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Commit d22524a4 authored by Christoph Hellwig's avatar Christoph Hellwig
Browse files

nvme: switch controller refcounting to use struct device 



Instead of allocating a separate struct device for the character device
handle embedd it into struct nvme_ctrl and use it for the main controller
refcounting.  This removes double refcounting and gets us an automatic
reference for the character device operations.  We keep ctrl->device as a
pointer for now to avoid chaning printks all over, but in the future we
could look into message printing helpers that take a controller structure
similar to what other subsystems do.

Note the delete_ctrl operation always already has a reference (either
through sysfs due this change, or because every open file on the
/dev/nvme-fabrics node has a refernece) when it is entered now, so we
don't need to do the unless_zero variant there.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarHannes Reinecke <hare@suse.com>
parent c6424a90

drivers/nvme/host/core.c

+22 −21
Original line number Diff line number Diff line
@@ -1915,7 +1915,7 @@ static int nvme_dev_open(struct inode *inode, struct file *file) 
			ret = -EWOULDBLOCK;

			break;

		}

		if (!kref_get_unless_zero(&ctrl->kref))

		if (!kobject_get_unless_zero(&ctrl->device->kobj))

			break;

		file->private_data = ctrl;

		ret = 0;
@@ -2374,7 +2374,7 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid) 
	list_add_tail(&ns->list, &ctrl->namespaces);

	mutex_unlock(&ctrl->namespaces_mutex);



	kref_get(&ctrl->kref);

	nvme_get_ctrl(ctrl);



	kfree(id);
@@ -2703,7 +2703,7 @@ EXPORT_SYMBOL_GPL(nvme_start_ctrl); 


void nvme_uninit_ctrl(struct nvme_ctrl *ctrl)

{

	device_destroy(nvme_class, MKDEV(nvme_char_major, ctrl->instance));

	device_del(ctrl->device);



	spin_lock(&dev_list_lock);

	list_del(&ctrl->node);
@@ -2711,23 +2711,17 @@ void nvme_uninit_ctrl(struct nvme_ctrl *ctrl) 
}

EXPORT_SYMBOL_GPL(nvme_uninit_ctrl);



static void nvme_free_ctrl(struct kref *kref)

static void nvme_free_ctrl(struct device *dev)

{

	struct nvme_ctrl *ctrl = container_of(kref, struct nvme_ctrl, kref);

	struct nvme_ctrl *ctrl =

		container_of(dev, struct nvme_ctrl, ctrl_device);



	put_device(ctrl->device);

	ida_simple_remove(&nvme_instance_ida, ctrl->instance);

	ida_destroy(&ctrl->ns_ida);



	ctrl->ops->free_ctrl(ctrl);

}



void nvme_put_ctrl(struct nvme_ctrl *ctrl)

{

	kref_put(&ctrl->kref, nvme_free_ctrl);

}

EXPORT_SYMBOL_GPL(nvme_put_ctrl);



/*

 * Initialize a NVMe controller structures.  This needs to be called during

 * earliest initialization so that we have the initialized structured around
@@ -2742,7 +2736,6 @@ int nvme_init_ctrl(struct nvme_ctrl *ctrl, struct device *dev, 
	spin_lock_init(&ctrl->lock);

	INIT_LIST_HEAD(&ctrl->namespaces);

	mutex_init(&ctrl->namespaces_mutex);

	kref_init(&ctrl->kref);

	ctrl->dev = dev;

	ctrl->ops = ops;

	ctrl->quirks = quirks;
@@ -2755,15 +2748,21 @@ int nvme_init_ctrl(struct nvme_ctrl *ctrl, struct device *dev, 
		goto out;

	ctrl->instance = ret;



	ctrl->device = device_create_with_groups(nvme_class, ctrl->dev,

				MKDEV(nvme_char_major, ctrl->instance),

				ctrl, nvme_dev_attr_groups,

				"nvme%d", ctrl->instance);

	if (IS_ERR(ctrl->device)) {

		ret = PTR_ERR(ctrl->device);

	device_initialize(&ctrl->ctrl_device);

	ctrl->device = &ctrl->ctrl_device;

	ctrl->device->devt = MKDEV(nvme_char_major, ctrl->instance);

	ctrl->device->class = nvme_class;

	ctrl->device->parent = ctrl->dev;

	ctrl->device->groups = nvme_dev_attr_groups;

	ctrl->device->release = nvme_free_ctrl;

	dev_set_drvdata(ctrl->device, ctrl);

	ret = dev_set_name(ctrl->device, "nvme%d", ctrl->instance);

	if (ret)

		goto out_release_instance;

