drivers/nvme/target/loop.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * NVMe over Fabrics loopback device.
   4  * Copyright (c) 2015-2016 HGST, a Western Digital Company.
   5  */
   6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   7 #include <linux/scatterlist.h>
   8 #include <linux/blk-mq.h>
   9 #include <linux/nvme.h>
  10 #include <linux/module.h>
  11 #include <linux/parser.h>
  12 #include "nvmet.h"
  13 #include "../host/nvme.h"
  14 #include "../host/fabrics.h"
  15
  16 #define NVME_LOOP_MAX_SEGMENTS          256
  17
  18 struct nvme_loop_iod {
  19         struct nvme_request     nvme_req;
  20         struct nvme_command     cmd;
  21         struct nvme_completion  cqe;
  22         struct nvmet_req        req;
  23         struct nvme_loop_queue  *queue;
  24         struct work_struct      work;
  25         struct sg_table         sg_table;
  26         struct scatterlist      first_sgl[];
  27 };
  28
  29 struct nvme_loop_ctrl {
  30         struct nvme_loop_queue  *queues;
  31
  32         struct blk_mq_tag_set   admin_tag_set;
  33
  34         struct list_head        list;
  35         struct blk_mq_tag_set   tag_set;
  36         struct nvme_loop_iod    async_event_iod;
  37         struct nvme_ctrl        ctrl;
  38
  39         struct nvmet_ctrl       *target_ctrl;
  40         struct nvmet_port       *port;
  41 };
  42
  43 static inline struct nvme_loop_ctrl *to_loop_ctrl(struct nvme_ctrl *ctrl)
  44 {
  45         return container_of(ctrl, struct nvme_loop_ctrl, ctrl);
  46 }
  47
  48 enum nvme_loop_queue_flags {
  49         NVME_LOOP_Q_LIVE        = 0,
  50 };
  51
  52 struct nvme_loop_queue {
  53         struct nvmet_cq         nvme_cq;
  54         struct nvmet_sq         nvme_sq;
  55         struct nvme_loop_ctrl   *ctrl;
  56         unsigned long           flags;
  57 };
  58
  59 static LIST_HEAD(nvme_loop_ports);
  60 static DEFINE_MUTEX(nvme_loop_ports_mutex);
  61
  62 static LIST_HEAD(nvme_loop_ctrl_list);
  63 static DEFINE_MUTEX(nvme_loop_ctrl_mutex);
  64
  65 static void nvme_loop_queue_response(struct nvmet_req *nvme_req);
  66 static void nvme_loop_delete_ctrl(struct nvmet_ctrl *ctrl);
  67
  68 static const struct nvmet_fabrics_ops nvme_loop_ops;
  69
  70 static inline int nvme_loop_queue_idx(struct nvme_loop_queue *queue)
  71 {
  72         return queue - queue->ctrl->queues;
  73 }
  74
  75 static void nvme_loop_complete_rq(struct request *req)
  76 {
  77         struct nvme_loop_iod *iod = blk_mq_rq_to_pdu(req);
  78
  79         sg_free_table_chained(&iod->sg_table, NVME_INLINE_SG_CNT);
  80         nvme_complete_rq(req);
  81 }
  82
  83 static struct blk_mq_tags *nvme_loop_tagset(struct nvme_loop_queue *queue)
  84 {
  85         u32 queue_idx = nvme_loop_queue_idx(queue);
  86
  87         if (queue_idx == 0)
  88                 return queue->ctrl->admin_tag_set.tags[queue_idx];
  89         return queue->ctrl->tag_set.tags[queue_idx - 1];
  90 }
  91
  92 static void nvme_loop_queue_response(struct nvmet_req *req)
  93 {
  94         struct nvme_loop_queue *queue =
  95                 container_of(req->sq, struct nvme_loop_queue, nvme_sq);
  96         struct nvme_completion *cqe = req->cqe;
  97
  98         /*
  99          * AEN requests are special as they don't time out and can
 100          * survive any kind of queue freeze and often don't respond to
 101          * aborts.  We don't even bother to allocate a struct request
 102          * for them but rather special case them here.
