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         struct nvmet_port       *port;
  49 };
  50
  51 static inline struct nvme_loop_ctrl *to_loop_ctrl(struct nvme_ctrl *ctrl)
  52 {
  53         return container_of(ctrl, struct nvme_loop_ctrl, ctrl);
  54 }
  55
  56 enum nvme_loop_queue_flags {
  57         NVME_LOOP_Q_LIVE        = 0,
  58 };
  59
  60 struct nvme_loop_queue {
  61         struct nvmet_cq         nvme_cq;
  62         struct nvmet_sq         nvme_sq;
  63         struct nvme_loop_ctrl   *ctrl;
  64         unsigned long           flags;
  65 };
  66
  67 static LIST_HEAD(nvme_loop_ports);
  68 static DEFINE_MUTEX(nvme_loop_ports_mutex);
  69
  70 static LIST_HEAD(nvme_loop_ctrl_list);
  71 static DEFINE_MUTEX(nvme_loop_ctrl_mutex);
  72
  73 static void nvme_loop_queue_response(struct nvmet_req *nvme_req);
  74 static void nvme_loop_delete_ctrl(struct nvmet_ctrl *ctrl);
  75
  76 static const struct nvmet_fabrics_ops nvme_loop_ops;
  77
  78 static inline int nvme_loop_queue_idx(struct nvme_loop_queue *queue)
  79 {
  80         return queue - queue->ctrl->queues;
  81 }
  82
  83 static void nvme_loop_complete_rq(struct request *req)
  84 {
  85         struct nvme_loop_iod *iod = blk_mq_rq_to_pdu(req);
  86
  87         nvme_cleanup_cmd(req);
  88         sg_free_table_chained(&iod->sg_table, true);
  89         nvme_complete_rq(req);
  90 }
  91
  92 static struct blk_mq_tags *nvme_loop_tagset(struct nvme_loop_queue *queue)
  93 {
  94         u32 queue_idx = nvme_loop_queue_idx(queue);
  95
  96         if (queue_idx == 0)
  97                 return queue->ctrl->admin_tag_set.tags[queue_idx];
  98         return queue->ctrl->tag_set.tags[queue_idx - 1];
  99 }
 100
 101 static void nvme_loop_queue_response(struct nvmet_req *req)
 102 {
 103         struct nvme_loop_queue *queue =
 104                 container_of(req->sq, struct nvme_loop_queue, nvme_sq);
 105         struct nvme_completion *cqe = req->rsp;
 106
 107         /*
 108          * AEN requests are special as they don't time out and can
 109          * survive any kind of queue freeze and often don't respond to
 110          * aborts.  We don't even bother to allocate a struct request
 111          * for them but rather special case them here.
 112          */
 113         if (unlikely(nvme_loop_queue_idx(queue) == 0 &&
 114                         cqe->command_id >= NVME_AQ_BLK_MQ_DEPTH)) {
 115                 nvme_complete_async_event(&queue->ctrl->ctrl, cqe->status,
 116                                 &cqe->result);
 117         } else {
 118                 struct request *rq;
 119
 120                 rq = blk_mq_tag_to_rq(nvme_loop_tagset(queue), cqe->command_id);
 121                 if (!rq) {
 122                         dev_err(queue->ctrl->ctrl.device,
 123                                 "tag 0x%x on queue %d not found\n",
 124                                 cqe->command_id, nvme_loop_queue_idx(queue));
 125                         return;
 126                 }
 127
 128                 nvme_end_request(rq, cqe->status, cqe->result);
 129         }
 130 }
 131
 132 static void nvme_loop_execute_work(struct work_struct *work)
 133 {
 134         struct nvme_loop_iod *iod =
 135                 container_of(work, struct nvme_loop_iod, work);
 136
 137         nvmet_req_execute(&iod->req);
 138 }
 139
 140 static enum blk_eh_timer_return
 141 nvme_loop_timeout(struct request *rq, bool reserved)
