Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 688 insertions, 0 deletions

diff --git a/drivers/nvme/target/loop.c b/drivers/nvme/target/loop.c
new file mode 100644
index 000000000..48d5df054
--- /dev/null
+++ b/drivers/nvme/target/loop.c
@@ -0,0 +1,688 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * NVMe over Fabrics loopback device.
+ * Copyright (c) 2015-2016 HGST, a Western Digital Company.
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/scatterlist.h>
+#include <linux/blk-mq.h>
+#include <linux/nvme.h>
+#include <linux/module.h>
+#include <linux/parser.h>
+#include "nvmet.h"
+#include "../host/nvme.h"
+#include "../host/fabrics.h"
+
+#define NVME_LOOP_MAX_SEGMENTS		256
+
+struct nvme_loop_iod {
+	struct nvme_request	nvme_req;
+	struct nvme_command	cmd;
+	struct nvme_completion	cqe;
+	struct nvmet_req	req;
+	struct nvme_loop_queue	*queue;
+	struct work_struct	work;
+	struct sg_table		sg_table;
+	struct scatterlist	first_sgl[];
+};
+
+struct nvme_loop_ctrl {
+	struct nvme_loop_queue	*queues;
+
+	struct blk_mq_tag_set	admin_tag_set;
+
+	struct list_head	list;
+	struct blk_mq_tag_set	tag_set;
+	struct nvme_loop_iod	async_event_iod;
+	struct nvme_ctrl	ctrl;
+
+	struct nvmet_port	*port;
+};
+
+static inline struct nvme_loop_ctrl *to_loop_ctrl(struct nvme_ctrl *ctrl)
+{
+	return container_of(ctrl, struct nvme_loop_ctrl, ctrl);
+}
+
+enum nvme_loop_queue_flags {
+	NVME_LOOP_Q_LIVE	= 0,
+};
+
+struct nvme_loop_queue {
+	struct nvmet_cq		nvme_cq;
+	struct nvmet_sq		nvme_sq;
+	struct nvme_loop_ctrl	*ctrl;
+	unsigned long		flags;
+};
+
+static LIST_HEAD(nvme_loop_ports);
+static DEFINE_MUTEX(nvme_loop_ports_mutex);
+
+static LIST_HEAD(nvme_loop_ctrl_list);
+static DEFINE_MUTEX(nvme_loop_ctrl_mutex);
+
+static void nvme_loop_queue_response(struct nvmet_req *nvme_req);
+static void nvme_loop_delete_ctrl(struct nvmet_ctrl *ctrl);
+
+static const struct nvmet_fabrics_ops nvme_loop_ops;
+
+static inline int nvme_loop_queue_idx(struct nvme_loop_queue *queue)
+{
+	return queue - queue->ctrl->queues;
+}
+
+static void nvme_loop_complete_rq(struct request *req)
+{
+	struct nvme_loop_iod *iod = blk_mq_rq_to_pdu(req);
+
+	sg_free_table_chained(&iod->sg_table, NVME_INLINE_SG_CNT);
+	nvme_complete_rq(req);
+}
+
+static struct blk_mq_tags *nvme_loop_tagset(struct nvme_loop_queue *queue)
+{
+	u32 queue_idx = nvme_loop_queue_idx(queue);
+
+	if (queue_idx == 0)
+		return queue->ctrl->admin_tag_set.tags[queue_idx];
+	return queue->ctrl->tag_set.tags[queue_idx - 1];
+}
+
+static void nvme_loop_queue_response(struct nvmet_req *req)
+{
+	struct nvme_loop_queue *queue =
+		container_of(req->sq, struct nvme_loop_queue, nvme_sq);
+	struct nvme_completion *cqe = req->cqe;
+
+	/*
+	 * AEN requests are special as they don't time out and can
+	 * survive any kind of queue freeze and often don't respond to
+	 * aborts.  We don't even bother to allocate a struct request
+	 * for them but rather special case them here.
