drivers/nvme/target/core.c

   1 /*
   2  * Common code for the NVMe target.
   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/module.h>
  16 #include <linux/random.h>
  17 #include <linux/rculist.h>
  18
  19 #include "nvmet.h"
  20
  21 struct workqueue_struct *buffered_io_wq;
  22 static const struct nvmet_fabrics_ops *nvmet_transports[NVMF_TRTYPE_MAX];
  23 static DEFINE_IDA(cntlid_ida);
  24
  25 /*
  26  * This read/write semaphore is used to synchronize access to configuration
  27  * information on a target system that will result in discovery log page
  28  * information change for at least one host.
  29  * The full list of resources to protected by this semaphore is:
  30  *
  31  *  - subsystems list
  32  *  - per-subsystem allowed hosts list
  33  *  - allow_any_host subsystem attribute
  34  *  - nvmet_genctr
  35  *  - the nvmet_transports array
  36  *
  37  * When updating any of those lists/structures write lock should be obtained,
  38  * while when reading (popolating discovery log page or checking host-subsystem
  39  * link) read lock is obtained to allow concurrent reads.
  40  */
  41 DECLARE_RWSEM(nvmet_config_sem);
  42
  43 u32 nvmet_ana_group_enabled[NVMET_MAX_ANAGRPS + 1];
  44 u64 nvmet_ana_chgcnt;
  45 DECLARE_RWSEM(nvmet_ana_sem);
  46
  47 static struct nvmet_subsys *nvmet_find_get_subsys(struct nvmet_port *port,
  48                 const char *subsysnqn);
  49
  50 u16 nvmet_copy_to_sgl(struct nvmet_req *req, off_t off, const void *buf,
  51                 size_t len)
  52 {
  53         if (sg_pcopy_from_buffer(req->sg, req->sg_cnt, buf, len, off) != len)
  54                 return NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR;
  55         return 0;
  56 }
  57
  58 u16 nvmet_copy_from_sgl(struct nvmet_req *req, off_t off, void *buf, size_t len)
  59 {
  60         if (sg_pcopy_to_buffer(req->sg, req->sg_cnt, buf, len, off) != len)
  61                 return NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR;
  62         return 0;
  63 }
  64
  65 u16 nvmet_zero_sgl(struct nvmet_req *req, off_t off, size_t len)
  66 {
  67         if (sg_zero_buffer(req->sg, req->sg_cnt, len, off) != len)
  68                 return NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR;
  69         return 0;
  70 }
  71
  72 static unsigned int nvmet_max_nsid(struct nvmet_subsys *subsys)
  73 {
  74         struct nvmet_ns *ns;
  75
  76         if (list_empty(&subsys->namespaces))
  77                 return 0;
  78
  79         ns = list_last_entry(&subsys->namespaces, struct nvmet_ns, dev_link);
  80         return ns->nsid;
  81 }
  82
  83 static u32 nvmet_async_event_result(struct nvmet_async_event *aen)
  84 {
  85         return aen->event_type | (aen->event_info << 8) | (aen->log_page << 16);
  86 }
  87
  88 static void nvmet_async_events_free(struct nvmet_ctrl *ctrl)
  89 {
  90         struct nvmet_req *req;
  91
  92         while (1) {
  93                 mutex_lock(&ctrl->lock);
  94                 if (!ctrl->nr_async_event_cmds) {
  95                         mutex_unlock(&ctrl->lock);
  96                         return;
  97                 }
  98
  99                 req = ctrl->async_event_cmds[--ctrl->nr_async_event_cmds];
 100                 mutex_unlock(&ctrl->lock);
 101                 nvmet_req_complete(req, NVME_SC_INTERNAL | NVME_SC_DNR);
 102         }
 103 }
 104
 105 static void nvmet_async_event_work(struct work_struct *work)
 106 {
 107         struct nvmet_ctrl *ctrl =
 108                 container_of(work, struct nvmet_ctrl, async_event_work);
 109         struct nvmet_async_event *aen;
 110         struct nvmet_req *req;
 111
 112         while (1) {
 113                 mutex_lock(&ctrl->lock);
 114                 aen = list_first_entry_or_null(&ctrl->async_events,
 115                                 struct nvmet_async_event, entry);
 116                 if (!aen || !ctrl->nr_async_event_cmds) {
 117                         mutex_unlock(&ctrl->lock);
 118                         return;
 119                 }
 120
 121                 req = ctrl->async_event_cmds[--ctrl->nr_async_event_cmds];
 122                 nvmet_set_result(req, nvmet_async_event_result(aen));
 123
 124                 list_del(&aen->entry);
 125                 kfree(aen);
 126
 127                 mutex_unlock(&ctrl->lock);
 128                 nvmet_req_complete(req, 0);
 129         }
 130 }
 131
 132 static void nvmet_add_async_event(struct nvmet_ctrl *ctrl, u8 event_type,
 133                 u8 event_info, u8 log_page)
 134 {
 135         struct nvmet_async_event *aen;
 136
 137         aen = kmalloc(sizeof(*aen), GFP_KERNEL);
 138         if (!aen)
 139                 return;
 140
 141         aen->event_type = event_type;
 142         aen->event_info = event_info;
 143         aen->log_page = log_page;
 144
 145         mutex_lock(&ctrl->lock);
 146         list_add_tail(&aen->entry, &ctrl->async_events);
 147         mutex_unlock(&ctrl->lock);
 148
 149         schedule_work(&ctrl->async_event_work);
 150 }
 151
 152 static bool nvmet_aen_disabled(struct nvmet_ctrl *ctrl, u32 aen)
