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 "nvmet.h"
  18
  19 static struct nvmet_fabrics_ops *nvmet_transports[NVMF_TRTYPE_MAX];
  20
  21 /*
  22  * This read/write semaphore is used to synchronize access to configuration
  23  * information on a target system that will result in discovery log page
  24  * information change for at least one host.
  25  * The full list of resources to protected by this semaphore is:
  26  *
  27  *  - subsystems list
  28  *  - per-subsystem allowed hosts list
  29  *  - allow_any_host subsystem attribute
  30  *  - nvmet_genctr
  31  *  - the nvmet_transports array
  32  *
  33  * When updating any of those lists/structures write lock should be obtained,
  34  * while when reading (popolating discovery log page or checking host-subsystem
  35  * link) read lock is obtained to allow concurrent reads.
  36  */
  37 DECLARE_RWSEM(nvmet_config_sem);
  38
  39 static struct nvmet_subsys *nvmet_find_get_subsys(struct nvmet_port *port,
  40                 const char *subsysnqn);
  41
  42 u16 nvmet_copy_to_sgl(struct nvmet_req *req, off_t off, const void *buf,
  43                 size_t len)
  44 {
  45         if (sg_pcopy_from_buffer(req->sg, req->sg_cnt, buf, len, off) != len)
  46                 return NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR;
  47         return 0;
  48 }
  49
  50 u16 nvmet_copy_from_sgl(struct nvmet_req *req, off_t off, void *buf, size_t len)
  51 {
  52         if (sg_pcopy_to_buffer(req->sg, req->sg_cnt, buf, len, off) != len)
  53                 return NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR;
  54         return 0;
  55 }
  56
  57 static u32 nvmet_async_event_result(struct nvmet_async_event *aen)
  58 {
  59         return aen->event_type | (aen->event_info << 8) | (aen->log_page << 16);
  60 }
  61
  62 static void nvmet_async_events_free(struct nvmet_ctrl *ctrl)
  63 {
  64         struct nvmet_req *req;
  65
  66         while (1) {
  67                 mutex_lock(&ctrl->lock);
  68                 if (!ctrl->nr_async_event_cmds) {
  69                         mutex_unlock(&ctrl->lock);
  70                         return;
  71                 }
  72
  73                 req = ctrl->async_event_cmds[--ctrl->nr_async_event_cmds];
  74                 mutex_unlock(&ctrl->lock);
  75                 nvmet_req_complete(req, NVME_SC_INTERNAL | NVME_SC_DNR);
  76         }
  77 }
  78
  79 static void nvmet_async_event_work(struct work_struct *work)
  80 {
  81         struct nvmet_ctrl *ctrl =
  82                 container_of(work, struct nvmet_ctrl, async_event_work);
  83         struct nvmet_async_event *aen;
  84         struct nvmet_req *req;
  85
  86         while (1) {
  87                 mutex_lock(&ctrl->lock);
  88                 aen = list_first_entry_or_null(&ctrl->async_events,
  89                                 struct nvmet_async_event, entry);
  90                 if (!aen || !ctrl->nr_async_event_cmds) {
  91                         mutex_unlock(&ctrl->lock);
  92                         return;
  93                 }
  94
  95                 req = ctrl->async_event_cmds[--ctrl->nr_async_event_cmds];
  96                 nvmet_set_result(req, nvmet_async_event_result(aen));
  97
  98                 list_del(&aen->entry);
  99                 kfree(aen);
 100
 101                 mutex_unlock(&ctrl->lock);
 102                 nvmet_req_complete(req, 0);
 103         }
 104 }
 105
 106 static void nvmet_add_async_event(struct nvmet_ctrl *ctrl, u8 event_type,
 107                 u8 event_info, u8 log_page)
 108 {
 109         struct nvmet_async_event *aen;
 110
 111         aen = kmalloc(sizeof(*aen), GFP_KERNEL);
 112         if (!aen)
 113                 return;
 114
 115         aen->event_type = event_type;
 116         aen->event_info = event_info;
