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_port       *port;
  40 };
  41
  42 static inline struct nvme_loop_ctrl *to_loop_ctrl(struct nvme_ctrl *ctrl)
  43 {
  44         return container_of(ctrl, struct nvme_loop_ctrl, ctrl);
  45 }
  46
  47 enum nvme_loop_queue_flags {
  48         NVME_LOOP_Q_LIVE        = 0,
  49 };
  50
  51 struct nvme_loop_queue {
  52         struct nvmet_cq         nvme_cq;
  53         struct nvmet_sq         nvme_sq;
  54         struct nvme_loop_ctrl   *ctrl;
  55         unsigned long           flags;
  56 };
  57
  58 static LIST_HEAD(nvme_loop_ports);
  59 static DEFINE_MUTEX(nvme_loop_ports_mutex);
  60
  61 static LIST_HEAD(nvme_loop_ctrl_list);
  62 static DEFINE_MUTEX(nvme_loop_ctrl_mutex);
  63
  64 static void nvme_loop_queue_response(struct nvmet_req *nvme_req);
  65 static void nvme_loop_delete_ctrl(struct nvmet_ctrl *ctrl);
  66
  67 static const struct nvmet_fabrics_ops nvme_loop_ops;
  68
  69 static inline int nvme_loop_queue_idx(struct nvme_loop_queue *queue)
  70 {
  71         return queue - queue->ctrl->queues;
  72 }
  73
  74 static void nvme_loop_complete_rq(struct request *req)
  75 {
  76         struct nvme_loop_iod *iod = blk_mq_rq_to_pdu(req);
  77
  78         sg_free_table_chained(&iod->sg_table, NVME_INLINE_SG_CNT);
  79         nvme_complete_rq(req);
  80 }
  81
  82 static struct blk_mq_tags *nvme_loop_tagset(struct nvme_loop_queue *queue)
  83 {
  84         u32 queue_idx = nvme_loop_queue_idx(queue);
  85
  86         if (queue_idx == 0)
  87                 return queue->ctrl->admin_tag_set.tags[queue_idx];
  88         return queue->ctrl->tag_set.tags[queue_idx - 1];
  89 }
  90
  91 static void nvme_loop_queue_response(struct nvmet_req *req)
  92 {
  93         struct nvme_loop_queue *queue =
  94                 container_of(req->sq, struct nvme_loop_queue, nvme_sq);
  95         struct nvme_completion *cqe = req->cqe;
  96
  97         /*
  98          * AEN requests are special as they don't time out and can
  99          * survive any kind of queue freeze and often don't respond to
 100          * aborts.  We don't even bother to allocate a struct request
 101          * for them but rather special case them here.
 102          */
 103         if (unlikely(nvme_is_aen_req(nvme_loop_queue_idx(queue),
 104                                      cqe->command_id))) {
 105                 nvme_complete_async_event(&queue->ctrl->ctrl, cqe->status,
 106                                 &cqe->result);
 107         } else {
 108                 struct request *rq;
 109
 110                 rq = nvme_find_rq(nvme_loop_tagset(queue), cqe->command_id);
 111                 if (!rq) {
 112                         dev_err(queue->ctrl->ctrl.device,
 113                                 "got bad command_id %#x on queue %d\n",
 114                                 cqe->command_id, nvme_loop_queue_idx(queue));
 115                         return;
 116                 }
 117
 118                 if (!nvme_try_complete_req(rq, cqe->status, cqe->result))
 119                         nvme_loop_complete_rq(rq);
 120         }
 121 }
 122
 123 static void nvme_loop_execute_work(struct work_struct *work)
 124 {
 125         struct nvme_loop_iod *iod =
 126                 container_of(work, struct nvme_loop_iod, work);
 127
 128         iod->req.execute(&iod->req);
 129 }
 130
 131 static blk_status_t nvme_loop_queue_rq(struct blk_mq_hw_ctx *hctx,
 132                 const struct blk_mq_queue_data *bd)
