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/delay.h>
  17 #include <linux/blk-mq.h>
  18 #include <linux/nvme.h>
  19 #include <linux/module.h>
  20 #include <linux/parser.h>
  21 #include <linux/t10-pi.h>
  22 #include "nvmet.h"
  23 #include "../host/nvme.h"
  24 #include "../host/fabrics.h"
  25
  26 #define NVME_LOOP_AQ_DEPTH              256
  27
  28 #define NVME_LOOP_MAX_SEGMENTS          256
  29
  30 /*
  31  * We handle AEN commands ourselves and don't even let the
  32  * block layer know about them.
  33  */
  34 #define NVME_LOOP_NR_AEN_COMMANDS       1
  35 #define NVME_LOOP_AQ_BLKMQ_DEPTH        \
  36         (NVME_LOOP_AQ_DEPTH - NVME_LOOP_NR_AEN_COMMANDS)
  37
  38 struct nvme_loop_iod {
  39         struct nvme_request     nvme_req;
  40         struct nvme_command     cmd;
  41         struct nvme_completion  rsp;
  42         struct nvmet_req        req;
  43         struct nvme_loop_queue  *queue;
  44         struct work_struct      work;
  45         struct sg_table         sg_table;
  46         struct scatterlist      first_sgl[];
  47 };
  48
  49 struct nvme_loop_ctrl {
  50         spinlock_t              lock;
  51         struct nvme_loop_queue  *queues;
  52         u32                     queue_count;
  53
  54         struct blk_mq_tag_set   admin_tag_set;
  55
  56         struct list_head        list;
  57         u64                     cap;
  58         struct blk_mq_tag_set   tag_set;
  59         struct nvme_loop_iod    async_event_iod;
  60         struct nvme_ctrl        ctrl;
  61
  62         struct nvmet_ctrl       *target_ctrl;
  63         struct work_struct      delete_work;
  64         struct work_struct      reset_work;
  65 };
  66
  67 static inline struct nvme_loop_ctrl *to_loop_ctrl(struct nvme_ctrl *ctrl)
  68 {
  69         return container_of(ctrl, struct nvme_loop_ctrl, ctrl);
  70 }
  71
  72 struct nvme_loop_queue {
  73         struct nvmet_cq         nvme_cq;
  74         struct nvmet_sq         nvme_sq;
  75         struct nvme_loop_ctrl   *ctrl;
  76 };
  77
  78 static struct nvmet_port *nvmet_loop_port;
  79
  80 static LIST_HEAD(nvme_loop_ctrl_list);
  81 static DEFINE_MUTEX(nvme_loop_ctrl_mutex);
  82
  83 static void nvme_loop_queue_response(struct nvmet_req *nvme_req);
  84 static void nvme_loop_delete_ctrl(struct nvmet_ctrl *ctrl);
  85
  86 static struct nvmet_fabrics_ops nvme_loop_ops;
  87
  88 static inline int nvme_loop_queue_idx(struct nvme_loop_queue *queue)
  89 {
  90         return queue - queue->ctrl->queues;
  91 }
  92
  93 static void nvme_loop_complete_rq(struct request *req)
  94 {
  95         struct nvme_loop_iod *iod = blk_mq_rq_to_pdu(req);
  96         int error = 0;
  97
  98         nvme_cleanup_cmd(req);
  99         sg_free_table_chained(&iod->sg_table, true);
 100
 101         if (unlikely(req->errors)) {
 102                 if (nvme_req_needs_retry(req, req->errors)) {
 103                         nvme_requeue_req(req);
 104                         return;
 105                 }
 106
 107                 if (req->cmd_type == REQ_TYPE_DRV_PRIV)
 108                         error = req->errors;
 109                 else
 110                         error = nvme_error_status(req->errors);
 111         }
 112
 113         blk_mq_end_request(req, error);
 114 }
 115
 116 static void nvme_loop_queue_response(struct nvmet_req *req)
 117 {
 118         struct nvme_loop_iod *iod =
 119                 container_of(req, struct nvme_loop_iod, req);
 120         struct nvme_completion *cqe = &iod->rsp;
 121
 122         /*
 123          * AEN requests are special as they don't time out and can
 124          * survive any kind of queue freeze and often don't respond to
 125          * aborts.  We don't even bother to allocate a struct request
 126          * for them but rather special case them here.
