1// SPDX-License-Identifier: GPL-2.0
2/*
3 * NVMe over Fabrics loopback device.
4 * Copyright (c) 2015-2016 HGST, a Western Digital Company.
5 */
6#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7#include <linux/scatterlist.h>
8#include <linux/blk-mq.h>
9#include <linux/nvme.h>
10#include <linux/module.h>
11#include <linux/parser.h>
12#include "nvmet.h"
13#include "../host/nvme.h"
14#include "../host/fabrics.h"
15
16#define NVME_LOOP_MAX_SEGMENTS		256
17
18struct nvme_loop_iod {
19	struct nvme_request	nvme_req;
20	struct nvme_command	cmd;
21	struct nvme_completion	cqe;
22	struct nvmet_req	req;
23	struct nvme_loop_queue	*queue;
24	struct work_struct	work;
25	struct sg_table		sg_table;
26	struct scatterlist	first_sgl[];
27};
28
29struct nvme_loop_ctrl {
30	struct nvme_loop_queue	*queues;
31
32	struct blk_mq_tag_set	admin_tag_set;
33
34	struct list_head	list;
35	struct blk_mq_tag_set	tag_set;
36	struct nvme_loop_iod	async_event_iod;
37	struct nvme_ctrl	ctrl;
38
39	struct nvmet_port	*port;
40};
41
42static inline struct nvme_loop_ctrl *to_loop_ctrl(struct nvme_ctrl *ctrl)
43{
44	return container_of(ctrl, struct nvme_loop_ctrl, ctrl);
45}
46
47enum nvme_loop_queue_flags {
48	NVME_LOOP_Q_LIVE	= 0,
49};
50
51struct nvme_loop_queue {
52	struct nvmet_cq		nvme_cq;
53	struct nvmet_sq		nvme_sq;
54	struct nvme_loop_ctrl	*ctrl;
55	unsigned long		flags;
56};
57
58static LIST_HEAD(nvme_loop_ports);
59static DEFINE_MUTEX(nvme_loop_ports_mutex);
60
61static LIST_HEAD(nvme_loop_ctrl_list);
62static DEFINE_MUTEX(nvme_loop_ctrl_mutex);
63
64static void nvme_loop_queue_response(struct nvmet_req *nvme_req);
65static void nvme_loop_delete_ctrl(struct nvmet_ctrl *ctrl);
66
67static const struct nvmet_fabrics_ops nvme_loop_ops;
68
69static inline int nvme_loop_queue_idx(struct nvme_loop_queue *queue)
70{
71	return queue - queue->ctrl->queues;
72}
73
74static void nvme_loop_complete_rq(struct request *req)
75{
76	struct nvme_loop_iod *iod = blk_mq_rq_to_pdu(req);
77
78	sg_free_table_chained(&iod->sg_table, NVME_INLINE_SG_CNT);
79	nvme_complete_rq(req);
80}
81
82static struct blk_mq_tags *nvme_loop_tagset(struct nvme_loop_queue *queue)
83{
84	u32 queue_idx = nvme_loop_queue_idx(queue);
85
86	if (queue_idx == 0)
87		return queue->ctrl->admin_tag_set.tags[queue_idx];
88	return queue->ctrl->tag_set.tags[queue_idx - 1];
89}
90
91static void nvme_loop_queue_response(struct nvmet_req *req)
92{
93	struct nvme_loop_queue *queue =
94		container_of(req->sq, struct nvme_loop_queue, nvme_sq);
95	struct nvme_completion *cqe = req->cqe;
96
97	/*
98	 * AEN requests are special as they don't time out and can
99	 * survive any kind of queue freeze and often don't respond to
100	 * aborts.  We don't even bother to allocate a struct request
101	 * for them but rather special case them here.