 103          */
 104         if (unlikely(nvme_is_aen_req(nvme_loop_queue_idx(queue),
 105                                      cqe->command_id))) {
 106                 nvme_complete_async_event(&queue->ctrl->ctrl, cqe->status,
 107                                 &cqe->result);
 108         } else {
 109                 struct request *rq;
 110
 111                 rq = blk_mq_tag_to_rq(nvme_loop_tagset(queue), cqe->command_id);
 112                 if (!rq) {
 113                         dev_err(queue->ctrl->ctrl.device,
 114                                 "tag 0x%x on queue %d not found\n",
 115                                 cqe->command_id, nvme_loop_queue_idx(queue));
 116                         return;
 117                 }
 118
 119                 if (!nvme_end_request(rq, cqe->status, cqe->result))
 120                         nvme_loop_complete_rq(rq);
 121         }
 122 }
 123
 124 static void nvme_loop_execute_work(struct work_struct *work)
 125 {
 126         struct nvme_loop_iod *iod =
 127                 container_of(work, struct nvme_loop_iod, work);
 128
 129         iod->req.execute(&iod->req);
 130 }
 131
 132 static blk_status_t nvme_loop_queue_rq(struct blk_mq_hw_ctx *hctx,
 133                 const struct blk_mq_queue_data *bd)
 134 {
 135         struct nvme_ns *ns = hctx->queue->queuedata;
 136         struct nvme_loop_queue *queue = hctx->driver_data;
 137         struct request *req = bd->rq;
 138         struct nvme_loop_iod *iod = blk_mq_rq_to_pdu(req);
 139         bool queue_ready = test_bit(NVME_LOOP_Q_LIVE, &queue->flags);
 140         blk_status_t ret;
 141
 142         if (!nvmf_check_ready(&queue->ctrl->ctrl, req, queue_ready))
 143                 return nvmf_fail_nonready_command(&queue->ctrl->ctrl, req);
 144
 145         ret = nvme_setup_cmd(ns, req, &iod->cmd);
 146         if (ret)
 147                 return ret;
 148
 149         blk_mq_start_request(req);
 150         iod->cmd.common.flags |= NVME_CMD_SGL_METABUF;
 151         iod->req.port = queue->ctrl->port;
 152         if (!nvmet_req_init(&iod->req, &queue->nvme_cq,
 153                         &queue->nvme_sq, &nvme_loop_ops))
 154                 return BLK_STS_OK;
 155
 156         if (blk_rq_nr_phys_segments(req)) {
 157                 iod->sg_table.sgl = iod->first_sgl;
 158                 if (sg_alloc_table_chained(&iod->sg_table,
 159                                 blk_rq_nr_phys_segments(req),
 160                                 iod->sg_table.sgl, NVME_INLINE_SG_CNT)) {
 161                         nvme_cleanup_cmd(req);
 162                         return BLK_STS_RESOURCE;
 163                 }
 164
 165                 iod->req.sg = iod->sg_table.sgl;
 166                 iod->req.sg_cnt = blk_rq_map_sg(req->q, req, iod->sg_table.sgl);
 167                 iod->req.transfer_len = blk_rq_payload_bytes(req);
 168         }
 169
 170         schedule_work(&iod->work);
 171         return BLK_STS_OK;
 172 }
 173
 174 static void nvme_loop_submit_async_event(struct nvme_ctrl *arg)
 175 {
 176         struct nvme_loop_ctrl *ctrl = to_loop_ctrl(arg);
 177         struct nvme_loop_queue *queue = &ctrl->queues[0];
 178         struct nvme_loop_iod *iod = &ctrl->async_event_iod;
 179
 180         memset(&iod->cmd, 0, sizeof(iod->cmd));