 153 {
 154         if (!(READ_ONCE(ctrl->aen_enabled) & aen))
 155                 return true;
 156         return test_and_set_bit(aen, &ctrl->aen_masked);
 157 }
 158
 159 static void nvmet_add_to_changed_ns_log(struct nvmet_ctrl *ctrl, __le32 nsid)
 160 {
 161         u32 i;
 162
 163         mutex_lock(&ctrl->lock);
 164         if (ctrl->nr_changed_ns > NVME_MAX_CHANGED_NAMESPACES)
 165                 goto out_unlock;
 166
 167         for (i = 0; i < ctrl->nr_changed_ns; i++) {
 168                 if (ctrl->changed_ns_list[i] == nsid)
 169                         goto out_unlock;
 170         }
 171
 172         if (ctrl->nr_changed_ns == NVME_MAX_CHANGED_NAMESPACES) {
 173                 ctrl->changed_ns_list[0] = cpu_to_le32(0xffffffff);
 174                 ctrl->nr_changed_ns = U32_MAX;
 175                 goto out_unlock;
 176         }
 177
 178         ctrl->changed_ns_list[ctrl->nr_changed_ns++] = nsid;
 179 out_unlock:
 180         mutex_unlock(&ctrl->lock);
 181 }
 182
 183 void nvmet_ns_changed(struct nvmet_subsys *subsys, u32 nsid)
 184 {
 185         struct nvmet_ctrl *ctrl;
 186
 187         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
 188                 nvmet_add_to_changed_ns_log(ctrl, cpu_to_le32(nsid));
 189                 if (nvmet_aen_disabled(ctrl, NVME_AEN_CFG_NS_ATTR))
 190                         continue;
 191                 nvmet_add_async_event(ctrl, NVME_AER_TYPE_NOTICE,
 192                                 NVME_AER_NOTICE_NS_CHANGED,
 193                                 NVME_LOG_CHANGED_NS);
 194         }
 195 }
 196
 197 void nvmet_send_ana_event(struct nvmet_subsys *subsys,
 198                 struct nvmet_port *port)
 199 {
 200         struct nvmet_ctrl *ctrl;
 201
 202         mutex_lock(&subsys->lock);
 203         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
 204                 if (port && ctrl->port != port)
 205                         continue;
 206                 if (nvmet_aen_disabled(ctrl, NVME_AEN_CFG_ANA_CHANGE))
 207                         continue;
 208                 nvmet_add_async_event(ctrl, NVME_AER_TYPE_NOTICE,
 209                                 NVME_AER_NOTICE_ANA, NVME_LOG_ANA);
 210         }
 211         mutex_unlock(&subsys->lock);
 212 }
 213
 214 void nvmet_port_send_ana_event(struct nvmet_port *port)
 215 {
 216         struct nvmet_subsys_link *p;
 217
 218         down_read(&nvmet_config_sem);
 219         list_for_each_entry(p, &port->subsystems, entry)
 220                 nvmet_send_ana_event(p->subsys, port);
 221         up_read(&nvmet_config_sem);
 222 }
 223
 224 int nvmet_register_transport(const struct nvmet_fabrics_ops *ops)
 225 {
 226         int ret = 0;
 227
 228         down_write(&nvmet_config_sem);
 229         if (nvmet_transports[ops->type])
 230                 ret = -EINVAL;
 231         else
 232                 nvmet_transports[ops->type] = ops;
 233         up_write(&nvmet_config_sem);
 234
 235         return ret;
 236 }
 237 EXPORT_SYMBOL_GPL(nvmet_register_transport);
 238
 239 void nvmet_unregister_transport(const struct nvmet_fabrics_ops *ops)
 240 {
 241         down_write(&nvmet_config_sem);
 242         nvmet_transports[ops->type] = NULL;
 243         up_write(&nvmet_config_sem);
 244 }
 245 EXPORT_SYMBOL_GPL(nvmet_unregister_transport);
 246
 247 int nvmet_enable_port(struct nvmet_port *port)
 248 {
 249         const struct nvmet_fabrics_ops *ops;
 250         int ret;
 251
 252         lockdep_assert_held(&nvmet_config_sem);
 253
 254         ops = nvmet_transports[port->disc_addr.trtype];
 255         if (!ops) {
 256                 up_write(&nvmet_config_sem);
 257                 request_module("nvmet-transport-%d", port->disc_addr.trtype);
 258                 down_write(&nvmet_config_sem);
 259                 ops = nvmet_transports[port->disc_addr.trtype];
 260                 if (!ops) {
 261                         pr_err("transport type %d not supported\n",
 262                                 port->disc_addr.trtype);
 263                         return -EINVAL;
 264                 }
 265         }
 266
 267         if (!try_module_get(ops->owner))
 268                 return -EINVAL;
 269
 270         ret = ops->add_port(port);
 271         if (ret) {
 272                 module_put(ops->owner);
 273                 return ret;
 274         }
 275
 276         /* If the transport didn't set inline_data_size, then disable it. */
 277         if (port->inline_data_size < 0)
 278                 port->inline_data_size = 0;
 279
 280         port->enabled = true;
 281         return 0;
 282 }
 283
 284 void nvmet_disable_port(struct nvmet_port *port)
 285 {
 286         const struct nvmet_fabrics_ops *ops;
 287
 288         lockdep_assert_held(&nvmet_config_sem);
 289
 290         port->enabled = false;
 291
 292         ops = nvmet_transports[port->disc_addr.trtype];
 293         ops->remove_port(port);
 294         module_put(ops->owner);
 295 }
 296
 297 static void nvmet_keep_alive_timer(struct work_struct *work)
 298 {