 142 {
 143         struct nvme_loop_iod *iod = blk_mq_rq_to_pdu(rq);
 144
 145         /* queue error recovery */
 146         nvme_reset_ctrl(&iod->queue->ctrl->ctrl);
 147
 148         /* fail with DNR on admin cmd timeout */
 149         nvme_req(rq)->status = NVME_SC_ABORT_REQ | NVME_SC_DNR;
 150
 151         return BLK_EH_DONE;
 152 }
 153
 154 static blk_status_t nvme_loop_queue_rq(struct blk_mq_hw_ctx *hctx,
 155                 const struct blk_mq_queue_data *bd)
 156 {
 157         struct nvme_ns *ns = hctx->queue->queuedata;
 158         struct nvme_loop_queue *queue = hctx->driver_data;
 159         struct request *req = bd->rq;
 160         struct nvme_loop_iod *iod = blk_mq_rq_to_pdu(req);
 161         bool queue_ready = test_bit(NVME_LOOP_Q_LIVE, &queue->flags);
 162         blk_status_t ret;
 163
 164         if (!nvmf_check_ready(&queue->ctrl->ctrl, req, queue_ready))
 165                 return nvmf_fail_nonready_command(&queue->ctrl->ctrl, req);
 166
 167         ret = nvme_setup_cmd(ns, req, &iod->cmd);
 168         if (ret)
 169                 return ret;
 170
 171         blk_mq_start_request(req);
 172         iod->cmd.common.flags |= NVME_CMD_SGL_METABUF;
 173         iod->req.port = queue->ctrl->port;
 174         if (!nvmet_req_init(&iod->req, &queue->nvme_cq,
 175                         &queue->nvme_sq, &nvme_loop_ops))
 176                 return BLK_STS_OK;
 177
 178         if (blk_rq_nr_phys_segments(req)) {
 179                 iod->sg_table.sgl = iod->first_sgl;
 180                 if (sg_alloc_table_chained(&iod->sg_table,
 181                                 blk_rq_nr_phys_segments(req),
 182                                 iod->sg_table.sgl))
 183                         return BLK_STS_RESOURCE;
 184
 185                 iod->req.sg = iod->sg_table.sgl;
 186                 iod->req.sg_cnt = blk_rq_map_sg(req->q, req, iod->sg_table.sgl);
 187                 iod->req.transfer_len = blk_rq_payload_bytes(req);
 188         }
 189
 190         schedule_work(&iod->work);
 191         return BLK_STS_OK;
 192 }
 193
 194 static void nvme_loop_submit_async_event(struct nvme_ctrl *arg)
 195 {
 196         struct nvme_loop_ctrl *ctrl = to_loop_ctrl(arg);
 197         struct nvme_loop_queue *queue = &ctrl->queues[0];
 198         struct nvme_loop_iod *iod = &ctrl->async_event_iod;
 199
 200         memset(&iod->cmd, 0, sizeof(iod->cmd));
 201         iod->cmd.common.opcode = nvme_admin_async_event;
 202         iod->cmd.common.command_id = NVME_AQ_BLK_MQ_DEPTH;
 203         iod->cmd.common.flags |= NVME_CMD_SGL_METABUF;
 204
 205         if (!nvmet_req_init(&iod->req, &queue->nvme_cq, &queue->nvme_sq,
 206                         &nvme_loop_ops)) {
 207                 dev_err(ctrl->ctrl.device, "failed async event work\n");
 208                 return;
 209         }
 210
 211         schedule_work(&iod->work);
 212 }
 213
 214 static int nvme_loop_init_iod(struct nvme_loop_ctrl *ctrl,
 215                 struct nvme_loop_iod *iod, unsigned int queue_idx)
 216 {
 217         iod->req.cmd = &iod->cmd;
 218         iod->req.rsp = &iod->rsp;
 219         iod->queue = &ctrl->queues[queue_idx];
 220         INIT_WORK(&iod->work, nvme_loop_execute_work);
 221         return 0;
 222 }
 223
 224 static int nvme_loop_init_request(struct blk_mq_tag_set *set,
 225                 struct request *req, unsigned int hctx_idx,
 226                 unsigned int numa_node)
 227 {
