drivers/nvme/target/loop.c

   1 /*
   2  * NVMe over Fabrics loopback device.
   3  * Copyright (c) 2015-2016 HGST, a Western Digital Company.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms and conditions of the GNU General Public License,
   7  * version 2, as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  */
  14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  15 #include <linux/scatterlist.h>
  16 #include <linux/blk-mq.h>
  17 #include <linux/nvme.h>
  18 #include <linux/module.h>
  19 #include <linux/parser.h>
  20 #include "nvmet.h"
  21 #include "../host/nvme.h"
  22 #include "../host/fabrics.h"
  23
  24 #define NVME_LOOP_MAX_SEGMENTS          256
  25
  26 struct nvme_loop_iod {
  27         struct nvme_request     nvme_req;
  28         struct nvme_command     cmd;
  29         struct nvme_completion  rsp;
  30         struct nvmet_req        req;
  31         struct nvme_loop_queue  *queue;
  32         struct work_struct      work;
  33         struct sg_table         sg_table;
  34         struct scatterlist      first_sgl[];
  35 };
  36
  37 struct nvme_loop_ctrl {
  38         struct nvme_loop_queue  *queues;
  39
  40         struct blk_mq_tag_set   admin_tag_set;
  41
  42         struct list_head        list;
  43         struct blk_mq_tag_set   tag_set;
  44         struct nvme_loop_iod    async_event_iod;
  45         struct nvme_ctrl        ctrl;
  46
  47         struct nvmet_ctrl       *target_ctrl;
  48 };
  49
  50 static inline struct nvme_loop_ctrl *to_loop_ctrl(struct nvme_ctrl *ctrl)
  51 {
  52         return container_of(ctrl, struct nvme_loop_ctrl, ctrl);
  53 }
  54
  55 enum nvme_loop_queue_flags {
  56         NVME_LOOP_Q_LIVE        = 0,
  57 };
  58
  59 struct nvme_loop_queue {
  60         struct nvmet_cq         nvme_cq;
  61         struct nvmet_sq         nvme_sq;
  62         struct nvme_loop_ctrl   *ctrl;
  63         unsigned long           flags;
  64 };
  65
  66 static struct nvmet_port *nvmet_loop_port;
  67
  68 static LIST_HEAD(nvme_loop_ctrl_list);
  69 static DEFINE_MUTEX(nvme_loop_ctrl_mutex);
  70
  71 static void nvme_loop_queue_response(struct nvmet_req *nvme_req);
  72 static void nvme_loop_delete_ctrl(struct nvmet_ctrl *ctrl);
  73
  74 static const struct nvmet_fabrics_ops nvme_loop_ops;
  75
  76 static inline int nvme_loop_queue_idx(struct nvme_loop_queue *queue)
  77 {
  78         return queue - queue->ctrl->queues;
  79 }
  80
  81 static void nvme_loop_complete_rq(struct request *req)
  82 {
  83         struct nvme_loop_iod *iod = blk_mq_rq_to_pdu(req);
  84
  85         nvme_cleanup_cmd(req);
  86         sg_free_table_chained(&iod->sg_table, true);
  87         nvme_complete_rq(req);
  88 }
  89
  90 static struct blk_mq_tags *nvme_loop_tagset(struct nvme_loop_queue *queue)
  91 {
  92         u32 queue_idx = nvme_loop_queue_idx(queue);
  93
  94         if (queue_idx == 0)
  95                 return queue->ctrl->admin_tag_set.tags[queue_idx];
  96         return queue->ctrl->tag_set.tags[queue_idx - 1];
  97 }
  98
  99 static void nvme_loop_queue_response(struct nvmet_req *req)
 100 {
 101         struct nvme_loop_queue *queue =
 102                 container_of(req->sq, struct nvme_loop_queue, nvme_sq);
 103         struct nvme_completion *cqe = req->rsp;
 104
 105         /*
 106          * AEN requests are special as they don't time out and can
 107          * survive any kind of queue freeze and often don't respond to
 108          * aborts.  We don't even bother to allocate a struct request
 109          * for them but rather special case them here.