 133 {
 134         struct nvme_ns *ns = hctx->queue->queuedata;
 135         struct nvme_loop_queue *queue = hctx->driver_data;
 136         struct request *req = bd->rq;
 137         struct nvme_loop_iod *iod = blk_mq_rq_to_pdu(req);
 138         bool queue_ready = test_bit(NVME_LOOP_Q_LIVE, &queue->flags);
 139         blk_status_t ret;
 140
 141         if (!nvmf_check_ready(&queue->ctrl->ctrl, req, queue_ready))
 142                 return nvmf_fail_nonready_command(&queue->ctrl->ctrl, req);
 143
 144         ret = nvme_setup_cmd(ns, req, &iod->cmd);
 145         if (ret)
 146                 return ret;
 147
 148         blk_mq_start_request(req);
 149         iod->cmd.common.flags |= NVME_CMD_SGL_METABUF;
 150         iod->req.port = queue->ctrl->port;
 151         if (!nvmet_req_init(&iod->req, &queue->nvme_cq,
 152                         &queue->nvme_sq, &nvme_loop_ops))
 153                 return BLK_STS_OK;
 154
 155         if (blk_rq_nr_phys_segments(req)) {
 156                 iod->sg_table.sgl = iod->first_sgl;
 157                 if (sg_alloc_table_chained(&iod->sg_table,
 158                                 blk_rq_nr_phys_segments(req),
 159                                 iod->sg_table.sgl, NVME_INLINE_SG_CNT)) {
 160                         nvme_cleanup_cmd(req);
 161                         return BLK_STS_RESOURCE;
 162                 }
 163
 164                 iod->req.sg = iod->sg_table.sgl;
 165                 iod->req.sg_cnt = blk_rq_map_sg(req->q, req, iod->sg_table.sgl);
 166                 iod->req.transfer_len = blk_rq_payload_bytes(req);
 167         }
 168
 169         schedule_work(&iod->work);
 170         return BLK_STS_OK;
 171 }
 172
 173 static void nvme_loop_submit_async_event(struct nvme_ctrl *arg)
 174 {
 175         struct nvme_loop_ctrl *ctrl = to_loop_ctrl(arg);
 176         struct nvme_loop_queue *queue = &ctrl->queues[0];
 177         struct nvme_loop_iod *iod = &ctrl->async_event_iod;
 178
 179         memset(&iod->cmd, 0, sizeof(iod->cmd));
 180         iod->cmd.common.opcode = nvme_admin_async_event;
 181         iod->cmd.common.command_id = NVME_AQ_BLK_MQ_DEPTH;
 182         iod->cmd.common.flags |= NVME_CMD_SGL_METABUF;
 183
 184         if (!nvmet_req_init(&iod->req, &queue->nvme_cq, &queue->nvme_sq,
 185                         &nvme_loop_ops)) {
 186                 dev_err(ctrl->ctrl.device, "failed async event work\n");
 187                 return;
 188         }
 189
 190         schedule_work(&iod->work);
 191 }
 192
 193 static int nvme_loop_init_iod(struct nvme_loop_ctrl *ctrl,
 194                 struct nvme_loop_iod *iod, unsigned int queue_idx)
 195 {
 196         iod->req.cmd = &iod->cmd;
 197         iod->req.cqe = &iod->cqe;
 198         iod->queue = &ctrl->queues[queue_idx];
 199         INIT_WORK(&iod->work, nvme_loop_execute_work);
 200         return 0;
 201 }
 202
 203 static int nvme_loop_init_request(struct blk_mq_tag_set *set,
 204                 struct request *req, unsigned int hctx_idx,
 205                 unsigned int numa_node)
 206 {
 207         struct nvme_loop_ctrl *ctrl = set->driver_data;
 208
 209         nvme_req(req)->ctrl = &ctrl->ctrl;
 210         return nvme_loop_init_iod(ctrl, blk_mq_rq_to_pdu(req),
 211                         (set == &ctrl->tag_set) ? hctx_idx + 1 : 0);
 212 }
 213
 214 static int nvme_loop_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
 215                 unsigned int hctx_idx)
 216 {
 217         struct nvme_loop_ctrl *ctrl = data;
