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 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 inline blk_status_t nvme_loop_is_ready(struct nvme_loop_queue *queue,
 153                 struct request *rq)
 154 {
 155         if (unlikely(!test_bit(NVME_LOOP_Q_LIVE, &queue->flags)))
 156                 return nvmf_check_init_req(&queue->ctrl->ctrl, rq);
 157         return BLK_STS_OK;
 158 }
 159
 160 static blk_status_t nvme_loop_queue_rq(struct blk_mq_hw_ctx *hctx,
 161                 const struct blk_mq_queue_data *bd)
 162 {
 163         struct nvme_ns *ns = hctx->queue->queuedata;
 164         struct nvme_loop_queue *queue = hctx->driver_data;
 165         struct request *req = bd->rq;
 166         struct nvme_loop_iod *iod = blk_mq_rq_to_pdu(req);
 167         blk_status_t ret;
 168
 169         ret = nvme_loop_is_ready(queue, req);
 170         if (unlikely(ret))
 171                 return ret;
 172
 173         ret = nvme_setup_cmd(ns, req, &iod->cmd);
 174         if (ret)
 175                 return ret;
 176
 177         iod->cmd.common.flags |= NVME_CMD_SGL_METABUF;
 178         iod->req.port = nvmet_loop_port;
 179         if (!nvmet_req_init(&iod->req, &queue->nvme_cq,
 180                         &queue->nvme_sq, &nvme_loop_ops)) {
 181                 nvme_cleanup_cmd(req);
 182                 blk_mq_start_request(req);
 183                 nvme_loop_queue_response(&iod->req);
 184                 return BLK_STS_OK;
 185         }
 186
 187         if (blk_rq_bytes(req)) {
 188                 iod->sg_table.sgl = iod->first_sgl;
 189                 if (sg_alloc_table_chained(&iod->sg_table,
 190                                 blk_rq_nr_phys_segments(req),
 191                                 iod->sg_table.sgl))
 192                         return BLK_STS_RESOURCE;
 193
 194                 iod->req.sg = iod->sg_table.sgl;
 195                 iod->req.sg_cnt = blk_rq_map_sg(req->q, req, iod->sg_table.sgl);
 196                 iod->req.transfer_len = blk_rq_bytes(req);
 197         }
 198
 199         blk_mq_start_request(req);
 200
 201         schedule_work(&iod->work);
 202         return BLK_STS_OK;
 203 }
 204
 205 static void nvme_loop_submit_async_event(struct nvme_ctrl *arg)
 206 {
 207         struct nvme_loop_ctrl *ctrl = to_loop_ctrl(arg);
 208         struct nvme_loop_queue *queue = &ctrl->queues[0];
 209         struct nvme_loop_iod *iod = &ctrl->async_event_iod;
 210
 211         memset(&iod->cmd, 0, sizeof(iod->cmd));
 212         iod->cmd.common.opcode = nvme_admin_async_event;
 213         iod->cmd.common.command_id = NVME_AQ_BLK_MQ_DEPTH;
 214         iod->cmd.common.flags |= NVME_CMD_SGL_METABUF;
 215
 216         if (!nvmet_req_init(&iod->req, &queue->nvme_cq, &queue->nvme_sq,
 217                         &nvme_loop_ops)) {
 218                 dev_err(ctrl->ctrl.device, "failed async event work\n");
 219                 return;
 220         }
 221
 222         schedule_work(&iod->work);
 223 }
 224
 225 static int nvme_loop_init_iod(struct nvme_loop_ctrl *ctrl,
 226                 struct nvme_loop_iod *iod, unsigned int queue_idx)
 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(struct blk_mq_tag_set *set,
 236                 struct request *req, unsigned int hctx_idx,
