nvme_admin_delete_sq, sqid);
 }
 
-/**
- * nvme_abort_req - Attempt aborting a request
- *
- * Schedule controller reset if the command was already aborted once before and
- * still hasn't been returned to the driver, or if this is the admin queue.
- */
-static void nvme_abort_req(struct request *req)
+static enum blk_eh_timer_return nvme_timeout(struct request *req, bool reserved)
 {
 	struct nvme_cmd_info *cmd_rq = blk_mq_rq_to_pdu(req);
 	struct nvme_queue *nvmeq = cmd_rq->nvmeq;
@@ -1093,6 +1087,11 @@ static void nvme_abort_req(struct request *req)
 	struct nvme_cmd_info *abort_cmd;
 	struct nvme_command cmd;
 
+	/*
+	 * Schedule controller reset if the command was already aborted once
+	 * before and still hasn't been returned to the driver, or if this is
+	 * the admin queue.
+	 */
 	if (!nvmeq->qid || cmd_rq->aborted) {
 		spin_lock_irq(&dev_list_lock);
 		if (!__nvme_reset(dev)) {
@@ -1101,16 +1100,16 @@ static void nvme_abort_req(struct request *req)
 				 req->tag, nvmeq->qid);
 		}
 		spin_unlock_irq(&dev_list_lock);
-		return;
+		return BLK_EH_RESET_TIMER;
 	}
 
 	if (!dev->ctrl.abort_limit)
-		return;
+		return BLK_EH_RESET_TIMER;
 
 	abort_req = blk_mq_alloc_request(dev->ctrl.admin_q, WRITE,
 			BLK_MQ_REQ_NOWAIT);
 	if (IS_ERR(abort_req))
-		return;
+		return BLK_EH_RESET_TIMER;
 
 	abort_cmd = blk_mq_rq_to_pdu(abort_req);
 	nvme_set_info(abort_cmd, abort_req, abort_completion);
@@ -1124,9 +1123,16 @@ static void nvme_abort_req(struct request *req)
 	--dev->ctrl.abort_limit;
 	cmd_rq->aborted = 1;
 
-	dev_warn(nvmeq->q_dmadev, "Aborting I/O %d QID %d\n", req->tag,
-							nvmeq->qid);
+	dev_warn(nvmeq->q_dmadev, "I/O %d QID %d timeout, aborting\n",
+				 req->tag, nvmeq->qid);
 	nvme_submit_cmd(dev->queues[0], &cmd);
+
+	/*
+	 * The aborted req will be completed on receiving the abort req.
+	 * We enable the timer again. If hit twice, it'll cause a device reset,
+	 * as the device then is in a faulty state.
+	 */
+	return BLK_EH_RESET_TIMER;
 }
 
 static void nvme_cancel_queue_ios(struct request *req, void *data, bool reserved)
@@ -1157,23 +1163,6 @@ static void nvme_cancel_queue_ios(struct request *req, void *data, bool reserved
 	fn(nvmeq, ctx, &cqe);
 }
 
-static enum blk_eh_timer_return nvme_timeout(struct request *req, bool reserved)
-{
-	struct nvme_cmd_info *cmd = blk_mq_rq_to_pdu(req);
-	struct nvme_queue *nvmeq = cmd->nvmeq;
-
-	dev_warn(nvmeq->q_dmadev, "Timeout I/O %d QID %d\n", req->tag,
-							nvmeq->qid);
-	nvme_abort_req(req);
-
-	/*
-	 * The aborted req will be completed on receiving the abort req.
-	 * We enable the timer again. If hit twice, it'll cause a device reset,
-	 * as the device then is in a faulty state.
-	 */
-	return BLK_EH_RESET_TIMER;
-}
-
 static void nvme_free_queue(struct nvme_queue *nvmeq)
 {
 	dma_free_coherent(nvmeq->q_dmadev, CQ_SIZE(nvmeq->q_depth),