drivers/nvme/target/core.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Common code for the NVMe target.
   4  * Copyright (c) 2015-2016 HGST, a Western Digital Company.
   5  */
   6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   7 #include <linux/module.h>
   8 #include <linux/random.h>
   9 #include <linux/rculist.h>
  10 #include <linux/pci-p2pdma.h>
  11 #include <linux/scatterlist.h>
  12
  13 #define CREATE_TRACE_POINTS
  14 #include "trace.h"
  15
  16 #include "nvmet.h"
  17
  18 struct workqueue_struct *buffered_io_wq;
  19 static const struct nvmet_fabrics_ops *nvmet_transports[NVMF_TRTYPE_MAX];
  20 static DEFINE_IDA(cntlid_ida);
  21
  22 /*
  23  * This read/write semaphore is used to synchronize access to configuration
  24  * information on a target system that will result in discovery log page
  25  * information change for at least one host.
  26  * The full list of resources to protected by this semaphore is:
  27  *
  28  *  - subsystems list
  29  *  - per-subsystem allowed hosts list
  30  *  - allow_any_host subsystem attribute
  31  *  - nvmet_genctr
  32  *  - the nvmet_transports array
  33  *
  34  * When updating any of those lists/structures write lock should be obtained,
  35  * while when reading (popolating discovery log page or checking host-subsystem
  36  * link) read lock is obtained to allow concurrent reads.
  37  */
  38 DECLARE_RWSEM(nvmet_config_sem);
  39
  40 u32 nvmet_ana_group_enabled[NVMET_MAX_ANAGRPS + 1];
  41 u64 nvmet_ana_chgcnt;
  42 DECLARE_RWSEM(nvmet_ana_sem);
  43
  44 inline u16 errno_to_nvme_status(struct nvmet_req *req, int errno)
  45 {
  46         u16 status;
  47
  48         switch (errno) {
  49         case -ENOSPC:
  50                 req->error_loc = offsetof(struct nvme_rw_command, length);
  51                 status = NVME_SC_CAP_EXCEEDED | NVME_SC_DNR;
  52                 break;
  53         case -EREMOTEIO:
  54                 req->error_loc = offsetof(struct nvme_rw_command, slba);
  55                 status = NVME_SC_LBA_RANGE | NVME_SC_DNR;
  56                 break;
  57         case -EOPNOTSUPP:
  58                 req->error_loc = offsetof(struct nvme_common_command, opcode);
  59                 switch (req->cmd->common.opcode) {
  60                 case nvme_cmd_dsm:
  61                 case nvme_cmd_write_zeroes:
  62                         status = NVME_SC_ONCS_NOT_SUPPORTED | NVME_SC_DNR;
  63                         break;
  64                 default:
  65                         status = NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
  66                 }
  67                 break;
  68         case -ENODATA:
  69                 req->error_loc = offsetof(struct nvme_rw_command, nsid);
  70                 status = NVME_SC_ACCESS_DENIED;
  71                 break;
  72         case -EIO:
  73                 /* FALLTHRU */
  74         default:
  75                 req->error_loc = offsetof(struct nvme_common_command, opcode);
  76                 status = NVME_SC_INTERNAL | NVME_SC_DNR;
  77         }
  78
  79         return status;
  80 }
  81
  82 static struct nvmet_subsys *nvmet_find_get_subsys(struct nvmet_port *port,
  83                 const char *subsysnqn);
  84
  85 u16 nvmet_copy_to_sgl(struct nvmet_req *req, off_t off, const void *buf,
  86                 size_t len)
  87 {
  88         if (sg_pcopy_from_buffer(req->sg, req->sg_cnt, buf, len, off) != len) {
  89                 req->error_loc = offsetof(struct nvme_common_command, dptr);
  90                 return NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR;
  91         }
  92         return 0;
  93 }
  94
  95 u16 nvmet_copy_from_sgl(struct nvmet_req *req, off_t off, void *buf, size_t len)
  96 {
  97         if (sg_pcopy_to_buffer(req->sg, req->sg_cnt, buf, len, off) != len) {
  98                 req->error_loc = offsetof(struct nvme_common_command, dptr);