 181         iod->cmd.common.opcode = nvme_admin_async_event;
 182         iod->cmd.common.command_id = NVME_AQ_BLK_MQ_DEPTH;
 183         iod->cmd.common.flags |= NVME_CMD_SGL_METABUF;
 184
 185         if (!nvmet_req_init(&iod->req, &queue->nvme_cq, &queue->nvme_sq,
 186                         &nvme_loop_ops)) {
 187                 dev_err(ctrl->ctrl.device, "failed async event work\n");
 188                 return;
 189         }
 190
 191         schedule_work(&iod->work);
 192 }
 193
 194 static int nvme_loop_init_iod(struct nvme_loop_ctrl *ctrl,
 195                 struct nvme_loop_iod *iod, unsigned int queue_idx)
 196 {
 197         iod->req.cmd = &iod->cmd;
 198         iod->req.cqe = &iod->cqe;
 199         iod->queue = &ctrl->queues[queue_idx];
 200         INIT_WORK(&iod->work, nvme_loop_execute_work);
 201         return 0;
 202 }
 203
 204 static int nvme_loop_init_request(struct blk_mq_tag_set *set,
 205                 struct request *req, unsigned int hctx_idx,
 206                 unsigned int numa_node)
 207 {
 208         struct nvme_loop_ctrl *ctrl = set->driver_data;
 209
 210         nvme_req(req)->ctrl = &ctrl->ctrl;
 211         return nvme_loop_init_iod(ctrl, blk_mq_rq_to_pdu(req),
 212                         (set == &ctrl->tag_set) ? hctx_idx + 1 : 0);
 213 }
 214
 215 static int nvme_loop_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
 216                 unsigned int hctx_idx)
 217 {
 218         struct nvme_loop_ctrl *ctrl = data;
 219         struct nvme_loop_queue *queue = &ctrl->queues[hctx_idx + 1];
 220
 221         BUG_ON(hctx_idx >= ctrl->ctrl.queue_count);
 222
 223         hctx->driver_data = queue;
 224         return 0;
 225 }
 226
 227 static int nvme_loop_init_admin_hctx(struct blk_mq_hw_ctx *hctx, void *data,
 228                 unsigned int hctx_idx)
 229 {
 230         struct nvme_loop_ctrl *ctrl = data;
 231         struct nvme_loop_queue *queue = &ctrl->queues[0];
 232
 233         BUG_ON(hctx_idx != 0);
 234
 235         hctx->driver_data = queue;
 236         return 0;
 237 }
 238
 239 static const struct blk_mq_ops nvme_loop_mq_ops = {
 240         .queue_rq       = nvme_loop_queue_rq,
 241         .complete       = nvme_loop_complete_rq,
 242         .init_request   = nvme_loop_init_request,
 243         .init_hctx      = nvme_loop_init_hctx,
 244 };
 245
 246 static const struct blk_mq_ops nvme_loop_admin_mq_ops = {
 247         .queue_rq       = nvme_loop_queue_rq,
 248         .complete       = nvme_loop_complete_rq,
 249         .init_request   = nvme_loop_init_request,
 250         .init_hctx      = nvme_loop_init_admin_hctx,
 251 };
 252
 253 static void nvme_loop_destroy_admin_queue(struct nvme_loop_ctrl *ctrl)
 254 {
 255         clear_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[0].flags);
 256         nvmet_sq_destroy(&ctrl->queues[0].nvme_sq);
 257         blk_cleanup_queue(ctrl->ctrl.admin_q);
 258         blk_cleanup_queue(ctrl->ctrl.fabrics_q);
 259         blk_mq_free_tag_set(&ctrl->admin_tag_set);
 260 }
 261
 262 static void nvme_loop_free_ctrl(struct nvme_ctrl *nctrl)
 263 {
 264         struct nvme_loop_ctrl *ctrl = to_loop_ctrl(nctrl);
 265
 266         if (list_empty(&ctrl->list))
 267                 goto free_ctrl;
 268