 127          */
 128         if (unlikely(nvme_loop_queue_idx(iod->queue) == 0 &&
 129                         cqe->command_id >= NVME_LOOP_AQ_BLKMQ_DEPTH)) {
 130                 nvme_complete_async_event(&iod->queue->ctrl->ctrl, cqe);
 131         } else {
 132                 struct request *rq = blk_mq_rq_from_pdu(iod);
 133
 134                 iod->nvme_req.result = cqe->result;
 135                 blk_mq_complete_request(rq, le16_to_cpu(cqe->status) >> 1);
 136         }
 137 }
 138
 139 static void nvme_loop_execute_work(struct work_struct *work)
 140 {
 141         struct nvme_loop_iod *iod =
 142                 container_of(work, struct nvme_loop_iod, work);
 143
 144         iod->req.execute(&iod->req);
 145 }
 146
 147 static enum blk_eh_timer_return
 148 nvme_loop_timeout(struct request *rq, bool reserved)
 149 {
 150         struct nvme_loop_iod *iod = blk_mq_rq_to_pdu(rq);
 151
 152         /* queue error recovery */
 153         schedule_work(&iod->queue->ctrl->reset_work);
 154
 155         /* fail with DNR on admin cmd timeout */
 156         rq->errors = NVME_SC_ABORT_REQ | NVME_SC_DNR;
 157
 158         return BLK_EH_HANDLED;
 159 }
 160
 161 static int nvme_loop_queue_rq(struct blk_mq_hw_ctx *hctx,
 162                 const struct blk_mq_queue_data *bd)
 163 {
 164         struct nvme_ns *ns = hctx->queue->queuedata;
 165         struct nvme_loop_queue *queue = hctx->driver_data;
 166         struct request *req = bd->rq;
 167         struct nvme_loop_iod *iod = blk_mq_rq_to_pdu(req);
 168         int ret;
 169
 170         ret = nvme_setup_cmd(ns, req, &iod->cmd);
 171         if (ret)
 172                 return ret;
 173
 174         iod->cmd.common.flags |= NVME_CMD_SGL_METABUF;
 175         iod->req.port = nvmet_loop_port;
 176         if (!nvmet_req_init(&iod->req, &queue->nvme_cq,
 177                         &queue->nvme_sq, &nvme_loop_ops)) {
 178                 nvme_cleanup_cmd(req);
 179                 blk_mq_start_request(req);
 180                 nvme_loop_queue_response(&iod->req);
 181                 return 0;
 182         }
 183
 184         if (blk_rq_bytes(req)) {
 185                 iod->sg_table.sgl = iod->first_sgl;
 186                 ret = sg_alloc_table_chained(&iod->sg_table,
 187                         req->nr_phys_segments, iod->sg_table.sgl);
 188                 if (ret)
 189                         return BLK_MQ_RQ_QUEUE_BUSY;
 190
 191                 iod->req.sg = iod->sg_table.sgl;
 192                 iod->req.sg_cnt = blk_rq_map_sg(req->q, req, iod->sg_table.sgl);
 193                 BUG_ON(iod->req.sg_cnt > req->nr_phys_segments);
 194         }
 195
 196         iod->cmd.common.command_id = req->tag;
 197         blk_mq_start_request(req);
 198
 199         schedule_work(&iod->work);
 200         return 0;
 201 }
 202
 203 static void nvme_loop_submit_async_event(struct nvme_ctrl *arg, int aer_idx)
 204 {
 205         struct nvme_loop_ctrl *ctrl = to_loop_ctrl(arg);
 206         struct nvme_loop_queue *queue = &ctrl->queues[0];
 207         struct nvme_loop_iod *iod = &ctrl->async_event_iod;
 208
 209         memset(&iod->cmd, 0, sizeof(iod->cmd));
 210         iod->cmd.common.opcode = nvme_admin_async_event;