 117         aen->log_page = log_page;
 118
 119         mutex_lock(&ctrl->lock);
 120         list_add_tail(&aen->entry, &ctrl->async_events);
 121         mutex_unlock(&ctrl->lock);
 122
 123         schedule_work(&ctrl->async_event_work);
 124 }
 125
 126 int nvmet_register_transport(struct nvmet_fabrics_ops *ops)
 127 {
 128         int ret = 0;
 129
 130         down_write(&nvmet_config_sem);
 131         if (nvmet_transports[ops->type])
 132                 ret = -EINVAL;
 133         else
 134                 nvmet_transports[ops->type] = ops;
 135         up_write(&nvmet_config_sem);
 136
 137         return ret;
 138 }
 139 EXPORT_SYMBOL_GPL(nvmet_register_transport);
 140
 141 void nvmet_unregister_transport(struct nvmet_fabrics_ops *ops)
 142 {
 143         down_write(&nvmet_config_sem);
 144         nvmet_transports[ops->type] = NULL;
 145         up_write(&nvmet_config_sem);
 146 }
 147 EXPORT_SYMBOL_GPL(nvmet_unregister_transport);
 148
 149 int nvmet_enable_port(struct nvmet_port *port)
 150 {
 151         struct nvmet_fabrics_ops *ops;
 152         int ret;
 153
 154         lockdep_assert_held(&nvmet_config_sem);
 155
 156         ops = nvmet_transports[port->disc_addr.trtype];
 157         if (!ops) {
 158                 up_write(&nvmet_config_sem);
 159                 request_module("nvmet-transport-%d", port->disc_addr.trtype);
 160                 down_write(&nvmet_config_sem);
 161                 ops = nvmet_transports[port->disc_addr.trtype];
 162                 if (!ops) {
 163                         pr_err("transport type %d not supported\n",
 164                                 port->disc_addr.trtype);
 165                         return -EINVAL;
 166                 }
 167         }
 168
 169         if (!try_module_get(ops->owner))
 170                 return -EINVAL;
 171
 172         ret = ops->add_port(port);
 173         if (ret) {
 174                 module_put(ops->owner);
 175                 return ret;
 176         }
 177
 178         port->enabled = true;
 179         return 0;
 180 }
 181
 182 void nvmet_disable_port(struct nvmet_port *port)
 183 {
 184         struct nvmet_fabrics_ops *ops;
 185
 186         lockdep_assert_held(&nvmet_config_sem);
 187
 188         port->enabled = false;
 189
 190         ops = nvmet_transports[port->disc_addr.trtype];
 191         ops->remove_port(port);
 192         module_put(ops->owner);
 193 }
 194
 195 static void nvmet_keep_alive_timer(struct work_struct *work)
 196 {
 197         struct nvmet_ctrl *ctrl = container_of(to_delayed_work(work),
 198                         struct nvmet_ctrl, ka_work);
 199
 200         pr_err("ctrl %d keep-alive timer (%d seconds) expired!\n",
 201                 ctrl->cntlid, ctrl->kato);
 202
 203         ctrl->ops->delete_ctrl(ctrl);
 204 }
 205
 206 static void nvmet_start_keep_alive_timer(struct nvmet_ctrl *ctrl)
 207 {
 208         pr_debug("ctrl %d start keep-alive timer for %d secs\n",
 209                 ctrl->cntlid, ctrl->kato);
 210
 211         INIT_DELAYED_WORK(&ctrl->ka_work, nvmet_keep_alive_timer);
 212         schedule_delayed_work(&ctrl->ka_work, ctrl->kato * HZ);
 213 }
 214
 215 static void nvmet_stop_keep_alive_timer(struct nvmet_ctrl *ctrl)
 216 {
 217         pr_debug("ctrl %d stop keep-alive\n", ctrl->cntlid);
 218
 219         cancel_delayed_work_sync(&ctrl->ka_work);
 220 }
 221
 222 static struct nvmet_ns *__nvmet_find_namespace(struct nvmet_ctrl *ctrl,
 223                 __le32 nsid)
 224 {
 225         struct nvmet_ns *ns;
 226
 227         list_for_each_entry_rcu(ns, &ctrl->subsys->namespaces, dev_link) {
 228                 if (ns->nsid == le32_to_cpu(nsid))
 229                         return ns;
 230         }
 231
 232         return NULL;
 233 }
 234
 235 struct nvmet_ns *nvmet_find_namespace(struct nvmet_ctrl *ctrl, __le32 nsid)
