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 = blk_mq_tag_to_rq(nvme_loop_tagset(queue), cqe->command_id);
 111                 if (!rq) {
 112                         dev_err(queue->ctrl->ctrl.device,
 113                                 "tag 0x%x on queue %d not found\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 (!nvmf_check_ready(&queue->ctrl->ctrl, req, queue_ready))
 142                 return nvmf_fail_nonready_command(&queue->ctrl->ctrl, req);
 143
 144         ret = nvme_setup_cmd(ns, req, &iod->cmd);
 145         if (ret)
 146                 return ret;
 147
 148         blk_mq_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         schedule_work(&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         schedule_work(&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 = set->driver_data;
 208
 209         nvme_req(req)->ctrl = &ctrl->ctrl;
 210         return nvme_loop_init_iod(ctrl, blk_mq_rq_to_pdu(req),
 211                         (set == &ctrl->tag_set) ? hctx_idx + 1 : 0);
 212 }
 213
 214 static struct lock_class_key loop_hctx_fq_lock_key;
 215
 216 static int nvme_loop_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
 217                 unsigned int hctx_idx)
 218 {
 219         struct nvme_loop_ctrl *ctrl = data;
 220         struct nvme_loop_queue *queue = &ctrl->queues[hctx_idx + 1];
 221
 222         BUG_ON(hctx_idx >= ctrl->ctrl.queue_count);
 223
 224         /*
 225          * flush_end_io() can be called recursively for us, so use our own
 226          * lock class key for avoiding lockdep possible recursive locking,
 227          * then we can remove the dynamically allocated lock class for each
 228          * flush queue, that way may cause horrible boot delay.
 229          */
 230         blk_mq_hctx_set_fq_lock_class(hctx, &loop_hctx_fq_lock_key);
 231
 232         hctx->driver_data = queue;
 233         return 0;
 234 }
 235
 236 static int nvme_loop_init_admin_hctx(struct blk_mq_hw_ctx *hctx, void *data,
 237                 unsigned int hctx_idx)
 238 {
 239         struct nvme_loop_ctrl *ctrl = data;
 240         struct nvme_loop_queue *queue = &ctrl->queues[0];
 241
 242         BUG_ON(hctx_idx != 0);
 243
 244         hctx->driver_data = queue;
 245         return 0;
 246 }
 247
 248 static const struct blk_mq_ops nvme_loop_mq_ops = {
 249         .queue_rq       = nvme_loop_queue_rq,
 250         .complete       = nvme_loop_complete_rq,
 251         .init_request   = nvme_loop_init_request,
 252         .init_hctx      = nvme_loop_init_hctx,
 253 };
 254
 255 static const struct blk_mq_ops nvme_loop_admin_mq_ops = {
 256         .queue_rq       = nvme_loop_queue_rq,
 257         .complete       = nvme_loop_complete_rq,
 258         .init_request   = nvme_loop_init_request,
 259         .init_hctx      = nvme_loop_init_admin_hctx,
 260 };
 261
 262 static void nvme_loop_destroy_admin_queue(struct nvme_loop_ctrl *ctrl)
 263 {
 264         clear_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[0].flags);
 265         nvmet_sq_destroy(&ctrl->queues[0].nvme_sq);
 266         blk_cleanup_queue(ctrl->ctrl.admin_q);
 267         blk_cleanup_queue(ctrl->ctrl.fabrics_q);
 268         blk_mq_free_tag_set(&ctrl->admin_tag_set);
 269 }
 270
 271 static void nvme_loop_free_ctrl(struct nvme_ctrl *nctrl)
 272 {
 273         struct nvme_loop_ctrl *ctrl = to_loop_ctrl(nctrl);
 274
 275         if (list_empty(&ctrl->list))
 276                 goto free_ctrl;
 277
 278         mutex_lock(&nvme_loop_ctrl_mutex);
 279         list_del(&ctrl->list);
 280         mutex_unlock(&nvme_loop_ctrl_mutex);
 281
 282         if (nctrl->tagset) {
 283                 blk_cleanup_queue(ctrl->ctrl.connect_q);
 284                 blk_mq_free_tag_set(&ctrl->tag_set);
 285         }
 286         kfree(ctrl->queues);