 228         struct nvme_loop_ctrl *ctrl = set->driver_data;
 229
 230         return nvme_loop_init_iod(ctrl, blk_mq_rq_to_pdu(req),
 231                         (set == &ctrl->tag_set) ? hctx_idx + 1 : 0);
 232 }
 233
 234 static int nvme_loop_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
 235                 unsigned int hctx_idx)
 236 {
 237         struct nvme_loop_ctrl *ctrl = data;
 238         struct nvme_loop_queue *queue = &ctrl->queues[hctx_idx + 1];
 239
 240         BUG_ON(hctx_idx >= ctrl->ctrl.queue_count);
 241
 242         hctx->driver_data = queue;
 243         return 0;
 244 }
 245
 246 static int nvme_loop_init_admin_hctx(struct blk_mq_hw_ctx *hctx, void *data,
 247                 unsigned int hctx_idx)
 248 {
 249         struct nvme_loop_ctrl *ctrl = data;
 250         struct nvme_loop_queue *queue = &ctrl->queues[0];
 251
 252         BUG_ON(hctx_idx != 0);
 253
 254         hctx->driver_data = queue;
 255         return 0;
 256 }
 257
 258 static const struct blk_mq_ops nvme_loop_mq_ops = {
 259         .queue_rq       = nvme_loop_queue_rq,
 260         .complete       = nvme_loop_complete_rq,
 261         .init_request   = nvme_loop_init_request,
 262         .init_hctx      = nvme_loop_init_hctx,
 263         .timeout        = nvme_loop_timeout,
 264 };
 265
 266 static const struct blk_mq_ops nvme_loop_admin_mq_ops = {
 267         .queue_rq       = nvme_loop_queue_rq,
 268         .complete       = nvme_loop_complete_rq,
 269         .init_request   = nvme_loop_init_request,
 270         .init_hctx      = nvme_loop_init_admin_hctx,
 271         .timeout        = nvme_loop_timeout,
 272 };
 273
 274 static void nvme_loop_destroy_admin_queue(struct nvme_loop_ctrl *ctrl)
 275 {
 276         clear_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[0].flags);
 277         nvmet_sq_destroy(&ctrl->queues[0].nvme_sq);
 278         blk_cleanup_queue(ctrl->ctrl.admin_q);
 279         blk_mq_free_tag_set(&ctrl->admin_tag_set);
 280 }
 281
 282 static void nvme_loop_free_ctrl(struct nvme_ctrl *nctrl)
 283 {
 284         struct nvme_loop_ctrl *ctrl = to_loop_ctrl(nctrl);
 285
 286         if (list_empty(&ctrl->list))
 287                 goto free_ctrl;
 288
 289         mutex_lock(&nvme_loop_ctrl_mutex);
 290         list_del(&ctrl->list);
 291         mutex_unlock(&nvme_loop_ctrl_mutex);
 292
 293         if (nctrl->tagset) {
 294                 blk_cleanup_queue(ctrl->ctrl.connect_q);
 295                 blk_mq_free_tag_set(&ctrl->tag_set);
 296         }
 297         kfree(ctrl->queues);
 298         nvmf_free_options(nctrl->opts);
 299 free_ctrl:
 300         kfree(ctrl);
 301 }
 302
 303 static void nvme_loop_destroy_io_queues(struct nvme_loop_ctrl *ctrl)
 304 {
 305         int i;
 306
 307         for (i = 1; i < ctrl->ctrl.queue_count; i++) {
 308                 clear_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[i].flags);
 309                 nvmet_sq_destroy(&ctrl->queues[i].nvme_sq);
 310         }
 311 }
 312
 313 static int nvme_loop_init_io_queues(struct nvme_loop_ctrl *ctrl)
 314 {
 315         struct nvmf_ctrl_options *opts = ctrl->ctrl.opts;
 316         unsigned int nr_io_queues;
 317         int ret, i;
 318
 319         nr_io_queues = min(opts->nr_io_queues, num_online_cpus());
 320         ret = nvme_set_queue_count(&ctrl->ctrl, &nr_io_queues);
 321         if (ret || !nr_io_queues)
 322                 return ret;
 323