 269         mutex_lock(&nvme_loop_ctrl_mutex);
 270         list_del(&ctrl->list);
 271         mutex_unlock(&nvme_loop_ctrl_mutex);
 272
 273         if (nctrl->tagset) {
 274                 blk_cleanup_queue(ctrl->ctrl.connect_q);
 275                 blk_mq_free_tag_set(&ctrl->tag_set);
 276         }
 277         kfree(ctrl->queues);
 278         nvmf_free_options(nctrl->opts);
 279 free_ctrl:
 280         kfree(ctrl);
 281 }
 282
 283 static void nvme_loop_destroy_io_queues(struct nvme_loop_ctrl *ctrl)
 284 {
 285         int i;
 286
 287         for (i = 1; i < ctrl->ctrl.queue_count; i++) {
 288                 clear_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[i].flags);
 289                 nvmet_sq_destroy(&ctrl->queues[i].nvme_sq);
 290         }
 291 }
 292
 293 static int nvme_loop_init_io_queues(struct nvme_loop_ctrl *ctrl)
 294 {
 295         struct nvmf_ctrl_options *opts = ctrl->ctrl.opts;
 296         unsigned int nr_io_queues;
 297         int ret, i;
 298
 299         nr_io_queues = min(opts->nr_io_queues, num_online_cpus());
 300         ret = nvme_set_queue_count(&ctrl->ctrl, &nr_io_queues);
 301         if (ret || !nr_io_queues)
 302                 return ret;
 303
 304         dev_info(ctrl->ctrl.device, "creating %d I/O queues.\n", nr_io_queues);
 305
 306         for (i = 1; i <= nr_io_queues; i++) {
 307                 ctrl->queues[i].ctrl = ctrl;
 308                 ret = nvmet_sq_init(&ctrl->queues[i].nvme_sq);
 309                 if (ret)
 310                         goto out_destroy_queues;
 311
 312                 ctrl->ctrl.queue_count++;
 313         }
 314
 315         return 0;
 316
 317 out_destroy_queues:
 318         nvme_loop_destroy_io_queues(ctrl);
 319         return ret;
 320 }
 321
 322 static int nvme_loop_connect_io_queues(struct nvme_loop_ctrl *ctrl)
 323 {
 324         int i, ret;
 325
 326         for (i = 1; i < ctrl->ctrl.queue_count; i++) {
 327                 ret = nvmf_connect_io_queue(&ctrl->ctrl, i, false);
 328                 if (ret)
 329                         return ret;
 330                 set_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[i].flags);
 331         }
 332
 333         return 0;
 334 }
 335
 336 static int nvme_loop_configure_admin_queue(struct nvme_loop_ctrl *ctrl)
 337 {
 338         int error;
 339
 340         memset(&ctrl->admin_tag_set, 0, sizeof(ctrl->admin_tag_set));
 341         ctrl->admin_tag_set.ops = &nvme_loop_admin_mq_ops;
 342         ctrl->admin_tag_set.queue_depth = NVME_AQ_MQ_TAG_DEPTH;
 343         ctrl->admin_tag_set.reserved_tags = 2; /* connect + keep-alive */
 344         ctrl->admin_tag_set.numa_node = ctrl->ctrl.numa_node;
 345         ctrl->admin_tag_set.cmd_size = sizeof(struct nvme_loop_iod) +
 346                 NVME_INLINE_SG_CNT * sizeof(struct scatterlist);
 347         ctrl->admin_tag_set.driver_data = ctrl;
 348         ctrl->admin_tag_set.nr_hw_queues = 1;
 349         ctrl->admin_tag_set.timeout = ADMIN_TIMEOUT;
 350         ctrl->admin_tag_set.flags = BLK_MQ_F_NO_SCHED;
 351
 352         ctrl->queues[0].ctrl = ctrl;
 353         error = nvmet_sq_init(&ctrl->queues[0].nvme_sq);
 354         if (error)
 355                 return error;
 356         ctrl->ctrl.queue_count = 1;
 357
 358         error = blk_mq_alloc_tag_set(&ctrl->admin_tag_set);
