drivers/nvme/target/loop.c

   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
  18 struct 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
  29 struct 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
  42 static 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
  47 enum nvme_loop_queue_flags {
  48         NVME_LOOP_Q_LIVE        = 0,
  49 };
  50
  51 struct 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
  58 static LIST_HEAD(nvme_loop_ports);
  59 static DEFINE_MUTEX(nvme_loop_ports_mutex);
  60
  61 static LIST_HEAD(nvme_loop_ctrl_list);
  62 static DEFINE_MUTEX(nvme_loop_ctrl_mutex);
  63
  64 static void nvme_loop_queue_response(struct nvmet_req *nvme_req);
  65 static void nvme_loop_delete_ctrl(struct nvmet_ctrl *ctrl);
  66
  67 static const struct nvmet_fabrics_ops nvme_loop_ops;
  68
  69 static inline int nvme_loop_queue_idx(struct nvme_loop_queue *queue)
  70 {
  71         return queue - queue->ctrl->queues;
  72 }
  73
  74 static 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
  82 static 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
  91 static 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
 123 static 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
 131 static 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
 173 static 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
 193 static 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
 203 static 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
 216 static struct lock_class_key loop_hctx_fq_lock_key;
 217
 218 static 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
 238 static 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
 250 static 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
 257 static 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
 264 static 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         /*
 269          * It's possible that some requests might have been added
 270          * after admin queue is stopped/quiesced. So now start the
 271          * queue to flush these requests to the completion.
 272          */
 273         nvme_unquiesce_admin_queue(&ctrl->ctrl);
 274
 275         nvmet_sq_destroy(&ctrl->queues[0].nvme_sq);
 276         nvme_remove_admin_tag_set(&ctrl->ctrl);
 277 }
 278
 279 static void nvme_loop_free_ctrl(struct nvme_ctrl *nctrl)
 280 {
 281         struct nvme_loop_ctrl *ctrl = to_loop_ctrl(nctrl);
 282
 283         if (list_empty(&ctrl->list))
 284                 goto free_ctrl;
 285
 286         mutex_lock(&nvme_loop_ctrl_mutex);
 287         list_del(&ctrl->list);
 288         mutex_unlock(&nvme_loop_ctrl_mutex);
 289
 290         if (nctrl->tagset)
 291                 nvme_remove_io_tag_set(nctrl);
 292         kfree(ctrl->queues);
 293         nvmf_free_options(nctrl->opts);
 294 free_ctrl:
 295         kfree(ctrl);
 296 }
 297
 298 static void nvme_loop_destroy_io_queues(struct nvme_loop_ctrl *ctrl)
 299 {
 300         int i;
 301
 302         for (i = 1; i < ctrl->ctrl.queue_count; i++) {
 303                 clear_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[i].flags);
 304                 nvmet_sq_destroy(&ctrl->queues[i].nvme_sq);
 305         }
 306         ctrl->ctrl.queue_count = 1;
 307         /*
 308          * It's possible that some requests might have been added
 309          * after io queue is stopped/quiesced. So now start the
 310          * queue to flush these requests to the completion.