+	 */
+	if (unlikely(nvme_is_aen_req(nvme_loop_queue_idx(queue),
+				     cqe->command_id))) {
+		nvme_complete_async_event(&queue->ctrl->ctrl, cqe->status,
+				&cqe->result);
+	} else {
+		struct request *rq;
+
+		rq = nvme_find_rq(nvme_loop_tagset(queue), cqe->command_id);
+		if (!rq) {
+			dev_err(queue->ctrl->ctrl.device,
+				"got bad command_id %#x on queue %d\n",
+				cqe->command_id, nvme_loop_queue_idx(queue));
+			return;
+		}
+
+		if (!nvme_try_complete_req(rq, cqe->status, cqe->result))
+			nvme_loop_complete_rq(rq);
+	}
+}
+
+static void nvme_loop_execute_work(struct work_struct *work)
+{
+	struct nvme_loop_iod *iod =
+		container_of(work, struct nvme_loop_iod, work);
+
+	iod->req.execute(&iod->req);
+}
+
+static blk_status_t nvme_loop_queue_rq(struct blk_mq_hw_ctx *hctx,
+		const struct blk_mq_queue_data *bd)
+{
+	struct nvme_ns *ns = hctx->queue->queuedata;
+	struct nvme_loop_queue *queue = hctx->driver_data;
+	struct request *req = bd->rq;
+	struct nvme_loop_iod *iod = blk_mq_rq_to_pdu(req);
+	bool queue_ready = test_bit(NVME_LOOP_Q_LIVE, &queue->flags);
+	blk_status_t ret;
+
+	if (!nvme_check_ready(&queue->ctrl->ctrl, req, queue_ready))
+		return nvme_fail_nonready_command(&queue->ctrl->ctrl, req);
+
+	ret = nvme_setup_cmd(ns, req);
+	if (ret)
+		return ret;
+
+	nvme_start_request(req);
+	iod->cmd.common.flags |= NVME_CMD_SGL_METABUF;
+	iod->req.port = queue->ctrl->port;
+	if (!nvmet_req_init(&iod->req, &queue->nvme_cq,
+			&queue->nvme_sq, &nvme_loop_ops))
+		return BLK_STS_OK;
+
+	if (blk_rq_nr_phys_segments(req)) {
+		iod->sg_table.sgl = iod->first_sgl;
+		if (sg_alloc_table_chained(&iod->sg_table,
+				blk_rq_nr_phys_segments(req),
+				iod->sg_table.sgl, NVME_INLINE_SG_CNT)) {
+			nvme_cleanup_cmd(req);
+			return BLK_STS_RESOURCE;
+		}
+
+		iod->req.sg = iod->sg_table.sgl;
+		iod->req.sg_cnt = blk_rq_map_sg(req->q, req, iod->sg_table.sgl);
+		iod->req.transfer_len = blk_rq_payload_bytes(req);
+	}
+
+	queue_work(nvmet_wq, &iod->work);
+	return BLK_STS_OK;
+}
+
+static void nvme_loop_submit_async_event(struct nvme_ctrl *arg)
+{
+	struct nvme_loop_ctrl *ctrl = to_loop_ctrl(arg);
+	struct nvme_loop_queue *queue = &ctrl->queues[0];
+	struct nvme_loop_iod *iod = &ctrl->async_event_iod;
+
+	memset(&iod->cmd, 0, sizeof(iod->cmd));
+	iod->cmd.common.opcode = nvme_admin_async_event;
+	iod->cmd.common.command_id = NVME_AQ_BLK_MQ_DEPTH;
+	iod->cmd.common.flags |= NVME_CMD_SGL_METABUF;
+
+	if (!nvmet_req_init(&iod->req, &queue->nvme_cq, &queue->nvme_sq,
+			&nvme_loop_ops)) {
+		dev_err(ctrl->ctrl.device, "failed async event work\n");
+		return;