 299         struct nvmet_ctrl *ctrl = container_of(to_delayed_work(work),
 300                         struct nvmet_ctrl, ka_work);
 301
 302         pr_err("ctrl %d keep-alive timer (%d seconds) expired!\n",
 303                 ctrl->cntlid, ctrl->kato);
 304
 305         nvmet_ctrl_fatal_error(ctrl);
 306 }
 307
 308 static void nvmet_start_keep_alive_timer(struct nvmet_ctrl *ctrl)
 309 {
 310         if (unlikely(ctrl->kato == 0))
 311                 return;
 312
 313         pr_debug("ctrl %d start keep-alive timer for %d secs\n",
 314                 ctrl->cntlid, ctrl->kato);
 315
 316         INIT_DELAYED_WORK(&ctrl->ka_work, nvmet_keep_alive_timer);
 317         schedule_delayed_work(&ctrl->ka_work, ctrl->kato * HZ);
 318 }
 319
 320 static void nvmet_stop_keep_alive_timer(struct nvmet_ctrl *ctrl)
 321 {
 322         if (unlikely(ctrl->kato == 0))
 323                 return;
 324
 325         pr_debug("ctrl %d stop keep-alive\n", ctrl->cntlid);
 326
 327         cancel_delayed_work_sync(&ctrl->ka_work);
 328 }
 329
 330 static struct nvmet_ns *__nvmet_find_namespace(struct nvmet_ctrl *ctrl,
 331                 __le32 nsid)
 332 {
 333         struct nvmet_ns *ns;
 334
 335         list_for_each_entry_rcu(ns, &ctrl->subsys->namespaces, dev_link) {
 336                 if (ns->nsid == le32_to_cpu(nsid))
 337                         return ns;
 338         }
 339
 340         return NULL;
 341 }
 342
 343 struct nvmet_ns *nvmet_find_namespace(struct nvmet_ctrl *ctrl, __le32 nsid)
 344 {
 345         struct nvmet_ns *ns;
 346
 347         rcu_read_lock();
 348         ns = __nvmet_find_namespace(ctrl, nsid);
 349         if (ns)
 350                 percpu_ref_get(&ns->ref);
 351         rcu_read_unlock();
 352
 353         return ns;
 354 }
 355
 356 static void nvmet_destroy_namespace(struct percpu_ref *ref)
 357 {
 358         struct nvmet_ns *ns = container_of(ref, struct nvmet_ns, ref);
 359
 360         complete(&ns->disable_done);
 361 }
 362
 363 void nvmet_put_namespace(struct nvmet_ns *ns)
 364 {
 365         percpu_ref_put(&ns->ref);
 366 }
 367
 368 static void nvmet_ns_dev_disable(struct nvmet_ns *ns)
 369 {
 370         nvmet_bdev_ns_disable(ns);
 371         nvmet_file_ns_disable(ns);
 372 }
 373
 374 int nvmet_ns_enable(struct nvmet_ns *ns)
 375 {
 376         struct nvmet_subsys *subsys = ns->subsys;
 377         int ret;
 378
 379         mutex_lock(&subsys->lock);
 380         ret = -EMFILE;
 381         if (subsys->nr_namespaces == NVMET_MAX_NAMESPACES)
 382                 goto out_unlock;
 383         ret = 0;
 384         if (ns->enabled)
 385                 goto out_unlock;
 386
 387         ret = nvmet_bdev_ns_enable(ns);
 388         if (ret == -ENOTBLK)
 389                 ret = nvmet_file_ns_enable(ns);
 390         if (ret)
 391                 goto out_unlock;
 392
 393         ret = percpu_ref_init(&ns->ref, nvmet_destroy_namespace,
 394                                 0, GFP_KERNEL);
 395         if (ret)
 396                 goto out_dev_put;
 397
 398         if (ns->nsid > subsys->max_nsid)
 399                 subsys->max_nsid = ns->nsid;
 400
 401         /*
 402          * The namespaces list needs to be sorted to simplify the implementation
 403          * of the Identify Namepace List subcommand.
 404          */
 405         if (list_empty(&subsys->namespaces)) {
 406                 list_add_tail_rcu(&ns->dev_link, &subsys->namespaces);
 407         } else {
 408                 struct nvmet_ns *old;
 409
 410                 list_for_each_entry_rcu(old, &subsys->namespaces, dev_link) {
 411                         BUG_ON(ns->nsid == old->nsid);
 412                         if (ns->nsid < old->nsid)
 413                                 break;
 414                 }
 415
 416                 list_add_tail_rcu(&ns->dev_link, &old->dev_link);
 417         }
 418         subsys->nr_namespaces++;
 419
 420         nvmet_ns_changed(subsys, ns->nsid);
 421         ns->enabled = true;
 422         ret = 0;
 423 out_unlock:
 424         mutex_unlock(&subsys->lock);
 425         return ret;
 426 out_dev_put:
 427         nvmet_ns_dev_disable(ns);
 428         goto out_unlock;
 429 }
 430
 431 void nvmet_ns_disable(struct nvmet_ns *ns)
 432 {
 433         struct nvmet_subsys *subsys = ns->subsys;
 434
 435         mutex_lock(&subsys->lock);
 436         if (!ns->enabled)
 437                 goto out_unlock;
 438
 439         ns->enabled = false;
 440         list_del_rcu(&ns->dev_link);
 441         if (ns->nsid == subsys->max_nsid)
 442                 subsys->max_nsid = nvmet_max_nsid(subsys);
 443         mutex_unlock(&subsys->lock);
 444
 445         /*
 446          * Now that we removed the namespaces from the lookup list, we
 447          * can kill the per_cpu ref and wait for any remaining references
 448          * to be dropped, as well as a RCU grace period for anyone only
 449          * using the namepace under rcu_read_lock().  Note that we can't
 450          * use call_rcu here as we need to ensure the namespaces have
 451          * been fully destroyed before unloading the module.