 236 {
 237         struct nvmet_ns *ns;
 238
 239         rcu_read_lock();
 240         ns = __nvmet_find_namespace(ctrl, nsid);
 241         if (ns)
 242                 percpu_ref_get(&ns->ref);
 243         rcu_read_unlock();
 244
 245         return ns;
 246 }
 247
 248 static void nvmet_destroy_namespace(struct percpu_ref *ref)
 249 {
 250         struct nvmet_ns *ns = container_of(ref, struct nvmet_ns, ref);
 251
 252         complete(&ns->disable_done);
 253 }
 254
 255 void nvmet_put_namespace(struct nvmet_ns *ns)
 256 {
 257         percpu_ref_put(&ns->ref);
 258 }
 259
 260 int nvmet_ns_enable(struct nvmet_ns *ns)
 261 {
 262         struct nvmet_subsys *subsys = ns->subsys;
 263         struct nvmet_ctrl *ctrl;
 264         int ret = 0;
 265
 266         mutex_lock(&subsys->lock);
 267         if (!list_empty(&ns->dev_link))
 268                 goto out_unlock;
 269
 270         ns->bdev = blkdev_get_by_path(ns->device_path, FMODE_READ | FMODE_WRITE,
 271                         NULL);
 272         if (IS_ERR(ns->bdev)) {
 273                 pr_err("nvmet: failed to open block device %s: (%ld)\n",
 274                         ns->device_path, PTR_ERR(ns->bdev));
 275                 ret = PTR_ERR(ns->bdev);
 276                 ns->bdev = NULL;
 277                 goto out_unlock;
 278         }
 279
 280         ns->size = i_size_read(ns->bdev->bd_inode);
 281         ns->blksize_shift = blksize_bits(bdev_logical_block_size(ns->bdev));
 282
 283         ret = percpu_ref_init(&ns->ref, nvmet_destroy_namespace,
 284                                 0, GFP_KERNEL);
 285         if (ret)
 286                 goto out_blkdev_put;
 287
 288         if (ns->nsid > subsys->max_nsid)
 289                 subsys->max_nsid = ns->nsid;
 290
 291         /*
 292          * The namespaces list needs to be sorted to simplify the implementation
 293          * of the Identify Namepace List subcommand.
 294          */
 295         if (list_empty(&subsys->namespaces)) {
 296                 list_add_tail_rcu(&ns->dev_link, &subsys->namespaces);
 297         } else {
 298                 struct nvmet_ns *old;
 299
 300                 list_for_each_entry_rcu(old, &subsys->namespaces, dev_link) {
 301                         BUG_ON(ns->nsid == old->nsid);
 302                         if (ns->nsid < old->nsid)
 303                                 break;
 304                 }
 305
 306                 list_add_tail_rcu(&ns->dev_link, &old->dev_link);
 307         }
 308
 309         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry)
 310                 nvmet_add_async_event(ctrl, NVME_AER_TYPE_NOTICE, 0, 0);
 311
 312         ret = 0;
 313 out_unlock:
 314         mutex_unlock(&subsys->lock);
 315         return ret;
 316 out_blkdev_put:
 317         blkdev_put(ns->bdev, FMODE_WRITE|FMODE_READ);
 318         ns->bdev = NULL;
 319         goto out_unlock;
 320 }
 321
 322 void nvmet_ns_disable(struct nvmet_ns *ns)
 323 {
 324         struct nvmet_subsys *subsys = ns->subsys;
 325         struct nvmet_ctrl *ctrl;
 326
 327         mutex_lock(&subsys->lock);
 328         if (list_empty(&ns->dev_link)) {
 329                 mutex_unlock(&subsys->lock);
 330                 return;
 331         }
 332         list_del_init(&ns->dev_link);
 333         mutex_unlock(&subsys->lock);
 334
 335         /*
 336          * Now that we removed the namespaces from the lookup list, we
 337          * can kill the per_cpu ref and wait for any remaining references
 338          * to be dropped, as well as a RCU grace period for anyone only
 339          * using the namepace under rcu_read_lock().  Note that we can't
 340          * use call_rcu here as we need to ensure the namespaces have
 341          * been fully destroyed before unloading the module.