102	 */
103	if (unlikely(nvme_is_aen_req(nvme_loop_queue_idx(queue),
104				     cqe->command_id))) {
105		nvme_complete_async_event(&queue->ctrl->ctrl, cqe->status,
106				&cqe->result);
107	} else {
108		struct request *rq;
109
110		rq = nvme_find_rq(nvme_loop_tagset(queue), cqe->command_id);
111		if (!rq) {
112			dev_err(queue->ctrl->ctrl.device,
113				"got bad command_id %#x on queue %d\n",
114				cqe->command_id, nvme_loop_queue_idx(queue));
115			return;
116		}
117
118		if (!nvme_try_complete_req(rq, cqe->status, cqe->result))
119			nvme_loop_complete_rq(rq);
120	}
121}
122
123static void nvme_loop_execute_work(struct work_struct *work)
124{
125	struct nvme_loop_iod *iod =
126		container_of(work, struct nvme_loop_iod, work);
127
128	iod->req.execute(&iod->req);
129}
130
131static blk_status_t nvme_loop_queue_rq(struct blk_mq_hw_ctx *hctx,
132		const struct blk_mq_queue_data *bd)
133{
134	struct nvme_ns *ns = hctx->queue->queuedata;
135	struct nvme_loop_queue *queue = hctx->driver_data;
136	struct request *req = bd->rq;
137	struct nvme_loop_iod *iod = blk_mq_rq_to_pdu(req);
138	bool queue_ready = test_bit(NVME_LOOP_Q_LIVE, &queue->flags);
139	blk_status_t ret;
140
141	if (!nvme_check_ready(&queue->ctrl->ctrl, req, queue_ready))
142		return nvme_fail_nonready_command(&queue->ctrl->ctrl, req);
143
144	ret = nvme_setup_cmd(ns, req);
145	if (ret)
146		return ret;
147
148	nvme_start_request(req);
149	iod->cmd.common.flags |= NVME_CMD_SGL_METABUF;
150	iod->req.port = queue->ctrl->port;
151	if (!nvmet_req_init(&iod->req, &queue->nvme_cq,
152			&queue->nvme_sq, &nvme_loop_ops))
153		return BLK_STS_OK;
154
155	if (blk_rq_nr_phys_segments(req)) {
156		iod->sg_table.sgl = iod->first_sgl;
157		if (sg_alloc_table_chained(&iod->sg_table,
158				blk_rq_nr_phys_segments(req),
159				iod->sg_table.sgl, NVME_INLINE_SG_CNT)) {
160			nvme_cleanup_cmd(req);
161			return BLK_STS_RESOURCE;
162		}
163
164		iod->req.sg = iod->sg_table.sgl;
165		iod->req.sg_cnt = blk_rq_map_sg(req->q, req, iod->sg_table.sgl);
166		iod->req.transfer_len = blk_rq_payload_bytes(req);
167	}
168
169	queue_work(nvmet_wq, &iod->work);
170	return BLK_STS_OK;
171}
172
173static void nvme_loop_submit_async_event(struct nvme_ctrl *arg)
174{
175	struct nvme_loop_ctrl *ctrl = to_loop_ctrl(arg);
176	struct nvme_loop_queue *queue = &ctrl->queues[0];
177	struct nvme_loop_iod *iod = &ctrl->async_event_iod;
178
179	memset(&iod->cmd, 0, sizeof(iod->cmd));
180	iod->cmd.common.opcode = nvme_admin_async_event;
181	iod->cmd.common.command_id = NVME_AQ_BLK_MQ_DEPTH;
182	iod->cmd.common.flags |= NVME_CMD_SGL_METABUF;
183
184	if (!nvmet_req_init(&iod->req, &queue->nvme_cq, &queue->nvme_sq,
185			&nvme_loop_ops)) {
186		dev_err(ctrl->ctrl.device, "failed async event work\n");
187		return;
188	}
189
190	queue_work(nvmet_wq, &iod->work);
191}
192