 237                 unsigned int numa_node)
 238 {
 239         struct nvme_loop_ctrl *ctrl = set->driver_data;
 240
 241         return nvme_loop_init_iod(ctrl, blk_mq_rq_to_pdu(req),
 242                         (set == &ctrl->tag_set) ? hctx_idx + 1 : 0);
 243 }
 244
 245 static int nvme_loop_init_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[hctx_idx + 1];
 250
 251         BUG_ON(hctx_idx >= ctrl->ctrl.queue_count);
 252
 253         hctx->driver_data = queue;
 254         return 0;
 255 }
 256
 257 static int nvme_loop_init_admin_hctx(struct blk_mq_hw_ctx *hctx, void *data,
 258                 unsigned int hctx_idx)
 259 {
 260         struct nvme_loop_ctrl *ctrl = data;
 261         struct nvme_loop_queue *queue = &ctrl->queues[0];
 262
 263         BUG_ON(hctx_idx != 0);
 264
 265         hctx->driver_data = queue;
 266         return 0;
 267 }
 268
 269 static const struct blk_mq_ops nvme_loop_mq_ops = {
 270         .queue_rq       = nvme_loop_queue_rq,
 271         .complete       = nvme_loop_complete_rq,
 272         .init_request   = nvme_loop_init_request,
 273         .init_hctx      = nvme_loop_init_hctx,
 274         .timeout        = nvme_loop_timeout,
 275 };
 276
 277 static const struct blk_mq_ops nvme_loop_admin_mq_ops = {
 278         .queue_rq       = nvme_loop_queue_rq,
 279         .complete       = nvme_loop_complete_rq,
 280         .init_request   = nvme_loop_init_request,
 281         .init_hctx      = nvme_loop_init_admin_hctx,
 282         .timeout        = nvme_loop_timeout,
 283 };
 284
 285 static void nvme_loop_destroy_admin_queue(struct nvme_loop_ctrl *ctrl)
 286 {
 287         clear_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[0].flags);
 288         nvmet_sq_destroy(&ctrl->queues[0].nvme_sq);
 289         blk_cleanup_queue(ctrl->ctrl.admin_q);
 290         blk_mq_free_tag_set(&ctrl->admin_tag_set);
 291 }
 292
 293 static void nvme_loop_free_ctrl(struct nvme_ctrl *nctrl)
 294 {
 295         struct nvme_loop_ctrl *ctrl = to_loop_ctrl(nctrl);
 296
 297         if (list_empty(&ctrl->list))
 298                 goto free_ctrl;
 299
 300         mutex_lock(&nvme_loop_ctrl_mutex);
 301         list_del(&ctrl->list);
 302         mutex_unlock(&nvme_loop_ctrl_mutex);
 303
 304         if (nctrl->tagset) {
 305                 blk_cleanup_queue(ctrl->ctrl.connect_q);
 306                 blk_mq_free_tag_set(&ctrl->tag_set);
 307         }
 308         kfree(ctrl->queues);
 309         nvmf_free_options(nctrl->opts);
 310 free_ctrl:
 311         kfree(ctrl);
 312 }
 313
 314 static void nvme_loop_destroy_io_queues(struct nvme_loop_ctrl *ctrl)
 315 {
 316         int i;
 317
 318         for (i = 1; i < ctrl->ctrl.queue_count; i++) {
 319                 clear_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[i].flags);
 320                 nvmet_sq_destroy(&ctrl->queues[i].nvme_sq);
 321         }
 322 }
 323
 324 static int nvme_loop_init_io_queues(struct nvme_loop_ctrl *ctrl)
 325 {
 326         struct nvmf_ctrl_options *opts = ctrl->ctrl.opts;
 327         unsigned int nr_io_queues;
 328         int ret, i;
 329
 330         nr_io_queues = min(opts->nr_io_queues, num_online_cpus());
 331         ret = nvme_set_queue_count(&ctrl->ctrl, &nr_io_queues);
 332         if (ret || !nr_io_queues)
 333                 return ret;