 110          */
 111         if (unlikely(nvme_loop_queue_idx(queue) == 0 &&
 112                         cqe->command_id >= NVME_AQ_BLK_MQ_DEPTH)) {
 113                 nvme_complete_async_event(&queue->ctrl->ctrl, cqe->status,
 114                                 &cqe->result);
 115         } else {
 116                 struct request *rq;
 117
 118                 rq = blk_mq_tag_to_rq(nvme_loop_tagset(queue), cqe->command_id);
 119                 if (!rq) {
 120                         dev_err(queue->ctrl->ctrl.device,
 121                                 "tag 0x%x on queue %d not found\n",
 122                                 cqe->command_id, nvme_loop_queue_idx(queue));
 123                         return;
 124                 }
 125
 126                 nvme_end_request(rq, cqe->status, cqe->result);
 127         }
 128 }
 129
 130 static void nvme_loop_execute_work(struct work_struct *work)
 131 {
 132         struct nvme_loop_iod *iod =
 133                 container_of(work, struct nvme_loop_iod, work);
 134
 135         nvmet_req_execute(&iod->req);
 136 }
 137
 138 static enum blk_eh_timer_return
 139 nvme_loop_timeout(struct request *rq, bool reserved)
 140 {
 141         struct nvme_loop_iod *iod = blk_mq_rq_to_pdu(rq);
 142
 143         /* queue error recovery */
 144         nvme_reset_ctrl(&iod->queue->ctrl->ctrl);
 145
 146         /* fail with DNR on admin cmd timeout */
 147         nvme_req(rq)->status = NVME_SC_ABORT_REQ | NVME_SC_DNR;
 148
 149         return BLK_EH_HANDLED;
 150 }
 151
 152 static blk_status_t nvme_loop_queue_rq(struct blk_mq_hw_ctx *hctx,
 153                 const struct blk_mq_queue_data *bd)
 154 {
 155         struct nvme_ns *ns = hctx->queue->queuedata;
 156         struct nvme_loop_queue *queue = hctx->driver_data;
 157         struct request *req = bd->rq;
 158         struct nvme_loop_iod *iod = blk_mq_rq_to_pdu(req);
 159         blk_status_t ret;
 160
 161         ret = nvmf_check_if_ready(&queue->ctrl->ctrl, req,
 162                 test_bit(NVME_LOOP_Q_LIVE, &queue->flags), true);
 163         if (unlikely(ret))
 164                 return ret;
 165
 166         ret = nvme_setup_cmd(ns, req, &iod->cmd);
 167         if (ret)
 168                 return ret;
 169
 170         blk_mq_start_request(req);
 171         iod->cmd.common.flags |= NVME_CMD_SGL_METABUF;
 172         iod->req.port = nvmet_loop_port;
 173         if (!nvmet_req_init(&iod->req, &queue->nvme_cq,
 174                         &queue->nvme_sq, &nvme_loop_ops))
 175                 return BLK_STS_OK;
 176
 177         if (blk_rq_payload_bytes(req)) {
 178                 iod->sg_table.sgl = iod->first_sgl;
 179                 if (sg_alloc_table_chained(&iod->sg_table,
 180                                 blk_rq_nr_phys_segments(req),
 181                                 iod->sg_table.sgl))
 182                         return BLK_STS_RESOURCE;
 183
 184                 iod->req.sg = iod->sg_table.sgl;
 185                 iod->req.sg_cnt = blk_rq_map_sg(req->q, req, iod->sg_table.sgl);
 186                 iod->req.transfer_len = blk_rq_payload_bytes(req);
 187         }
 188
 189         schedule_work(&iod->work);
 190         return BLK_STS_OK;
 191 }
 192
 193 static void nvme_loop_submit_async_event(struct nvme_ctrl *arg)
 194 {
 195         struct nvme_loop_ctrl *ctrl = to_loop_ctrl(arg);
 196         struct nvme_loop_queue *queue = &ctrl->queues[0];
 197         struct nvme_loop_iod *iod = &ctrl->async_event_iod;
 198
 199         memset(&iod->cmd, 0, sizeof(iod->cmd));
 200         iod->cmd.common.opcode = nvme_admin_async_event;
 201         iod->cmd.common.command_id = NVME_AQ_BLK_MQ_DEPTH;
 202         iod->cmd.common.flags |= NVME_CMD_SGL_METABUF;