193static int nvme_loop_init_iod(struct nvme_loop_ctrl *ctrl,
194		struct nvme_loop_iod *iod, unsigned int queue_idx)
195{
196	iod->req.cmd = &iod->cmd;
197	iod->req.cqe = &iod->cqe;
198	iod->queue = &ctrl->queues[queue_idx];
199	INIT_WORK(&iod->work, nvme_loop_execute_work);
200	return 0;
201}
202
203static int nvme_loop_init_request(struct blk_mq_tag_set *set,
204		struct request *req, unsigned int hctx_idx,
205		unsigned int numa_node)
206{
207	struct nvme_loop_ctrl *ctrl = to_loop_ctrl(set->driver_data);
208	struct nvme_loop_iod *iod = blk_mq_rq_to_pdu(req);
209
210	nvme_req(req)->ctrl = &ctrl->ctrl;
211	nvme_req(req)->cmd = &iod->cmd;
212	return nvme_loop_init_iod(ctrl, blk_mq_rq_to_pdu(req),
213			(set == &ctrl->tag_set) ? hctx_idx + 1 : 0);
214}
215
216static struct lock_class_key loop_hctx_fq_lock_key;
217
218static int nvme_loop_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
219		unsigned int hctx_idx)
220{
221	struct nvme_loop_ctrl *ctrl = to_loop_ctrl(data);
222	struct nvme_loop_queue *queue = &ctrl->queues[hctx_idx + 1];
223
224	BUG_ON(hctx_idx >= ctrl->ctrl.queue_count);
225
226	/*
227	 * flush_end_io() can be called recursively for us, so use our own
228	 * lock class key for avoiding lockdep possible recursive locking,
229	 * then we can remove the dynamically allocated lock class for each
230	 * flush queue, that way may cause horrible boot delay.
231	 */
232	blk_mq_hctx_set_fq_lock_class(hctx, &loop_hctx_fq_lock_key);
233
234	hctx->driver_data = queue;
235	return 0;
236}
237
238static int nvme_loop_init_admin_hctx(struct blk_mq_hw_ctx *hctx, void *data,
239		unsigned int hctx_idx)
240{
241	struct nvme_loop_ctrl *ctrl = to_loop_ctrl(data);
242	struct nvme_loop_queue *queue = &ctrl->queues[0];
243
244	BUG_ON(hctx_idx != 0);
245
246	hctx->driver_data = queue;
247	return 0;
248}
249
250static const struct blk_mq_ops nvme_loop_mq_ops = {
251	.queue_rq	= nvme_loop_queue_rq,
252	.complete	= nvme_loop_complete_rq,
253	.init_request	= nvme_loop_init_request,
254	.init_hctx	= nvme_loop_init_hctx,
255};
256
257static const struct blk_mq_ops nvme_loop_admin_mq_ops = {
258	.queue_rq	= nvme_loop_queue_rq,
259	.complete	= nvme_loop_complete_rq,
260	.init_request	= nvme_loop_init_request,
261	.init_hctx	= nvme_loop_init_admin_hctx,
262};
263
264static void nvme_loop_destroy_admin_queue(struct nvme_loop_ctrl *ctrl)
265{
266	if (!test_and_clear_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[0].flags))
267		return;
268	nvmet_sq_destroy(&ctrl->queues[0].nvme_sq);
269	nvme_remove_admin_tag_set(&ctrl->ctrl);
270}
271
272static void nvme_loop_free_ctrl(struct nvme_ctrl *nctrl)
273{
274	struct nvme_loop_ctrl *ctrl = to_loop_ctrl(nctrl);
275
276	if (list_empty(&ctrl->list))
277		goto free_ctrl;
278
279	mutex_lock(&nvme_loop_ctrl_mutex);
280	list_del(&ctrl->list);
281	mutex_unlock(&nvme_loop_ctrl_mutex);