 334
 335         dev_info(ctrl->ctrl.device, "creating %d I/O queues.\n", nr_io_queues);
 336
 337         for (i = 1; i <= nr_io_queues; i++) {
 338                 ctrl->queues[i].ctrl = ctrl;
 339                 ret = nvmet_sq_init(&ctrl->queues[i].nvme_sq);
 340                 if (ret)
 341                         goto out_destroy_queues;
 342
 343                 ctrl->ctrl.queue_count++;
 344         }
 345
 346         return 0;
 347
 348 out_destroy_queues:
 349         nvme_loop_destroy_io_queues(ctrl);
 350         return ret;
 351 }
 352
 353 static int nvme_loop_connect_io_queues(struct nvme_loop_ctrl *ctrl)
 354 {
 355         int i, ret;
 356
 357         for (i = 1; i < ctrl->ctrl.queue_count; i++) {
 358                 ret = nvmf_connect_io_queue(&ctrl->ctrl, i);
 359                 if (ret)
 360                         return ret;
 361                 set_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[i].flags);
 362         }
 363
 364         return 0;
 365 }
 366
 367 static int nvme_loop_configure_admin_queue(struct nvme_loop_ctrl *ctrl)
 368 {
 369         int error;
 370
 371         memset(&ctrl->admin_tag_set, 0, sizeof(ctrl->admin_tag_set));
 372         ctrl->admin_tag_set.ops = &nvme_loop_admin_mq_ops;
 373         ctrl->admin_tag_set.queue_depth = NVME_AQ_MQ_TAG_DEPTH;
 374         ctrl->admin_tag_set.reserved_tags = 2; /* connect + keep-alive */
 375         ctrl->admin_tag_set.numa_node = NUMA_NO_NODE;
 376         ctrl->admin_tag_set.cmd_size = sizeof(struct nvme_loop_iod) +
 377                 SG_CHUNK_SIZE * sizeof(struct scatterlist);
 378         ctrl->admin_tag_set.driver_data = ctrl;
 379         ctrl->admin_tag_set.nr_hw_queues = 1;
 380         ctrl->admin_tag_set.timeout = ADMIN_TIMEOUT;
 381         ctrl->admin_tag_set.flags = BLK_MQ_F_NO_SCHED;
 382
 383         ctrl->queues[0].ctrl = ctrl;
 384         error = nvmet_sq_init(&ctrl->queues[0].nvme_sq);
 385         if (error)
 386                 return error;
 387         ctrl->ctrl.queue_count = 1;
 388
 389         error = blk_mq_alloc_tag_set(&ctrl->admin_tag_set);
 390         if (error)
 391                 goto out_free_sq;
 392         ctrl->ctrl.admin_tagset = &ctrl->admin_tag_set;
 393
 394         ctrl->ctrl.admin_q = blk_mq_init_queue(&ctrl->admin_tag_set);
 395         if (IS_ERR(ctrl->ctrl.admin_q)) {
 396                 error = PTR_ERR(ctrl->ctrl.admin_q);
 397                 goto out_free_tagset;
 398         }
 399
 400         error = nvmf_connect_admin_queue(&ctrl->ctrl);
 401         if (error)
 402                 goto out_cleanup_queue;
 403
 404         set_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[0].flags);
 405
 406         error = nvmf_reg_read64(&ctrl->ctrl, NVME_REG_CAP, &ctrl->ctrl.cap);
 407         if (error) {
 408                 dev_err(ctrl->ctrl.device,
 409                         "prop_get NVME_REG_CAP failed\n");
 410                 goto out_cleanup_queue;
 411         }
 412
 413         ctrl->ctrl.sqsize =
 414                 min_t(int, NVME_CAP_MQES(ctrl->ctrl.cap), ctrl->ctrl.sqsize);
 415
 416         error = nvme_enable_ctrl(&ctrl->ctrl, ctrl->ctrl.cap);
 417         if (error)
 418                 goto out_cleanup_queue;
 419
 420         ctrl->ctrl.max_hw_sectors =