 359         if (error)
 360                 goto out_free_sq;
 361         ctrl->ctrl.admin_tagset = &ctrl->admin_tag_set;
 362
 363         ctrl->ctrl.fabrics_q = blk_mq_init_queue(&ctrl->admin_tag_set);
 364         if (IS_ERR(ctrl->ctrl.fabrics_q)) {
 365                 error = PTR_ERR(ctrl->ctrl.fabrics_q);
 366                 goto out_free_tagset;
 367         }
 368
 369         ctrl->ctrl.admin_q = blk_mq_init_queue(&ctrl->admin_tag_set);
 370         if (IS_ERR(ctrl->ctrl.admin_q)) {
 371                 error = PTR_ERR(ctrl->ctrl.admin_q);
 372                 goto out_cleanup_fabrics_q;
 373         }
 374
 375         error = nvmf_connect_admin_queue(&ctrl->ctrl);
 376         if (error)
 377                 goto out_cleanup_queue;
 378
 379         set_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[0].flags);
 380
 381         error = nvme_enable_ctrl(&ctrl->ctrl);
 382         if (error)
 383                 goto out_cleanup_queue;
 384
 385         ctrl->ctrl.max_hw_sectors =
 386                 (NVME_LOOP_MAX_SEGMENTS - 1) << (PAGE_SHIFT - 9);
 387
 388         blk_mq_unquiesce_queue(ctrl->ctrl.admin_q);
 389
 390         error = nvme_init_identify(&ctrl->ctrl);
 391         if (error)
 392                 goto out_cleanup_queue;
 393
 394         return 0;
 395
 396 out_cleanup_queue:
 397         blk_cleanup_queue(ctrl->ctrl.admin_q);
 398 out_cleanup_fabrics_q:
 399         blk_cleanup_queue(ctrl->ctrl.fabrics_q);
 400 out_free_tagset:
 401         blk_mq_free_tag_set(&ctrl->admin_tag_set);
 402 out_free_sq:
 403         nvmet_sq_destroy(&ctrl->queues[0].nvme_sq);
 404         return error;
 405 }
 406
 407 static void nvme_loop_shutdown_ctrl(struct nvme_loop_ctrl *ctrl)
 408 {
 409         if (ctrl->ctrl.queue_count > 1) {
 410                 nvme_stop_queues(&ctrl->ctrl);
 411                 blk_mq_tagset_busy_iter(&ctrl->tag_set,
 412                                         nvme_cancel_request, &ctrl->ctrl);
 413                 blk_mq_tagset_wait_completed_request(&ctrl->tag_set);
 414                 nvme_loop_destroy_io_queues(ctrl);
 415         }
 416
 417         blk_mq_quiesce_queue(ctrl->ctrl.admin_q);
 418         if (ctrl->ctrl.state == NVME_CTRL_LIVE)
 419                 nvme_shutdown_ctrl(&ctrl->ctrl);
 420
 421         blk_mq_tagset_busy_iter(&ctrl->admin_tag_set,
 422                                 nvme_cancel_request, &ctrl->ctrl);
 423         blk_mq_tagset_wait_completed_request(&ctrl->admin_tag_set);
 424         nvme_loop_destroy_admin_queue(ctrl);
 425 }
 426
 427 static void nvme_loop_delete_ctrl_host(struct nvme_ctrl *ctrl)
 428 {
 429         nvme_loop_shutdown_ctrl(to_loop_ctrl(ctrl));
 430 }
 431
 432 static void nvme_loop_delete_ctrl(struct nvmet_ctrl *nctrl)
 433 {
 434         struct nvme_loop_ctrl *ctrl;
 435
 436         mutex_lock(&nvme_loop_ctrl_mutex);
 437         list_for_each_entry(ctrl, &nvme_loop_ctrl_list, list) {
 438                 if (ctrl->ctrl.cntlid == nctrl->cntlid)
 439                         nvme_delete_ctrl(&ctrl->ctrl);
 440         }
 441         mutex_unlock(&nvme_loop_ctrl_mutex);
 442 }
 443
 444 static void nvme_loop_reset_ctrl_work(struct work_struct *work)
 445 {
 446         struct nvme_loop_ctrl *ctrl =