 324         dev_info(ctrl->ctrl.device, "creating %d I/O queues.\n", nr_io_queues);
 325
 326         for (i = 1; i <= nr_io_queues; i++) {
 327                 ctrl->queues[i].ctrl = ctrl;
 328                 ret = nvmet_sq_init(&ctrl->queues[i].nvme_sq);
 329                 if (ret)
 330                         goto out_destroy_queues;
 331
 332                 ctrl->ctrl.queue_count++;
 333         }
 334
 335         return 0;
 336
 337 out_destroy_queues:
 338         nvme_loop_destroy_io_queues(ctrl);
 339         return ret;
 340 }
 341
 342 static int nvme_loop_connect_io_queues(struct nvme_loop_ctrl *ctrl)
 343 {
 344         int i, ret;
 345
 346         for (i = 1; i < ctrl->ctrl.queue_count; i++) {
 347                 ret = nvmf_connect_io_queue(&ctrl->ctrl, i);
 348                 if (ret)
 349                         return ret;
 350                 set_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[i].flags);
 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_AQ_MQ_TAG_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         ctrl->admin_tag_set.flags = BLK_MQ_F_NO_SCHED;
 371
 372         ctrl->queues[0].ctrl = ctrl;
 373         error = nvmet_sq_init(&ctrl->queues[0].nvme_sq);
 374         if (error)
 375                 return error;
 376         ctrl->ctrl.queue_count = 1;
 377
 378         error = blk_mq_alloc_tag_set(&ctrl->admin_tag_set);
 379         if (error)
 380                 goto out_free_sq;
 381         ctrl->ctrl.admin_tagset = &ctrl->admin_tag_set;
 382
 383         ctrl->ctrl.admin_q = blk_mq_init_queue(&ctrl->admin_tag_set);
 384         if (IS_ERR(ctrl->ctrl.admin_q)) {
 385                 error = PTR_ERR(ctrl->ctrl.admin_q);
 386                 goto out_free_tagset;
 387         }
 388
 389         error = nvmf_connect_admin_queue(&ctrl->ctrl);
 390         if (error)
 391                 goto out_cleanup_queue;
 392
 393         set_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[0].flags);
 394
 395         error = nvmf_reg_read64(&ctrl->ctrl, NVME_REG_CAP, &ctrl->ctrl.cap);
 396         if (error) {
 397                 dev_err(ctrl->ctrl.device,
 398                         "prop_get NVME_REG_CAP failed\n");
 399                 goto out_cleanup_queue;
 400         }
 401
 402         ctrl->ctrl.sqsize =
 403                 min_t(int, NVME_CAP_MQES(ctrl->ctrl.cap), ctrl->ctrl.sqsize);
 404
 405         error = nvme_enable_ctrl(&ctrl->ctrl, ctrl->ctrl.cap);
 406         if (error)
 407                 goto out_cleanup_queue;
 408
 409         ctrl->ctrl.max_hw_sectors =
 410                 (NVME_LOOP_MAX_SEGMENTS - 1) << (PAGE_SHIFT - 9);
 411
 412         error = nvme_init_identify(&ctrl->ctrl);
 413         if (error)
 414                 goto out_cleanup_queue;
 415
 416         return 0;
 417
 418 out_cleanup_queue:
 419         blk_cleanup_queue(ctrl->ctrl.admin_q);
 420 out_free_tagset:
 421         blk_mq_free_tag_set(&ctrl->admin_tag_set);
 422 out_free_sq:
 423         nvmet_sq_destroy(&ctrl->queues[0].nvme_sq);
 424         return error;
 425 }
 426
 427 static void nvme_loop_shutdown_ctrl(struct nvme_loop_ctrl *ctrl)
 428 {
 429         if (ctrl->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_quiesce_queue(ctrl->ctrl.admin_q);
 440         blk_mq_tagset_busy_iter(&ctrl->admin_tag_set,
 441                                 nvme_cancel_request, &ctrl->ctrl);
 442         blk_mq_unquiesce_queue(ctrl->ctrl.admin_q);
 443         nvme_loop_destroy_admin_queue(ctrl);