 287         nvmf_free_options(nctrl->opts);
 288 free_ctrl:
 289         kfree(ctrl);
 290 }
 291
 292 static void nvme_loop_destroy_io_queues(struct nvme_loop_ctrl *ctrl)
 293 {
 294         int i;
 295
 296         for (i = 1; i < ctrl->ctrl.queue_count; i++) {
 297                 clear_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[i].flags);
 298                 nvmet_sq_destroy(&ctrl->queues[i].nvme_sq);
 299         }
 300 }
 301
 302 static 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
 326 out_destroy_queues:
 327         nvme_loop_destroy_io_queues(ctrl);
 328         return ret;
 329 }
 330
 331 static 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, false);
 337                 if (ret)
 338                         return ret;
 339                 set_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[i].flags);
 340         }
 341
 342         return 0;
 343 }
 344
 345 static int nvme_loop_configure_admin_queue(struct nvme_loop_ctrl *ctrl)
 346 {
 347         int error;
 348
 349         memset(&ctrl->admin_tag_set, 0, sizeof(ctrl->admin_tag_set));
 350         ctrl->admin_tag_set.ops = &nvme_loop_admin_mq_ops;
 351         ctrl->admin_tag_set.queue_depth = NVME_AQ_MQ_TAG_DEPTH;
 352         ctrl->admin_tag_set.reserved_tags = 2; /* connect + keep-alive */
 353         ctrl->admin_tag_set.numa_node = ctrl->ctrl.numa_node;
 354         ctrl->admin_tag_set.cmd_size = sizeof(struct nvme_loop_iod) +
 355                 NVME_INLINE_SG_CNT * sizeof(struct scatterlist);
 356         ctrl->admin_tag_set.driver_data = ctrl;
 357         ctrl->admin_tag_set.nr_hw_queues = 1;
 358         ctrl->admin_tag_set.timeout = NVME_ADMIN_TIMEOUT;
 359         ctrl->admin_tag_set.flags = BLK_MQ_F_NO_SCHED;
 360
 361         ctrl->queues[0].ctrl = ctrl;
 362         error = nvmet_sq_init(&ctrl->queues[0].nvme_sq);
 363         if (error)
 364                 return error;
 365         ctrl->ctrl.queue_count = 1;
 366
 367         error = blk_mq_alloc_tag_set(&ctrl->admin_tag_set);
 368         if (error)
 369                 goto out_free_sq;
 370         ctrl->ctrl.admin_tagset = &ctrl->admin_tag_set;
 371
 372         ctrl->ctrl.fabrics_q = blk_mq_init_queue(&ctrl->admin_tag_set);
 373         if (IS_ERR(ctrl->ctrl.fabrics_q)) {
 374                 error = PTR_ERR(ctrl->ctrl.fabrics_q);
 375                 goto out_free_tagset;
 376         }
 377
 378         ctrl->ctrl.admin_q = blk_mq_init_queue(&ctrl->admin_tag_set);
 379         if (IS_ERR(ctrl->ctrl.admin_q)) {
 380                 error = PTR_ERR(ctrl->ctrl.admin_q);
 381                 goto out_cleanup_fabrics_q;
 382         }
 383
 384         error = nvmf_connect_admin_queue(&ctrl->ctrl);
 385         if (error)
 386                 goto out_cleanup_queue;
 387
 388         set_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[0].flags);
 389
 390         error = nvme_enable_ctrl(&ctrl->ctrl);
 391         if (error)
 392                 goto out_cleanup_queue;
 393
 394         ctrl->ctrl.max_hw_sectors =
 395                 (NVME_LOOP_MAX_SEGMENTS - 1) << (PAGE_SHIFT - 9);
 396
 397         blk_mq_unquiesce_queue(ctrl->ctrl.admin_q);
 398
 399         error = nvme_init_identify(&ctrl->ctrl);
 400         if (error)
 401                 goto out_cleanup_queue;
 402
 403         return 0;
 404
 405 out_cleanup_queue:
 406         blk_cleanup_queue(ctrl->ctrl.admin_q);
 407 out_cleanup_fabrics_q:
 408         blk_cleanup_queue(ctrl->ctrl.fabrics_q);
 409 out_free_tagset:
 410         blk_mq_free_tag_set(&ctrl->admin_tag_set);
 411 out_free_sq:
 412         nvmet_sq_destroy(&ctrl->queues[0].nvme_sq);
 413         return error;
 414 }
 415
 416 static void nvme_loop_shutdown_ctrl(struct nvme_loop_ctrl *ctrl)
 417 {
 418         if (ctrl->ctrl.queue_count > 1) {