 342          */
 343         percpu_ref_kill(&ns->ref);
 344         synchronize_rcu();
 345         wait_for_completion(&ns->disable_done);
 346         percpu_ref_exit(&ns->ref);
 347
 348         mutex_lock(&subsys->lock);
 349         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry)
 350                 nvmet_add_async_event(ctrl, NVME_AER_TYPE_NOTICE, 0, 0);
 351
 352         if (ns->bdev)
 353                 blkdev_put(ns->bdev, FMODE_WRITE|FMODE_READ);
 354         mutex_unlock(&subsys->lock);
 355 }
 356
 357 void nvmet_ns_free(struct nvmet_ns *ns)
 358 {
 359         nvmet_ns_disable(ns);
 360
 361         kfree(ns->device_path);
 362         kfree(ns);
 363 }
 364
 365 struct nvmet_ns *nvmet_ns_alloc(struct nvmet_subsys *subsys, u32 nsid)
 366 {
 367         struct nvmet_ns *ns;
 368
 369         ns = kzalloc(sizeof(*ns), GFP_KERNEL);
 370         if (!ns)
 371                 return NULL;
 372
 373         INIT_LIST_HEAD(&ns->dev_link);
 374         init_completion(&ns->disable_done);
 375
 376         ns->nsid = nsid;
 377         ns->subsys = subsys;
 378
 379         return ns;
 380 }
 381
 382 static void __nvmet_req_complete(struct nvmet_req *req, u16 status)
 383 {
 384         if (status)
 385                 nvmet_set_status(req, status);
 386
 387         /* XXX: need to fill in something useful for sq_head */
 388         req->rsp->sq_head = 0;
 389         if (likely(req->sq)) /* may happen during early failure */
 390                 req->rsp->sq_id = cpu_to_le16(req->sq->qid);
 391         req->rsp->command_id = req->cmd->common.command_id;
 392
 393         if (req->ns)
 394                 nvmet_put_namespace(req->ns);
 395         req->ops->queue_response(req);
 396 }
 397
 398 void nvmet_req_complete(struct nvmet_req *req, u16 status)
 399 {
 400         __nvmet_req_complete(req, status);
 401         percpu_ref_put(&req->sq->ref);
 402 }
 403 EXPORT_SYMBOL_GPL(nvmet_req_complete);
 404
 405 void nvmet_cq_setup(struct nvmet_ctrl *ctrl, struct nvmet_cq *cq,
 406                 u16 qid, u16 size)
 407 {
 408         cq->qid = qid;
 409         cq->size = size;
 410
 411         ctrl->cqs[qid] = cq;
 412 }
 413
 414 void nvmet_sq_setup(struct nvmet_ctrl *ctrl, struct nvmet_sq *sq,
 415                 u16 qid, u16 size)
 416 {
 417         sq->qid = qid;
 418         sq->size = size;
 419
 420         ctrl->sqs[qid] = sq;
 421 }
 422
 423 void nvmet_sq_destroy(struct nvmet_sq *sq)
 424 {
 425         /*
 426          * If this is the admin queue, complete all AERs so that our
 427          * queue doesn't have outstanding requests on it.
 428          */
 429         if (sq->ctrl && sq->ctrl->sqs && sq->ctrl->sqs[0] == sq)
 430                 nvmet_async_events_free(sq->ctrl);
 431         percpu_ref_kill(&sq->ref);
 432         wait_for_completion(&sq->free_done);
 433         percpu_ref_exit(&sq->ref);
 434
 435         if (sq->ctrl) {
 436                 nvmet_ctrl_put(sq->ctrl);
 437                 sq->ctrl = NULL; /* allows reusing the queue later */
 438         }
 439 }
 440 EXPORT_SYMBOL_GPL(nvmet_sq_destroy);
 441
 442 static void nvmet_sq_free(struct percpu_ref *ref)
 443 {
 444         struct nvmet_sq *sq = container_of(ref, struct nvmet_sq, ref);
 445
 446         complete(&sq->free_done);
 447 }
 448
 449 int nvmet_sq_init(struct nvmet_sq *sq)
 450 {
 451         int ret;
 452
 453         ret = percpu_ref_init(&sq->ref, nvmet_sq_free, 0, GFP_KERNEL);
 454         if (ret) {
 455                 pr_err("percpu_ref init failed!\n");
 456                 return ret;
 457         }
 458         init_completion(&sq->free_done);
 459
 460         return 0;
 461 }
 462 EXPORT_SYMBOL_GPL(nvmet_sq_init);
 463
 464 bool nvmet_req_init(struct nvmet_req *req, struct nvmet_cq *cq,
 465                 struct nvmet_sq *sq, struct nvmet_fabrics_ops *ops)
 466 {
 467         u8 flags = req->cmd->common.flags;
 468         u16 status;
 469
 470         req->cq = cq;
 471         req->sq = sq;
 472         req->ops = ops;
 473         req->sg = NULL;
 474         req->sg_cnt = 0;
 475         req->rsp->status = 0;
 476
 477         /* no support for fused commands yet */
 478         if (unlikely(flags & (NVME_CMD_FUSE_FIRST | NVME_CMD_FUSE_SECOND))) {
