nvme-pci: Suspend queues after deleting them

The driver had been abusing the cq_vector state to know if new submissions
were safe, but that was before we could quiesce blk-mq. If the controller
happens to get an interrupt through while we're suspending those queues,
'no irq handler' warnings may occur.

This patch will disable the interrupts only after the queues are deleted.
Reported-by: Jianchao Wang <jianchao.w.wang@oracle.com>
Tested-by: Jianchao Wang <jianchao.w.wang@oracle.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/nvme/host/pci.c

@@ -1324,9 +1324,6 @@ static void nvme_disable_admin_queue(struct nvme_dev *dev, bool shutdown)
 {
 	struct nvme_queue *nvmeq = &dev->queues[0];
 
-	if (nvme_suspend_queue(nvmeq))
-		return;
-
 	if (shutdown)
 		nvme_shutdown_ctrl(&dev->ctrl);
 	else
@@ -2011,9 +2008,9 @@ static int nvme_delete_queue(struct nvme_queue *nvmeq, u8 opcode)
 	return 0;
 }
 
-static void nvme_disable_io_queues(struct nvme_dev *dev, int queues)
+static void nvme_disable_io_queues(struct nvme_dev *dev)
 {
-	int pass;
+	int pass, queues = dev->online_queues - 1;
 	unsigned long timeout;
 	u8 opcode = nvme_admin_delete_sq;
 
@@ -2164,7 +2161,7 @@ static void nvme_pci_disable(struct nvme_dev *dev)
 
 static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown)
 {
-	int i, queues;
+	int i;
 	bool dead = true;
 	struct pci_dev *pdev = to_pci_dev(dev->dev);
 
@@ -2199,21 +2196,13 @@ static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown)
 	}
 	nvme_stop_queues(&dev->ctrl);
 
-	queues = dev->online_queues - 1;
-	for (i = dev->ctrl.queue_count - 1; i > 0; i--)
-		nvme_suspend_queue(&dev->queues[i]);
-
-	if (dead) {
-		/* A device might become IO incapable very soon during
-		 * probe, before the admin queue is configured. Thus,
-		 * queue_count can be 0 here.
-		 */
-		if (dev->ctrl.queue_count)
-			nvme_suspend_queue(&dev->queues[0]);
-	} else {
-		nvme_disable_io_queues(dev, queues);
+	if (!dead) {
+		nvme_disable_io_queues(dev);
 		nvme_disable_admin_queue(dev, shutdown);
 	}
+	for (i = dev->ctrl.queue_count - 1; i >= 0; i--)
+		nvme_suspend_queue(&dev->queues[i]);
+
 	nvme_pci_disable(dev);
 
 	blk_mq_tagset_busy_iter(&dev->tagset, nvme_cancel_request, &dev->ctrl);