 421                 (NVME_LOOP_MAX_SEGMENTS - 1) << (PAGE_SHIFT - 9);
 422
 423         error = nvme_init_identify(&ctrl->ctrl);
 424         if (error)
 425                 goto out_cleanup_queue;
 426
 427         return 0;
 428
 429 out_cleanup_queue:
 430         blk_cleanup_queue(ctrl->ctrl.admin_q);
 431 out_free_tagset:
 432         blk_mq_free_tag_set(&ctrl->admin_tag_set);
 433 out_free_sq:
 434         nvmet_sq_destroy(&ctrl->queues[0].nvme_sq);
 435         return error;
 436 }
 437
 438 static void nvme_loop_shutdown_ctrl(struct nvme_loop_ctrl *ctrl)
 439 {
 440         if (ctrl->ctrl.queue_count > 1) {
 441                 nvme_stop_queues(&ctrl->ctrl);
 442                 blk_mq_tagset_busy_iter(&ctrl->tag_set,
 443                                         nvme_cancel_request, &ctrl->ctrl);
 444                 nvme_loop_destroy_io_queues(ctrl);
 445         }
 446
 447         if (ctrl->ctrl.state == NVME_CTRL_LIVE)
 448                 nvme_shutdown_ctrl(&ctrl->ctrl);
 449
 450         blk_mq_quiesce_queue(ctrl->ctrl.admin_q);
 451         blk_mq_tagset_busy_iter(&ctrl->admin_tag_set,
 452                                 nvme_cancel_request, &ctrl->ctrl);
 453         blk_mq_unquiesce_queue(ctrl->ctrl.admin_q);
 454         nvme_loop_destroy_admin_queue(ctrl);
 455 }
 456
 457 static void nvme_loop_delete_ctrl_host(struct nvme_ctrl *ctrl)
 458 {
 459         nvme_loop_shutdown_ctrl(to_loop_ctrl(ctrl));
 460 }
 461
 462 static void nvme_loop_delete_ctrl(struct nvmet_ctrl *nctrl)
 463 {
 464         struct nvme_loop_ctrl *ctrl;
 465
 466         mutex_lock(&nvme_loop_ctrl_mutex);
 467         list_for_each_entry(ctrl, &nvme_loop_ctrl_list, list) {
 468                 if (ctrl->ctrl.cntlid == nctrl->cntlid)
 469                         nvme_delete_ctrl(&ctrl->ctrl);
 470         }
 471         mutex_unlock(&nvme_loop_ctrl_mutex);
 472 }
 473
 474 static void nvme_loop_reset_ctrl_work(struct work_struct *work)
 475 {
 476         struct nvme_loop_ctrl *ctrl =
 477                 container_of(work, struct nvme_loop_ctrl, ctrl.reset_work);
 478         bool changed;
 479         int ret;
 480
 481         nvme_stop_ctrl(&ctrl->ctrl);
 482         nvme_loop_shutdown_ctrl(ctrl);
 483
 484         ret = nvme_loop_configure_admin_queue(ctrl);
 485         if (ret)
 486                 goto out_disable;
 487
 488         ret = nvme_loop_init_io_queues(ctrl);
 489         if (ret)
 490                 goto out_destroy_admin;
 491
 492         ret = nvme_loop_connect_io_queues(ctrl);
 493         if (ret)
 494                 goto out_destroy_io;
 495
 496         blk_mq_update_nr_hw_queues(&ctrl->tag_set,
 497                         ctrl->ctrl.queue_count - 1);
 498
 499         changed = nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE);
 500         WARN_ON_ONCE(!changed);
 501
 502         nvme_start_ctrl(&ctrl->ctrl);
 503
 504         return;
 505
 506 out_destroy_io:
 507         nvme_loop_destroy_io_queues(ctrl);
 508 out_destroy_admin:
 509         nvme_loop_destroy_admin_queue(ctrl);
 510 out_disable:
 511         dev_warn(ctrl->ctrl.device, "Removing after reset failure\n");
 512         nvme_uninit_ctrl(&ctrl->ctrl);
 513         nvme_put_ctrl(&ctrl->ctrl);
 514 }
 515
 516 static const struct nvme_ctrl_ops nvme_loop_ctrl_ops = {