 479                 status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 480                 goto fail;
 481         }
 482
 483         /* either variant of SGLs is fine, as we don't support metadata */
 484         if (unlikely((flags & NVME_CMD_SGL_ALL) != NVME_CMD_SGL_METABUF &&
 485                      (flags & NVME_CMD_SGL_ALL) != NVME_CMD_SGL_METASEG)) {
 486                 status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 487                 goto fail;
 488         }
 489
 490         if (unlikely(!req->sq->ctrl))
 491                 /* will return an error for any Non-connect command: */
 492                 status = nvmet_parse_connect_cmd(req);
 493         else if (likely(req->sq->qid != 0))
 494                 status = nvmet_parse_io_cmd(req);
 495         else if (req->cmd->common.opcode == nvme_fabrics_command)
 496                 status = nvmet_parse_fabrics_cmd(req);
 497         else if (req->sq->ctrl->subsys->type == NVME_NQN_DISC)
 498                 status = nvmet_parse_discovery_cmd(req);
 499         else
 500                 status = nvmet_parse_admin_cmd(req);
 501
 502         if (status)
 503                 goto fail;
 504
 505         if (unlikely(!percpu_ref_tryget_live(&sq->ref))) {
 506                 status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 507                 goto fail;
 508         }
 509
 510         return true;
 511
 512 fail:
 513         __nvmet_req_complete(req, status);
 514         return false;
 515 }
 516 EXPORT_SYMBOL_GPL(nvmet_req_init);
 517
 518 static inline bool nvmet_cc_en(u32 cc)
 519 {
 520         return cc & 0x1;
 521 }
 522
 523 static inline u8 nvmet_cc_css(u32 cc)
 524 {
 525         return (cc >> 4) & 0x7;
 526 }
 527
 528 static inline u8 nvmet_cc_mps(u32 cc)
 529 {
 530         return (cc >> 7) & 0xf;
 531 }
 532
 533 static inline u8 nvmet_cc_ams(u32 cc)
 534 {
 535         return (cc >> 11) & 0x7;
 536 }
 537
 538 static inline u8 nvmet_cc_shn(u32 cc)
 539 {
 540         return (cc >> 14) & 0x3;
 541 }
 542
 543 static inline u8 nvmet_cc_iosqes(u32 cc)
 544 {
 545         return (cc >> 16) & 0xf;
 546 }
 547
 548 static inline u8 nvmet_cc_iocqes(u32 cc)
 549 {
 550         return (cc >> 20) & 0xf;
 551 }
 552
 553 static void nvmet_start_ctrl(struct nvmet_ctrl *ctrl)
 554 {
 555         lockdep_assert_held(&ctrl->lock);
 556
 557         if (nvmet_cc_iosqes(ctrl->cc) != NVME_NVM_IOSQES ||
 558             nvmet_cc_iocqes(ctrl->cc) != NVME_NVM_IOCQES ||
 559             nvmet_cc_mps(ctrl->cc) != 0 ||
 560             nvmet_cc_ams(ctrl->cc) != 0 ||
 561             nvmet_cc_css(ctrl->cc) != 0) {
 562                 ctrl->csts = NVME_CSTS_CFS;
 563                 return;
 564         }
 565
 566         ctrl->csts = NVME_CSTS_RDY;
 567 }
 568
 569 static void nvmet_clear_ctrl(struct nvmet_ctrl *ctrl)
 570 {
 571         lockdep_assert_held(&ctrl->lock);
 572
 573         /* XXX: tear down queues? */
 574         ctrl->csts &= ~NVME_CSTS_RDY;
 575         ctrl->cc = 0;
 576 }
 577
 578 void nvmet_update_cc(struct nvmet_ctrl *ctrl, u32 new)
 579 {
 580         u32 old;
 581
 582         mutex_lock(&ctrl->lock);
 583         old = ctrl->cc;
 584         ctrl->cc = new;
 585
 586         if (nvmet_cc_en(new) && !nvmet_cc_en(old))
 587                 nvmet_start_ctrl(ctrl);
 588         if (!nvmet_cc_en(new) && nvmet_cc_en(old))
 589                 nvmet_clear_ctrl(ctrl);
 590         if (nvmet_cc_shn(new) && !nvmet_cc_shn(old)) {
 591                 nvmet_clear_ctrl(ctrl);
 592                 ctrl->csts |= NVME_CSTS_SHST_CMPLT;
 593         }
 594         if (!nvmet_cc_shn(new) && nvmet_cc_shn(old))
 595                 ctrl->csts &= ~NVME_CSTS_SHST_CMPLT;
 596         mutex_unlock(&ctrl->lock);
 597 }
 598
 599 static void nvmet_init_cap(struct nvmet_ctrl *ctrl)
 600 {
 601         /* command sets supported: NVMe command set: */
 602         ctrl->cap = (1ULL << 37);
 603         /* CC.EN timeout in 500msec units: */
 604         ctrl->cap |= (15ULL << 24);
 605         /* maximum queue entries supported: */
 606         ctrl->cap |= NVMET_QUEUE_SIZE - 1;
 607 }
 608
 609 u16 nvmet_ctrl_find_get(const char *subsysnqn, const char *hostnqn, u16 cntlid,