 452          */
 453         percpu_ref_kill(&ns->ref);
 454         synchronize_rcu();
 455         wait_for_completion(&ns->disable_done);
 456         percpu_ref_exit(&ns->ref);
 457
 458         mutex_lock(&subsys->lock);
 459         subsys->nr_namespaces--;
 460         nvmet_ns_changed(subsys, ns->nsid);
 461         nvmet_ns_dev_disable(ns);
 462 out_unlock:
 463         mutex_unlock(&subsys->lock);
 464 }
 465
 466 void nvmet_ns_free(struct nvmet_ns *ns)
 467 {
 468         nvmet_ns_disable(ns);
 469
 470         down_write(&nvmet_ana_sem);
 471         nvmet_ana_group_enabled[ns->anagrpid]--;
 472         up_write(&nvmet_ana_sem);
 473
 474         kfree(ns->device_path);
 475         kfree(ns);
 476 }
 477
 478 struct nvmet_ns *nvmet_ns_alloc(struct nvmet_subsys *subsys, u32 nsid)
 479 {
 480         struct nvmet_ns *ns;
 481
 482         ns = kzalloc(sizeof(*ns), GFP_KERNEL);
 483         if (!ns)
 484                 return NULL;
 485
 486         INIT_LIST_HEAD(&ns->dev_link);
 487         init_completion(&ns->disable_done);
 488
 489         ns->nsid = nsid;
 490         ns->subsys = subsys;
 491
 492         down_write(&nvmet_ana_sem);
 493         ns->anagrpid = NVMET_DEFAULT_ANA_GRPID;
 494         nvmet_ana_group_enabled[ns->anagrpid]++;
 495         up_write(&nvmet_ana_sem);
 496
 497         uuid_gen(&ns->uuid);
 498         ns->buffered_io = false;
 499
 500         return ns;
 501 }
 502
 503 static void __nvmet_req_complete(struct nvmet_req *req, u16 status)
 504 {
 505         u32 old_sqhd, new_sqhd;
 506         u16 sqhd;
 507
 508         if (status)
 509                 nvmet_set_status(req, status);
 510
 511         if (req->sq->size) {
 512                 do {
 513                         old_sqhd = req->sq->sqhd;
 514                         new_sqhd = (old_sqhd + 1) % req->sq->size;
 515                 } while (cmpxchg(&req->sq->sqhd, old_sqhd, new_sqhd) !=
 516                                         old_sqhd);
 517         }
 518         sqhd = req->sq->sqhd & 0x0000FFFF;
 519         req->rsp->sq_head = cpu_to_le16(sqhd);
 520         req->rsp->sq_id = cpu_to_le16(req->sq->qid);
 521         req->rsp->command_id = req->cmd->common.command_id;
 522
 523         if (req->ns)
 524                 nvmet_put_namespace(req->ns);
 525         req->ops->queue_response(req);
 526 }
 527
 528 void nvmet_req_complete(struct nvmet_req *req, u16 status)
 529 {
 530         __nvmet_req_complete(req, status);
 531         percpu_ref_put(&req->sq->ref);
 532 }
 533 EXPORT_SYMBOL_GPL(nvmet_req_complete);
 534
 535 void nvmet_cq_setup(struct nvmet_ctrl *ctrl, struct nvmet_cq *cq,
 536                 u16 qid, u16 size)
 537 {
 538         cq->qid = qid;
 539         cq->size = size;
 540
 541         ctrl->cqs[qid] = cq;
 542 }
 543
 544 void nvmet_sq_setup(struct nvmet_ctrl *ctrl, struct nvmet_sq *sq,
 545                 u16 qid, u16 size)
 546 {
 547         sq->sqhd = 0;
 548         sq->qid = qid;
 549         sq->size = size;
 550
 551         ctrl->sqs[qid] = sq;
 552 }
 553
 554 static void nvmet_confirm_sq(struct percpu_ref *ref)
 555 {
 556         struct nvmet_sq *sq = container_of(ref, struct nvmet_sq, ref);
 557
 558         complete(&sq->confirm_done);
 559 }
 560
 561 void nvmet_sq_destroy(struct nvmet_sq *sq)
 562 {
 563         /*
 564          * If this is the admin queue, complete all AERs so that our
 565          * queue doesn't have outstanding requests on it.
 566          */
 567         if (sq->ctrl && sq->ctrl->sqs && sq->ctrl->sqs[0] == sq)
 568                 nvmet_async_events_free(sq->ctrl);
 569         percpu_ref_kill_and_confirm(&sq->ref, nvmet_confirm_sq);
 570         wait_for_completion(&sq->confirm_done);
 571         wait_for_completion(&sq->free_done);
 572         percpu_ref_exit(&sq->ref);
 573
 574         if (sq->ctrl) {
 575                 nvmet_ctrl_put(sq->ctrl);
 576                 sq->ctrl = NULL; /* allows reusing the queue later */
 577         }
 578 }
 579 EXPORT_SYMBOL_GPL(nvmet_sq_destroy);
 580
 581 static void nvmet_sq_free(struct percpu_ref *ref)
 582 {
 583         struct nvmet_sq *sq = container_of(ref, struct nvmet_sq, ref);
 584
 585         complete(&sq->free_done);
 586 }
 587
 588 int nvmet_sq_init(struct nvmet_sq *sq)
 589 {
 590         int ret;
 591
 592         ret = percpu_ref_init(&sq->ref, nvmet_sq_free, 0, GFP_KERNEL);
 593         if (ret) {
 594                 pr_err("percpu_ref init failed!\n");
 595                 return ret;
 596         }
 597         init_completion(&sq->free_done);
 598         init_completion(&sq->confirm_done);
 599
 600         return 0;
 601 }
 602 EXPORT_SYMBOL_GPL(nvmet_sq_init);
 603
 604 static inline u16 nvmet_check_ana_state(struct nvmet_port *port,
 605                 struct nvmet_ns *ns)
 606 {
 607         enum nvme_ana_state state = port->ana_state[ns->anagrpid];
 608
 609         if (unlikely(state == NVME_ANA_INACCESSIBLE))
 610                 return NVME_SC_ANA_INACCESSIBLE;
 611         if (unlikely(state == NVME_ANA_PERSISTENT_LOSS))
 612                 return NVME_SC_ANA_PERSISTENT_LOSS;
 613         if (unlikely(state == NVME_ANA_CHANGE))
 614                 return NVME_SC_ANA_TRANSITION;
 615         return 0;
 616 }
 617
 618 static inline u16 nvmet_io_cmd_check_access(struct nvmet_req *req)
 619 {
 620         if (unlikely(req->ns->readonly)) {
 621                 switch (req->cmd->common.opcode) {
 622                 case nvme_cmd_read:
 623                 case nvme_cmd_flush:
 624                         break;
 625                 default:
 626                         return NVME_SC_NS_WRITE_PROTECTED;
 627                 }
 628         }
 629
 630         return 0;
 631 }
 632
 633 static u16 nvmet_parse_io_cmd(struct nvmet_req *req)
 634 {
 635         struct nvme_command *cmd = req->cmd;
 636         u16 ret;
 637
 638         ret = nvmet_check_ctrl_status(req, cmd);
 639         if (unlikely(ret))
 640                 return ret;
 641
 642         req->ns = nvmet_find_namespace(req->sq->ctrl, cmd->rw.nsid);
 643         if (unlikely(!req->ns))
 644                 return NVME_SC_INVALID_NS | NVME_SC_DNR;
 645         ret = nvmet_check_ana_state(req->port, req->ns);
 646         if (unlikely(ret))
 647                 return ret;
 648         ret = nvmet_io_cmd_check_access(req);
 649         if (unlikely(ret))
 650                 return ret;
 651
 652         if (req->ns->file)
 653                 return nvmet_file_parse_io_cmd(req);
 654         else
 655                 return nvmet_bdev_parse_io_cmd(req);
 656 }
 657
 658 bool nvmet_req_init(struct nvmet_req *req, struct nvmet_cq *cq,
 659                 struct nvmet_sq *sq, const struct nvmet_fabrics_ops *ops)
 660 {
 661         u8 flags = req->cmd->common.flags;
 662         u16 status;
 663
 664         req->cq = cq;
 665         req->sq = sq;
 666         req->ops = ops;
 667         req->sg = NULL;
 668         req->sg_cnt = 0;
 669         req->transfer_len = 0;
 670         req->rsp->status = 0;
 671         req->ns = NULL;
 672
 673         /* no support for fused commands yet */
 674         if (unlikely(flags & (NVME_CMD_FUSE_FIRST | NVME_CMD_FUSE_SECOND))) {
 675                 status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 676                 goto fail;
 677         }
 678
 679         /*
 680          * For fabrics, PSDT field shall describe metadata pointer (MPTR) that
 681          * contains an address of a single contiguous physical buffer that is
 682          * byte aligned.