 211         iod->cmd.common.command_id = NVME_LOOP_AQ_BLKMQ_DEPTH;
 212         iod->cmd.common.flags |= NVME_CMD_SGL_METABUF;
 213
 214         if (!nvmet_req_init(&iod->req, &queue->nvme_cq, &queue->nvme_sq,
 215                         &nvme_loop_ops)) {
 216                 dev_err(ctrl->ctrl.device, "failed async event work\n");
 217                 return;
 218         }
 219
 220         schedule_work(&iod->work);
 221 }
 222
 223 static int nvme_loop_init_iod(struct nvme_loop_ctrl *ctrl,
 224                 struct nvme_loop_iod *iod, unsigned int queue_idx)
 225 {
 226         BUG_ON(queue_idx >= ctrl->queue_count);
 227
 228         iod->req.cmd = &iod->cmd;
 229         iod->req.rsp = &iod->rsp;
 230         iod->queue = &ctrl->queues[queue_idx];
 231         INIT_WORK(&iod->work, nvme_loop_execute_work);
 232         return 0;
 233 }
 234
 235 static int nvme_loop_init_request(void *data, struct request *req,
 236                                 unsigned int hctx_idx, unsigned int rq_idx,
 237                                 unsigned int numa_node)
 238 {
 239         return nvme_loop_init_iod(data, blk_mq_rq_to_pdu(req), hctx_idx + 1);
 240 }
 241
 242 static int nvme_loop_init_admin_request(void *data, struct request *req,
 243                                 unsigned int hctx_idx, unsigned int rq_idx,
 244                                 unsigned int numa_node)
 245 {
 246         return nvme_loop_init_iod(data, blk_mq_rq_to_pdu(req), 0);
 247 }
 248
 249 static int nvme_loop_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
 250                 unsigned int hctx_idx)
 251 {
 252         struct nvme_loop_ctrl *ctrl = data;
 253         struct nvme_loop_queue *queue = &ctrl->queues[hctx_idx + 1];
 254
 255         BUG_ON(hctx_idx >= ctrl->queue_count);
 256
 257         hctx->driver_data = queue;
 258         return 0;
 259 }
 260
 261 static int nvme_loop_init_admin_hctx(struct blk_mq_hw_ctx *hctx, void *data,
 262                 unsigned int hctx_idx)
 263 {
 264         struct nvme_loop_ctrl *ctrl = data;
 265         struct nvme_loop_queue *queue = &ctrl->queues[0];
 266
 267         BUG_ON(hctx_idx != 0);
 268
 269         hctx->driver_data = queue;
 270         return 0;
 271 }
 272
 273 static struct blk_mq_ops nvme_loop_mq_ops = {
 274         .queue_rq       = nvme_loop_queue_rq,
 275         .complete       = nvme_loop_complete_rq,
 276         .init_request   = nvme_loop_init_request,
 277         .init_hctx      = nvme_loop_init_hctx,
 278         .timeout        = nvme_loop_timeout,
 279 };
 280
 281 static struct blk_mq_ops nvme_loop_admin_mq_ops = {
 282         .queue_rq       = nvme_loop_queue_rq,
 283         .complete       = nvme_loop_complete_rq,
 284         .init_request   = nvme_loop_init_admin_request,
 285         .init_hctx      = nvme_loop_init_admin_hctx,
 286         .timeout        = nvme_loop_timeout,
 287 };
 288
 289 static void nvme_loop_destroy_admin_queue(struct nvme_loop_ctrl *ctrl)
 290 {
 291         blk_cleanup_queue(ctrl->ctrl.admin_q);
 292         blk_mq_free_tag_set(&ctrl->admin_tag_set);
 293         nvmet_sq_destroy(&ctrl->queues[0].nvme_sq);
 294 }
 295
 296 static void nvme_loop_free_ctrl(struct nvme_ctrl *nctrl)
 297 {