 517         .name                   = "loop",
 518         .module                 = THIS_MODULE,
 519         .flags                  = NVME_F_FABRICS,
 520         .reg_read32             = nvmf_reg_read32,
 521         .reg_read64             = nvmf_reg_read64,
 522         .reg_write32            = nvmf_reg_write32,
 523         .free_ctrl              = nvme_loop_free_ctrl,
 524         .submit_async_event     = nvme_loop_submit_async_event,
 525         .delete_ctrl            = nvme_loop_delete_ctrl_host,
 526 };
 527
 528 static int nvme_loop_create_io_queues(struct nvme_loop_ctrl *ctrl)
 529 {
 530         int ret;
 531
 532         ret = nvme_loop_init_io_queues(ctrl);
 533         if (ret)
 534                 return ret;
 535
 536         memset(&ctrl->tag_set, 0, sizeof(ctrl->tag_set));
 537         ctrl->tag_set.ops = &nvme_loop_mq_ops;
 538         ctrl->tag_set.queue_depth = ctrl->ctrl.opts->queue_size;
 539         ctrl->tag_set.reserved_tags = 1; /* fabric connect */
 540         ctrl->tag_set.numa_node = NUMA_NO_NODE;
 541         ctrl->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
 542         ctrl->tag_set.cmd_size = sizeof(struct nvme_loop_iod) +
 543                 SG_CHUNK_SIZE * sizeof(struct scatterlist);
 544         ctrl->tag_set.driver_data = ctrl;
 545         ctrl->tag_set.nr_hw_queues = ctrl->ctrl.queue_count - 1;
 546         ctrl->tag_set.timeout = NVME_IO_TIMEOUT;
 547         ctrl->ctrl.tagset = &ctrl->tag_set;
 548
 549         ret = blk_mq_alloc_tag_set(&ctrl->tag_set);
 550         if (ret)
 551                 goto out_destroy_queues;
 552
 553         ctrl->ctrl.connect_q = blk_mq_init_queue(&ctrl->tag_set);
 554         if (IS_ERR(ctrl->ctrl.connect_q)) {
 555                 ret = PTR_ERR(ctrl->ctrl.connect_q);
 556                 goto out_free_tagset;
 557         }
 558
 559         ret = nvme_loop_connect_io_queues(ctrl);
 560         if (ret)
 561                 goto out_cleanup_connect_q;
 562
 563         return 0;
 564
 565 out_cleanup_connect_q:
 566         blk_cleanup_queue(ctrl->ctrl.connect_q);
 567 out_free_tagset:
 568         blk_mq_free_tag_set(&ctrl->tag_set);
 569 out_destroy_queues:
 570         nvme_loop_destroy_io_queues(ctrl);
 571         return ret;
 572 }
 573
 574 static struct nvme_ctrl *nvme_loop_create_ctrl(struct device *dev,
 575                 struct nvmf_ctrl_options *opts)
 576 {
 577         struct nvme_loop_ctrl *ctrl;
 578         bool changed;
 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_put_ctrl;
 593
 594         ret = -ENOMEM;
 595
 596         ctrl->ctrl.sqsize = opts->queue_size - 1;
 597         ctrl->ctrl.kato = opts->kato;
 598
 599         ctrl->queues = kcalloc(opts->nr_io_queues + 1, sizeof(*ctrl->queues),
 600                         GFP_KERNEL);
 601         if (!ctrl->queues)
 602                 goto out_uninit_ctrl;
 603
 604         ret = nvme_loop_configure_admin_queue(ctrl);
 605         if (ret)
 606                 goto out_free_queues;
 607
 608         if (opts->queue_size > ctrl->ctrl.maxcmd) {
 609                 /* warn if maxcmd is lower than queue_size */
 610                 dev_warn(ctrl->ctrl.device,
 611                         "queue_size %zu > ctrl maxcmd %u, clamping down\n",
 612                         opts->queue_size, ctrl->ctrl.maxcmd);