282
283	if (nctrl->tagset)
284		nvme_remove_io_tag_set(nctrl);
285	kfree(ctrl->queues);
286	nvmf_free_options(nctrl->opts);
287free_ctrl:
288	kfree(ctrl);
289}
290
291static void nvme_loop_destroy_io_queues(struct nvme_loop_ctrl *ctrl)
292{
293	int i;
294
295	for (i = 1; i < ctrl->ctrl.queue_count; i++) {
296		clear_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[i].flags);
297		nvmet_sq_destroy(&ctrl->queues[i].nvme_sq);
298	}
299	ctrl->ctrl.queue_count = 1;
300}
301
302static int nvme_loop_init_io_queues(struct nvme_loop_ctrl *ctrl)
303{
304	struct nvmf_ctrl_options *opts = ctrl->ctrl.opts;
305	unsigned int nr_io_queues;
306	int ret, i;
307
308	nr_io_queues = min(opts->nr_io_queues, num_online_cpus());
309	ret = nvme_set_queue_count(&ctrl->ctrl, &nr_io_queues);
310	if (ret || !nr_io_queues)
311		return ret;
312
313	dev_info(ctrl->ctrl.device, "creating %d I/O queues.\n", nr_io_queues);
314
315	for (i = 1; i <= nr_io_queues; i++) {
316		ctrl->queues[i].ctrl = ctrl;
317		ret = nvmet_sq_init(&ctrl->queues[i].nvme_sq);
318		if (ret)
319			goto out_destroy_queues;
320
321		ctrl->ctrl.queue_count++;
322	}
323
324	return 0;
325
326out_destroy_queues:
327	nvme_loop_destroy_io_queues(ctrl);
328	return ret;
329}
330
331static int nvme_loop_connect_io_queues(struct nvme_loop_ctrl *ctrl)
332{
333	int i, ret;
334
335	for (i = 1; i < ctrl->ctrl.queue_count; i++) {
336		ret = nvmf_connect_io_queue(&ctrl->ctrl, i);
337		if (ret)
338			return ret;
339		set_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[i].flags);
340	}
341
342	return 0;
343}
344
345static int nvme_loop_configure_admin_queue(struct nvme_loop_ctrl *ctrl)
346{
347	int error;
348
349	ctrl->queues[0].ctrl = ctrl;
350	error = nvmet_sq_init(&ctrl->queues[0].nvme_sq);
351	if (error)
352		return error;
353	ctrl->ctrl.queue_count = 1;
354
355	error = nvme_alloc_admin_tag_set(&ctrl->ctrl, &ctrl->admin_tag_set,
356			&nvme_loop_admin_mq_ops,
357			sizeof(struct nvme_loop_iod) +
358			NVME_INLINE_SG_CNT * sizeof(struct scatterlist));
359	if (error)
360		goto out_free_sq;
361
362	/* reset stopped state for the fresh admin queue */
363	clear_bit(NVME_CTRL_ADMIN_Q_STOPPED, &ctrl->ctrl.flags);
364
365	error = nvmf_connect_admin_queue(&ctrl->ctrl);
366	if (error)
367		goto out_cleanup_tagset;
368
369	set_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[0].flags);
370
371	error = nvme_enable_ctrl(&ctrl->ctrl);
372	if (error)
373		goto out_cleanup_tagset;
374
375	ctrl->ctrl.max_hw_sectors =
376		(NVME_LOOP_MAX_SEGMENTS - 1) << PAGE_SECTORS_SHIFT;
377
378	nvme_unquiesce_admin_queue(&ctrl->ctrl);
379
380	error = nvme_init_ctrl_finish(&ctrl->ctrl, false);
381	if (error)
382		goto out_cleanup_tagset;
383
384	return 0;
385
386out_cleanup_tagset:
387	clear_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[0].flags);
388	nvme_remove_admin_tag_set(&ctrl->ctrl);