 683          */
 684         if (unlikely((flags & NVME_CMD_SGL_ALL) != NVME_CMD_SGL_METABUF)) {
 685                 status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 686                 goto fail;
 687         }
 688
 689         if (unlikely(!req->sq->ctrl))
 690                 /* will return an error for any Non-connect command: */
 691                 status = nvmet_parse_connect_cmd(req);
 692         else if (likely(req->sq->qid != 0))
 693                 status = nvmet_parse_io_cmd(req);
 694         else if (req->cmd->common.opcode == nvme_fabrics_command)
 695                 status = nvmet_parse_fabrics_cmd(req);
 696         else if (req->sq->ctrl->subsys->type == NVME_NQN_DISC)
 697                 status = nvmet_parse_discovery_cmd(req);
 698         else
 699                 status = nvmet_parse_admin_cmd(req);
 700
 701         if (status)
 702                 goto fail;
 703
 704         if (unlikely(!percpu_ref_tryget_live(&sq->ref))) {
 705                 status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 706                 goto fail;
 707         }
 708
 709         return true;
 710
 711 fail:
 712         __nvmet_req_complete(req, status);
 713         return false;
 714 }
 715 EXPORT_SYMBOL_GPL(nvmet_req_init);
 716
 717 void nvmet_req_uninit(struct nvmet_req *req)
 718 {
 719         percpu_ref_put(&req->sq->ref);
 720         if (req->ns)
 721                 nvmet_put_namespace(req->ns);
 722 }
 723 EXPORT_SYMBOL_GPL(nvmet_req_uninit);
 724
 725 void nvmet_req_execute(struct nvmet_req *req)
 726 {
 727         if (unlikely(req->data_len != req->transfer_len))
 728                 nvmet_req_complete(req, NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR);
 729         else
 730                 req->execute(req);
 731 }
 732 EXPORT_SYMBOL_GPL(nvmet_req_execute);
 733
 734 static inline bool nvmet_cc_en(u32 cc)
 735 {
 736         return (cc >> NVME_CC_EN_SHIFT) & 0x1;
 737 }
 738
 739 static inline u8 nvmet_cc_css(u32 cc)
 740 {
 741         return (cc >> NVME_CC_CSS_SHIFT) & 0x7;
 742 }
 743
 744 static inline u8 nvmet_cc_mps(u32 cc)
 745 {
 746         return (cc >> NVME_CC_MPS_SHIFT) & 0xf;
 747 }
 748
 749 static inline u8 nvmet_cc_ams(u32 cc)
 750 {
 751         return (cc >> NVME_CC_AMS_SHIFT) & 0x7;
 752 }
 753
 754 static inline u8 nvmet_cc_shn(u32 cc)
 755 {
 756         return (cc >> NVME_CC_SHN_SHIFT) & 0x3;
 757 }
 758
 759 static inline u8 nvmet_cc_iosqes(u32 cc)
 760 {
 761         return (cc >> NVME_CC_IOSQES_SHIFT) & 0xf;
 762 }
 763
 764 static inline u8 nvmet_cc_iocqes(u32 cc)
 765 {
 766         return (cc >> NVME_CC_IOCQES_SHIFT) & 0xf;
 767 }
 768
 769 static void nvmet_start_ctrl(struct nvmet_ctrl *ctrl)
 770 {
 771         lockdep_assert_held(&ctrl->lock);
 772
 773         /*
 774          * Only I/O controllers should verify iosqes,iocqes.
 775          * Strictly speaking, the spec says a discovery controller
 776          * should verify iosqes,iocqes are zeroed, however that
 777          * would break backwards compatibility, so don't enforce it.
 778          */
 779         if (ctrl->subsys->type != NVME_NQN_DISC &&
 780             (nvmet_cc_iosqes(ctrl->cc) != NVME_NVM_IOSQES ||
 781              nvmet_cc_iocqes(ctrl->cc) != NVME_NVM_IOCQES)) {
 782                 ctrl->csts = NVME_CSTS_CFS;
 783                 return;
 784         }
 785
 786         if (nvmet_cc_mps(ctrl->cc) != 0 ||
 787             nvmet_cc_ams(ctrl->cc) != 0 ||
 788             nvmet_cc_css(ctrl->cc) != 0) {
 789                 ctrl->csts = NVME_CSTS_CFS;
 790                 return;
 791         }
 792
 793         ctrl->csts = NVME_CSTS_RDY;
 794
 795         /*
 796          * Controllers that are not yet enabled should not really enforce the
 797          * keep alive timeout, but we still want to track a timeout and cleanup
 798          * in case a host died before it enabled the controller.  Hence, simply
 799          * reset the keep alive timer when the controller is enabled.