 610                 struct nvmet_req *req, struct nvmet_ctrl **ret)
 611 {
 612         struct nvmet_subsys *subsys;
 613         struct nvmet_ctrl *ctrl;
 614         u16 status = 0;
 615
 616         subsys = nvmet_find_get_subsys(req->port, subsysnqn);
 617         if (!subsys) {
 618                 pr_warn("connect request for invalid subsystem %s!\n",
 619                         subsysnqn);
 620                 req->rsp->result = IPO_IATTR_CONNECT_DATA(subsysnqn);
 621                 return NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR;
 622         }
 623
 624         mutex_lock(&subsys->lock);
 625         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
 626                 if (ctrl->cntlid == cntlid) {
 627                         if (strncmp(hostnqn, ctrl->hostnqn, NVMF_NQN_SIZE)) {
 628                                 pr_warn("hostnqn mismatch.\n");
 629                                 continue;
 630                         }
 631                         if (!kref_get_unless_zero(&ctrl->ref))
 632                                 continue;
 633
 634                         *ret = ctrl;
 635                         goto out;
 636                 }
 637         }
 638
 639         pr_warn("could not find controller %d for subsys %s / host %s\n",
 640                 cntlid, subsysnqn, hostnqn);
 641         req->rsp->result = IPO_IATTR_CONNECT_DATA(cntlid);
 642         status = NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR;
 643
 644 out:
 645         mutex_unlock(&subsys->lock);
 646         nvmet_subsys_put(subsys);
 647         return status;
 648 }
 649
 650 static bool __nvmet_host_allowed(struct nvmet_subsys *subsys,
 651                 const char *hostnqn)
 652 {
 653         struct nvmet_host_link *p;
 654
 655         if (subsys->allow_any_host)
 656                 return true;
 657
 658         list_for_each_entry(p, &subsys->hosts, entry) {
 659                 if (!strcmp(nvmet_host_name(p->host), hostnqn))
 660                         return true;
 661         }
 662
 663         return false;
 664 }
 665
 666 static bool nvmet_host_discovery_allowed(struct nvmet_req *req,
 667                 const char *hostnqn)
 668 {
 669         struct nvmet_subsys_link *s;
 670
 671         list_for_each_entry(s, &req->port->subsystems, entry) {
 672                 if (__nvmet_host_allowed(s->subsys, hostnqn))
 673                         return true;
 674         }
 675
 676         return false;
 677 }
 678
 679 bool nvmet_host_allowed(struct nvmet_req *req, struct nvmet_subsys *subsys,
 680                 const char *hostnqn)
 681 {
 682         lockdep_assert_held(&nvmet_config_sem);
 683
 684         if (subsys->type == NVME_NQN_DISC)
 685                 return nvmet_host_discovery_allowed(req, hostnqn);
 686         else
 687                 return __nvmet_host_allowed(subsys, hostnqn);
 688 }
 689
 690 u16 nvmet_alloc_ctrl(const char *subsysnqn, const char *hostnqn,
 691                 struct nvmet_req *req, u32 kato, struct nvmet_ctrl **ctrlp)
 692 {
 693         struct nvmet_subsys *subsys;
 694         struct nvmet_ctrl *ctrl;
 695         int ret;
 696         u16 status;
 697
 698         status = NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR;
 699         subsys = nvmet_find_get_subsys(req->port, subsysnqn);
 700         if (!subsys) {
 701                 pr_warn("connect request for invalid subsystem %s!\n",
 702                         subsysnqn);
 703                 req->rsp->result = IPO_IATTR_CONNECT_DATA(subsysnqn);
 704                 goto out;
 705         }
 706
 707         status = NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR;
 708         down_read(&nvmet_config_sem);
 709         if (!nvmet_host_allowed(req, subsys, hostnqn)) {
 710                 pr_info("connect by host %s for subsystem %s not allowed\n",
 711                         hostnqn, subsysnqn);
 712                 req->rsp->result = IPO_IATTR_CONNECT_DATA(hostnqn);
 713                 up_read(&nvmet_config_sem);
 714                 goto out_put_subsystem;
 715         }
 716         up_read(&nvmet_config_sem);
 717
 718         status = NVME_SC_INTERNAL;
 719         ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