 447                 container_of(work, struct nvme_loop_ctrl, ctrl.reset_work);
 448         bool changed;
 449         int ret;
 450
 451         nvme_stop_ctrl(&ctrl->ctrl);
 452         nvme_loop_shutdown_ctrl(ctrl);
 453
 454         if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_CONNECTING)) {
 455                 /* state change failure should never happen */
 456                 WARN_ON_ONCE(1);
 457                 return;
 458         }
 459
 460         ret = nvme_loop_configure_admin_queue(ctrl);
 461         if (ret)
 462                 goto out_disable;
 463
 464         ret = nvme_loop_init_io_queues(ctrl);
 465         if (ret)
 466                 goto out_destroy_admin;
 467
 468         ret = nvme_loop_connect_io_queues(ctrl);
 469         if (ret)
 470                 goto out_destroy_io;
 471
 472         blk_mq_update_nr_hw_queues(&ctrl->tag_set,
 473                         ctrl->ctrl.queue_count - 1);
 474
 475         changed = nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE);
 476         WARN_ON_ONCE(!changed);
 477
 478         nvme_start_ctrl(&ctrl->ctrl);
 479
 480         return;
 481
 482 out_destroy_io:
 483         nvme_loop_destroy_io_queues(ctrl);
 484 out_destroy_admin:
 485         nvme_loop_destroy_admin_queue(ctrl);
 486 out_disable:
 487         dev_warn(ctrl->ctrl.device, "Removing after reset failure\n");
 488         nvme_uninit_ctrl(&ctrl->ctrl);
 489 }
 490
 491 static const struct nvme_ctrl_ops nvme_loop_ctrl_ops = {
 492         .name                   = "loop",
 493         .module                 = THIS_MODULE,
 494         .flags                  = NVME_F_FABRICS,
 495         .reg_read32             = nvmf_reg_read32,
 496         .reg_read64             = nvmf_reg_read64,
 497         .reg_write32            = nvmf_reg_write32,
 498         .free_ctrl              = nvme_loop_free_ctrl,
 499         .submit_async_event     = nvme_loop_submit_async_event,
 500         .delete_ctrl            = nvme_loop_delete_ctrl_host,
 501         .get_address            = nvmf_get_address,
 502 };
 503
 504 static int nvme_loop_create_io_queues(struct nvme_loop_ctrl *ctrl)
 505 {
 506         int ret;
 507
 508         ret = nvme_loop_init_io_queues(ctrl);
 509         if (ret)
 510                 return ret;
 511
 512         memset(&ctrl->tag_set, 0, sizeof(ctrl->tag_set));
 513         ctrl->tag_set.ops = &nvme_loop_mq_ops;
 514         ctrl->tag_set.queue_depth = ctrl->ctrl.opts->queue_size;
 515         ctrl->tag_set.reserved_tags = 1; /* fabric connect */
 516         ctrl->tag_set.numa_node = ctrl->ctrl.numa_node;
 517         ctrl->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
 518         ctrl->tag_set.cmd_size = sizeof(struct nvme_loop_iod) +
 519                 NVME_INLINE_SG_CNT * sizeof(struct scatterlist);
 520         ctrl->tag_set.driver_data = ctrl;
 521         ctrl->tag_set.nr_hw_queues = ctrl->ctrl.queue_count - 1;
 522         ctrl->tag_set.timeout = NVME_IO_TIMEOUT;
 523         ctrl->ctrl.tagset = &ctrl->tag_set;
 524
 525         ret = blk_mq_alloc_tag_set(&ctrl->tag_set);
 526         if (ret)
 527                 goto out_destroy_queues;
 528
 529         ctrl->ctrl.connect_q = blk_mq_init_queue(&ctrl->tag_set);
 530         if (IS_ERR(ctrl->ctrl.connect_q)) {