 298         struct nvme_loop_ctrl *ctrl = to_loop_ctrl(nctrl);
 299
 300         if (list_empty(&ctrl->list))
 301                 goto free_ctrl;
 302
 303         mutex_lock(&nvme_loop_ctrl_mutex);
 304         list_del(&ctrl->list);
 305         mutex_unlock(&nvme_loop_ctrl_mutex);
 306
 307         if (nctrl->tagset) {
 308                 blk_cleanup_queue(ctrl->ctrl.connect_q);
 309                 blk_mq_free_tag_set(&ctrl->tag_set);
 310         }
 311         kfree(ctrl->queues);
 312         nvmf_free_options(nctrl->opts);
 313 free_ctrl:
 314         kfree(ctrl);
 315 }
 316
 317 static int nvme_loop_configure_admin_queue(struct nvme_loop_ctrl *ctrl)
 318 {
 319         int error;
 320
 321         memset(&ctrl->admin_tag_set, 0, sizeof(ctrl->admin_tag_set));
 322         ctrl->admin_tag_set.ops = &nvme_loop_admin_mq_ops;
 323         ctrl->admin_tag_set.queue_depth = NVME_LOOP_AQ_BLKMQ_DEPTH;
 324         ctrl->admin_tag_set.reserved_tags = 2; /* connect + keep-alive */
 325         ctrl->admin_tag_set.numa_node = NUMA_NO_NODE;
 326         ctrl->admin_tag_set.cmd_size = sizeof(struct nvme_loop_iod) +
 327                 SG_CHUNK_SIZE * sizeof(struct scatterlist);
 328         ctrl->admin_tag_set.driver_data = ctrl;
 329         ctrl->admin_tag_set.nr_hw_queues = 1;
 330         ctrl->admin_tag_set.timeout = ADMIN_TIMEOUT;
 331
 332         ctrl->queues[0].ctrl = ctrl;
 333         error = nvmet_sq_init(&ctrl->queues[0].nvme_sq);
 334         if (error)
 335                 return error;
 336         ctrl->queue_count = 1;
 337
 338         error = blk_mq_alloc_tag_set(&ctrl->admin_tag_set);
 339         if (error)
 340                 goto out_free_sq;
 341
 342         ctrl->ctrl.admin_q = blk_mq_init_queue(&ctrl->admin_tag_set);
 343         if (IS_ERR(ctrl->ctrl.admin_q)) {
 344                 error = PTR_ERR(ctrl->ctrl.admin_q);
 345                 goto out_free_tagset;
 346         }
 347
 348         error = nvmf_connect_admin_queue(&ctrl->ctrl);
 349         if (error)
 350                 goto out_cleanup_queue;
 351
 352         error = nvmf_reg_read64(&ctrl->ctrl, NVME_REG_CAP, &ctrl->cap);
 353         if (error) {
 354                 dev_err(ctrl->ctrl.device,
 355                         "prop_get NVME_REG_CAP failed\n");
 356                 goto out_cleanup_queue;
 357         }
 358
 359         ctrl->ctrl.sqsize =
 360                 min_t(int, NVME_CAP_MQES(ctrl->cap) + 1, ctrl->ctrl.sqsize);
 361
 362         error = nvme_enable_ctrl(&ctrl->ctrl, ctrl->cap);
 363         if (error)
 364                 goto out_cleanup_queue;
 365
 366         ctrl->ctrl.max_hw_sectors =
 367                 (NVME_LOOP_MAX_SEGMENTS - 1) << (PAGE_SHIFT - 9);
 368
 369         error = nvme_init_identify(&ctrl->ctrl);
 370         if (error)
 371                 goto out_cleanup_queue;
 372
 373         nvme_start_keep_alive(&ctrl->ctrl);
 374
 375         return 0;
 376
 377 out_cleanup_queue:
 378         blk_cleanup_queue(ctrl->ctrl.admin_q);
 379 out_free_tagset:
 380         blk_mq_free_tag_set(&ctrl->admin_tag_set);
 381 out_free_sq:
 382         nvmet_sq_destroy(&ctrl->queues[0].nvme_sq);
 383         return error;
 384 }
 385
 386 static void nvme_loop_shutdown_ctrl(struct nvme_loop_ctrl *ctrl)