 444 }
 445
 446 static void nvme_loop_delete_ctrl_host(struct nvme_ctrl *ctrl)
 447 {
 448         nvme_loop_shutdown_ctrl(to_loop_ctrl(ctrl));
 449 }
 450
 451 static void nvme_loop_delete_ctrl(struct nvmet_ctrl *nctrl)
 452 {
 453         struct nvme_loop_ctrl *ctrl;
 454
 455         mutex_lock(&nvme_loop_ctrl_mutex);
 456         list_for_each_entry(ctrl, &nvme_loop_ctrl_list, list) {
 457                 if (ctrl->ctrl.cntlid == nctrl->cntlid)
 458                         nvme_delete_ctrl(&ctrl->ctrl);
 459         }
 460         mutex_unlock(&nvme_loop_ctrl_mutex);
 461 }
 462
 463 static void nvme_loop_reset_ctrl_work(struct work_struct *work)
 464 {
 465         struct nvme_loop_ctrl *ctrl =
 466                 container_of(work, struct nvme_loop_ctrl, ctrl.reset_work);
 467         bool changed;
 468         int ret;
 469
 470         nvme_stop_ctrl(&ctrl->ctrl);
 471         nvme_loop_shutdown_ctrl(ctrl);
 472
 473         if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_CONNECTING)) {
 474                 /* state change failure should never happen */
 475                 WARN_ON_ONCE(1);
 476                 return;
 477         }
 478
 479         ret = nvme_loop_configure_admin_queue(ctrl);
 480         if (ret)
 481                 goto out_disable;
 482
 483         ret = nvme_loop_init_io_queues(ctrl);
 484         if (ret)
 485                 goto out_destroy_admin;
 486
 487         ret = nvme_loop_connect_io_queues(ctrl);
 488         if (ret)
 489                 goto out_destroy_io;
 490
 491         blk_mq_update_nr_hw_queues(&ctrl->tag_set,
 492                         ctrl->ctrl.queue_count - 1);
 493
 494         changed = nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE);
 495         WARN_ON_ONCE(!changed);
 496
 497         nvme_start_ctrl(&ctrl->ctrl);
 498
 499         return;
 500
 501 out_destroy_io:
 502         nvme_loop_destroy_io_queues(ctrl);
 503 out_destroy_admin:
 504         nvme_loop_destroy_admin_queue(ctrl);
 505 out_disable:
 506         dev_warn(ctrl->ctrl.device, "Removing after reset failure\n");
 507         nvme_uninit_ctrl(&ctrl->ctrl);
 508         nvme_put_ctrl(&ctrl->ctrl);
 509 }
 510
 511 static const struct nvme_ctrl_ops nvme_loop_ctrl_ops = {
 512         .name                   = "loop",
 513         .module                 = THIS_MODULE,
 514         .flags                  = NVME_F_FABRICS,
 515         .reg_read32             = nvmf_reg_read32,
 516         .reg_read64             = nvmf_reg_read64,
 517         .reg_write32            = nvmf_reg_write32,
 518         .free_ctrl              = nvme_loop_free_ctrl,
 519         .submit_async_event     = nvme_loop_submit_async_event,
 520         .delete_ctrl            = nvme_loop_delete_ctrl_host,
 521         .get_address            = nvmf_get_address,
 522 };
 523
 524 static int nvme_loop_create_io_queues(struct nvme_loop_ctrl *ctrl)
 525 {
 526         int ret;
 527
 528         ret = nvme_loop_init_io_queues(ctrl);
 529         if (ret)
 530                 return ret;
 531
 532         memset(&ctrl->tag_set, 0, sizeof(ctrl->tag_set));
 533         ctrl->tag_set.ops = &nvme_loop_mq_ops;
 534         ctrl->tag_set.queue_depth = ctrl->ctrl.opts->queue_size;
 535         ctrl->tag_set.reserved_tags = 1; /* fabric connect */
 536         ctrl->tag_set.numa_node = NUMA_NO_NODE;
 537         ctrl->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