 720         if (!ctrl)
 721                 goto out_put_subsystem;
 722         mutex_init(&ctrl->lock);
 723
 724         nvmet_init_cap(ctrl);
 725
 726         INIT_WORK(&ctrl->async_event_work, nvmet_async_event_work);
 727         INIT_LIST_HEAD(&ctrl->async_events);
 728
 729         memcpy(ctrl->subsysnqn, subsysnqn, NVMF_NQN_SIZE);
 730         memcpy(ctrl->hostnqn, hostnqn, NVMF_NQN_SIZE);
 731
 732         /* generate a random serial number as our controllers are ephemeral: */
 733         get_random_bytes(&ctrl->serial, sizeof(ctrl->serial));
 734
 735         kref_init(&ctrl->ref);
 736         ctrl->subsys = subsys;
 737
 738         ctrl->cqs = kcalloc(subsys->max_qid + 1,
 739                         sizeof(struct nvmet_cq *),
 740                         GFP_KERNEL);
 741         if (!ctrl->cqs)
 742                 goto out_free_ctrl;
 743
 744         ctrl->sqs = kcalloc(subsys->max_qid + 1,
 745                         sizeof(struct nvmet_sq *),
 746                         GFP_KERNEL);
 747         if (!ctrl->sqs)
 748                 goto out_free_cqs;
 749
 750         ret = ida_simple_get(&subsys->cntlid_ida,
 751                              NVME_CNTLID_MIN, NVME_CNTLID_MAX,
 752                              GFP_KERNEL);
 753         if (ret < 0) {
 754                 status = NVME_SC_CONNECT_CTRL_BUSY | NVME_SC_DNR;
 755                 goto out_free_sqs;
 756         }
 757         ctrl->cntlid = ret;
 758
 759         ctrl->ops = req->ops;
 760         if (ctrl->subsys->type == NVME_NQN_DISC) {
 761                 /* Don't accept keep-alive timeout for discovery controllers */
 762                 if (kato) {
 763                         status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 764                         goto out_free_sqs;
 765                 }
 766
 767                 /*
 768                  * Discovery controllers use some arbitrary high value in order
 769                  * to cleanup stale discovery sessions
 770                  *
 771                  * From the latest base diff RC:
 772                  * "The Keep Alive command is not supported by
 773                  * Discovery controllers. A transport may specify a
 774                  * fixed Discovery controller activity timeout value
 775                  * (e.g., 2 minutes).  If no commands are received
 776                  * by a Discovery controller within that time
 777                  * period, the controller may perform the
 778                  * actions for Keep Alive Timer expiration".
 779                  */
 780                 ctrl->kato = NVMET_DISC_KATO;
 781         } else {
 782                 /* keep-alive timeout in seconds */
 783                 ctrl->kato = DIV_ROUND_UP(kato, 1000);
 784         }
 785         nvmet_start_keep_alive_timer(ctrl);
 786
 787         mutex_lock(&subsys->lock);
 788         list_add_tail(&ctrl->subsys_entry, &subsys->ctrls);
 789         mutex_unlock(&subsys->lock);
 790
 791         *ctrlp = ctrl;
 792         return 0;
 793
 794 out_free_sqs:
 795         kfree(ctrl->sqs);
 796 out_free_cqs:
 797         kfree(ctrl->cqs);
 798 out_free_ctrl:
 799         kfree(ctrl);
 800 out_put_subsystem:
 801         nvmet_subsys_put(subsys);
 802 out:
 803         return status;
 804 }
 805
 806 static void nvmet_ctrl_free(struct kref *ref)
 807 {
 808         struct nvmet_ctrl *ctrl = container_of(ref, struct nvmet_ctrl, ref);
 809         struct nvmet_subsys *subsys = ctrl->subsys;
 810
 811         nvmet_stop_keep_alive_timer(ctrl);
 812
 813         mutex_lock(&subsys->lock);
 814         list_del(&ctrl->subsys_entry);
 815         mutex_unlock(&subsys->lock);
 816
 817         ida_simple_remove(&subsys->cntlid_ida, ctrl->cntlid);
 818         nvmet_subsys_put(subsys);
 819
 820         kfree(ctrl->sqs);
 821         kfree(ctrl->cqs);
 822         kfree(ctrl);
 823 }
 824
 825 void nvmet_ctrl_put(struct nvmet_ctrl *ctrl)
 826 {
 827         kref_put(&ctrl->ref, nvmet_ctrl_free);
 828 }
 829
 830 static void nvmet_fatal_error_handler(struct work_struct *work)
 831 {
 832         struct nvmet_ctrl *ctrl =
 833                         container_of(work, struct nvmet_ctrl, fatal_err_work);