 203
 204         if (!nvmet_req_init(&iod->req, &queue->nvme_cq, &queue->nvme_sq,
 205                         &nvme_loop_ops)) {
 206                 dev_err(ctrl->ctrl.device, "failed async event work\n");
 207                 return;
 208         }
 209
 210         schedule_work(&iod->work);
 211 }
 212
 213 static int nvme_loop_init_iod(struct nvme_loop_ctrl *ctrl,
 214                 struct nvme_loop_iod *iod, unsigned int queue_idx)
 215 {
 216         iod->req.cmd = &iod->cmd;
 217         iod->req.rsp = &iod->rsp;
 218         iod->queue = &ctrl->queues[queue_idx];
 219         INIT_WORK(&iod->work, nvme_loop_execute_work);
 220         return 0;
 221 }
 222
 223 static int nvme_loop_init_request(struct blk_mq_tag_set *set,
 224                 struct request *req, unsigned int hctx_idx,
 225                 unsigned int numa_node)
 226 {
 227         struct nvme_loop_ctrl *ctrl = set->driver_data;
 228
 229         return nvme_loop_init_iod(ctrl, blk_mq_rq_to_pdu(req),
 230                         (set == &ctrl->tag_set) ? hctx_idx + 1 : 0);
 231 }
 232
 233 static int nvme_loop_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
 234                 unsigned int hctx_idx)
 235 {
 236         struct nvme_loop_ctrl *ctrl = data;
 237         struct nvme_loop_queue *queue = &ctrl->queues[hctx_idx + 1];
 238
 239         BUG_ON(hctx_idx >= ctrl->ctrl.queue_count);
 240
 241         hctx->driver_data = queue;
 242         return 0;
 243 }
 244
 245 static int nvme_loop_init_admin_hctx(struct blk_mq_hw_ctx *hctx, void *data,
 246                 unsigned int hctx_idx)
 247 {
 248         struct nvme_loop_ctrl *ctrl = data;
 249         struct nvme_loop_queue *queue = &ctrl->queues[0];
 250
 251         BUG_ON(hctx_idx != 0);
 252
 253         hctx->driver_data = queue;
 254         return 0;
 255 }
 256
 257 static const struct blk_mq_ops nvme_loop_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_hctx,
 262         .timeout        = nvme_loop_timeout,
 263 };
 264
 265 static const struct blk_mq_ops nvme_loop_admin_mq_ops = {
 266         .queue_rq       = nvme_loop_queue_rq,
 267         .complete       = nvme_loop_complete_rq,
 268         .init_request   = nvme_loop_init_request,
 269         .init_hctx      = nvme_loop_init_admin_hctx,
 270         .timeout        = nvme_loop_timeout,
 271 };
 272
 273 static void nvme_loop_destroy_admin_queue(struct nvme_loop_ctrl *ctrl)
 274 {
 275         clear_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[0].flags);
 276         nvmet_sq_destroy(&ctrl->queues[0].nvme_sq);
 277         blk_cleanup_queue(ctrl->ctrl.admin_q);
 278         blk_mq_free_tag_set(&ctrl->admin_tag_set);
 279 }
 280
 281 static void nvme_loop_free_ctrl(struct nvme_ctrl *nctrl)
 282 {
 283         struct nvme_loop_ctrl *ctrl = to_loop_ctrl(nctrl);
 284
 285         if (list_empty(&ctrl->list))
 286                 goto free_ctrl;
 287
 288         mutex_lock(&nvme_loop_ctrl_mutex);
 289         list_del(&ctrl->list);
 290         mutex_unlock(&nvme_loop_ctrl_mutex);
 291
 292         if (nctrl->tagset) {
 293                 blk_cleanup_queue(ctrl->ctrl.connect_q);
 294                 blk_mq_free_tag_set(&ctrl->tag_set);
 295         }
 296         kfree(ctrl->queues);
 297         nvmf_free_options(nctrl->opts);
 298 free_ctrl:
 299         kfree(ctrl);
 300 }
 301
 302 static void nvme_loop_destroy_io_queues(struct nvme_loop_ctrl *ctrl)
 303 {
 304         int i;
 305
 306         for (i = 1; i < ctrl->ctrl.queue_count; i++) {
 307                 clear_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[i].flags);
 308                 nvmet_sq_destroy(&ctrl->queues[i].nvme_sq);
 309         }