 538         ctrl->tag_set.cmd_size = sizeof(struct nvme_loop_iod) +
 539                 SG_CHUNK_SIZE * sizeof(struct scatterlist);
 540         ctrl->tag_set.driver_data = ctrl;
 541         ctrl->tag_set.nr_hw_queues = ctrl->ctrl.queue_count - 1;
 542         ctrl->tag_set.timeout = NVME_IO_TIMEOUT;
 543         ctrl->ctrl.tagset = &ctrl->tag_set;
 544
 545         ret = blk_mq_alloc_tag_set(&ctrl->tag_set);
 546         if (ret)
 547                 goto out_destroy_queues;
 548
 549         ctrl->ctrl.connect_q = blk_mq_init_queue(&ctrl->tag_set);
 550         if (IS_ERR(ctrl->ctrl.connect_q)) {
 551                 ret = PTR_ERR(ctrl->ctrl.connect_q);
 552                 goto out_free_tagset;
 553         }
 554
 555         ret = nvme_loop_connect_io_queues(ctrl);
 556         if (ret)
 557                 goto out_cleanup_connect_q;
 558
 559         return 0;
 560
 561 out_cleanup_connect_q:
 562         blk_cleanup_queue(ctrl->ctrl.connect_q);
 563 out_free_tagset:
 564         blk_mq_free_tag_set(&ctrl->tag_set);
 565 out_destroy_queues:
 566         nvme_loop_destroy_io_queues(ctrl);
 567         return ret;
 568 }
 569
 570 static struct nvmet_port *nvme_loop_find_port(struct nvme_ctrl *ctrl)
 571 {
 572         struct nvmet_port *p, *found = NULL;
 573
 574         mutex_lock(&nvme_loop_ports_mutex);
 575         list_for_each_entry(p, &nvme_loop_ports, entry) {
 576                 /* if no transport address is specified use the first port */
 577                 if ((ctrl->opts->mask & NVMF_OPT_TRADDR) &&
 578                     strcmp(ctrl->opts->traddr, p->disc_addr.traddr))
 579                         continue;
 580                 found = p;
 581                 break;
 582         }
 583         mutex_unlock(&nvme_loop_ports_mutex);
 584         return found;
 585 }
 586
 587 static struct nvme_ctrl *nvme_loop_create_ctrl(struct device *dev,
 588                 struct nvmf_ctrl_options *opts)
 589 {
 590         struct nvme_loop_ctrl *ctrl;
 591         bool changed;
 592         int ret;
 593
 594         ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
 595         if (!ctrl)
 596                 return ERR_PTR(-ENOMEM);
 597         ctrl->ctrl.opts = opts;
 598         INIT_LIST_HEAD(&ctrl->list);
 599
 600         INIT_WORK(&ctrl->ctrl.reset_work, nvme_loop_reset_ctrl_work);
 601
 602         ret = nvme_init_ctrl(&ctrl->ctrl, dev, &nvme_loop_ctrl_ops,
 603                                 0 /* no quirks, we're perfect! */);
 604         if (ret)
 605                 goto out_put_ctrl;
 606
 607         ret = -ENOMEM;
 608
 609         ctrl->ctrl.sqsize = opts->queue_size - 1;
 610         ctrl->ctrl.kato = opts->kato;
 611         ctrl->port = nvme_loop_find_port(&ctrl->ctrl);
 612
 613         ctrl->queues = kcalloc(opts->nr_io_queues + 1, sizeof(*ctrl->queues),
 614                         GFP_KERNEL);
 615         if (!ctrl->queues)
 616                 goto out_uninit_ctrl;
 617
 618         ret = nvme_loop_configure_admin_queue(ctrl);
 619         if (ret)
 620                 goto out_free_queues;
 621
 622         if (opts->queue_size > ctrl->ctrl.maxcmd) {
 623                 /* warn if maxcmd is lower than queue_size */
 624                 dev_warn(ctrl->ctrl.device,
 625                         "queue_size %zu > ctrl maxcmd %u, clamping down\n",
 626                         opts->queue_size, ctrl->ctrl.maxcmd);
 627                 opts->queue_size = ctrl->ctrl.maxcmd;