 311          */
 312         nvme_unquiesce_io_queues(&ctrl->ctrl);
 313 }
 314
 315 static int nvme_loop_init_io_queues(struct nvme_loop_ctrl *ctrl)
 316 {
 317         struct nvmf_ctrl_options *opts = ctrl->ctrl.opts;
 318         unsigned int nr_io_queues;
 319         int ret, i;
 320
 321         nr_io_queues = min(opts->nr_io_queues, num_online_cpus());
 322         ret = nvme_set_queue_count(&ctrl->ctrl, &nr_io_queues);
 323         if (ret || !nr_io_queues)
 324                 return ret;
 325
 326         dev_info(ctrl->ctrl.device, "creating %d I/O queues.\n", nr_io_queues);
 327
 328         for (i = 1; i <= nr_io_queues; i++) {
 329                 ctrl->queues[i].ctrl = ctrl;
 330                 ret = nvmet_sq_init(&ctrl->queues[i].nvme_sq);
 331                 if (ret)
 332                         goto out_destroy_queues;
 333
 334                 ctrl->ctrl.queue_count++;
 335         }
 336
 337         return 0;
 338
 339 out_destroy_queues:
 340         nvme_loop_destroy_io_queues(ctrl);
 341         return ret;
 342 }
 343
 344 static int nvme_loop_connect_io_queues(struct nvme_loop_ctrl *ctrl)
 345 {
 346         int i, ret;
 347
 348         for (i = 1; i < ctrl->ctrl.queue_count; i++) {
 349                 ret = nvmf_connect_io_queue(&ctrl->ctrl, i);
 350                 if (ret)
 351                         return ret;
 352                 set_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[i].flags);
 353         }
 354
 355         return 0;
 356 }
 357
 358 static int nvme_loop_configure_admin_queue(struct nvme_loop_ctrl *ctrl)
 359 {
 360         int error;
 361
 362         ctrl->queues[0].ctrl = ctrl;
 363         error = nvmet_sq_init(&ctrl->queues[0].nvme_sq);
 364         if (error)
 365                 return error;
 366         ctrl->ctrl.queue_count = 1;
 367
 368         error = nvme_alloc_admin_tag_set(&ctrl->ctrl, &ctrl->admin_tag_set,
 369                         &nvme_loop_admin_mq_ops,
 370                         sizeof(struct nvme_loop_iod) +
 371                         NVME_INLINE_SG_CNT * sizeof(struct scatterlist));
 372         if (error)
 373                 goto out_free_sq;
 374
 375         /* reset stopped state for the fresh admin queue */
 376         clear_bit(NVME_CTRL_ADMIN_Q_STOPPED, &ctrl->ctrl.flags);
 377
 378         error = nvmf_connect_admin_queue(&ctrl->ctrl);
 379         if (error)
 380                 goto out_cleanup_tagset;
 381
 382         set_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[0].flags);
 383
 384         error = nvme_enable_ctrl(&ctrl->ctrl);
 385         if (error)
 386                 goto out_cleanup_tagset;
 387
 388         ctrl->ctrl.max_hw_sectors =
 389                 (NVME_LOOP_MAX_SEGMENTS - 1) << PAGE_SECTORS_SHIFT;
 390
 391         nvme_unquiesce_admin_queue(&ctrl->ctrl);
 392
 393         error = nvme_init_ctrl_finish(&ctrl->ctrl, false);
 394         if (error)
 395                 goto out_cleanup_tagset;
 396
 397         return 0;
 398
 399 out_cleanup_tagset:
 400         clear_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[0].flags);
 401         nvme_remove_admin_tag_set(&ctrl->ctrl);
 402 out_free_sq:
 403         nvmet_sq_destroy(&ctrl->queues[0].nvme_sq);
 404         return error;
 405 }
 406
 407 static void nvme_loop_shutdown_ctrl(struct nvme_loop_ctrl *ctrl)
 408 {
 409         if (ctrl->ctrl.queue_count > 1) {
 410                 nvme_quiesce_io_queues(&ctrl->ctrl);
 411                 nvme_cancel_tagset(&ctrl->ctrl);
 412                 nvme_loop_destroy_io_queues(ctrl);
 413         }