 310 }
 311
 312 static int nvme_loop_init_io_queues(struct nvme_loop_ctrl *ctrl)
 313 {
 314         struct nvmf_ctrl_options *opts = ctrl->ctrl.opts;
 315         unsigned int nr_io_queues;
 316         int ret, i;
 317
 318         nr_io_queues = min(opts->nr_io_queues, num_online_cpus());
 319         ret = nvme_set_queue_count(&ctrl->ctrl, &nr_io_queues);
 320         if (ret || !nr_io_queues)
 321                 return ret;
 322
 323         dev_info(ctrl->ctrl.device, "creating %d I/O queues.\n", nr_io_queues);
 324
 325         for (i = 1; i <= nr_io_queues; i++) {
 326                 ctrl->queues[i].ctrl = ctrl;
 327                 ret = nvmet_sq_init(&ctrl->queues[i].nvme_sq);
 328                 if (ret)
 329                         goto out_destroy_queues;
 330
 331                 ctrl->ctrl.queue_count++;
 332         }
 333
 334         return 0;
 335
 336 out_destroy_queues:
 337         nvme_loop_destroy_io_queues(ctrl);
 338         return ret;
 339 }
 340
 341 static int nvme_loop_connect_io_queues(struct nvme_loop_ctrl *ctrl)
 342 {
 343         int i, ret;
 344
 345         for (i = 1; i < ctrl->ctrl.queue_count; i++) {
 346                 ret = nvmf_connect_io_queue(&ctrl->ctrl, i);
 347                 if (ret)
 348                         return ret;
 349                 set_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[i].flags);
 350         }
 351
 352         return 0;
 353 }
 354
 355 static int nvme_loop_configure_admin_queue(struct nvme_loop_ctrl *ctrl)
 356 {
 357         int error;
 358
 359         memset(&ctrl->admin_tag_set, 0, sizeof(ctrl->admin_tag_set));
 360         ctrl->admin_tag_set.ops = &nvme_loop_admin_mq_ops;
 361         ctrl->admin_tag_set.queue_depth = NVME_AQ_MQ_TAG_DEPTH;
 362         ctrl->admin_tag_set.reserved_tags = 2; /* connect + keep-alive */
 363         ctrl->admin_tag_set.numa_node = NUMA_NO_NODE;
 364         ctrl->admin_tag_set.cmd_size = sizeof(struct nvme_loop_iod) +
 365                 SG_CHUNK_SIZE * sizeof(struct scatterlist);
 366         ctrl->admin_tag_set.driver_data = ctrl;
 367         ctrl->admin_tag_set.nr_hw_queues = 1;
 368         ctrl->admin_tag_set.timeout = ADMIN_TIMEOUT;
 369         ctrl->admin_tag_set.flags = BLK_MQ_F_NO_SCHED;
 370
 371         ctrl->queues[0].ctrl = ctrl;
 372         error = nvmet_sq_init(&ctrl->queues[0].nvme_sq);
 373         if (error)
 374                 return error;
 375         ctrl->ctrl.queue_count = 1;
 376
 377         error = blk_mq_alloc_tag_set(&ctrl->admin_tag_set);
 378         if (error)
 379                 goto out_free_sq;
 380         ctrl->ctrl.admin_tagset = &ctrl->admin_tag_set;
 381
 382         ctrl->ctrl.admin_q = blk_mq_init_queue(&ctrl->admin_tag_set);
 383         if (IS_ERR(ctrl->ctrl.admin_q)) {
 384                 error = PTR_ERR(ctrl->ctrl.admin_q);
 385                 goto out_free_tagset;
 386         }
 387
 388         error = nvmf_connect_admin_queue(&ctrl->ctrl);
 389         if (error)
 390                 goto out_cleanup_queue;
 391
 392         set_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[0].flags);
 393
 394         error = nvmf_reg_read64(&ctrl->ctrl, NVME_REG_CAP, &ctrl->ctrl.cap);
 395         if (error) {
 396                 dev_err(ctrl->ctrl.device,
 397                         "prop_get NVME_REG_CAP failed\n");
 398                 goto out_cleanup_queue;
 399         }
 400
 401         ctrl->ctrl.sqsize =
 402                 min_t(int, NVME_CAP_MQES(ctrl->ctrl.cap), ctrl->ctrl.sqsize);
 403
 404         error = nvme_enable_ctrl(&ctrl->ctrl, ctrl->ctrl.cap);
 405         if (error)
 406                 goto out_cleanup_queue;
 407
 408         ctrl->ctrl.max_hw_sectors =