	}

	get_device(ctrl->device);

	ret = device_add(ctrl->device);

	if (ret)

		goto out_free_name;



	ida_init(&ctrl->ns_ida);



	spin_lock(&dev_list_lock);
@@ -2779,6 +2778,8 @@ int nvme_init_ctrl(struct nvme_ctrl *ctrl, struct device *dev, 
		min(default_ps_max_latency_us, (unsigned long)S32_MAX));



	return 0;

out_free_name:

	kfree_const(dev->kobj.name);

out_release_instance:

	ida_simple_remove(&nvme_instance_ida, ctrl->instance);

out:

drivers/nvme/host/fc.c

+2 −6
Original line number Diff line number Diff line
@@ -2692,14 +2692,10 @@ nvme_fc_del_nvme_ctrl(struct nvme_ctrl *nctrl) 
	struct nvme_fc_ctrl *ctrl = to_fc_ctrl(nctrl);

	int ret;



	if (!kref_get_unless_zero(&ctrl->ctrl.kref))

		return -EBUSY;



	nvme_get_ctrl(&ctrl->ctrl);

	ret = __nvme_fc_del_ctrl(ctrl);



	if (!ret)

		flush_workqueue(nvme_wq);



	nvme_put_ctrl(&ctrl->ctrl);



	return ret;
@@ -2918,7 +2914,7 @@ nvme_fc_init_ctrl(struct device *dev, struct nvmf_ctrl_options *opts, 
		return ERR_PTR(ret);

	}



	kref_get(&ctrl->ctrl.kref);

	nvme_get_ctrl(&ctrl->ctrl);



	dev_info(ctrl->ctrl.device,

		"NVME-FC{%d}: new ctrl: NQN \"%s\"\n",

drivers/nvme/host/nvme.h

+11 −1
Original line number Diff line number Diff line
@@ -127,12 +127,12 @@ struct nvme_ctrl { 
	struct request_queue *admin_q;

	struct request_queue *connect_q;

	struct device *dev;

	struct kref kref;

	int instance;

	struct blk_mq_tag_set *tagset;

	struct blk_mq_tag_set *admin_tagset;

	struct list_head namespaces;

	struct mutex namespaces_mutex;

	struct device ctrl_device;

	struct device *device;	/* char device */

	struct list_head node;

	struct ida ns_ida;
@@ -279,6 +279,16 @@ static inline void nvme_end_request(struct request *req, __le16 status, 
	blk_mq_complete_request(req);

}



static inline void nvme_get_ctrl(struct nvme_ctrl *ctrl)

{

	get_device(ctrl->device);

}



static inline void nvme_put_ctrl(struct nvme_ctrl *ctrl)

{

	put_device(ctrl->device);

}



void nvme_complete_rq(struct request *req);

void nvme_cancel_request(struct request *req, void *data, bool reserved);

bool nvme_change_ctrl_state(struct nvme_ctrl *ctrl,

drivers/nvme/host/pci.c

+1 −1
Original line number Diff line number Diff line
@@ -2292,7 +2292,7 @@ static void nvme_remove_dead_ctrl(struct nvme_dev *dev, int status) 
{

	dev_warn(dev->ctrl.device, "Removing after probe failure status: %d\n", status);



	kref_get(&dev->ctrl.kref);

	nvme_get_ctrl(&dev->ctrl);

	nvme_dev_disable(dev, false);

	if (!schedule_work(&dev->remove_work))

		nvme_put_ctrl(&dev->ctrl);

drivers/nvme/host/rdma.c

+2 −3
Original line number Diff line number Diff line
@@ -1793,8 +1793,7 @@ static int nvme_rdma_del_ctrl(struct nvme_ctrl *nctrl) 
	 * Keep a reference until all work is flushed since

	 * __nvme_rdma_del_ctrl can free the ctrl mem

	 */

	if (!kref_get_unless_zero(&ctrl->ctrl.kref))

		return -EBUSY;

	nvme_get_ctrl(&ctrl->ctrl);

	ret = __nvme_rdma_del_ctrl(ctrl);

	if (!ret)

		flush_work(&ctrl->delete_work);
@@ -1955,7 +1954,7 @@ static struct nvme_ctrl *nvme_rdma_create_ctrl(struct device *dev, 
	dev_info(ctrl->ctrl.device, "new ctrl: NQN \"%s\", addr %pISpcs\n",

		ctrl->ctrl.opts->subsysnqn, &ctrl->addr);



	kref_get(&ctrl->ctrl.kref);

	nvme_get_ctrl(&ctrl->ctrl);



	mutex_lock(&nvme_rdma_ctrl_mutex);

	list_add_tail(&ctrl->list, &nvme_rdma_ctrl_list);