+	}
+
+	queue_work(nvmet_wq, &iod->work);
+}
+
+static int nvme_loop_init_iod(struct nvme_loop_ctrl *ctrl,
+		struct nvme_loop_iod *iod, unsigned int queue_idx)
+{
+	iod->req.cmd = &iod->cmd;
+	iod->req.cqe = &iod->cqe;
+	iod->queue = &ctrl->queues[queue_idx];
+	INIT_WORK(&iod->work, nvme_loop_execute_work);
+	return 0;
+}
+
+static int nvme_loop_init_request(struct blk_mq_tag_set *set,
+		struct request *req, unsigned int hctx_idx,
+		unsigned int numa_node)
+{
+	struct nvme_loop_ctrl *ctrl = to_loop_ctrl(set->driver_data);
+	struct nvme_loop_iod *iod = blk_mq_rq_to_pdu(req);
+
+	nvme_req(req)->ctrl = &ctrl->ctrl;
+	nvme_req(req)->cmd = &iod->cmd;
+	return nvme_loop_init_iod(ctrl, blk_mq_rq_to_pdu(req),
+			(set == &ctrl->tag_set) ? hctx_idx + 1 : 0);
+}
+
+static struct lock_class_key loop_hctx_fq_lock_key;
+
+static int nvme_loop_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
+		unsigned int hctx_idx)
+{
+	struct nvme_loop_ctrl *ctrl = to_loop_ctrl(data);
+	struct nvme_loop_queue *queue = &ctrl->queues[hctx_idx + 1];
+
+	BUG_ON(hctx_idx >= ctrl->ctrl.queue_count);
+
+	/*
+	 * flush_end_io() can be called recursively for us, so use our own
+	 * lock class key for avoiding lockdep possible recursive locking,
+	 * then we can remove the dynamically allocated lock class for each
+	 * flush queue, that way may cause horrible boot delay.
+	 */
+	blk_mq_hctx_set_fq_lock_class(hctx, &loop_hctx_fq_lock_key);
+
+	hctx->driver_data = queue;
+	return 0;
+}
+
+static int nvme_loop_init_admin_hctx(struct blk_mq_hw_ctx *hctx, void *data,
+		unsigned int hctx_idx)
+{
+	struct nvme_loop_ctrl *ctrl = to_loop_ctrl(data);
+	struct nvme_loop_queue *queue = &ctrl->queues[0];
+
+	BUG_ON(hctx_idx != 0);
+
+	hctx->driver_data = queue;
+	return 0;
+}
+
+static const struct blk_mq_ops nvme_loop_mq_ops = {
+	.queue_rq	= nvme_loop_queue_rq,
+	.complete	= nvme_loop_complete_rq,
+	.init_request	= nvme_loop_init_request,
+	.init_hctx	= nvme_loop_init_hctx,
+};
+
+static const struct blk_mq_ops nvme_loop_admin_mq_ops = {
+	.queue_rq	= nvme_loop_queue_rq,
+	.complete	= nvme_loop_complete_rq,
+	.init_request	= nvme_loop_init_request,
+	.init_hctx	= nvme_loop_init_admin_hctx,
+};
+
+static void nvme_loop_destroy_admin_queue(struct nvme_loop_ctrl *ctrl)
+{
+	if (!test_and_clear_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[0].flags))
+		return;
+	nvmet_sq_destroy(&ctrl->queues[0].nvme_sq);
+	nvme_remove_admin_tag_set(&ctrl->ctrl);
+}
+
+static void nvme_loop_free_ctrl(struct nvme_ctrl *nctrl)
+{
+	struct nvme_loop_ctrl *ctrl = to_loop_ctrl(nctrl);
+
+	if (list_empty(&ctrl->list))