 218         struct nvme_loop_queue *queue = &ctrl->queues[hctx_idx + 1];
 219
 220         BUG_ON(hctx_idx >= ctrl->ctrl.queue_count);
 221
 222         hctx->driver_data = queue;
 223         return 0;
 224 }
 225
 226 static int nvme_loop_init_admin_hctx(struct blk_mq_hw_ctx *hctx, void *data,
 227                 unsigned int hctx_idx)
 228 {
 229         struct nvme_loop_ctrl *ctrl = data;
 230         struct nvme_loop_queue *queue = &ctrl->queues[0];
 231
 232         BUG_ON(hctx_idx != 0);
 233
 234         hctx->driver_data = queue;
 235         return 0;
 236 }
 237
 238 static const struct blk_mq_ops nvme_loop_mq_ops = {
 239         .queue_rq       = nvme_loop_queue_rq,
 240         .complete       = nvme_loop_complete_rq,
 241         .init_request   = nvme_loop_init_request,
 242         .init_hctx      = nvme_loop_init_hctx,
 243 };
 244
 245 static const struct blk_mq_ops nvme_loop_admin_mq_ops = {
 246         .queue_rq       = nvme_loop_queue_rq,
 247         .complete       = nvme_loop_complete_rq,
 248         .init_request   = nvme_loop_init_request,
 249         .init_hctx      = nvme_loop_init_admin_hctx,
 250 };
 251
 252 static void nvme_loop_destroy_admin_queue(struct nvme_loop_ctrl *ctrl)
 253 {
 254         if (!test_and_clear_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[0].flags))
 255                 return;
 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         ctrl->ctrl.queue_count = 1;
 292 }
 293
 294 static int nvme_loop_init_io_queues(struct nvme_loop_ctrl *ctrl)
 295 {
 296         struct nvmf_ctrl_options *opts = ctrl->ctrl.opts;
 297         unsigned int nr_io_queues;
 298         int ret, i;
 299
 300         nr_io_queues = min(opts->nr_io_queues, num_online_cpus());
 301         ret = nvme_set_queue_count(&ctrl->ctrl, &nr_io_queues);
 302         if (ret || !nr_io_queues)
 303                 return ret;
 304
 305         dev_info(ctrl->ctrl.device, "creating %d I/O queues.\n", nr_io_queues);
 306
 307         for (i = 1; i <= nr_io_queues; i++) {
 308                 ctrl->queues[i].ctrl = ctrl;
 309                 ret = nvmet_sq_init(&ctrl->queues[i].nvme_sq);
 310                 if (ret)
 311                         goto out_destroy_queues;
 312
 313                 ctrl->ctrl.queue_count++;
 314         }
 315
 316         return 0;
 317
 318 out_destroy_queues:
 319         nvme_loop_destroy_io_queues(ctrl);
 320         return ret;
 321 }
 322
 323 static int nvme_loop_connect_io_queues(struct nvme_loop_ctrl *ctrl)
 324 {
 325         int i, ret;
 326
 327         for (i = 1; i < ctrl->ctrl.queue_count; i++) {
 328                 ret = nvmf_connect_io_queue(&ctrl->ctrl, i, false);
 329                 if (ret)
 330                         return ret;
 331                 set_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[i].flags);
 332         }
 333
 334         return 0;
 335 }
 336
 337 static int nvme_loop_configure_admin_queue(struct nvme_loop_ctrl *ctrl)
 338 {
 339         int error;
 340
 341         memset(&ctrl->admin_tag_set, 0, sizeof(ctrl->admin_tag_set));
 342         ctrl->admin_tag_set.ops = &nvme_loop_admin_mq_ops;
 343         ctrl->admin_tag_set.queue_depth = NVME_AQ_MQ_TAG_DEPTH;
 344         ctrl->admin_tag_set.reserved_tags = 2; /* connect + keep-alive */
 345         ctrl->admin_tag_set.numa_node = ctrl->ctrl.numa_node;
 346         ctrl->admin_tag_set.cmd_size = sizeof(struct nvme_loop_iod) +