 419                 nvme_stop_queues(&ctrl->ctrl);
 420                 blk_mq_tagset_busy_iter(&ctrl->tag_set,
 421                                         nvme_cancel_request, &ctrl->ctrl);
 422                 blk_mq_tagset_wait_completed_request(&ctrl->tag_set);
 423                 nvme_loop_destroy_io_queues(ctrl);
 424         }
 425
 426         blk_mq_quiesce_queue(ctrl->ctrl.admin_q);
 427         if (ctrl->ctrl.state == NVME_CTRL_LIVE)
 428                 nvme_shutdown_ctrl(&ctrl->ctrl);
 429
 430         blk_mq_tagset_busy_iter(&ctrl->admin_tag_set,
 431                                 nvme_cancel_request, &ctrl->ctrl);
 432         blk_mq_tagset_wait_completed_request(&ctrl->admin_tag_set);
 433         nvme_loop_destroy_admin_queue(ctrl);
 434 }
 435
 436 static void nvme_loop_delete_ctrl_host(struct nvme_ctrl *ctrl)
 437 {
 438         nvme_loop_shutdown_ctrl(to_loop_ctrl(ctrl));
 439 }
 440
 441 static void nvme_loop_delete_ctrl(struct nvmet_ctrl *nctrl)
 442 {
 443         struct nvme_loop_ctrl *ctrl;
 444
 445         mutex_lock(&nvme_loop_ctrl_mutex);
 446         list_for_each_entry(ctrl, &nvme_loop_ctrl_list, list) {
 447                 if (ctrl->ctrl.cntlid == nctrl->cntlid)
 448                         nvme_delete_ctrl(&ctrl->ctrl);
 449         }
 450         mutex_unlock(&nvme_loop_ctrl_mutex);
 451 }
 452
 453 static void nvme_loop_reset_ctrl_work(struct work_struct *work)
 454 {
 455         struct nvme_loop_ctrl *ctrl =
 456                 container_of(work, struct nvme_loop_ctrl, ctrl.reset_work);
 457         int ret;
 458
 459         nvme_stop_ctrl(&ctrl->ctrl);
 460         nvme_loop_shutdown_ctrl(ctrl);
 461
 462         if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_CONNECTING)) {
 463                 /* state change failure should never happen */
 464                 WARN_ON_ONCE(1);
 465                 return;
 466         }
 467
 468         ret = nvme_loop_configure_admin_queue(ctrl);
 469         if (ret)
 470                 goto out_disable;
 471
 472         ret = nvme_loop_init_io_queues(ctrl);
 473         if (ret)
 474                 goto out_destroy_admin;
 475
 476         ret = nvme_loop_connect_io_queues(ctrl);
 477         if (ret)
 478                 goto out_destroy_io;
 479
 480         blk_mq_update_nr_hw_queues(&ctrl->tag_set,
 481                         ctrl->ctrl.queue_count - 1);
 482
 483         if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE))
 484                 WARN_ON_ONCE(1);
 485
 486         nvme_start_ctrl(&ctrl->ctrl);
 487
 488         return;
 489
 490 out_destroy_io:
 491         nvme_loop_destroy_io_queues(ctrl);
 492 out_destroy_admin:
 493         nvme_loop_destroy_admin_queue(ctrl);
 494 out_disable:
 495         dev_warn(ctrl->ctrl.device, "Removing after reset failure\n");
 496         nvme_uninit_ctrl(&ctrl->ctrl);
 497 }
 498
 499 static const struct nvme_ctrl_ops nvme_loop_ctrl_ops = {
 500         .name                   = "loop",
 501         .module                 = THIS_MODULE,
 502         .flags                  = NVME_F_FABRICS,
 503         .reg_read32             = nvmf_reg_read32,
 504         .reg_read64             = nvmf_reg_read64,
 505         .reg_write32            = nvmf_reg_write32,
 506         .free_ctrl              = nvme_loop_free_ctrl,
 507         .submit_async_event     = nvme_loop_submit_async_event,
 508         .delete_ctrl            = nvme_loop_delete_ctrl_host,
 509         .get_address            = nvmf_get_address,
 510 };
 511
 512 static int nvme_loop_create_io_queues(struct nvme_loop_ctrl *ctrl)
 513 {
 514         int ret;
 515
 516         ret = nvme_loop_init_io_queues(ctrl);
 517         if (ret)
 518                 return ret;
 519
 520         memset(&ctrl->tag_set, 0, sizeof(ctrl->tag_set));