+		goto free_ctrl;
+
+	mutex_lock(&nvme_loop_ctrl_mutex);
+	list_del(&ctrl->list);
+	mutex_unlock(&nvme_loop_ctrl_mutex);
+
+	if (nctrl->tagset)
+		nvme_remove_io_tag_set(nctrl);
+	kfree(ctrl->queues);
+	nvmf_free_options(nctrl->opts);
+free_ctrl:
+	kfree(ctrl);
+}
+
+static void nvme_loop_destroy_io_queues(struct nvme_loop_ctrl *ctrl)
+{
+	int i;
+
+	for (i = 1; i < ctrl->ctrl.queue_count; i++) {
+		clear_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[i].flags);
+		nvmet_sq_destroy(&ctrl->queues[i].nvme_sq);
+	}
+	ctrl->ctrl.queue_count = 1;
+}
+
+static int nvme_loop_init_io_queues(struct nvme_loop_ctrl *ctrl)
+{
+	struct nvmf_ctrl_options *opts = ctrl->ctrl.opts;
+	unsigned int nr_io_queues;
+	int ret, i;
+
+	nr_io_queues = min(opts->nr_io_queues, num_online_cpus());
+	ret = nvme_set_queue_count(&ctrl->ctrl, &nr_io_queues);
+	if (ret || !nr_io_queues)
+		return ret;
+
+	dev_info(ctrl->ctrl.device, "creating %d I/O queues.\n", nr_io_queues);
+
+	for (i = 1; i <= nr_io_queues; i++) {
+		ctrl->queues[i].ctrl = ctrl;
+		ret = nvmet_sq_init(&ctrl->queues[i].nvme_sq);
+		if (ret)
+			goto out_destroy_queues;
+
+		ctrl->ctrl.queue_count++;
+	}
+
+	return 0;
+
+out_destroy_queues:
+	nvme_loop_destroy_io_queues(ctrl);
+	return ret;
+}
+
+static int nvme_loop_connect_io_queues(struct nvme_loop_ctrl *ctrl)
+{
+	int i, ret;
+
+	for (i = 1; i < ctrl->ctrl.queue_count; i++) {
+		ret = nvmf_connect_io_queue(&ctrl->ctrl, i);
+		if (ret)
+			return ret;
+		set_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[i].flags);
+	}
+
+	return 0;
+}
+
+static int nvme_loop_configure_admin_queue(struct nvme_loop_ctrl *ctrl)
+{
+	int error;
+
+	ctrl->queues[0].ctrl = ctrl;
+	error = nvmet_sq_init(&ctrl->queues[0].nvme_sq);
+	if (error)
+		return error;
+	ctrl->ctrl.queue_count = 1;
+
+	error = nvme_alloc_admin_tag_set(&ctrl->ctrl, &ctrl->admin_tag_set,
+			&nvme_loop_admin_mq_ops,
+			sizeof(struct nvme_loop_iod) +
+			NVME_INLINE_SG_CNT * sizeof(struct scatterlist));
+	if (error)
+		goto out_free_sq;
+
+	/* reset stopped state for the fresh admin queue */
+	clear_bit(NVME_CTRL_ADMIN_Q_STOPPED, &ctrl->ctrl.flags);
+
+	error = nvmf_connect_admin_queue(&ctrl->ctrl);
+	if (error)
+		goto out_cleanup_tagset;
+
+	set_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[0].flags);
+
+	error = nvme_enable_ctrl(&ctrl->ctrl);
+	if (error)
+		goto out_cleanup_tagset;
+
+	ctrl->ctrl.max_hw_sectors =
+		(NVME_LOOP_MAX_SEGMENTS - 1) << PAGE_SECTORS_SHIFT;
+
+	nvme_unquiesce_admin_queue(&ctrl->ctrl);
+
+	error = nvme_init_ctrl_finish(&ctrl->ctrl, false);
+	if (error)