 347                 NVME_INLINE_SG_CNT * sizeof(struct scatterlist);
 348         ctrl->admin_tag_set.driver_data = ctrl;
 349         ctrl->admin_tag_set.nr_hw_queues = 1;
 350         ctrl->admin_tag_set.timeout = ADMIN_TIMEOUT;
 351         ctrl->admin_tag_set.flags = BLK_MQ_F_NO_SCHED;
 352
 353         ctrl->queues[0].ctrl = ctrl;
 354         error = nvmet_sq_init(&ctrl->queues[0].nvme_sq);
 355         if (error)
 356                 return error;
 357         ctrl->ctrl.queue_count = 1;
 358
 359         error = blk_mq_alloc_tag_set(&ctrl->admin_tag_set);
 360         if (error)
 361                 goto out_free_sq;
 362         ctrl->ctrl.admin_tagset = &ctrl->admin_tag_set;
 363
 364         ctrl->ctrl.fabrics_q = blk_mq_init_queue(&ctrl->admin_tag_set);
 365         if (IS_ERR(ctrl->ctrl.fabrics_q)) {
 366                 error = PTR_ERR(ctrl->ctrl.fabrics_q);
 367                 goto out_free_tagset;
 368         }
 369
 370         ctrl->ctrl.admin_q = blk_mq_init_queue(&ctrl->admin_tag_set);
 371         if (IS_ERR(ctrl->ctrl.admin_q)) {
 372                 error = PTR_ERR(ctrl->ctrl.admin_q);
 373                 goto out_cleanup_fabrics_q;
 374         }
 375
 376         error = nvmf_connect_admin_queue(&ctrl->ctrl);
 377         if (error)
 378                 goto out_cleanup_queue;
 379
 380         set_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[0].flags);
 381
 382         error = nvme_enable_ctrl(&ctrl->ctrl);
 383         if (error)
 384                 goto out_cleanup_queue;
 385
 386         ctrl->ctrl.max_hw_sectors =
 387                 (NVME_LOOP_MAX_SEGMENTS - 1) << (PAGE_SHIFT - 9);
 388
 389         blk_mq_unquiesce_queue(ctrl->ctrl.admin_q);
 390
 391         error = nvme_init_identify(&ctrl->ctrl);
 392         if (error)
 393                 goto out_cleanup_queue;
 394
 395         return 0;
 396
 397 out_cleanup_queue:
 398         clear_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[0].flags);
 399         blk_cleanup_queue(ctrl->ctrl.admin_q);
 400 out_cleanup_fabrics_q:
 401         blk_cleanup_queue(ctrl->ctrl.fabrics_q);
 402 out_free_tagset:
 403         blk_mq_free_tag_set(&ctrl->admin_tag_set);
 404 out_free_sq:
 405         nvmet_sq_destroy(&ctrl->queues[0].nvme_sq);
 406         return error;
 407 }
 408
 409 static void nvme_loop_shutdown_ctrl(struct nvme_loop_ctrl *ctrl)
 410 {
 411         if (ctrl->ctrl.queue_count > 1) {
 412                 nvme_stop_queues(&ctrl->ctrl);
 413                 blk_mq_tagset_busy_iter(&ctrl->tag_set,
 414                                         nvme_cancel_request, &ctrl->ctrl);
 415                 blk_mq_tagset_wait_completed_request(&ctrl->tag_set);
 416                 nvme_loop_destroy_io_queues(ctrl);
 417         }
 418
 419         blk_mq_quiesce_queue(ctrl->ctrl.admin_q);
 420         if (ctrl->ctrl.state == NVME_CTRL_LIVE)
 421                 nvme_shutdown_ctrl(&ctrl->ctrl);
 422
 423         blk_mq_tagset_busy_iter(&ctrl->admin_tag_set,
 424                                 nvme_cancel_request, &ctrl->ctrl);
 425         blk_mq_tagset_wait_completed_request(&ctrl->admin_tag_set);
 426         nvme_loop_destroy_admin_queue(ctrl);
 427 }
 428
 429 static void nvme_loop_delete_ctrl_host(struct nvme_ctrl *ctrl)
 430 {
 431         nvme_loop_shutdown_ctrl(to_loop_ctrl(ctrl));
 432 }
 433
 434 static void nvme_loop_delete_ctrl(struct nvmet_ctrl *nctrl)
 435 {
 436         struct nvme_loop_ctrl *ctrl;
 437
 438         mutex_lock(&nvme_loop_ctrl_mutex);