389out_free_sq:
390	nvmet_sq_destroy(&ctrl->queues[0].nvme_sq);
391	return error;
392}
393
394static void nvme_loop_shutdown_ctrl(struct nvme_loop_ctrl *ctrl)
395{
396	if (ctrl->ctrl.queue_count > 1) {
397		nvme_quiesce_io_queues(&ctrl->ctrl);
398		nvme_cancel_tagset(&ctrl->ctrl);
399		nvme_loop_destroy_io_queues(ctrl);
400	}
401
402	nvme_quiesce_admin_queue(&ctrl->ctrl);
403	if (nvme_ctrl_state(&ctrl->ctrl) == NVME_CTRL_LIVE)
404		nvme_disable_ctrl(&ctrl->ctrl, true);
405
406	nvme_cancel_admin_tagset(&ctrl->ctrl);
407	nvme_loop_destroy_admin_queue(ctrl);
408}
409
410static void nvme_loop_delete_ctrl_host(struct nvme_ctrl *ctrl)
411{
412	nvme_loop_shutdown_ctrl(to_loop_ctrl(ctrl));
413}
414
415static void nvme_loop_delete_ctrl(struct nvmet_ctrl *nctrl)
416{
417	struct nvme_loop_ctrl *ctrl;
418
419	mutex_lock(&nvme_loop_ctrl_mutex);
420	list_for_each_entry(ctrl, &nvme_loop_ctrl_list, list) {
421		if (ctrl->ctrl.cntlid == nctrl->cntlid)
422			nvme_delete_ctrl(&ctrl->ctrl);
423	}
424	mutex_unlock(&nvme_loop_ctrl_mutex);
425}
426
427static void nvme_loop_reset_ctrl_work(struct work_struct *work)
428{
429	struct nvme_loop_ctrl *ctrl =
430		container_of(work, struct nvme_loop_ctrl, ctrl.reset_work);
431	int ret;
432
433	nvme_stop_ctrl(&ctrl->ctrl);
434	nvme_loop_shutdown_ctrl(ctrl);
435
436	if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_CONNECTING)) {
437		enum nvme_ctrl_state state = nvme_ctrl_state(&ctrl->ctrl);
438
439		if (state != NVME_CTRL_DELETING &&
440		    state != NVME_CTRL_DELETING_NOIO)
441			/* state change failure for non-deleted ctrl? */
442			WARN_ON_ONCE(1);
443		return;
444	}
445
446	ret = nvme_loop_configure_admin_queue(ctrl);
447	if (ret)
448		goto out_disable;
449
450	ret = nvme_loop_init_io_queues(ctrl);
451	if (ret)
452		goto out_destroy_admin;
453
454	ret = nvme_loop_connect_io_queues(ctrl);
455	if (ret)
456		goto out_destroy_io;
457
458	blk_mq_update_nr_hw_queues(&ctrl->tag_set,
459			ctrl->ctrl.queue_count - 1);
460
461	if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE))
462		WARN_ON_ONCE(1);
463
464	nvme_start_ctrl(&ctrl->ctrl);
465
466	return;
467
468out_destroy_io:
469	nvme_loop_destroy_io_queues(ctrl);
470out_destroy_admin:
471	nvme_quiesce_admin_queue(&ctrl->ctrl);
472	nvme_cancel_admin_tagset(&ctrl->ctrl);
473	nvme_loop_destroy_admin_queue(ctrl);
474out_disable:
475	dev_warn(ctrl->ctrl.device, "Removing after reset failure\n");
476	nvme_uninit_ctrl(&ctrl->ctrl);
477}
478
479static const struct nvme_ctrl_ops nvme_loop_ctrl_ops = {
480	.name			= "loop",
481	.module			= THIS_MODULE,
482	.flags			= NVME_F_FABRICS,
483	.reg_read32		= nvmf_reg_read32,
484	.reg_read64		= nvmf_reg_read64,
485	.reg_write32		= nvmf_reg_write32,
486	.free_ctrl		= nvme_loop_free_ctrl,
487	.submit_async_event	= nvme_loop_submit_async_event,
488	.delete_ctrl		= nvme_loop_delete_ctrl_host,
