nvme: Make nvme_uninit_ctrl symmetric to nvme_init_ctrl

Put the ctrl reference count at nvme_uninit_ctrl as opposed to
nvme_init_ctrl which takes it. This decrease the reference count at the
core layer instead of decreasing it on each transport separately.
Also move the call of nvme_uninit_ctrl at PCI driver after calling to
nvme_release_prp_pools and nvme_dev_unmap, in order to put the reference
count after using the dev. This is safe because those functions use
nvme_dev which is freed only later at nvme_pci_free_ctrl.
Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>

drivers/nvme/host/core.c

@@ -171,7 +171,6 @@ static void nvme_do_delete_ctrl(struct nvme_ctrl *ctrl)
 	nvme_remove_namespaces(ctrl);
 	ctrl->ops->delete_ctrl(ctrl);
 	nvme_uninit_ctrl(ctrl);
-	nvme_put_ctrl(ctrl);
 }
 
 static void nvme_delete_ctrl_work(struct work_struct *work)
@@ -4048,6 +4047,7 @@ void nvme_uninit_ctrl(struct nvme_ctrl *ctrl)
 	nvme_fault_inject_fini(&ctrl->fault_inject);
 	dev_pm_qos_hide_latency_tolerance(ctrl->device);
 	cdev_device_del(&ctrl->cdev, ctrl->device);
+	nvme_put_ctrl(ctrl);
 }
 EXPORT_SYMBOL_GPL(nvme_uninit_ctrl);
 

drivers/nvme/host/fc.c

@@ -3206,7 +3206,6 @@ nvme_fc_init_ctrl(struct device *dev, struct nvmf_ctrl_options *opts,
 
 	/* initiate nvme ctrl ref counting teardown */
 	nvme_uninit_ctrl(&ctrl->ctrl);
-	nvme_put_ctrl(&ctrl->ctrl);
 
 	/* Remove core ctrl ref. */
 	nvme_put_ctrl(&ctrl->ctrl);

drivers/nvme/host/pci.c

@@ -2873,10 +2873,9 @@ static void nvme_remove(struct pci_dev *pdev)
 	nvme_free_host_mem(dev);
 	nvme_dev_remove_admin(dev);
 	nvme_free_queues(dev, 0);
-	nvme_uninit_ctrl(&dev->ctrl);
 	nvme_release_prp_pools(dev);
 	nvme_dev_unmap(dev);
-	nvme_put_ctrl(&dev->ctrl);
+	nvme_uninit_ctrl(&dev->ctrl);
 }
 
 #ifdef CONFIG_PM_SLEEP

drivers/nvme/host/rdma.c

@@ -2052,7 +2052,6 @@ static struct nvme_ctrl *nvme_rdma_create_ctrl(struct device *dev,
 out_uninit_ctrl:
 	nvme_uninit_ctrl(&ctrl->ctrl);
 	nvme_put_ctrl(&ctrl->ctrl);
-	nvme_put_ctrl(&ctrl->ctrl);
 	if (ret > 0)
 		ret = -EIO;
 	return ERR_PTR(ret);

drivers/nvme/host/tcp.c

@@ -2437,7 +2437,6 @@ static struct nvme_ctrl *nvme_tcp_create_ctrl(struct device *dev,
 out_uninit_ctrl:
 	nvme_uninit_ctrl(&ctrl->ctrl);
 	nvme_put_ctrl(&ctrl->ctrl);
-	nvme_put_ctrl(&ctrl->ctrl);
 	if (ret > 0)
 		ret = -EIO;
 	return ERR_PTR(ret);

drivers/nvme/target/loop.c

@@ -485,7 +485,6 @@ static void nvme_loop_reset_ctrl_work(struct work_struct *work)
 out_disable:
 	dev_warn(ctrl->ctrl.device, "Removing after reset failure\n");
 	nvme_uninit_ctrl(&ctrl->ctrl);
-	nvme_put_ctrl(&ctrl->ctrl);
 }
 
 static const struct nvme_ctrl_ops nvme_loop_ctrl_ops = {
@@ -635,7 +634,6 @@ static struct nvme_ctrl *nvme_loop_create_ctrl(struct device *dev,
 	kfree(ctrl->queues);
 out_uninit_ctrl:
 	nvme_uninit_ctrl(&ctrl->ctrl);
-	nvme_put_ctrl(&ctrl->ctrl);
 out_put_ctrl:
 	nvme_put_ctrl(&ctrl->ctrl);
 	if (ret > 0)