 439         list_for_each_entry(ctrl, &nvme_loop_ctrl_list, list) {
 440                 if (ctrl->ctrl.cntlid == nctrl->cntlid)
 441                         nvme_delete_ctrl(&ctrl->ctrl);
 442         }
 443         mutex_unlock(&nvme_loop_ctrl_mutex);
 444 }
 445
 446 static void nvme_loop_reset_ctrl_work(struct work_struct *work)
 447 {
 448         struct nvme_loop_ctrl *ctrl =
 449                 container_of(work, struct nvme_loop_ctrl, ctrl.reset_work);
 450         int ret;
 451
 452         nvme_stop_ctrl(&ctrl->ctrl);
 453         nvme_loop_shutdown_ctrl(ctrl);
 454
 455         if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_CONNECTING)) {
 456                 if (ctrl->ctrl.state != NVME_CTRL_DELETING &&
 457                     ctrl->ctrl.state != NVME_CTRL_DELETING_NOIO)
 458                         /* state change failure for non-deleted ctrl? */
 459                         WARN_ON_ONCE(1);
 460                 return;
 461         }
 462
 463         ret = nvme_loop_configure_admin_queue(ctrl);
 464         if (ret)
 465                 goto out_disable;
 466
 467         ret = nvme_loop_init_io_queues(ctrl);
 468         if (ret)
 469                 goto out_destroy_admin;
 470
 471         ret = nvme_loop_connect_io_queues(ctrl);
 472         if (ret)
 473                 goto out_destroy_io;
 474
 475         blk_mq_update_nr_hw_queues(&ctrl->tag_set,
 476                         ctrl->ctrl.queue_count - 1);
 477
 478         if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE))
 479                 WARN_ON_ONCE(1);
 480
 481         nvme_start_ctrl(&ctrl->ctrl);
 482
 483         return;
 484
 485 out_destroy_io:
 486         nvme_loop_destroy_io_queues(ctrl);
 487 out_destroy_admin:
 488         nvme_loop_destroy_admin_queue(ctrl);
 489 out_disable:
 490         dev_warn(ctrl->ctrl.device, "Removing after reset failure\n");
 491         nvme_uninit_ctrl(&ctrl->ctrl);
 492 }
 493
 494 static const struct nvme_ctrl_ops nvme_loop_ctrl_ops = {
 495         .name                   = "loop",
 496         .module                 = THIS_MODULE,
 497         .flags                  = NVME_F_FABRICS,
 498         .reg_read32             = nvmf_reg_read32,
 499         .reg_read64             = nvmf_reg_read64,
 500         .reg_write32            = nvmf_reg_write32,
 501         .free_ctrl              = nvme_loop_free_ctrl,
 502         .submit_async_event     = nvme_loop_submit_async_event,
 503         .delete_ctrl            = nvme_loop_delete_ctrl_host,
 504         .get_address            = nvmf_get_address,
 505 };
 506
 507 static int nvme_loop_create_io_queues(struct nvme_loop_ctrl *ctrl)
 508 {
 509         int ret;
 510
 511         ret = nvme_loop_init_io_queues(ctrl);
 512         if (ret)
 513                 return ret;
 514
 515         memset(&ctrl->tag_set, 0, sizeof(ctrl->tag_set));
 516         ctrl->tag_set.ops = &nvme_loop_mq_ops;
 517         ctrl->tag_set.queue_depth = ctrl->ctrl.opts->queue_size;
 518         ctrl->tag_set.reserved_tags = 1; /* fabric connect */
 519         ctrl->tag_set.numa_node = ctrl->ctrl.numa_node;
 520         ctrl->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
 521         ctrl->tag_set.cmd_size = sizeof(struct nvme_loop_iod) +
 522                 NVME_INLINE_SG_CNT * sizeof(struct scatterlist);
 523         ctrl->tag_set.driver_data = ctrl;
 524         ctrl->tag_set.nr_hw_queues = ctrl->ctrl.queue_count - 1;
 525         ctrl->tag_set.timeout = NVME_IO_TIMEOUT;