 387 {
 388         int i;
 389
 390         nvme_stop_keep_alive(&ctrl->ctrl);
 391
 392         if (ctrl->queue_count > 1) {
 393                 nvme_stop_queues(&ctrl->ctrl);
 394                 blk_mq_tagset_busy_iter(&ctrl->tag_set,
 395                                         nvme_cancel_request, &ctrl->ctrl);
 396
 397                 for (i = 1; i < ctrl->queue_count; i++)
 398                         nvmet_sq_destroy(&ctrl->queues[i].nvme_sq);
 399         }
 400
 401         if (ctrl->ctrl.state == NVME_CTRL_LIVE)
 402                 nvme_shutdown_ctrl(&ctrl->ctrl);
 403
 404         blk_mq_stop_hw_queues(ctrl->ctrl.admin_q);
 405         blk_mq_tagset_busy_iter(&ctrl->admin_tag_set,
 406                                 nvme_cancel_request, &ctrl->ctrl);
 407         nvme_loop_destroy_admin_queue(ctrl);
 408 }
 409
 410 static void nvme_loop_del_ctrl_work(struct work_struct *work)
 411 {
 412         struct nvme_loop_ctrl *ctrl = container_of(work,
 413                                 struct nvme_loop_ctrl, delete_work);
 414
 415         nvme_uninit_ctrl(&ctrl->ctrl);
 416         nvme_loop_shutdown_ctrl(ctrl);
 417         nvme_put_ctrl(&ctrl->ctrl);
 418 }
 419
 420 static int __nvme_loop_del_ctrl(struct nvme_loop_ctrl *ctrl)
 421 {
 422         if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_DELETING))
 423                 return -EBUSY;
 424
 425         if (!schedule_work(&ctrl->delete_work))
 426                 return -EBUSY;
 427
 428         return 0;
 429 }
 430
 431 static int nvme_loop_del_ctrl(struct nvme_ctrl *nctrl)
 432 {
 433         struct nvme_loop_ctrl *ctrl = to_loop_ctrl(nctrl);
 434         int ret;
 435
 436         ret = __nvme_loop_del_ctrl(ctrl);
 437         if (ret)
 438                 return ret;
 439
 440         flush_work(&ctrl->delete_work);
 441
 442         return 0;
 443 }
 444
 445 static void nvme_loop_delete_ctrl(struct nvmet_ctrl *nctrl)
 446 {
 447         struct nvme_loop_ctrl *ctrl;
 448
 449         mutex_lock(&nvme_loop_ctrl_mutex);
 450         list_for_each_entry(ctrl, &nvme_loop_ctrl_list, list) {
 451                 if (ctrl->ctrl.cntlid == nctrl->cntlid)
 452                         __nvme_loop_del_ctrl(ctrl);
 453         }
 454         mutex_unlock(&nvme_loop_ctrl_mutex);
 455 }
 456
 457 static void nvme_loop_reset_ctrl_work(struct work_struct *work)
 458 {
 459         struct nvme_loop_ctrl *ctrl = container_of(work,
 460                                         struct nvme_loop_ctrl, reset_work);
 461         bool changed;
 462         int i, ret;
 463
 464         nvme_loop_shutdown_ctrl(ctrl);
 465
 466         ret = nvme_loop_configure_admin_queue(ctrl);
 467         if (ret)
 468                 goto out_disable;
 469
 470         for (i = 1; i <= ctrl->ctrl.opts->nr_io_queues; i++) {
 471                 ctrl->queues[i].ctrl = ctrl;
 472                 ret = nvmet_sq_init(&ctrl->queues[i].nvme_sq);
 473                 if (ret)
 474                         goto out_free_queues;
 475
 476                 ctrl->queue_count++;
 477         }
 478
 479         for (i = 1; i <= ctrl->ctrl.opts->nr_io_queues; i++) {
 480                 ret = nvmf_connect_io_queue(&ctrl->ctrl, i);
 481                 if (ret)