+		goto out_cleanup_tagset;
+
+	return 0;
+
+out_cleanup_tagset:
+	clear_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[0].flags);
+	nvme_remove_admin_tag_set(&ctrl->ctrl);
+out_free_sq:
+	nvmet_sq_destroy(&ctrl->queues[0].nvme_sq);
+	return error;
+}
+
+static void nvme_loop_shutdown_ctrl(struct nvme_loop_ctrl *ctrl)
+{
+	if (ctrl->ctrl.queue_count > 1) {
+		nvme_quiesce_io_queues(&ctrl->ctrl);
+		nvme_cancel_tagset(&ctrl->ctrl);
+		nvme_loop_destroy_io_queues(ctrl);
+	}
+
+	nvme_quiesce_admin_queue(&ctrl->ctrl);
+	if (ctrl->ctrl.state == NVME_CTRL_LIVE)
+		nvme_disable_ctrl(&ctrl->ctrl, true);
+
+	nvme_cancel_admin_tagset(&ctrl->ctrl);
+	nvme_loop_destroy_admin_queue(ctrl);
+}
+
+static void nvme_loop_delete_ctrl_host(struct nvme_ctrl *ctrl)
+{
+	nvme_loop_shutdown_ctrl(to_loop_ctrl(ctrl));
+}
+
+static void nvme_loop_delete_ctrl(struct nvmet_ctrl *nctrl)
+{
+	struct nvme_loop_ctrl *ctrl;
+
+	mutex_lock(&nvme_loop_ctrl_mutex);
+	list_for_each_entry(ctrl, &nvme_loop_ctrl_list, list) {
+		if (ctrl->ctrl.cntlid == nctrl->cntlid)
+			nvme_delete_ctrl(&ctrl->ctrl);
+	}
+	mutex_unlock(&nvme_loop_ctrl_mutex);
+}
+
+static void nvme_loop_reset_ctrl_work(struct work_struct *work)
+{
+	struct nvme_loop_ctrl *ctrl =
+		container_of(work, struct nvme_loop_ctrl, ctrl.reset_work);
+	int ret;
+
+	nvme_stop_ctrl(&ctrl->ctrl);
+	nvme_loop_shutdown_ctrl(ctrl);
+
+	if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_CONNECTING)) {
+		if (ctrl->ctrl.state != NVME_CTRL_DELETING &&
+		    ctrl->ctrl.state != NVME_CTRL_DELETING_NOIO)
+			/* state change failure for non-deleted ctrl? */
+			WARN_ON_ONCE(1);
+		return;
+	}
+
+	ret = nvme_loop_configure_admin_queue(ctrl);
+	if (ret)
+		goto out_disable;
+
+	ret = nvme_loop_init_io_queues(ctrl);
+	if (ret)
+		goto out_destroy_admin;
+
+	ret = nvme_loop_connect_io_queues(ctrl);
+	if (ret)
+		goto out_destroy_io;
+
+	blk_mq_update_nr_hw_queues(&ctrl->tag_set,
+			ctrl->ctrl.queue_count - 1);
+
+	if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE))
+		WARN_ON_ONCE(1);
+
+	nvme_start_ctrl(&ctrl->ctrl);
+
+	return;
+
+out_destroy_io:
+	nvme_loop_destroy_io_queues(ctrl);
+out_destroy_admin:
+	nvme_loop_destroy_admin_queue(ctrl);
+out_disable:
+	dev_warn(ctrl->ctrl.device, "Removing after reset failure\n");
+	nvme_uninit_ctrl(&ctrl->ctrl);
+}
+
+static const struct nvme_ctrl_ops nvme_loop_ctrl_ops = {
+	.name			= "loop",
+	.module			= THIS_MODULE,
+	.flags			= NVME_F_FABRICS,
+	.reg_read32		= nvmf_reg_read32,
+	.reg_read64		= nvmf_reg_read64,
+	.reg_write32		= nvmf_reg_write32,
+	.free_ctrl		= nvme_loop_free_ctrl,