 526         ctrl->ctrl.tagset = &ctrl->tag_set;
 527
 528         ret = blk_mq_alloc_tag_set(&ctrl->tag_set);
 529         if (ret)
 530                 goto out_destroy_queues;
 531
 532         ctrl->ctrl.connect_q = blk_mq_init_queue(&ctrl->tag_set);
 533         if (IS_ERR(ctrl->ctrl.connect_q)) {
 534                 ret = PTR_ERR(ctrl->ctrl.connect_q);
 535                 goto out_free_tagset;
 536         }
 537
 538         ret = nvme_loop_connect_io_queues(ctrl);
 539         if (ret)
 540                 goto out_cleanup_connect_q;
 541
 542         return 0;
 543
 544 out_cleanup_connect_q:
 545         blk_cleanup_queue(ctrl->ctrl.connect_q);
 546 out_free_tagset:
 547         blk_mq_free_tag_set(&ctrl->tag_set);
 548 out_destroy_queues:
 549         nvme_loop_destroy_io_queues(ctrl);
 550         return ret;
 551 }
 552
 553 static struct nvmet_port *nvme_loop_find_port(struct nvme_ctrl *ctrl)
 554 {
 555         struct nvmet_port *p, *found = NULL;
 556
 557         mutex_lock(&nvme_loop_ports_mutex);
 558         list_for_each_entry(p, &nvme_loop_ports, entry) {
 559                 /* if no transport address is specified use the first port */
 560                 if ((ctrl->opts->mask & NVMF_OPT_TRADDR) &&
 561                     strcmp(ctrl->opts->traddr, p->disc_addr.traddr))
 562                         continue;
 563                 found = p;
 564                 break;
 565         }
 566         mutex_unlock(&nvme_loop_ports_mutex);
 567         return found;
 568 }
 569
 570 static struct nvme_ctrl *nvme_loop_create_ctrl(struct device *dev,
 571                 struct nvmf_ctrl_options *opts)
 572 {
 573         struct nvme_loop_ctrl *ctrl;
 574         int ret;
 575
 576         ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
 577         if (!ctrl)
 578                 return ERR_PTR(-ENOMEM);
 579         ctrl->ctrl.opts = opts;
 580         INIT_LIST_HEAD(&ctrl->list);
 581
 582         INIT_WORK(&ctrl->ctrl.reset_work, nvme_loop_reset_ctrl_work);
 583
 584         ret = nvme_init_ctrl(&ctrl->ctrl, dev, &nvme_loop_ctrl_ops,
 585                                 0 /* no quirks, we're perfect! */);
 586         if (ret) {
 587                 kfree(ctrl);
 588                 goto out;
 589         }
 590
 591         if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_CONNECTING))
 592                 WARN_ON_ONCE(1);
 593
 594         ret = -ENOMEM;
 595
 596         ctrl->ctrl.sqsize = opts->queue_size - 1;
 597         ctrl->ctrl.kato = opts->kato;
 598         ctrl->port = nvme_loop_find_port(&ctrl->ctrl);
 599
 600         ctrl->queues = kcalloc(opts->nr_io_queues + 1, sizeof(*ctrl->queues),
 601                         GFP_KERNEL);
 602         if (!ctrl->queues)
 603                 goto out_uninit_ctrl;
 604
 605         ret = nvme_loop_configure_admin_queue(ctrl);
 606         if (ret)
 607                 goto out_free_queues;
 608
 609         if (opts->queue_size > ctrl->ctrl.maxcmd) {
 610                 /* warn if maxcmd is lower than queue_size */
 611                 dev_warn(ctrl->ctrl.device,
 612                         "queue_size %zu > ctrl maxcmd %u, clamping down\n",
 613                         opts->queue_size, ctrl->ctrl.maxcmd);
 614                 opts->queue_size = ctrl->ctrl.maxcmd;
 615         }
 616
 617         if (opts->nr_io_queues) {
 618                 ret = nvme_loop_create_io_queues(ctrl);
 619                 if (ret)
 620                         goto out_remove_admin_queue;
