NVMe: Remove device management handles on remove

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

We don't want to allow new references to open on a device that is
removed. This ties the lifetime of these handles to the physical device's
presence rather than to the open reference count.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
(cherry picked from commit 53029b04)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

drivers/nvme/host/core.c

@@ -1200,17 +1200,22 @@ static void nvme_release_instance(struct nvme_ctrl *ctrl)
 	spin_unlock(&dev_list_lock);
 }
 
-static void nvme_free_ctrl(struct kref *kref)
-{
-	struct nvme_ctrl *ctrl = container_of(kref, struct nvme_ctrl, kref);
+void nvme_uninit_ctrl(struct nvme_ctrl *ctrl)
+ {
+	device_remove_file(ctrl->device, &dev_attr_reset_controller);
+	device_destroy(nvme_class, MKDEV(nvme_char_major, ctrl->instance));
 
 	spin_lock(&dev_list_lock);
 	list_del(&ctrl->node);
 	spin_unlock(&dev_list_lock);
+}
+
+static void nvme_free_ctrl(struct kref *kref)
+{
+	struct nvme_ctrl *ctrl = container_of(kref, struct nvme_ctrl, kref);
 
 	put_device(ctrl->device);
 	nvme_release_instance(ctrl);
-	device_destroy(nvme_class, MKDEV(nvme_char_major, ctrl->instance));
 
 	ctrl->ops->free_ctrl(ctrl);
 }

drivers/nvme/host/nvme.h

@@ -221,6 +221,7 @@ int nvme_enable_ctrl(struct nvme_ctrl *ctrl, u64 cap);
 int nvme_shutdown_ctrl(struct nvme_ctrl *ctrl);
 int nvme_init_ctrl(struct nvme_ctrl *ctrl, struct device *dev,
 		const struct nvme_ctrl_ops *ops, unsigned long quirks);
+void nvme_uninit_ctrl(struct nvme_ctrl *ctrl);
 void nvme_put_ctrl(struct nvme_ctrl *ctrl);
 int nvme_init_identify(struct nvme_ctrl *ctrl);
 

drivers/nvme/host/pci.c

@@ -2385,6 +2385,7 @@ static void nvme_remove(struct pci_dev *pdev)
 	flush_work(&dev->reset_work);
 	flush_work(&dev->scan_work);
 	nvme_remove_namespaces(&dev->ctrl);
+	nvme_uninit_ctrl(&dev->ctrl);
 	nvme_dev_shutdown(dev);
 	nvme_dev_remove_admin(dev);
 	nvme_free_queues(dev, 0);