 414
 415         nvme_quiesce_admin_queue(&ctrl->ctrl);
 416         if (nvme_ctrl_state(&ctrl->ctrl) == NVME_CTRL_LIVE)
 417                 nvme_disable_ctrl(&ctrl->ctrl, true);
 418
 419         nvme_cancel_admin_tagset(&ctrl->ctrl);
 420         nvme_loop_destroy_admin_queue(ctrl);
 421 }
 422
 423 static void nvme_loop_delete_ctrl_host(struct nvme_ctrl *ctrl)
 424 {
 425         nvme_loop_shutdown_ctrl(to_loop_ctrl(ctrl));
 426 }
 427
 428 static void nvme_loop_delete_ctrl(struct nvmet_ctrl *nctrl)
 429 {
 430         struct nvme_loop_ctrl *ctrl;
 431
 432         mutex_lock(&nvme_loop_ctrl_mutex);
 433         list_for_each_entry(ctrl, &nvme_loop_ctrl_list, list) {
 434                 if (ctrl->ctrl.cntlid == nctrl->cntlid)
 435                         nvme_delete_ctrl(&ctrl->ctrl);
 436         }
 437         mutex_unlock(&nvme_loop_ctrl_mutex);
 438 }
 439
 440 static void nvme_loop_reset_ctrl_work(struct work_struct *work)
 441 {
 442         struct nvme_loop_ctrl *ctrl =
 443                 container_of(work, struct nvme_loop_ctrl, ctrl.reset_work);
 444         int ret;
 445
 446         nvme_stop_ctrl(&ctrl->ctrl);
 447         nvme_loop_shutdown_ctrl(ctrl);
 448
 449         if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_CONNECTING)) {
 450                 enum nvme_ctrl_state state = nvme_ctrl_state(&ctrl->ctrl);
 451
 452                 if (state != NVME_CTRL_DELETING &&
 453                     state != NVME_CTRL_DELETING_NOIO)
 454                         /* state change failure for non-deleted ctrl? */
 455                         WARN_ON_ONCE(1);
 456                 return;
 457         }
 458
 459         ret = nvme_loop_configure_admin_queue(ctrl);
 460         if (ret)
 461                 goto out_disable;
 462
 463         ret = nvme_loop_init_io_queues(ctrl);
 464         if (ret)
 465                 goto out_destroy_admin;
 466
 467         ret = nvme_loop_connect_io_queues(ctrl);
 468         if (ret)
 469                 goto out_destroy_io;
 470
 471         blk_mq_update_nr_hw_queues(&ctrl->tag_set,
 472                         ctrl->ctrl.queue_count - 1);
 473
 474         if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE))
 475                 WARN_ON_ONCE(1);
 476
 477         nvme_start_ctrl(&ctrl->ctrl);
 478
 479         return;
 480
 481 out_destroy_io:
 482         nvme_loop_destroy_io_queues(ctrl);
 483 out_destroy_admin:
 484         nvme_quiesce_admin_queue(&ctrl->ctrl);
 485         nvme_cancel_admin_tagset(&ctrl->ctrl);
 486         nvme_loop_destroy_admin_queue(ctrl);
 487 out_disable:
 488         dev_warn(ctrl->ctrl.device, "Removing after reset failure\n");
 489         nvme_uninit_ctrl(&ctrl->ctrl);
 490 }
 491
 492 static const struct nvme_ctrl_ops nvme_loop_ctrl_ops = {
 493         .name                   = "loop",
 494         .module                 = THIS_MODULE,
 495         .flags                  = NVME_F_FABRICS,
 496         .reg_read32             = nvmf_reg_read32,
 497         .reg_read64             = nvmf_reg_read64,
 498         .reg_write32            = nvmf_reg_write32,
 499         .free_ctrl              = nvme_loop_free_ctrl,
 500         .submit_async_event     = nvme_loop_submit_async_event,
 501         .delete_ctrl            = nvme_loop_delete_ctrl_host,
 502         .get_address            = nvmf_get_address,
 503 };
 504
 505 static int nvme_loop_create_io_queues(struct nvme_loop_ctrl *ctrl)
 506 {
 507         int ret;
 508
 509         ret = nvme_loop_init_io_queues(ctrl);
 510         if (ret)
 511                 return ret;