 800          */
 801         if (ctrl->kato)
 802                 mod_delayed_work(system_wq, &ctrl->ka_work, ctrl->kato * HZ);
 803 }
 804
 805 static void nvmet_clear_ctrl(struct nvmet_ctrl *ctrl)
 806 {
 807         lockdep_assert_held(&ctrl->lock);
 808
 809         /* XXX: tear down queues? */
 810         ctrl->csts &= ~NVME_CSTS_RDY;
 811         ctrl->cc = 0;
 812 }
 813
 814 void nvmet_update_cc(struct nvmet_ctrl *ctrl, u32 new)
 815 {
 816         u32 old;
 817
 818         mutex_lock(&ctrl->lock);
 819         old = ctrl->cc;
 820         ctrl->cc = new;
 821
 822         if (nvmet_cc_en(new) && !nvmet_cc_en(old))
 823                 nvmet_start_ctrl(ctrl);
 824         if (!nvmet_cc_en(new) && nvmet_cc_en(old))
 825                 nvmet_clear_ctrl(ctrl);
 826         if (nvmet_cc_shn(new) && !nvmet_cc_shn(old)) {
 827                 nvmet_clear_ctrl(ctrl);
 828                 ctrl->csts |= NVME_CSTS_SHST_CMPLT;
 829         }
 830         if (!nvmet_cc_shn(new) && nvmet_cc_shn(old))
 831                 ctrl->csts &= ~NVME_CSTS_SHST_CMPLT;
 832         mutex_unlock(&ctrl->lock);
 833 }
 834
 835 static void nvmet_init_cap(struct nvmet_ctrl *ctrl)
 836 {
 837         /* command sets supported: NVMe command set: */
 838         ctrl->cap = (1ULL << 37);
 839         /* CC.EN timeout in 500msec units: */
 840         ctrl->cap |= (15ULL << 24);
 841         /* maximum queue entries supported: */
 842         ctrl->cap |= NVMET_QUEUE_SIZE - 1;
 843 }
 844
 845 u16 nvmet_ctrl_find_get(const char *subsysnqn, const char *hostnqn, u16 cntlid,
 846                 struct nvmet_req *req, struct nvmet_ctrl **ret)
 847 {
 848         struct nvmet_subsys *subsys;
 849         struct nvmet_ctrl *ctrl;
 850         u16 status = 0;
 851
 852         subsys = nvmet_find_get_subsys(req->port, subsysnqn);
 853         if (!subsys) {
 854                 pr_warn("connect request for invalid subsystem %s!\n",
 855                         subsysnqn);
 856                 req->rsp->result.u32 = IPO_IATTR_CONNECT_DATA(subsysnqn);
 857                 return NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR;
 858         }
 859
 860         mutex_lock(&subsys->lock);
 861         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
 862                 if (ctrl->cntlid == cntlid) {
 863                         if (strncmp(hostnqn, ctrl->hostnqn, NVMF_NQN_SIZE)) {
 864                                 pr_warn("hostnqn mismatch.\n");
 865                                 continue;
 866                         }
 867                         if (!kref_get_unless_zero(&ctrl->ref))
 868                                 continue;
 869
 870                         *ret = ctrl;
 871                         goto out;
 872                 }
 873         }
 874
 875         pr_warn("could not find controller %d for subsys %s / host %s\n",
 876                 cntlid, subsysnqn, hostnqn);
 877         req->rsp->result.u32 = IPO_IATTR_CONNECT_DATA(cntlid);
 878         status = NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR;
 879
 880 out:
 881         mutex_unlock(&subsys->lock);
 882         nvmet_subsys_put(subsys);
 883         return status;
 884 }
 885
 886 u16 nvmet_check_ctrl_status(struct nvmet_req *req, struct nvme_command *cmd)
 887 {
 888         if (unlikely(!(req->sq->ctrl->cc & NVME_CC_ENABLE))) {
 889                 pr_err("got cmd %d while CC.EN == 0 on qid = %d\n",
 890                        cmd->common.opcode, req->sq->qid);
 891                 return NVME_SC_CMD_SEQ_ERROR | NVME_SC_DNR;
 892         }
 893
 894         if (unlikely(!(req->sq->ctrl->csts & NVME_CSTS_RDY))) {
 895                 pr_err("got cmd %d while CSTS.RDY == 0 on qid = %d\n",
 896                        cmd->common.opcode, req->sq->qid);
 897                 return NVME_SC_CMD_SEQ_ERROR | NVME_SC_DNR;
 898         }
 899         return 0;
 900 }
 901
 902 static bool __nvmet_host_allowed(struct nvmet_subsys *subsys,
 903                 const char *hostnqn)
 904 {
 905         struct nvmet_host_link *p;
 906
 907         if (subsys->allow_any_host)
 908                 return true;
 909
 910         list_for_each_entry(p, &subsys->hosts, entry) {
 911                 if (!strcmp(nvmet_host_name(p->host), hostnqn))
 912                         return true;
 913         }
 914
 915         return false;
 916 }
 917
 918 static bool nvmet_host_discovery_allowed(struct nvmet_req *req,
 919                 const char *hostnqn)
 920 {
 921         struct nvmet_subsys_link *s;
 922
 923         list_for_each_entry(s, &req->port->subsystems, entry) {
 924                 if (__nvmet_host_allowed(s->subsys, hostnqn))
 925                         return true;
 926         }
 927
 928         return false;
 929 }
 930
 931 bool nvmet_host_allowed(struct nvmet_req *req, struct nvmet_subsys *subsys,
 932                 const char *hostnqn)
 933 {
 934         lockdep_assert_held(&nvmet_config_sem);
 935
 936         if (subsys->type == NVME_NQN_DISC)
 937                 return nvmet_host_discovery_allowed(req, hostnqn);
 938         else
 939                 return __nvmet_host_allowed(subsys, hostnqn);
 940 }
 941
 942 static void nvmet_fatal_error_handler(struct work_struct *work)
 943 {
 944         struct nvmet_ctrl *ctrl =
 945                         container_of(work, struct nvmet_ctrl, fatal_err_work);
 946
 947         pr_err("ctrl %d fatal error occurred!\n", ctrl->cntlid);
 948         ctrl->ops->delete_ctrl(ctrl);
 949 }
 950