 482                         goto out_free_queues;
 483         }
 484
 485         changed = nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE);
 486         WARN_ON_ONCE(!changed);
 487
 488         nvme_queue_scan(&ctrl->ctrl);
 489         nvme_queue_async_events(&ctrl->ctrl);
 490
 491         nvme_start_queues(&ctrl->ctrl);
 492
 493         return;
 494
 495 out_free_queues:
 496         for (i = 1; i < ctrl->queue_count; i++)
 497                 nvmet_sq_destroy(&ctrl->queues[i].nvme_sq);
 498         nvme_loop_destroy_admin_queue(ctrl);
 499 out_disable:
 500         dev_warn(ctrl->ctrl.device, "Removing after reset failure\n");
 501         nvme_uninit_ctrl(&ctrl->ctrl);
 502         nvme_put_ctrl(&ctrl->ctrl);
 503 }
 504
 505 static int nvme_loop_reset_ctrl(struct nvme_ctrl *nctrl)
 506 {
 507         struct nvme_loop_ctrl *ctrl = to_loop_ctrl(nctrl);
 508
 509         if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_RESETTING))
 510                 return -EBUSY;
 511
 512         if (!schedule_work(&ctrl->reset_work))
 513                 return -EBUSY;
 514
 515         flush_work(&ctrl->reset_work);
 516
 517         return 0;
 518 }
 519
 520 static const struct nvme_ctrl_ops nvme_loop_ctrl_ops = {
 521         .name                   = "loop",
 522         .module                 = THIS_MODULE,
 523         .is_fabrics             = true,
 524         .reg_read32             = nvmf_reg_read32,
 525         .reg_read64             = nvmf_reg_read64,
 526         .reg_write32            = nvmf_reg_write32,
 527         .reset_ctrl             = nvme_loop_reset_ctrl,
 528         .free_ctrl              = nvme_loop_free_ctrl,
 529         .submit_async_event     = nvme_loop_submit_async_event,
 530         .delete_ctrl            = nvme_loop_del_ctrl,
 531         .get_subsysnqn          = nvmf_get_subsysnqn,
 532 };
 533
 534 static int nvme_loop_create_io_queues(struct nvme_loop_ctrl *ctrl)
 535 {
 536         struct nvmf_ctrl_options *opts = ctrl->ctrl.opts;
 537         int ret, i;
 538
 539         ret = nvme_set_queue_count(&ctrl->ctrl, &opts->nr_io_queues);
 540         if (ret || !opts->nr_io_queues)
 541                 return ret;
 542
 543         dev_info(ctrl->ctrl.device, "creating %d I/O queues.\n",
 544                 opts->nr_io_queues);
 545
 546         for (i = 1; i <= opts->nr_io_queues; i++) {
 547                 ctrl->queues[i].ctrl = ctrl;
 548                 ret = nvmet_sq_init(&ctrl->queues[i].nvme_sq);
 549                 if (ret)
 550                         goto out_destroy_queues;
 551
 552                 ctrl->queue_count++;
 553         }
 554
 555         memset(&ctrl->tag_set, 0, sizeof(ctrl->tag_set));
 556         ctrl->tag_set.ops = &nvme_loop_mq_ops;
 557         ctrl->tag_set.queue_depth = ctrl->ctrl.opts->queue_size;
 558         ctrl->tag_set.reserved_tags = 1; /* fabric connect */
 559         ctrl->tag_set.numa_node = NUMA_NO_NODE;
 560         ctrl->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
 561         ctrl->tag_set.cmd_size = sizeof(struct nvme_loop_iod) +
 562                 SG_CHUNK_SIZE * sizeof(struct scatterlist);
 563         ctrl->tag_set.driver_data = ctrl;
 564         ctrl->tag_set.nr_hw_queues = ctrl->queue_count - 1;