+	.submit_async_event	= nvme_loop_submit_async_event,
+	.delete_ctrl		= nvme_loop_delete_ctrl_host,
+	.get_address		= nvmf_get_address,
+};
+
+static int nvme_loop_create_io_queues(struct nvme_loop_ctrl *ctrl)
+{
+	int ret;
+
+	ret = nvme_loop_init_io_queues(ctrl);
+	if (ret)
+		return ret;
+
+	ret = nvme_alloc_io_tag_set(&ctrl->ctrl, &ctrl->tag_set,
+			&nvme_loop_mq_ops, 1,
+			sizeof(struct nvme_loop_iod) +
+			NVME_INLINE_SG_CNT * sizeof(struct scatterlist));
+	if (ret)
+		goto out_destroy_queues;
+
+	ret = nvme_loop_connect_io_queues(ctrl);
+	if (ret)
+		goto out_cleanup_tagset;
+
+	return 0;
+
+out_cleanup_tagset:
+	nvme_remove_io_tag_set(&ctrl->ctrl);
+out_destroy_queues:
+	nvme_loop_destroy_io_queues(ctrl);
+	return ret;
+}
+
+static struct nvmet_port *nvme_loop_find_port(struct nvme_ctrl *ctrl)
+{
+	struct nvmet_port *p, *found = NULL;
+
+	mutex_lock(&nvme_loop_ports_mutex);
+	list_for_each_entry(p, &nvme_loop_ports, entry) {
+		/* if no transport address is specified use the first port */
+		if ((ctrl->opts->mask & NVMF_OPT_TRADDR) &&
+		    strcmp(ctrl->opts->traddr, p->disc_addr.traddr))
+			continue;
+		found = p;
+		break;
+	}
+	mutex_unlock(&nvme_loop_ports_mutex);
+	return found;
+}
+
+static struct nvme_ctrl *nvme_loop_create_ctrl(struct device *dev,
+		struct nvmf_ctrl_options *opts)
+{
+	struct nvme_loop_ctrl *ctrl;
+	int ret;
+
+	ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
+	if (!ctrl)
+		return ERR_PTR(-ENOMEM);
+	ctrl->ctrl.opts = opts;
+	INIT_LIST_HEAD(&ctrl->list);
+
+	INIT_WORK(&ctrl->ctrl.reset_work, nvme_loop_reset_ctrl_work);
+
+	ret = nvme_init_ctrl(&ctrl->ctrl, dev, &nvme_loop_ctrl_ops,
+				0 /* no quirks, we're perfect! */);
+	if (ret) {
+		kfree(ctrl);
+		goto out;
+	}
+
+	if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_CONNECTING))
+		WARN_ON_ONCE(1);
+
+	ret = -ENOMEM;
+
+	ctrl->ctrl.kato = opts->kato;
+	ctrl->port = nvme_loop_find_port(&ctrl->ctrl);
+
+	ctrl->queues = kcalloc(opts->nr_io_queues + 1, sizeof(*ctrl->queues),
+			GFP_KERNEL);
+	if (!ctrl->queues)
+		goto out_uninit_ctrl;
+
+	ret = nvme_loop_configure_admin_queue(ctrl);
+	if (ret)
+		goto out_free_queues;
+
+	if (opts->queue_size > ctrl->ctrl.maxcmd) {
+		/* warn if maxcmd is lower than queue_size */
+		dev_warn(ctrl->ctrl.device,
+			"queue_size %zu > ctrl maxcmd %u, clamping down\n",
+			opts->queue_size, ctrl->ctrl.maxcmd);
+		opts->queue_size = ctrl->ctrl.maxcmd;
+	}
+	ctrl->ctrl.sqsize = opts->queue_size - 1;
+
+	if (opts->nr_io_queues) {
+		ret = nvme_loop_create_io_queues(ctrl);
+		if (ret)
+			goto out_remove_admin_queue;
+	}
+