 834
 835         pr_err("ctrl %d fatal error occurred!\n", ctrl->cntlid);
 836         ctrl->ops->delete_ctrl(ctrl);
 837 }
 838
 839 void nvmet_ctrl_fatal_error(struct nvmet_ctrl *ctrl)
 840 {
 841         ctrl->csts |= NVME_CSTS_CFS;
 842         INIT_WORK(&ctrl->fatal_err_work, nvmet_fatal_error_handler);
 843         schedule_work(&ctrl->fatal_err_work);
 844 }
 845 EXPORT_SYMBOL_GPL(nvmet_ctrl_fatal_error);
 846
 847 static struct nvmet_subsys *nvmet_find_get_subsys(struct nvmet_port *port,
 848                 const char *subsysnqn)
 849 {
 850         struct nvmet_subsys_link *p;
 851
 852         if (!port)
 853                 return NULL;
 854
 855         if (!strncmp(NVME_DISC_SUBSYS_NAME, subsysnqn,
 856                         NVMF_NQN_SIZE)) {
 857                 if (!kref_get_unless_zero(&nvmet_disc_subsys->ref))
 858                         return NULL;
 859                 return nvmet_disc_subsys;
 860         }
 861
 862         down_read(&nvmet_config_sem);
 863         list_for_each_entry(p, &port->subsystems, entry) {
 864                 if (!strncmp(p->subsys->subsysnqn, subsysnqn,
 865                                 NVMF_NQN_SIZE)) {
 866                         if (!kref_get_unless_zero(&p->subsys->ref))
 867                                 break;
 868                         up_read(&nvmet_config_sem);
 869                         return p->subsys;
 870                 }
 871         }
 872         up_read(&nvmet_config_sem);
 873         return NULL;
 874 }
 875
 876 struct nvmet_subsys *nvmet_subsys_alloc(const char *subsysnqn,
 877                 enum nvme_subsys_type type)
 878 {
 879         struct nvmet_subsys *subsys;
 880
 881         subsys = kzalloc(sizeof(*subsys), GFP_KERNEL);
 882         if (!subsys)
 883                 return NULL;
 884
 885         subsys->ver = NVME_VS(1, 2, 1); /* NVMe 1.2.1 */
 886
 887         switch (type) {
 888         case NVME_NQN_NVME:
 889                 subsys->max_qid = NVMET_NR_QUEUES;
 890                 break;
 891         case NVME_NQN_DISC:
 892                 subsys->max_qid = 0;
 893                 break;
 894         default:
 895                 pr_err("%s: Unknown Subsystem type - %d\n", __func__, type);
 896                 kfree(subsys);
 897                 return NULL;
 898         }
 899         subsys->type = type;
 900         subsys->subsysnqn = kstrndup(subsysnqn, NVMF_NQN_SIZE,
 901                         GFP_KERNEL);
 902         if (!subsys->subsysnqn) {
 903                 kfree(subsys);
 904                 return NULL;
 905         }
 906
 907         kref_init(&subsys->ref);
 908
 909         mutex_init(&subsys->lock);
 910         INIT_LIST_HEAD(&subsys->namespaces);
 911         INIT_LIST_HEAD(&subsys->ctrls);
 912
 913         ida_init(&subsys->cntlid_ida);
 914
 915         INIT_LIST_HEAD(&subsys->hosts);
 916
 917         return subsys;
 918 }
 919
 920 static void nvmet_subsys_free(struct kref *ref)
 921 {
 922         struct nvmet_subsys *subsys =
 923                 container_of(ref, struct nvmet_subsys, ref);
 924
 925         WARN_ON_ONCE(!list_empty(&subsys->namespaces));
 926
 927         ida_destroy(&subsys->cntlid_ida);
 928         kfree(subsys->subsysnqn);
 929         kfree(subsys);
 930 }
 931
 932 void nvmet_subsys_put(struct nvmet_subsys *subsys)
 933 {
 934         kref_put(&subsys->ref, nvmet_subsys_free);
 935 }
 936
 937 static int __init nvmet_init(void)
 938 {
 939         int error;
 940
 941         error = nvmet_init_discovery();
 942         if (error)
 943                 goto out;
 944
 945         error = nvmet_init_configfs();
 946         if (error)
 947                 goto out_exit_discovery;
 948         return 0;
 949
 950 out_exit_discovery:
 951         nvmet_exit_discovery();
 952 out:
 953         return error;
 954 }
 955
 956 static void __exit nvmet_exit(void)
 957 {
 958         nvmet_exit_configfs();
 959         nvmet_exit_discovery();
 960
 961         BUILD_BUG_ON(sizeof(struct nvmf_disc_rsp_page_entry) != 1024);
 962         BUILD_BUG_ON(sizeof(struct nvmf_disc_rsp_page_hdr) != 1024);
 963 }
 964
 965 module_init(nvmet_init);
 966 module_exit(nvmet_exit);
 967
 968 MODULE_LICENSE("GPL v2");