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