 951 u16 nvmet_alloc_ctrl(const char *subsysnqn, const char *hostnqn,
 952                 struct nvmet_req *req, u32 kato, struct nvmet_ctrl **ctrlp)
 953 {
 954         struct nvmet_subsys *subsys;
 955         struct nvmet_ctrl *ctrl;
 956         int ret;
 957         u16 status;
 958
 959         status = NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR;
 960         subsys = nvmet_find_get_subsys(req->port, subsysnqn);
 961         if (!subsys) {
 962                 pr_warn("connect request for invalid subsystem %s!\n",
 963                         subsysnqn);
 964                 req->rsp->result.u32 = IPO_IATTR_CONNECT_DATA(subsysnqn);
 965                 goto out;
 966         }
 967
 968         status = NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR;
 969         down_read(&nvmet_config_sem);
 970         if (!nvmet_host_allowed(req, subsys, hostnqn)) {
 971                 pr_info("connect by host %s for subsystem %s not allowed\n",
 972                         hostnqn, subsysnqn);
 973                 req->rsp->result.u32 = IPO_IATTR_CONNECT_DATA(hostnqn);
 974                 up_read(&nvmet_config_sem);
 975                 status = NVME_SC_CONNECT_INVALID_HOST | NVME_SC_DNR;
 976                 goto out_put_subsystem;
 977         }
 978         up_read(&nvmet_config_sem);
 979
 980         status = NVME_SC_INTERNAL;
 981         ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
 982         if (!ctrl)
 983                 goto out_put_subsystem;
 984         mutex_init(&ctrl->lock);
 985
 986         nvmet_init_cap(ctrl);
 987
 988         ctrl->port = req->port;
 989
 990         INIT_WORK(&ctrl->async_event_work, nvmet_async_event_work);
 991         INIT_LIST_HEAD(&ctrl->async_events);
 992         INIT_WORK(&ctrl->fatal_err_work, nvmet_fatal_error_handler);
 993
 994         memcpy(ctrl->subsysnqn, subsysnqn, NVMF_NQN_SIZE);
 995         memcpy(ctrl->hostnqn, hostnqn, NVMF_NQN_SIZE);
 996
 997         kref_init(&ctrl->ref);
 998         ctrl->subsys = subsys;
 999         WRITE_ONCE(ctrl->aen_enabled, NVMET_AEN_CFG_OPTIONAL);
1000
1001         ctrl->changed_ns_list = kmalloc_array(NVME_MAX_CHANGED_NAMESPACES,
1002                         sizeof(__le32), GFP_KERNEL);
1003         if (!ctrl->changed_ns_list)
1004                 goto out_free_ctrl;
1005
1006         ctrl->cqs = kcalloc(subsys->max_qid + 1,
1007                         sizeof(struct nvmet_cq *),
1008                         GFP_KERNEL);
1009         if (!ctrl->cqs)
1010                 goto out_free_changed_ns_list;
1011
1012         ctrl->sqs = kcalloc(subsys->max_qid + 1,
1013                         sizeof(struct nvmet_sq *),
1014                         GFP_KERNEL);
1015         if (!ctrl->sqs)
1016                 goto out_free_cqs;
1017
1018         ret = ida_simple_get(&cntlid_ida,
1019                              NVME_CNTLID_MIN, NVME_CNTLID_MAX,
1020                              GFP_KERNEL);
1021         if (ret < 0) {
1022                 status = NVME_SC_CONNECT_CTRL_BUSY | NVME_SC_DNR;
1023                 goto out_free_sqs;
1024         }
1025         ctrl->cntlid = ret;
1026
1027         ctrl->ops = req->ops;
1028         if (ctrl->subsys->type == NVME_NQN_DISC) {
1029                 /* Don't accept keep-alive timeout for discovery controllers */
1030                 if (kato) {
1031                         status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
1032                         goto out_remove_ida;
1033                 }
1034
1035                 /*
1036                  * Discovery controllers use some arbitrary high value in order
1037                  * to cleanup stale discovery sessions
1038                  *
1039                  * From the latest base diff RC:
1040                  * "The Keep Alive command is not supported by
1041                  * Discovery controllers. A transport may specify a
1042                  * fixed Discovery controller activity timeout value
1043                  * (e.g., 2 minutes).  If no commands are received
1044                  * by a Discovery controller within that time
1045                  * period, the controller may perform the
1046                  * actions for Keep Alive Timer expiration".
1047                  */
1048                 ctrl->kato = NVMET_DISC_KATO;
1049         } else {
1050                 /* keep-alive timeout in seconds */
1051                 ctrl->kato = DIV_ROUND_UP(kato, 1000);
1052         }
1053         nvmet_start_keep_alive_timer(ctrl);
1054
1055         mutex_lock(&subsys->lock);
1056         list_add_tail(&ctrl->subsys_entry, &subsys->ctrls);
1057         mutex_unlock(&subsys->lock);
1058
1059         *ctrlp = ctrl;
1060         return 0;
1061
1062 out_remove_ida:
1063         ida_simple_remove(&cntlid_ida, ctrl->cntlid);
1064 out_free_sqs:
1065         kfree(ctrl->sqs);
1066 out_free_cqs:
1067         kfree(ctrl->cqs);
1068 out_free_changed_ns_list:
1069         kfree(ctrl->changed_ns_list);
1070 out_free_ctrl:
1071         kfree(ctrl);
1072 out_put_subsystem:
1073         nvmet_subsys_put(subsys);
1074 out:
1075         return status;
1076 }
1077
1078 static void nvmet_ctrl_free(struct kref *ref)
1079 {
1080         struct nvmet_ctrl *ctrl = container_of(ref, struct nvmet_ctrl, ref);
1081         struct nvmet_subsys *subsys = ctrl->subsys;
1082
1083         mutex_lock(&subsys->lock);
1084         list_del(&ctrl->subsys_entry);
1085         mutex_unlock(&subsys->lock);
1086
1087         nvmet_stop_keep_alive_timer(ctrl);
1088