 531                 ret = PTR_ERR(ctrl->ctrl.connect_q);
 532                 goto out_free_tagset;
 533         }
 534
 535         ret = nvme_loop_connect_io_queues(ctrl);
 536         if (ret)
 537                 goto out_cleanup_connect_q;
 538
 539         return 0;
 540
 541 out_cleanup_connect_q:
 542         blk_cleanup_queue(ctrl->ctrl.connect_q);
 543 out_free_tagset:
 544         blk_mq_free_tag_set(&ctrl->tag_set);
 545 out_destroy_queues:
 546         nvme_loop_destroy_io_queues(ctrl);
 547         return ret;
 548 }
 549
 550 static struct nvmet_port *nvme_loop_find_port(struct nvme_ctrl *ctrl)
 551 {
 552         struct nvmet_port *p, *found = NULL;
 553
 554         mutex_lock(&nvme_loop_ports_mutex);
 555         list_for_each_entry(p, &nvme_loop_ports, entry) {
 556                 /* if no transport address is specified use the first port */
 557                 if ((ctrl->opts->mask & NVMF_OPT_TRADDR) &&
 558                     strcmp(ctrl->opts->traddr, p->disc_addr.traddr))
 559                         continue;
 560                 found = p;
 561                 break;
 562         }
 563         mutex_unlock(&nvme_loop_ports_mutex);
 564         return found;
 565 }
 566
 567 static struct nvme_ctrl *nvme_loop_create_ctrl(struct device *dev,
 568                 struct nvmf_ctrl_options *opts)
 569 {
 570         struct nvme_loop_ctrl *ctrl;
 571         bool changed;
 572         int ret;
 573
 574         ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
 575         if (!ctrl)
 576                 return ERR_PTR(-ENOMEM);
 577         ctrl->ctrl.opts = opts;
 578         INIT_LIST_HEAD(&ctrl->list);
 579
 580         INIT_WORK(&ctrl->ctrl.reset_work, nvme_loop_reset_ctrl_work);
 581
 582         ret = nvme_init_ctrl(&ctrl->ctrl, dev, &nvme_loop_ctrl_ops,
 583                                 0 /* no quirks, we're perfect! */);
 584         if (ret)
 585                 goto out_put_ctrl;
 586
 587         ret = -ENOMEM;
 588
 589         ctrl->ctrl.sqsize = opts->queue_size - 1;
 590         ctrl->ctrl.kato = opts->kato;
 591         ctrl->port = nvme_loop_find_port(&ctrl->ctrl);
 592
 593         ctrl->queues = kcalloc(opts->nr_io_queues + 1, sizeof(*ctrl->queues),
 594                         GFP_KERNEL);
 595         if (!ctrl->queues)
 596                 goto out_uninit_ctrl;
 597
 598         ret = nvme_loop_configure_admin_queue(ctrl);
 599         if (ret)
 600                 goto out_free_queues;
 601
 602         if (opts->queue_size > ctrl->ctrl.maxcmd) {
 603                 /* warn if maxcmd is lower than queue_size */
 604                 dev_warn(ctrl->ctrl.device,
 605                         "queue_size %zu > ctrl maxcmd %u, clamping down\n",
 606                         opts->queue_size, ctrl->ctrl.maxcmd);
 607                 opts->queue_size = ctrl->ctrl.maxcmd;
 608         }
 609
 610         if (opts->nr_io_queues) {
 611                 ret = nvme_loop_create_io_queues(ctrl);
 612                 if (ret)
 613                         goto out_remove_admin_queue;
 614         }
 615
 616         nvme_loop_init_iod(ctrl, &ctrl->async_event_iod, 0);
 617
 618         dev_info(ctrl->ctrl.device,
 619                  "new ctrl: \"%s\"\n", ctrl->ctrl.opts->subsysnqn);
 620