 409                 (NVME_LOOP_MAX_SEGMENTS - 1) << (PAGE_SHIFT - 9);
 410
 411         error = nvme_init_identify(&ctrl->ctrl);
 412         if (error)
 413                 goto out_cleanup_queue;
 414
 415         return 0;
 416
 417 out_cleanup_queue:
 418         blk_cleanup_queue(ctrl->ctrl.admin_q);
 419 out_free_tagset:
 420         blk_mq_free_tag_set(&ctrl->admin_tag_set);
 421 out_free_sq:
 422         nvmet_sq_destroy(&ctrl->queues[0].nvme_sq);
 423         return error;
 424 }
 425
 426 static void nvme_loop_shutdown_ctrl(struct nvme_loop_ctrl *ctrl)
 427 {
 428         if (ctrl->ctrl.queue_count > 1) {
 429                 nvme_stop_queues(&ctrl->ctrl);
 430                 blk_mq_tagset_busy_iter(&ctrl->tag_set,
 431                                         nvme_cancel_request, &ctrl->ctrl);
 432                 nvme_loop_destroy_io_queues(ctrl);
 433         }
 434
 435         if (ctrl->ctrl.state == NVME_CTRL_LIVE)
 436                 nvme_shutdown_ctrl(&ctrl->ctrl);
 437
 438         blk_mq_quiesce_queue(ctrl->ctrl.admin_q);
 439         blk_mq_tagset_busy_iter(&ctrl->admin_tag_set,
 440                                 nvme_cancel_request, &ctrl->ctrl);
 441         blk_mq_unquiesce_queue(ctrl->ctrl.admin_q);
 442         nvme_loop_destroy_admin_queue(ctrl);
 443 }
 444
 445 static void nvme_loop_delete_ctrl_host(struct nvme_ctrl *ctrl)
 446 {
 447         nvme_loop_shutdown_ctrl(to_loop_ctrl(ctrl));
 448 }
 449
 450 static void nvme_loop_delete_ctrl(struct nvmet_ctrl *nctrl)
 451 {
 452         struct nvme_loop_ctrl *ctrl;
 453
 454         mutex_lock(&nvme_loop_ctrl_mutex);
 455         list_for_each_entry(ctrl, &nvme_loop_ctrl_list, list) {
 456                 if (ctrl->ctrl.cntlid == nctrl->cntlid)
 457                         nvme_delete_ctrl(&ctrl->ctrl);
 458         }
 459         mutex_unlock(&nvme_loop_ctrl_mutex);
 460 }
 461
 462 static void nvme_loop_reset_ctrl_work(struct work_struct *work)
 463 {
 464         struct nvme_loop_ctrl *ctrl =
 465                 container_of(work, struct nvme_loop_ctrl, ctrl.reset_work);
 466         bool changed;
 467         int ret;
 468
 469         nvme_stop_ctrl(&ctrl->ctrl);
 470         nvme_loop_shutdown_ctrl(ctrl);
 471
 472         if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_CONNECTING)) {
 473                 /* state change failure should never happen */
 474                 WARN_ON_ONCE(1);
 475                 return;
 476         }
 477
 478         ret = nvme_loop_configure_admin_queue(ctrl);
 479         if (ret)
 480                 goto out_disable;
 481
 482         ret = nvme_loop_init_io_queues(ctrl);
 483         if (ret)
 484                 goto out_destroy_admin;
 485
 486         ret = nvme_loop_connect_io_queues(ctrl);
 487         if (ret)
 488                 goto out_destroy_io;
 489
 490         blk_mq_update_nr_hw_queues(&ctrl->tag_set,
 491                         ctrl->ctrl.queue_count - 1);
 492
 493         changed = nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE);
 494         WARN_ON_ONCE(!changed);
 495
 496         nvme_start_ctrl(&ctrl->ctrl);
 497
 498         return;
 499
 500 out_destroy_io:
 501         nvme_loop_destroy_io_queues(ctrl);
 502 out_destroy_admin:
 503         nvme_loop_destroy_admin_queue(ctrl);
 504 out_disable:
 505         dev_warn(ctrl->ctrl.device, "Removing after reset failure\n");
 506         nvme_uninit_ctrl(&ctrl->ctrl);
 507         nvme_put_ctrl(&ctrl->ctrl);
 508 }
 509
 510 static const struct nvme_ctrl_ops nvme_loop_ctrl_ops = {
 511         .name                   = "loop",
 512         .module                 = THIS_MODULE,
 513         .flags                  = NVME_F_FABRICS,