 521         ctrl->tag_set.ops = &nvme_loop_mq_ops;
 522         ctrl->tag_set.queue_depth = ctrl->ctrl.opts->queue_size;
 523         ctrl->tag_set.reserved_tags = 1; /* fabric connect */
 524         ctrl->tag_set.numa_node = ctrl->ctrl.numa_node;
 525         ctrl->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
 526         ctrl->tag_set.cmd_size = sizeof(struct nvme_loop_iod) +
 527                 NVME_INLINE_SG_CNT * sizeof(struct scatterlist);
 528         ctrl->tag_set.driver_data = ctrl;
 529         ctrl->tag_set.nr_hw_queues = ctrl->ctrl.queue_count - 1;
 530         ctrl->tag_set.timeout = NVME_IO_TIMEOUT;
 531         ctrl->ctrl.tagset = &ctrl->tag_set;
 532
 533         ret = blk_mq_alloc_tag_set(&ctrl->tag_set);
 534         if (ret)
 535                 goto out_destroy_queues;
 536
 537         ctrl->ctrl.connect_q = blk_mq_init_queue(&ctrl->tag_set);
 538         if (IS_ERR(ctrl->ctrl.connect_q)) {
 539                 ret = PTR_ERR(ctrl->ctrl.connect_q);
 540                 goto out_free_tagset;
 541         }
 542
 543         ret = nvme_loop_connect_io_queues(ctrl);
 544         if (ret)
 545                 goto out_cleanup_connect_q;
 546
 547         return 0;
 548
 549 out_cleanup_connect_q:
 550         blk_cleanup_queue(ctrl->ctrl.connect_q);
 551 out_free_tagset:
 552         blk_mq_free_tag_set(&ctrl->tag_set);
 553 out_destroy_queues:
 554         nvme_loop_destroy_io_queues(ctrl);
 555         return ret;
 556 }
 557
 558 static struct nvmet_port *nvme_loop_find_port(struct nvme_ctrl *ctrl)
 559 {
 560         struct nvmet_port *p, *found = NULL;
 561
 562         mutex_lock(&nvme_loop_ports_mutex);
 563         list_for_each_entry(p, &nvme_loop_ports, entry) {
 564                 /* if no transport address is specified use the first port */
 565                 if ((ctrl->opts->mask & NVMF_OPT_TRADDR) &&
 566                     strcmp(ctrl->opts->traddr, p->disc_addr.traddr))
 567                         continue;
 568                 found = p;
 569                 break;
 570         }
 571         mutex_unlock(&nvme_loop_ports_mutex);
 572         return found;
 573 }
 574
 575 static struct nvme_ctrl *nvme_loop_create_ctrl(struct device *dev,
 576                 struct nvmf_ctrl_options *opts)
 577 {
 578         struct nvme_loop_ctrl *ctrl;
 579         int ret;
 580
 581         ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
 582         if (!ctrl)
 583                 return ERR_PTR(-ENOMEM);
 584         ctrl->ctrl.opts = opts;
 585         INIT_LIST_HEAD(&ctrl->list);
 586
 587         INIT_WORK(&ctrl->ctrl.reset_work, nvme_loop_reset_ctrl_work);
 588
 589         ret = nvme_init_ctrl(&ctrl->ctrl, dev, &nvme_loop_ctrl_ops,
 590                                 0 /* no quirks, we're perfect! */);
 591         if (ret)
 592                 goto out;
 593
 594         if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_CONNECTING))
 595                 WARN_ON_ONCE(1);
 596
 597         ret = -ENOMEM;
 598
 599         ctrl->ctrl.sqsize = opts->queue_size - 1;
 600         ctrl->ctrl.kato = opts->kato;
 601         ctrl->port = nvme_loop_find_port(&ctrl->ctrl);
 602
 603         ctrl->queues = kcalloc(opts->nr_io_queues + 1, sizeof(*ctrl->queues),
 604                         GFP_KERNEL);
 605         if (!ctrl->queues)
 606                 goto out_uninit_ctrl;
 607
 608         ret = nvme_loop_configure_admin_queue(ctrl);
 609         if (ret)
 610                 goto out_free_queues;
 611
 612         if (opts->queue_size > ctrl->ctrl.maxcmd) {
 613                 /* warn if maxcmd is lower than queue_size */
 614                 dev_warn(ctrl->ctrl.device,
 615                         "queue_size %zu > ctrl maxcmd %u, clamping down\n",
 616                         opts->queue_size, ctrl->ctrl.maxcmd);