1089         flush_work(&ctrl->async_event_work);
1090         cancel_work_sync(&ctrl->fatal_err_work);
1091
1092         ida_simple_remove(&cntlid_ida, ctrl->cntlid);
1093
1094         kfree(ctrl->sqs);
1095         kfree(ctrl->cqs);
1096         kfree(ctrl->changed_ns_list);
1097         kfree(ctrl);
1098
1099         nvmet_subsys_put(subsys);
1100 }
1101
1102 void nvmet_ctrl_put(struct nvmet_ctrl *ctrl)
1103 {
1104         kref_put(&ctrl->ref, nvmet_ctrl_free);
1105 }
1106
1107 void nvmet_ctrl_fatal_error(struct nvmet_ctrl *ctrl)
1108 {
1109         mutex_lock(&ctrl->lock);
1110         if (!(ctrl->csts & NVME_CSTS_CFS)) {
1111                 ctrl->csts |= NVME_CSTS_CFS;
1112                 schedule_work(&ctrl->fatal_err_work);
1113         }
1114         mutex_unlock(&ctrl->lock);
1115 }
1116 EXPORT_SYMBOL_GPL(nvmet_ctrl_fatal_error);
1117
1118 static struct nvmet_subsys *nvmet_find_get_subsys(struct nvmet_port *port,
1119                 const char *subsysnqn)
1120 {
1121         struct nvmet_subsys_link *p;
1122
1123         if (!port)
1124                 return NULL;
1125
1126         if (!strncmp(NVME_DISC_SUBSYS_NAME, subsysnqn,
1127                         NVMF_NQN_SIZE)) {
1128                 if (!kref_get_unless_zero(&nvmet_disc_subsys->ref))
1129                         return NULL;
1130                 return nvmet_disc_subsys;
1131         }
1132
1133         down_read(&nvmet_config_sem);
1134         list_for_each_entry(p, &port->subsystems, entry) {
1135                 if (!strncmp(p->subsys->subsysnqn, subsysnqn,
1136                                 NVMF_NQN_SIZE)) {
1137                         if (!kref_get_unless_zero(&p->subsys->ref))
1138                                 break;
1139                         up_read(&nvmet_config_sem);
1140                         return p->subsys;
1141                 }
1142         }
1143         up_read(&nvmet_config_sem);
1144         return NULL;
1145 }
1146
1147 struct nvmet_subsys *nvmet_subsys_alloc(const char *subsysnqn,
1148                 enum nvme_subsys_type type)
1149 {
1150         struct nvmet_subsys *subsys;
1151
1152         subsys = kzalloc(sizeof(*subsys), GFP_KERNEL);
1153         if (!subsys)
1154                 return NULL;
1155
1156         subsys->ver = NVME_VS(1, 3, 0); /* NVMe 1.3.0 */
1157         /* generate a random serial number as our controllers are ephemeral: */
1158         get_random_bytes(&subsys->serial, sizeof(subsys->serial));
1159
1160         switch (type) {
1161         case NVME_NQN_NVME:
1162                 subsys->max_qid = NVMET_NR_QUEUES;
1163                 break;
1164         case NVME_NQN_DISC:
1165                 subsys->max_qid = 0;
1166                 break;
1167         default:
1168                 pr_err("%s: Unknown Subsystem type - %d\n", __func__, type);
1169                 kfree(subsys);
1170                 return NULL;
1171         }
1172         subsys->type = type;
1173         subsys->subsysnqn = kstrndup(subsysnqn, NVMF_NQN_SIZE,
1174                         GFP_KERNEL);
1175         if (!subsys->subsysnqn) {
1176                 kfree(subsys);
1177                 return NULL;
1178         }
1179
1180         kref_init(&subsys->ref);
1181
1182         mutex_init(&subsys->lock);
1183         INIT_LIST_HEAD(&subsys->namespaces);
1184         INIT_LIST_HEAD(&subsys->ctrls);
1185         INIT_LIST_HEAD(&subsys->hosts);
1186
1187         return subsys;
1188 }
1189
1190 static void nvmet_subsys_free(struct kref *ref)
1191 {
1192         struct nvmet_subsys *subsys =
1193                 container_of(ref, struct nvmet_subsys, ref);
1194
1195         WARN_ON_ONCE(!list_empty(&subsys->namespaces));
1196
1197         kfree(subsys->subsysnqn);
1198         kfree(subsys);
1199 }
1200
1201 void nvmet_subsys_del_ctrls(struct nvmet_subsys *subsys)
1202 {
1203         struct nvmet_ctrl *ctrl;
1204
1205         mutex_lock(&subsys->lock);
1206         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry)
1207                 ctrl->ops->delete_ctrl(ctrl);
1208         mutex_unlock(&subsys->lock);
1209 }
1210
1211 void nvmet_subsys_put(struct nvmet_subsys *subsys)
1212 {
1213         kref_put(&subsys->ref, nvmet_subsys_free);
1214 }
1215
1216 static int __init nvmet_init(void)
1217 {
1218         int error;
1219
1220         nvmet_ana_group_enabled[NVMET_DEFAULT_ANA_GRPID] = 1;
1221
1222         buffered_io_wq = alloc_workqueue("nvmet-buffered-io-wq",
1223                         WQ_MEM_RECLAIM, 0);
1224         if (!buffered_io_wq) {
1225                 error = -ENOMEM;
1226                 goto out;
1227         }
1228
1229         error = nvmet_init_discovery();
1230         if (error)
1231                 goto out_free_work_queue;
1232
1233         error = nvmet_init_configfs();
1234         if (error)
1235                 goto out_exit_discovery;
1236         return 0;
1237
1238 out_exit_discovery:
1239         nvmet_exit_discovery();
1240 out_free_work_queue:
1241         destroy_workqueue(buffered_io_wq);
1242 out:
1243         return error;
1244 }
1245
1246 static void __exit nvmet_exit(void)
1247 {
1248         nvmet_exit_configfs();
1249         nvmet_exit_discovery();
1250         ida_destroy(&cntlid_ida);
1251         destroy_workqueue(buffered_io_wq);
1252
1253         BUILD_BUG_ON(sizeof(struct nvmf_disc_rsp_page_entry) != 1024);
1254         BUILD_BUG_ON(sizeof(struct nvmf_disc_rsp_page_hdr) != 1024);
1255 }
1256
1257 module_init(nvmet_init);
1258 module_exit(nvmet_exit);
1259
1260 MODULE_LICENSE("GPL v2");