 514         .reg_read32             = nvmf_reg_read32,
 515         .reg_read64             = nvmf_reg_read64,
 516         .reg_write32            = nvmf_reg_write32,
 517         .free_ctrl              = nvme_loop_free_ctrl,
 518         .submit_async_event     = nvme_loop_submit_async_event,
 519         .delete_ctrl            = nvme_loop_delete_ctrl_host,
 520 };
 521
 522 static int nvme_loop_create_io_queues(struct nvme_loop_ctrl *ctrl)
 523 {
 524         int ret;
 525
 526         ret = nvme_loop_init_io_queues(ctrl);
 527         if (ret)
 528                 return ret;
 529
 530         memset(&ctrl->tag_set, 0, sizeof(ctrl->tag_set));
 531         ctrl->tag_set.ops = &nvme_loop_mq_ops;
 532         ctrl->tag_set.queue_depth = ctrl->ctrl.opts->queue_size;
 533         ctrl->tag_set.reserved_tags = 1; /* fabric connect */
 534         ctrl->tag_set.numa_node = NUMA_NO_NODE;
 535         ctrl->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
 536         ctrl->tag_set.cmd_size = sizeof(struct nvme_loop_iod) +
 537                 SG_CHUNK_SIZE * sizeof(struct scatterlist);
 538         ctrl->tag_set.driver_data = ctrl;
 539         ctrl->tag_set.nr_hw_queues = ctrl->ctrl.queue_count - 1;
 540         ctrl->tag_set.timeout = NVME_IO_TIMEOUT;
 541         ctrl->ctrl.tagset = &ctrl->tag_set;
 542
 543         ret = blk_mq_alloc_tag_set(&ctrl->tag_set);
 544         if (ret)
 545                 goto out_destroy_queues;
 546
 547         ctrl->ctrl.connect_q = blk_mq_init_queue(&ctrl->tag_set);
 548         if (IS_ERR(ctrl->ctrl.connect_q)) {
 549                 ret = PTR_ERR(ctrl->ctrl.connect_q);
 550                 goto out_free_tagset;
 551         }
 552
 553         ret = nvme_loop_connect_io_queues(ctrl);
 554         if (ret)
 555                 goto out_cleanup_connect_q;
 556
 557         return 0;
 558
 559 out_cleanup_connect_q:
 560         blk_cleanup_queue(ctrl->ctrl.connect_q);
 561 out_free_tagset:
 562         blk_mq_free_tag_set(&ctrl->tag_set);
 563 out_destroy_queues:
 564         nvme_loop_destroy_io_queues(ctrl);
 565         return ret;
 566 }
 567
 568 static struct nvme_ctrl *nvme_loop_create_ctrl(struct device *dev,
 569                 struct nvmf_ctrl_options *opts)
 570 {
 571         struct nvme_loop_ctrl *ctrl;
 572         bool changed;
 573         int ret;
 574
 575         ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
 576         if (!ctrl)
 577                 return ERR_PTR(-ENOMEM);
 578         ctrl->ctrl.opts = opts;
 579         INIT_LIST_HEAD(&ctrl->list);
 580
 581         INIT_WORK(&ctrl->ctrl.reset_work, nvme_loop_reset_ctrl_work);
 582
 583         ret = nvme_init_ctrl(&ctrl->ctrl, dev, &nvme_loop_ctrl_ops,
 584                                 0 /* no quirks, we're perfect! */);
 585         if (ret)
 586                 goto out_put_ctrl;
 587
 588         ret = -ENOMEM;
 589
 590         ctrl->ctrl.sqsize = opts->queue_size - 1;
 591         ctrl->ctrl.kato = opts->kato;
 592
 593         ctrl->queues = kcalloc(opts->nr_io_queues + 1, sizeof(*ctrl->queues),
 594                         GFP_KERNEL);
 595         if (!ctrl->queues)
 596                 goto out_uninit_ctrl;
 597
 598         ret = nvme_loop_configure_admin_queue(ctrl);
 599         if (ret)
 600                 goto out_free_queues;
 601
 602         if (opts->queue_size > ctrl->ctrl.maxcmd) {
 603                 /* warn if maxcmd is lower than queue_size */
 604                 dev_warn(ctrl->ctrl.device,
 605                         "queue_size %zu > ctrl maxcmd %u, clamping down\n",
 606                         opts->queue_size, ctrl->ctrl.maxcmd);
 607                 opts->queue_size = ctrl->ctrl.maxcmd;
 608         }
 609