 565         ctrl->tag_set.timeout = NVME_IO_TIMEOUT;
 566         ctrl->ctrl.tagset = &ctrl->tag_set;
 567
 568         ret = blk_mq_alloc_tag_set(&ctrl->tag_set);
 569         if (ret)
 570                 goto out_destroy_queues;
 571
 572         ctrl->ctrl.connect_q = blk_mq_init_queue(&ctrl->tag_set);
 573         if (IS_ERR(ctrl->ctrl.connect_q)) {
 574                 ret = PTR_ERR(ctrl->ctrl.connect_q);
 575                 goto out_free_tagset;
 576         }
 577
 578         for (i = 1; i <= opts->nr_io_queues; i++) {
 579                 ret = nvmf_connect_io_queue(&ctrl->ctrl, i);
 580                 if (ret)
 581                         goto out_cleanup_connect_q;
 582         }
 583
 584         return 0;
 585
 586 out_cleanup_connect_q:
 587         blk_cleanup_queue(ctrl->ctrl.connect_q);
 588 out_free_tagset:
 589         blk_mq_free_tag_set(&ctrl->tag_set);
 590 out_destroy_queues:
 591         for (i = 1; i < ctrl->queue_count; i++)
 592                 nvmet_sq_destroy(&ctrl->queues[i].nvme_sq);
 593         return ret;
 594 }
 595
 596 static struct nvme_ctrl *nvme_loop_create_ctrl(struct device *dev,
 597                 struct nvmf_ctrl_options *opts)
 598 {
 599         struct nvme_loop_ctrl *ctrl;
 600         bool changed;
 601         int ret;
 602
 603         ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
 604         if (!ctrl)
 605                 return ERR_PTR(-ENOMEM);
 606         ctrl->ctrl.opts = opts;
 607         INIT_LIST_HEAD(&ctrl->list);
 608
 609         INIT_WORK(&ctrl->delete_work, nvme_loop_del_ctrl_work);
 610         INIT_WORK(&ctrl->reset_work, nvme_loop_reset_ctrl_work);
 611
 612         ret = nvme_init_ctrl(&ctrl->ctrl, dev, &nvme_loop_ctrl_ops,
 613                                 0 /* no quirks, we're perfect! */);
 614         if (ret)
 615                 goto out_put_ctrl;
 616
 617         spin_lock_init(&ctrl->lock);
 618
 619         ret = -ENOMEM;
 620
 621         ctrl->ctrl.sqsize = opts->queue_size - 1;
 622         ctrl->ctrl.kato = opts->kato;
 623
 624         ctrl->queues = kcalloc(opts->nr_io_queues + 1, sizeof(*ctrl->queues),
 625                         GFP_KERNEL);
 626         if (!ctrl->queues)
 627                 goto out_uninit_ctrl;
 628
 629         ret = nvme_loop_configure_admin_queue(ctrl);
 630         if (ret)
 631                 goto out_free_queues;
 632
 633         if (opts->queue_size > ctrl->ctrl.maxcmd) {
 634                 /* warn if maxcmd is lower than queue_size */
 635                 dev_warn(ctrl->ctrl.device,
 636                         "queue_size %zu > ctrl maxcmd %u, clamping down\n",
 637                         opts->queue_size, ctrl->ctrl.maxcmd);
 638                 opts->queue_size = ctrl->ctrl.maxcmd;
 639         }
 640
 641         if (opts->nr_io_queues) {
 642                 ret = nvme_loop_create_io_queues(ctrl);
 643                 if (ret)
 644                         goto out_remove_admin_queue;
 645         }
 646
 647         nvme_loop_init_iod(ctrl, &ctrl->async_event_iod, 0);
 648
 649         dev_info(ctrl->ctrl.device,
 650                  "new ctrl: \"%s\"\n", ctrl->ctrl.opts->subsysnqn);
 651
 652         kref_get(&ctrl->ctrl.kref);