 621         }
 622
 623         nvme_loop_init_iod(ctrl, &ctrl->async_event_iod, 0);
 624
 625         dev_info(ctrl->ctrl.device,
 626                  "new ctrl: \"%s\"\n", ctrl->ctrl.opts->subsysnqn);
 627
 628         if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE))
 629                 WARN_ON_ONCE(1);
 630
 631         mutex_lock(&nvme_loop_ctrl_mutex);
 632         list_add_tail(&ctrl->list, &nvme_loop_ctrl_list);
 633         mutex_unlock(&nvme_loop_ctrl_mutex);
 634
 635         nvme_start_ctrl(&ctrl->ctrl);
 636
 637         return &ctrl->ctrl;
 638
 639 out_remove_admin_queue:
 640         nvme_loop_destroy_admin_queue(ctrl);
 641 out_free_queues:
 642         kfree(ctrl->queues);
 643 out_uninit_ctrl:
 644         nvme_uninit_ctrl(&ctrl->ctrl);
 645         nvme_put_ctrl(&ctrl->ctrl);
 646 out:
 647         if (ret > 0)
 648                 ret = -EIO;
 649         return ERR_PTR(ret);
 650 }
 651
 652 static int nvme_loop_add_port(struct nvmet_port *port)
 653 {
 654         mutex_lock(&nvme_loop_ports_mutex);
 655         list_add_tail(&port->entry, &nvme_loop_ports);
 656         mutex_unlock(&nvme_loop_ports_mutex);
 657         return 0;
 658 }
 659
 660 static void nvme_loop_remove_port(struct nvmet_port *port)
 661 {
 662         mutex_lock(&nvme_loop_ports_mutex);
 663         list_del_init(&port->entry);
 664         mutex_unlock(&nvme_loop_ports_mutex);
 665
 666         /*
 667          * Ensure any ctrls that are in the process of being
 668          * deleted are in fact deleted before we return
 669          * and free the port. This is to prevent active
 670          * ctrls from using a port after it's freed.
 671          */
 672         flush_workqueue(nvme_delete_wq);
 673 }
 674
 675 static const struct nvmet_fabrics_ops nvme_loop_ops = {
 676         .owner          = THIS_MODULE,
 677         .type           = NVMF_TRTYPE_LOOP,
 678         .add_port       = nvme_loop_add_port,
 679         .remove_port    = nvme_loop_remove_port,
 680         .queue_response = nvme_loop_queue_response,
 681         .delete_ctrl    = nvme_loop_delete_ctrl,
 682 };
 683
 684 static struct nvmf_transport_ops nvme_loop_transport = {
 685         .name           = "loop",
 686         .module         = THIS_MODULE,
 687         .create_ctrl    = nvme_loop_create_ctrl,
 688         .allowed_opts   = NVMF_OPT_TRADDR,
 689 };
 690
 691 static int __init nvme_loop_init_module(void)
 692 {
 693         int ret;
 694
 695         ret = nvmet_register_transport(&nvme_loop_ops);
 696         if (ret)
 697                 return ret;
 698
 699         ret = nvmf_register_transport(&nvme_loop_transport);
 700         if (ret)
 701                 nvmet_unregister_transport(&nvme_loop_ops);
 702
 703         return ret;
 704 }
 705
 706 static void __exit nvme_loop_cleanup_module(void)
 707 {
 708         struct nvme_loop_ctrl *ctrl, *next;
 709
 710         nvmf_unregister_transport(&nvme_loop_transport);
 711         nvmet_unregister_transport(&nvme_loop_ops);
 712
 713         mutex_lock(&nvme_loop_ctrl_mutex);
 714         list_for_each_entry_safe(ctrl, next, &nvme_loop_ctrl_list, list)
 715                 nvme_delete_ctrl(&ctrl->ctrl);
 716         mutex_unlock(&nvme_loop_ctrl_mutex);
 717
 718         flush_workqueue(nvme_delete_wq);
 719 }
 720
 721 module_init(nvme_loop_init_module);
 722 module_exit(nvme_loop_cleanup_module);
 723
 724 MODULE_LICENSE("GPL v2");
 725 MODULE_ALIAS("nvmet-transport-254"); /* 254 == NVMF_TRTYPE_LOOP */