 610         if (opts->nr_io_queues) {
 611                 ret = nvme_loop_create_io_queues(ctrl);
 612                 if (ret)
 613                         goto out_remove_admin_queue;
 614         }
 615
 616         nvme_loop_init_iod(ctrl, &ctrl->async_event_iod, 0);
 617
 618         dev_info(ctrl->ctrl.device,
 619                  "new ctrl: \"%s\"\n", ctrl->ctrl.opts->subsysnqn);
 620
 621         nvme_get_ctrl(&ctrl->ctrl);
 622
 623         changed = nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE);
 624         WARN_ON_ONCE(!changed);
 625
 626         mutex_lock(&nvme_loop_ctrl_mutex);
 627         list_add_tail(&ctrl->list, &nvme_loop_ctrl_list);
 628         mutex_unlock(&nvme_loop_ctrl_mutex);
 629
 630         nvme_start_ctrl(&ctrl->ctrl);
 631
 632         return &ctrl->ctrl;
 633
 634 out_remove_admin_queue:
 635         nvme_loop_destroy_admin_queue(ctrl);
 636 out_free_queues:
 637         kfree(ctrl->queues);
 638 out_uninit_ctrl:
 639         nvme_uninit_ctrl(&ctrl->ctrl);
 640 out_put_ctrl:
 641         nvme_put_ctrl(&ctrl->ctrl);
 642         if (ret > 0)
 643                 ret = -EIO;
 644         return ERR_PTR(ret);
 645 }
 646
 647 static int nvme_loop_add_port(struct nvmet_port *port)
 648 {
 649         /*
 650          * XXX: disalow adding more than one port so
 651          * there is no connection rejections when a
 652          * a subsystem is assigned to a port for which
 653          * loop doesn't have a pointer.
 654          * This scenario would be possible if we allowed
 655          * more than one port to be added and a subsystem
 656          * was assigned to a port other than nvmet_loop_port.
 657          */
 658
 659         if (nvmet_loop_port)
 660                 return -EPERM;
 661
 662         nvmet_loop_port = port;
 663         return 0;
 664 }
 665
 666 static void nvme_loop_remove_port(struct nvmet_port *port)
 667 {
 668         if (port == nvmet_loop_port)
 669                 nvmet_loop_port = NULL;
 670 }
 671
 672 static const struct nvmet_fabrics_ops nvme_loop_ops = {
 673         .owner          = THIS_MODULE,
 674         .type           = NVMF_TRTYPE_LOOP,
 675         .add_port       = nvme_loop_add_port,
 676         .remove_port    = nvme_loop_remove_port,
 677         .queue_response = nvme_loop_queue_response,
 678         .delete_ctrl    = nvme_loop_delete_ctrl,
 679 };
 680
 681 static struct nvmf_transport_ops nvme_loop_transport = {
 682         .name           = "loop",
 683         .module         = THIS_MODULE,
 684         .create_ctrl    = nvme_loop_create_ctrl,
 685 };
 686
 687 static int __init nvme_loop_init_module(void)
 688 {
 689         int ret;
 690
 691         ret = nvmet_register_transport(&nvme_loop_ops);
 692         if (ret)
 693                 return ret;
 694
 695         ret = nvmf_register_transport(&nvme_loop_transport);
 696         if (ret)
 697                 nvmet_unregister_transport(&nvme_loop_ops);
 698
 699         return ret;
 700 }
 701
 702 static void __exit nvme_loop_cleanup_module(void)
 703 {
 704         struct nvme_loop_ctrl *ctrl, *next;
 705
 706         nvmf_unregister_transport(&nvme_loop_transport);
 707         nvmet_unregister_transport(&nvme_loop_ops);
 708
 709         mutex_lock(&nvme_loop_ctrl_mutex);
 710         list_for_each_entry_safe(ctrl, next, &nvme_loop_ctrl_list, list)
 711                 nvme_delete_ctrl(&ctrl->ctrl);
 712         mutex_unlock(&nvme_loop_ctrl_mutex);
 713
 714         flush_workqueue(nvme_delete_wq);
 715 }
 716
 717 module_init(nvme_loop_init_module);
 718 module_exit(nvme_loop_cleanup_module);
 719
 720 MODULE_LICENSE("GPL v2");
 721 MODULE_ALIAS("nvmet-transport-254"); /* 254 == NVMF_TRTYPE_LOOP */