 653
 654         changed = nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE);
 655         WARN_ON_ONCE(!changed);
 656
 657         mutex_lock(&nvme_loop_ctrl_mutex);
 658         list_add_tail(&ctrl->list, &nvme_loop_ctrl_list);
 659         mutex_unlock(&nvme_loop_ctrl_mutex);
 660
 661         if (opts->nr_io_queues) {
 662                 nvme_queue_scan(&ctrl->ctrl);
 663                 nvme_queue_async_events(&ctrl->ctrl);
 664         }
 665
 666         return &ctrl->ctrl;
 667
 668 out_remove_admin_queue:
 669         nvme_loop_destroy_admin_queue(ctrl);
 670 out_free_queues:
 671         kfree(ctrl->queues);
 672 out_uninit_ctrl:
 673         nvme_uninit_ctrl(&ctrl->ctrl);
 674 out_put_ctrl:
 675         nvme_put_ctrl(&ctrl->ctrl);
 676         if (ret > 0)
 677                 ret = -EIO;
 678         return ERR_PTR(ret);
 679 }
 680
 681 static int nvme_loop_add_port(struct nvmet_port *port)
 682 {
 683         /*
 684          * XXX: disalow adding more than one port so
 685          * there is no connection rejections when a
 686          * a subsystem is assigned to a port for which
 687          * loop doesn't have a pointer.
 688          * This scenario would be possible if we allowed
 689          * more than one port to be added and a subsystem
 690          * was assigned to a port other than nvmet_loop_port.
 691          */
 692
 693         if (nvmet_loop_port)
 694                 return -EPERM;
 695
 696         nvmet_loop_port = port;
 697         return 0;
 698 }
 699
 700 static void nvme_loop_remove_port(struct nvmet_port *port)
 701 {
 702         if (port == nvmet_loop_port)
 703                 nvmet_loop_port = NULL;
 704 }
 705
 706 static struct nvmet_fabrics_ops nvme_loop_ops = {
 707         .owner          = THIS_MODULE,
 708         .type           = NVMF_TRTYPE_LOOP,
 709         .add_port       = nvme_loop_add_port,
 710         .remove_port    = nvme_loop_remove_port,
 711         .queue_response = nvme_loop_queue_response,
 712         .delete_ctrl    = nvme_loop_delete_ctrl,
 713 };
 714
 715 static struct nvmf_transport_ops nvme_loop_transport = {
 716         .name           = "loop",
 717         .create_ctrl    = nvme_loop_create_ctrl,
 718 };
 719
 720 static int __init nvme_loop_init_module(void)
 721 {
 722         int ret;
 723
 724         ret = nvmet_register_transport(&nvme_loop_ops);
 725         if (ret)
 726                 return ret;
 727         nvmf_register_transport(&nvme_loop_transport);
 728         return 0;
 729 }
 730
 731 static void __exit nvme_loop_cleanup_module(void)
 732 {
 733         struct nvme_loop_ctrl *ctrl, *next;
 734
 735         nvmf_unregister_transport(&nvme_loop_transport);
 736         nvmet_unregister_transport(&nvme_loop_ops);
 737
 738         mutex_lock(&nvme_loop_ctrl_mutex);
 739         list_for_each_entry_safe(ctrl, next, &nvme_loop_ctrl_list, list)
 740                 __nvme_loop_del_ctrl(ctrl);
 741         mutex_unlock(&nvme_loop_ctrl_mutex);
 742
 743         flush_scheduled_work();
 744 }
 745
 746 module_init(nvme_loop_init_module);
 747 module_exit(nvme_loop_cleanup_module);
 748
 749 MODULE_LICENSE("GPL v2");
 750 MODULE_ALIAS("nvmet-transport-254"); /* 254 == NVMF_TRTYPE_LOOP */