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