+	nvme_loop_init_iod(ctrl, &ctrl->async_event_iod, 0);
+
+	dev_info(ctrl->ctrl.device,
+		 "new ctrl: \"%s\"\n", ctrl->ctrl.opts->subsysnqn);
+
+	if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE))
+		WARN_ON_ONCE(1);
+
+	mutex_lock(&nvme_loop_ctrl_mutex);
+	list_add_tail(&ctrl->list, &nvme_loop_ctrl_list);
+	mutex_unlock(&nvme_loop_ctrl_mutex);
+
+	nvme_start_ctrl(&ctrl->ctrl);
+
+	return &ctrl->ctrl;
+
+out_remove_admin_queue:
+	nvme_loop_destroy_admin_queue(ctrl);
+out_free_queues:
+	kfree(ctrl->queues);
+out_uninit_ctrl:
+	nvme_uninit_ctrl(&ctrl->ctrl);
+	nvme_put_ctrl(&ctrl->ctrl);
+out:
+	if (ret > 0)
+		ret = -EIO;
+	return ERR_PTR(ret);
+}
+
+static int nvme_loop_add_port(struct nvmet_port *port)
+{
+	mutex_lock(&nvme_loop_ports_mutex);
+	list_add_tail(&port->entry, &nvme_loop_ports);
+	mutex_unlock(&nvme_loop_ports_mutex);
+	return 0;
+}
+
+static void nvme_loop_remove_port(struct nvmet_port *port)
+{
+	mutex_lock(&nvme_loop_ports_mutex);
+	list_del_init(&port->entry);
+	mutex_unlock(&nvme_loop_ports_mutex);
+
+	/*
+	 * Ensure any ctrls that are in the process of being
+	 * deleted are in fact deleted before we return
+	 * and free the port. This is to prevent active
+	 * ctrls from using a port after it's freed.
+	 */
+	flush_workqueue(nvme_delete_wq);
+}
+
+static const struct nvmet_fabrics_ops nvme_loop_ops = {
+	.owner		= THIS_MODULE,
+	.type		= NVMF_TRTYPE_LOOP,
+	.add_port	= nvme_loop_add_port,
+	.remove_port	= nvme_loop_remove_port,
+	.queue_response = nvme_loop_queue_response,
+	.delete_ctrl	= nvme_loop_delete_ctrl,
+};
+
+static struct nvmf_transport_ops nvme_loop_transport = {
+	.name		= "loop",
+	.module		= THIS_MODULE,
+	.create_ctrl	= nvme_loop_create_ctrl,
+	.allowed_opts	= NVMF_OPT_TRADDR,
+};
+
+static int __init nvme_loop_init_module(void)
+{
+	int ret;
+
+	ret = nvmet_register_transport(&nvme_loop_ops);
+	if (ret)
+		return ret;
+
+	ret = nvmf_register_transport(&nvme_loop_transport);
+	if (ret)
+		nvmet_unregister_transport(&nvme_loop_ops);
+
+	return ret;
+}
+
+static void __exit nvme_loop_cleanup_module(void)
+{
+	struct nvme_loop_ctrl *ctrl, *next;
+
+	nvmf_unregister_transport(&nvme_loop_transport);
+	nvmet_unregister_transport(&nvme_loop_ops);
+
+	mutex_lock(&nvme_loop_ctrl_mutex);
+	list_for_each_entry_safe(ctrl, next, &nvme_loop_ctrl_list, list)
+		nvme_delete_ctrl(&ctrl->ctrl);
+	mutex_unlock(&nvme_loop_ctrl_mutex);
+
+	flush_workqueue(nvme_delete_wq);
+}
+
+module_init(nvme_loop_init_module);
+module_exit(nvme_loop_cleanup_module);
+
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("nvmet-transport-254"); /* 254 == NVMF_TRTYPE_LOOP */