nvme-pci: Free tagset if no IO queues

If a controller becomes degraded after a reset, we will not be able to
perform any IO. We currently teardown previously created request
queues and namespaces, but we had kept the unusable tagset. Free
it after all queues using it have been released.

Tested-by: Edmund Nadolski <[email protected]>
Reviewed-by: James Smart <[email protected]>
Reviewed-by: Sagi Grimberg <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Keith Busch <[email protected]>

Author: keithbusch

drivers/nvme/host/pci.c

@@ -2490,14 +2490,20 @@ static void nvme_release_prp_pools(struct nvme_dev *dev)
 	dma_pool_destroy(dev->prp_small_pool);
 }
 
+static void nvme_free_tagset(struct nvme_dev *dev)
+{
+	if (dev->tagset.tags)
+		blk_mq_free_tag_set(&dev->tagset);
+	dev->ctrl.tagset = NULL;
+}
+
 static void nvme_pci_free_ctrl(struct nvme_ctrl *ctrl)
 {
 	struct nvme_dev *dev = to_nvme_dev(ctrl);
 
 	nvme_dbbuf_dma_free(dev);
 	put_device(dev->dev);
-	if (dev->tagset.tags)
-		blk_mq_free_tag_set(&dev->tagset);
+	nvme_free_tagset(dev);
 	if (dev->ctrl.admin_q)
 		blk_put_queue(dev->ctrl.admin_q);
 	kfree(dev->queues);
@@ -2616,6 +2622,7 @@ static void nvme_reset_work(struct work_struct *work)
 		nvme_kill_queues(&dev->ctrl);
 		nvme_remove_namespaces(&dev->ctrl);
 		new_state = NVME_CTRL_ADMIN_ONLY;
+		nvme_free_tagset(dev);
 	} else {
 		nvme_start_queues(&dev->ctrl);
 		nvme_wait_freeze(&dev->ctrl);