 512
 513         ret = nvme_alloc_io_tag_set(&ctrl->ctrl, &ctrl->tag_set,
 514                         &nvme_loop_mq_ops, 1,
 515                         sizeof(struct nvme_loop_iod) +
 516                         NVME_INLINE_SG_CNT * sizeof(struct scatterlist));
 517         if (ret)
 518                 goto out_destroy_queues;
 519
 520         ret = nvme_loop_connect_io_queues(ctrl);
 521         if (ret)
 522                 goto out_cleanup_tagset;
 523
 524         return 0;
 525
 526 out_cleanup_tagset:
 527         nvme_remove_io_tag_set(&ctrl->ctrl);
 528 out_destroy_queues:
 529         nvme_loop_destroy_io_queues(ctrl);
 530         return ret;
 531 }
 532
 533 static struct nvmet_port *nvme_loop_find_port(struct nvme_ctrl *ctrl)
 534 {
 535         struct nvmet_port *p, *found = NULL;
 536
 537         mutex_lock(&nvme_loop_ports_mutex);
 538         list_for_each_entry(p, &nvme_loop_ports, entry) {
 539                 /* if no transport address is specified use the first port */
 540                 if ((ctrl->opts->mask & NVMF_OPT_TRADDR) &&
 541                     strcmp(ctrl->opts->traddr, p->disc_addr.traddr))
 542                         continue;
 543                 found = p;
 544                 break;
 545         }
 546         mutex_unlock(&nvme_loop_ports_mutex);
 547         return found;
 548 }
 549
 550 static struct nvme_ctrl *nvme_loop_create_ctrl(struct device *dev,
 551                 struct nvmf_ctrl_options *opts)
 552 {
 553         struct nvme_loop_ctrl *ctrl;
 554         int ret;
 555
 556         ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
 557         if (!ctrl)
 558                 return ERR_PTR(-ENOMEM);
 559         ctrl->ctrl.opts = opts;
 560         INIT_LIST_HEAD(&ctrl->list);
 561
 562         INIT_WORK(&ctrl->ctrl.reset_work, nvme_loop_reset_ctrl_work);
 563
 564         ret = nvme_init_ctrl(&ctrl->ctrl, dev, &nvme_loop_ctrl_ops,
 565                                 0 /* no quirks, we're perfect! */);
 566         if (ret) {
 567                 kfree(ctrl);
 568                 goto out;
 569         }
 570
 571         ret = nvme_add_ctrl(&ctrl->ctrl);
 572         if (ret)
 573                 goto out_put_ctrl;
 574
 575         if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_CONNECTING))
 576                 WARN_ON_ONCE(1);
 577
 578         ret = -ENOMEM;
 579
 580         ctrl->ctrl.kato = opts->kato;
 581         ctrl->port = nvme_loop_find_port(&ctrl->ctrl);
 582
 583         ctrl->queues = kcalloc(opts->nr_io_queues + 1, sizeof(*ctrl->queues),
 584                         GFP_KERNEL);
 585         if (!ctrl->queues)
 586                 goto out_uninit_ctrl;
 587
 588         ret = nvme_loop_configure_admin_queue(ctrl);
 589         if (ret)
 590                 goto out_free_queues;
 591
 592         if (opts->queue_size > ctrl->ctrl.maxcmd) {
 593                 /* warn if maxcmd is lower than queue_size */
 594                 dev_warn(ctrl->ctrl.device,
 595                         "queue_size %zu > ctrl maxcmd %u, clamping down\n",
 596                         opts->queue_size, ctrl->ctrl.maxcmd);
 597                 opts->queue_size = ctrl->ctrl.maxcmd;
 598         }
 599         ctrl->ctrl.sqsize = opts->queue_size - 1;
 600
 601         if (opts->nr_io_queues) {
 602                 ret = nvme_loop_create_io_queues(ctrl);
 603                 if (ret)
 604                         goto out_remove_admin_queue;
 605         }
 606
 607         nvme_loop_init_iod(ctrl, &ctrl->async_event_iod, 0);
 608
 609         dev_info(ctrl->ctrl.device,