 617                 opts->queue_size = ctrl->ctrl.maxcmd;
 618         }
 619
 620         if (opts->nr_io_queues) {
 621                 ret = nvme_loop_create_io_queues(ctrl);
 622                 if (ret)
 623                         goto out_remove_admin_queue;
 624         }
 625
 626         nvme_loop_init_iod(ctrl, &ctrl->async_event_iod, 0);
 627
 628         dev_info(ctrl->ctrl.device,
 629                  "new ctrl: \"%s\"\n", ctrl->ctrl.opts->subsysnqn);
 630
 631         if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE))
 632                 WARN_ON_ONCE(1);
 633
 634         mutex_lock(&nvme_loop_ctrl_mutex);
 635         list_add_tail(&ctrl->list, &nvme_loop_ctrl_list);
 636         mutex_unlock(&nvme_loop_ctrl_mutex);
 637
 638         nvme_start_ctrl(&ctrl->ctrl);
 639
 640         return &ctrl->ctrl;
 641
 642 out_remove_admin_queue:
 643         nvme_loop_destroy_admin_queue(ctrl);
 644 out_free_queues:
 645         kfree(ctrl->queues);
 646 out_uninit_ctrl:
 647         nvme_uninit_ctrl(&ctrl->ctrl);
 648         nvme_put_ctrl(&ctrl->ctrl);
 649 out:
 650         if (ret > 0)
 651                 ret = -EIO;
 652         return ERR_PTR(ret);
 653 }
 654
 655 static int nvme_loop_add_port(struct nvmet_port *port)
 656 {
 657         mutex_lock(&nvme_loop_ports_mutex);
 658         list_add_tail(&port->entry, &nvme_loop_ports);
 659         mutex_unlock(&nvme_loop_ports_mutex);
 660         return 0;
 661 }
 662
 663 static void nvme_loop_remove_port(struct nvmet_port *port)
 664 {
 665         mutex_lock(&nvme_loop_ports_mutex);
 666         list_del_init(&port->entry);
 667         mutex_unlock(&nvme_loop_ports_mutex);
 668
 669         /*
 670          * Ensure any ctrls that are in the process of being
 671          * deleted are in fact deleted before we return
 672          * and free the port. This is to prevent active
 673          * ctrls from using a port after it's freed.
 674          */
 675         flush_workqueue(nvme_delete_wq);
 676 }
 677
 678 static const struct nvmet_fabrics_ops nvme_loop_ops = {
 679         .owner          = THIS_MODULE,
 680         .type           = NVMF_TRTYPE_LOOP,
 681         .add_port       = nvme_loop_add_port,
 682         .remove_port    = nvme_loop_remove_port,
 683         .queue_response = nvme_loop_queue_response,
 684         .delete_ctrl    = nvme_loop_delete_ctrl,
 685 };
 686
 687 static struct nvmf_transport_ops nvme_loop_transport = {
 688         .name           = "loop",
 689         .module         = THIS_MODULE,
 690         .create_ctrl    = nvme_loop_create_ctrl,
 691         .allowed_opts   = NVMF_OPT_TRADDR,
 692 };
 693
 694 static int __init nvme_loop_init_module(void)
 695 {
 696         int ret;
 697
 698         ret = nvmet_register_transport(&nvme_loop_ops);
 699         if (ret)
 700                 return ret;
 701
 702         ret = nvmf_register_transport(&nvme_loop_transport);
 703         if (ret)
 704                 nvmet_unregister_transport(&nvme_loop_ops);
 705
 706         return ret;
 707 }
 708
 709 static void __exit nvme_loop_cleanup_module(void)
 710 {
 711         struct nvme_loop_ctrl *ctrl, *next;
 712
 713         nvmf_unregister_transport(&nvme_loop_transport);
 714         nvmet_unregister_transport(&nvme_loop_ops);
 715
 716         mutex_lock(&nvme_loop_ctrl_mutex);
 717         list_for_each_entry_safe(ctrl, next, &nvme_loop_ctrl_list, list)
 718                 nvme_delete_ctrl(&ctrl->ctrl);
 719         mutex_unlock(&nvme_loop_ctrl_mutex);
 720
 721         flush_workqueue(nvme_delete_wq);
 722 }
 723
 724 module_init(nvme_loop_init_module);
 725 module_exit(nvme_loop_cleanup_module);
 726
 727 MODULE_LICENSE("GPL v2");
 728 MODULE_ALIAS("nvmet-transport-254"); /* 254 == NVMF_TRTYPE_LOOP */