 621         changed = nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE);
 622         WARN_ON_ONCE(!changed);
 623
 624         mutex_lock(&nvme_loop_ctrl_mutex);
 625         list_add_tail(&ctrl->list, &nvme_loop_ctrl_list);
 626         mutex_unlock(&nvme_loop_ctrl_mutex);
 627
 628         nvme_start_ctrl(&ctrl->ctrl);
 629
 630         return &ctrl->ctrl;
 631
 632 out_remove_admin_queue:
 633         nvme_loop_destroy_admin_queue(ctrl);
 634 out_free_queues:
 635         kfree(ctrl->queues);
 636 out_uninit_ctrl:
 637         nvme_uninit_ctrl(&ctrl->ctrl);
 638 out_put_ctrl:
 639         nvme_put_ctrl(&ctrl->ctrl);
 640         if (ret > 0)
 641                 ret = -EIO;
 642         return ERR_PTR(ret);
 643 }
 644
 645 static int nvme_loop_add_port(struct nvmet_port *port)
 646 {
 647         mutex_lock(&nvme_loop_ports_mutex);
 648         list_add_tail(&port->entry, &nvme_loop_ports);
 649         mutex_unlock(&nvme_loop_ports_mutex);
 650         return 0;
 651 }
 652
 653 static void nvme_loop_remove_port(struct nvmet_port *port)
 654 {
 655         mutex_lock(&nvme_loop_ports_mutex);
 656         list_del_init(&port->entry);
 657         mutex_unlock(&nvme_loop_ports_mutex);
 658
 659         /*
 660          * Ensure any ctrls that are in the process of being
 661          * deleted are in fact deleted before we return
 662          * and free the port. This is to prevent active
 663          * ctrls from using a port after it's freed.
 664          */
 665         flush_workqueue(nvme_delete_wq);
 666 }
 667
 668 static const struct nvmet_fabrics_ops nvme_loop_ops = {
 669         .owner          = THIS_MODULE,
 670         .type           = NVMF_TRTYPE_LOOP,
 671         .add_port       = nvme_loop_add_port,
 672         .remove_port    = nvme_loop_remove_port,
 673         .queue_response = nvme_loop_queue_response,
 674         .delete_ctrl    = nvme_loop_delete_ctrl,
 675 };
 676
 677 static struct nvmf_transport_ops nvme_loop_transport = {
 678         .name           = "loop",
 679         .module         = THIS_MODULE,
 680         .create_ctrl    = nvme_loop_create_ctrl,
 681         .allowed_opts   = NVMF_OPT_TRADDR,
 682 };
 683
 684 static int __init nvme_loop_init_module(void)
 685 {
 686         int ret;
 687
 688         ret = nvmet_register_transport(&nvme_loop_ops);
 689         if (ret)
 690                 return ret;
 691
 692         ret = nvmf_register_transport(&nvme_loop_transport);
 693         if (ret)
 694                 nvmet_unregister_transport(&nvme_loop_ops);
 695
 696         return ret;
 697 }
 698
 699 static void __exit nvme_loop_cleanup_module(void)
 700 {
 701         struct nvme_loop_ctrl *ctrl, *next;
 702
 703         nvmf_unregister_transport(&nvme_loop_transport);
 704         nvmet_unregister_transport(&nvme_loop_ops);
 705
 706         mutex_lock(&nvme_loop_ctrl_mutex);
 707         list_for_each_entry_safe(ctrl, next, &nvme_loop_ctrl_list, list)
 708                 nvme_delete_ctrl(&ctrl->ctrl);
 709         mutex_unlock(&nvme_loop_ctrl_mutex);
 710
 711         flush_workqueue(nvme_delete_wq);
 712 }
 713
 714 module_init(nvme_loop_init_module);
 715 module_exit(nvme_loop_cleanup_module);
 716
 717 MODULE_LICENSE("GPL v2");
 718 MODULE_ALIAS("nvmet-transport-254"); /* 254 == NVMF_TRTYPE_LOOP */