 610                  "new ctrl: \"%s\"\n", ctrl->ctrl.opts->subsysnqn);
 611
 612         if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE))
 613                 WARN_ON_ONCE(1);
 614
 615         mutex_lock(&nvme_loop_ctrl_mutex);
 616         list_add_tail(&ctrl->list, &nvme_loop_ctrl_list);
 617         mutex_unlock(&nvme_loop_ctrl_mutex);
 618
 619         nvme_start_ctrl(&ctrl->ctrl);
 620
 621         return &ctrl->ctrl;
 622
 623 out_remove_admin_queue:
 624         nvme_quiesce_admin_queue(&ctrl->ctrl);
 625         nvme_cancel_admin_tagset(&ctrl->ctrl);
 626         nvme_loop_destroy_admin_queue(ctrl);
 627 out_free_queues:
 628         kfree(ctrl->queues);
 629 out_uninit_ctrl:
 630         nvme_uninit_ctrl(&ctrl->ctrl);
 631 out_put_ctrl:
 632         nvme_put_ctrl(&ctrl->ctrl);
 633 out:
 634         if (ret > 0)
 635                 ret = -EIO;
 636         return ERR_PTR(ret);
 637 }
 638
 639 static int nvme_loop_add_port(struct nvmet_port *port)
 640 {
 641         mutex_lock(&nvme_loop_ports_mutex);
 642         list_add_tail(&port->entry, &nvme_loop_ports);
 643         mutex_unlock(&nvme_loop_ports_mutex);
 644         return 0;
 645 }
 646
 647 static void nvme_loop_remove_port(struct nvmet_port *port)
 648 {
 649         mutex_lock(&nvme_loop_ports_mutex);
 650         list_del_init(&port->entry);
 651         mutex_unlock(&nvme_loop_ports_mutex);
 652
 653         /*
 654          * Ensure any ctrls that are in the process of being
 655          * deleted are in fact deleted before we return
 656          * and free the port. This is to prevent active
 657          * ctrls from using a port after it's freed.
 658          */
 659         flush_workqueue(nvme_delete_wq);
 660 }
 661
 662 static const struct nvmet_fabrics_ops nvme_loop_ops = {
 663         .owner          = THIS_MODULE,
 664         .type           = NVMF_TRTYPE_LOOP,
 665         .add_port       = nvme_loop_add_port,
 666         .remove_port    = nvme_loop_remove_port,
 667         .queue_response = nvme_loop_queue_response,
 668         .delete_ctrl    = nvme_loop_delete_ctrl,
 669 };
 670
 671 static struct nvmf_transport_ops nvme_loop_transport = {
 672         .name           = "loop",
 673         .module         = THIS_MODULE,
 674         .create_ctrl    = nvme_loop_create_ctrl,
 675         .allowed_opts   = NVMF_OPT_TRADDR,
 676 };
 677
 678 static int __init nvme_loop_init_module(void)
 679 {
 680         int ret;
 681
 682         ret = nvmet_register_transport(&nvme_loop_ops);
 683         if (ret)
 684                 return ret;
 685
 686         ret = nvmf_register_transport(&nvme_loop_transport);
 687         if (ret)
 688                 nvmet_unregister_transport(&nvme_loop_ops);
 689
 690         return ret;
 691 }
 692
 693 static void __exit nvme_loop_cleanup_module(void)
 694 {
 695         struct nvme_loop_ctrl *ctrl, *next;
 696
 697         nvmf_unregister_transport(&nvme_loop_transport);
 698         nvmet_unregister_transport(&nvme_loop_ops);
 699
 700         mutex_lock(&nvme_loop_ctrl_mutex);
 701         list_for_each_entry_safe(ctrl, next, &nvme_loop_ctrl_list, list)
 702                 nvme_delete_ctrl(&ctrl->ctrl);
 703         mutex_unlock(&nvme_loop_ctrl_mutex);
 704
 705         flush_workqueue(nvme_delete_wq);
 706 }
 707
 708 module_init(nvme_loop_init_module);
 709 module_exit(nvme_loop_cleanup_module);
 710
 711 MODULE_DESCRIPTION("NVMe target loop transport driver");
 712 MODULE_LICENSE("GPL v2");
 713 MODULE_ALIAS("nvmet-transport-254"); /* 254 == NVMF_TRTYPE_LOOP */