489	.get_address		= nvmf_get_address,
490};
491
492static int nvme_loop_create_io_queues(struct nvme_loop_ctrl *ctrl)
493{
494	int ret;
495
496	ret = nvme_loop_init_io_queues(ctrl);
497	if (ret)
498		return ret;
499
500	ret = nvme_alloc_io_tag_set(&ctrl->ctrl, &ctrl->tag_set,
501			&nvme_loop_mq_ops, 1,
502			sizeof(struct nvme_loop_iod) +
503			NVME_INLINE_SG_CNT * sizeof(struct scatterlist));
504	if (ret)
505		goto out_destroy_queues;
506
507	ret = nvme_loop_connect_io_queues(ctrl);
508	if (ret)
509		goto out_cleanup_tagset;
510
511	return 0;
512
513out_cleanup_tagset:
514	nvme_remove_io_tag_set(&ctrl->ctrl);
515out_destroy_queues:
516	nvme_loop_destroy_io_queues(ctrl);
517	return ret;
518}
519
520static struct nvmet_port *nvme_loop_find_port(struct nvme_ctrl *ctrl)
521{
522	struct nvmet_port *p, *found = NULL;
523
524	mutex_lock(&nvme_loop_ports_mutex);
525	list_for_each_entry(p, &nvme_loop_ports, entry) {
526		/* if no transport address is specified use the first port */
527		if ((ctrl->opts->mask & NVMF_OPT_TRADDR) &&
528		    strcmp(ctrl->opts->traddr, p->disc_addr.traddr))
529			continue;
530		found = p;
531		break;
532	}
533	mutex_unlock(&nvme_loop_ports_mutex);
534	return found;
535}
536
537static struct nvme_ctrl *nvme_loop_create_ctrl(struct device *dev,
538		struct nvmf_ctrl_options *opts)
539{
540	struct nvme_loop_ctrl *ctrl;
541	int ret;
542
543	ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
544	if (!ctrl)
545		return ERR_PTR(-ENOMEM);
546	ctrl->ctrl.opts = opts;
547	INIT_LIST_HEAD(&ctrl->list);
548
549	INIT_WORK(&ctrl->ctrl.reset_work, nvme_loop_reset_ctrl_work);
550
551	ret = nvme_init_ctrl(&ctrl->ctrl, dev, &nvme_loop_ctrl_ops,
552				0 /* no quirks, we're perfect! */);
553	if (ret) {
554		kfree(ctrl);
555		goto out;
556	}
557
558	if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_CONNECTING))
559		WARN_ON_ONCE(1);
560
561	ret = -ENOMEM;
562
563	ctrl->ctrl.kato = opts->kato;
564	ctrl->port = nvme_loop_find_port(&ctrl->ctrl);
565
566	ctrl->queues = kcalloc(opts->nr_io_queues + 1, sizeof(*ctrl->queues),
567			GFP_KERNEL);
568	if (!ctrl->queues)
569		goto out_uninit_ctrl;
570
571	ret = nvme_loop_configure_admin_queue(ctrl);
572	if (ret)
573		goto out_free_queues;
574
575	if (opts->queue_size > ctrl->ctrl.maxcmd) {
576		/* warn if maxcmd is lower than queue_size */
577		dev_warn(ctrl->ctrl.device,
578			"queue_size %zu > ctrl maxcmd %u, clamping down\n",
579			opts->queue_size, ctrl->ctrl.maxcmd);
580		opts->queue_size = ctrl->ctrl.maxcmd;
581	}
582	ctrl->ctrl.sqsize = opts->queue_size - 1;
583
584	if (opts->nr_io_queues) {
585		ret = nvme_loop_create_io_queues(ctrl);
586		if (ret)
587			goto out_remove_admin_queue;
588	}
589
590	nvme_loop_init_iod(ctrl, &ctrl->async_event_iod, 0);
591
592	dev_info(ctrl->ctrl.device,
593		 "new ctrl: \"%s\"\n", ctrl->ctrl.opts->subsysnqn);