 613                 opts->queue_size = ctrl->ctrl.maxcmd;
 614         }
 615
 616         if (opts->nr_io_queues) {
 617                 ret = nvme_loop_create_io_queues(ctrl);
 618                 if (ret)
 619                         goto out_remove_admin_queue;
 620         }
 621
 622         nvme_loop_init_iod(ctrl, &ctrl->async_event_iod, 0);
 623
 624         dev_info(ctrl->ctrl.device,
 625                  "new ctrl: \"%s\"\n", ctrl->ctrl.opts->subsysnqn);
 626
 627         nvme_get_ctrl(&ctrl->ctrl);
 628
 629         changed = nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE);
 630         WARN_ON_ONCE(!changed);
 631
 632         mutex_lock(&nvme_loop_ctrl_mutex);
 633         list_add_tail(&ctrl->list, &nvme_loop_ctrl_list);
 634         mutex_unlock(&nvme_loop_ctrl_mutex);
 635
 636         nvme_start_ctrl(&ctrl->ctrl);
 637
 638         return &ctrl->ctrl;
 639
 640 out_remove_admin_queue:
 641         nvme_loop_destroy_admin_queue(ctrl);
 642 out_free_queues:
 643         kfree(ctrl->queues);
 644 out_uninit_ctrl:
 645         nvme_uninit_ctrl(&ctrl->ctrl);
 646 out_put_ctrl:
 647         nvme_put_ctrl(&ctrl->ctrl);
 648         if (ret > 0)
 649                 ret = -EIO;
 650         return ERR_PTR(ret);
 651 }
 652
 653 static int nvme_loop_add_port(struct nvmet_port *port)
 654 {
 655         /*
 656          * XXX: disalow adding more than one port so
 657          * there is no connection rejections when a
 658          * a subsystem is assigned to a port for which
 659          * loop doesn't have a pointer.
 660          * This scenario would be possible if we allowed
 661          * more than one port to be added and a subsystem
 662          * was assigned to a port other than nvmet_loop_port.
 663          */
 664
 665         if (nvmet_loop_port)
 666                 return -EPERM;
 667
 668         nvmet_loop_port = port;
 669         return 0;
 670 }
 671
 672 static void nvme_loop_remove_port(struct nvmet_port *port)
 673 {
 674         if (port == nvmet_loop_port)
 675                 nvmet_loop_port = NULL;
 676 }
 677
 678 static 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 };
 692
 693 static int __init nvme_loop_init_module(void)
 694 {
 695         int ret;
 696
 697         ret = nvmet_register_transport(&nvme_loop_ops);
 698         if (ret)
 699                 return ret;
 700
 701         ret = nvmf_register_transport(&nvme_loop_transport);
 702         if (ret)
 703                 nvmet_unregister_transport(&nvme_loop_ops);
 704
 705         return ret;
 706 }
 707
 708 static void __exit nvme_loop_cleanup_module(void)
 709 {
 710         struct nvme_loop_ctrl *ctrl, *next;
 711
 712         nvmf_unregister_transport(&nvme_loop_transport);
 713         nvmet_unregister_transport(&nvme_loop_ops);
 714
 715         mutex_lock(&nvme_loop_ctrl_mutex);
 716         list_for_each_entry_safe(ctrl, next, &nvme_loop_ctrl_list, list)
 717                 nvme_delete_ctrl(&ctrl->ctrl);
 718         mutex_unlock(&nvme_loop_ctrl_mutex);
 719
 720         flush_workqueue(nvme_delete_wq);
 721 }
 722
 723 module_init(nvme_loop_init_module);
 724 module_exit(nvme_loop_cleanup_module);
 725
 726 MODULE_LICENSE("GPL v2");
 727 MODULE_ALIAS("nvmet-transport-254"); /* 254 == NVMF_TRTYPE_LOOP */