 628         }
 629
 630         if (opts->nr_io_queues) {
 631                 ret = nvme_loop_create_io_queues(ctrl);
 632                 if (ret)
 633                         goto out_remove_admin_queue;
 634         }
 635
 636         nvme_loop_init_iod(ctrl, &ctrl->async_event_iod, 0);
 637
 638         dev_info(ctrl->ctrl.device,
 639                  "new ctrl: \"%s\"\n", ctrl->ctrl.opts->subsysnqn);
 640
 641         nvme_get_ctrl(&ctrl->ctrl);
 642
 643         changed = nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE);
 644         WARN_ON_ONCE(!changed);
 645
 646         mutex_lock(&nvme_loop_ctrl_mutex);
 647         list_add_tail(&ctrl->list, &nvme_loop_ctrl_list);
 648         mutex_unlock(&nvme_loop_ctrl_mutex);
 649
 650         nvme_start_ctrl(&ctrl->ctrl);
 651
 652         return &ctrl->ctrl;
 653
 654 out_remove_admin_queue:
 655         nvme_loop_destroy_admin_queue(ctrl);
 656 out_free_queues:
 657         kfree(ctrl->queues);
 658 out_uninit_ctrl:
 659         nvme_uninit_ctrl(&ctrl->ctrl);
 660 out_put_ctrl:
 661         nvme_put_ctrl(&ctrl->ctrl);
 662         if (ret > 0)
 663                 ret = -EIO;
 664         return ERR_PTR(ret);
 665 }
 666
 667 static int nvme_loop_add_port(struct nvmet_port *port)
 668 {
 669         mutex_lock(&nvme_loop_ports_mutex);
 670         list_add_tail(&port->entry, &nvme_loop_ports);
 671         mutex_unlock(&nvme_loop_ports_mutex);
 672         return 0;
 673 }
 674
 675 static void nvme_loop_remove_port(struct nvmet_port *port)
 676 {
 677         mutex_lock(&nvme_loop_ports_mutex);
 678         list_del_init(&port->entry);
 679         mutex_unlock(&nvme_loop_ports_mutex);
 680 }
 681
 682 static const struct nvmet_fabrics_ops nvme_loop_ops = {
 683         .owner          = THIS_MODULE,
 684         .type           = NVMF_TRTYPE_LOOP,
 685         .add_port       = nvme_loop_add_port,
 686         .remove_port    = nvme_loop_remove_port,
 687         .queue_response = nvme_loop_queue_response,
 688         .delete_ctrl    = nvme_loop_delete_ctrl,
 689 };
 690
 691 static struct nvmf_transport_ops nvme_loop_transport = {
 692         .name           = "loop",
 693         .module         = THIS_MODULE,
 694         .create_ctrl    = nvme_loop_create_ctrl,
 695         .allowed_opts   = NVMF_OPT_TRADDR,
 696 };
 697
 698 static int __init nvme_loop_init_module(void)
 699 {
 700         int ret;
 701
 702         ret = nvmet_register_transport(&nvme_loop_ops);
 703         if (ret)
 704                 return ret;
 705
 706         ret = nvmf_register_transport(&nvme_loop_transport);
 707         if (ret)
 708                 nvmet_unregister_transport(&nvme_loop_ops);
 709
 710         return ret;
 711 }
 712
 713 static void __exit nvme_loop_cleanup_module(void)
 714 {
 715         struct nvme_loop_ctrl *ctrl, *next;
 716
 717         nvmf_unregister_transport(&nvme_loop_transport);
 718         nvmet_unregister_transport(&nvme_loop_ops);
 719
 720         mutex_lock(&nvme_loop_ctrl_mutex);
 721         list_for_each_entry_safe(ctrl, next, &nvme_loop_ctrl_list, list)
 722                 nvme_delete_ctrl(&ctrl->ctrl);
 723         mutex_unlock(&nvme_loop_ctrl_mutex);
 724
 725         flush_workqueue(nvme_delete_wq);
 726 }
 727
 728 module_init(nvme_loop_init_module);
 729 module_exit(nvme_loop_cleanup_module);
 730
 731 MODULE_LICENSE("GPL v2");
 732 MODULE_ALIAS("nvmet-transport-254"); /* 254 == NVMF_TRTYPE_LOOP */