594
595	if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE))
596		WARN_ON_ONCE(1);
597
598	mutex_lock(&nvme_loop_ctrl_mutex);
599	list_add_tail(&ctrl->list, &nvme_loop_ctrl_list);
600	mutex_unlock(&nvme_loop_ctrl_mutex);
601
602	nvme_start_ctrl(&ctrl->ctrl);
603
604	return &ctrl->ctrl;
605
606out_remove_admin_queue:
607	nvme_quiesce_admin_queue(&ctrl->ctrl);
608	nvme_cancel_admin_tagset(&ctrl->ctrl);
609	nvme_loop_destroy_admin_queue(ctrl);
610out_free_queues:
611	kfree(ctrl->queues);
612out_uninit_ctrl:
613	nvme_uninit_ctrl(&ctrl->ctrl);
614	nvme_put_ctrl(&ctrl->ctrl);
615out:
616	if (ret > 0)
617		ret = -EIO;
618	return ERR_PTR(ret);
619}
620
621static int nvme_loop_add_port(struct nvmet_port *port)
622{
623	mutex_lock(&nvme_loop_ports_mutex);
624	list_add_tail(&port->entry, &nvme_loop_ports);
625	mutex_unlock(&nvme_loop_ports_mutex);
626	return 0;
627}
628
629static void nvme_loop_remove_port(struct nvmet_port *port)
630{
631	mutex_lock(&nvme_loop_ports_mutex);
632	list_del_init(&port->entry);
633	mutex_unlock(&nvme_loop_ports_mutex);
634
635	/*
636	 * Ensure any ctrls that are in the process of being
637	 * deleted are in fact deleted before we return
638	 * and free the port. This is to prevent active
639	 * ctrls from using a port after it's freed.
640	 */
641	flush_workqueue(nvme_delete_wq);
642}
643
644static const struct nvmet_fabrics_ops nvme_loop_ops = {
645	.owner		= THIS_MODULE,
646	.type		= NVMF_TRTYPE_LOOP,
647	.add_port	= nvme_loop_add_port,
648	.remove_port	= nvme_loop_remove_port,
649	.queue_response = nvme_loop_queue_response,
650	.delete_ctrl	= nvme_loop_delete_ctrl,
651};
652
653static struct nvmf_transport_ops nvme_loop_transport = {
654	.name		= "loop",
655	.module		= THIS_MODULE,
656	.create_ctrl	= nvme_loop_create_ctrl,
657	.allowed_opts	= NVMF_OPT_TRADDR,
658};
659
660static int __init nvme_loop_init_module(void)
661{
662	int ret;
663
664	ret = nvmet_register_transport(&nvme_loop_ops);
665	if (ret)
666		return ret;
667
668	ret = nvmf_register_transport(&nvme_loop_transport);
669	if (ret)
670		nvmet_unregister_transport(&nvme_loop_ops);
671
672	return ret;
673}
674
675static void __exit nvme_loop_cleanup_module(void)
676{
677	struct nvme_loop_ctrl *ctrl, *next;
678
679	nvmf_unregister_transport(&nvme_loop_transport);
680	nvmet_unregister_transport(&nvme_loop_ops);
681
682	mutex_lock(&nvme_loop_ctrl_mutex);
683	list_for_each_entry_safe(ctrl, next, &nvme_loop_ctrl_list, list)
684		nvme_delete_ctrl(&ctrl->ctrl);
685	mutex_unlock(&nvme_loop_ctrl_mutex);
686
687	flush_workqueue(nvme_delete_wq);
688}
689
690module_init(nvme_loop_init_module);
691module_exit(nvme_loop_cleanup_module);
692
693MODULE_DESCRIPTION("NVMe target loop transport driver");
694MODULE_LICENSE("GPL v2");
695MODULE_ALIAS("nvmet-transport-254"); /* 254 == NVMF_TRTYPE_LOOP */
696