  99                 return NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR;
 100         }
 101         return 0;
 102 }
 103
 104 u16 nvmet_zero_sgl(struct nvmet_req *req, off_t off, size_t len)
 105 {
 106         if (sg_zero_buffer(req->sg, req->sg_cnt, len, off) != len) {
 107                 req->error_loc = offsetof(struct nvme_common_command, dptr);
 108                 return NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR;
 109         }
 110         return 0;
 111 }
 112
 113 static unsigned int nvmet_max_nsid(struct nvmet_subsys *subsys)
 114 {
 115         struct nvmet_ns *ns;
 116
 117         if (list_empty(&subsys->namespaces))
 118                 return 0;
 119
 120         ns = list_last_entry(&subsys->namespaces, struct nvmet_ns, dev_link);
 121         return ns->nsid;
 122 }
 123
 124 static u32 nvmet_async_event_result(struct nvmet_async_event *aen)
 125 {
 126         return aen->event_type | (aen->event_info << 8) | (aen->log_page << 16);
 127 }
 128
 129 static void nvmet_async_events_free(struct nvmet_ctrl *ctrl)
 130 {
 131         struct nvmet_req *req;
 132
 133         while (1) {
 134                 mutex_lock(&ctrl->lock);
 135                 if (!ctrl->nr_async_event_cmds) {
 136                         mutex_unlock(&ctrl->lock);
 137                         return;
 138                 }
 139
 140                 req = ctrl->async_event_cmds[--ctrl->nr_async_event_cmds];
 141                 mutex_unlock(&ctrl->lock);
 142                 nvmet_req_complete(req, NVME_SC_INTERNAL | NVME_SC_DNR);
 143         }
 144 }
 145
 146 static void nvmet_async_event_work(struct work_struct *work)
 147 {
 148         struct nvmet_ctrl *ctrl =
 149                 container_of(work, struct nvmet_ctrl, async_event_work);
 150         struct nvmet_async_event *aen;
 151         struct nvmet_req *req;
 152
 153         while (1) {
 154                 mutex_lock(&ctrl->lock);
 155                 aen = list_first_entry_or_null(&ctrl->async_events,
 156                                 struct nvmet_async_event, entry);
 157                 if (!aen || !ctrl->nr_async_event_cmds) {
 158                         mutex_unlock(&ctrl->lock);
 159                         return;
 160                 }
 161
 162                 req = ctrl->async_event_cmds[--ctrl->nr_async_event_cmds];
 163                 nvmet_set_result(req, nvmet_async_event_result(aen));
 164
 165                 list_del(&aen->entry);
 166                 kfree(aen);
 167
 168                 mutex_unlock(&ctrl->lock);
 169                 nvmet_req_complete(req, 0);
 170         }
 171 }
 172
 173 void nvmet_add_async_event(struct nvmet_ctrl *ctrl, u8 event_type,
 174                 u8 event_info, u8 log_page)
 175 {
 176         struct nvmet_async_event *aen;
 177
 178         aen = kmalloc(sizeof(*aen), GFP_KERNEL);
 179         if (!aen)
 180                 return;
 181
 182         aen->event_type = event_type;
 183         aen->event_info = event_info;
 184         aen->log_page = log_page;
 185
 186         mutex_lock(&ctrl->lock);
 187         list_add_tail(&aen->entry, &ctrl->async_events);
 188         mutex_unlock(&ctrl->lock);
 189
 190         schedule_work(&ctrl->async_event_work);
 191 }
 192
 193 static void nvmet_add_to_changed_ns_log(struct nvmet_ctrl *ctrl, __le32 nsid)
 194 {
 195         u32 i;
 196
 197         mutex_lock(&ctrl->lock);
 198         if (ctrl->nr_changed_ns > NVME_MAX_CHANGED_NAMESPACES)
 199                 goto out_unlock;
 200
 201         for (i = 0; i < ctrl->nr_changed_ns; i++) {
 202                 if (ctrl->changed_ns_list[i] == nsid)
 203                         goto out_unlock;
 204         }
 205
 206         if (ctrl->nr_changed_ns == NVME_MAX_CHANGED_NAMESPACES) {
 207                 ctrl->changed_ns_list[0] = cpu_to_le32(0xffffffff);
 208                 ctrl->nr_changed_ns = U32_MAX;
 209                 goto out_unlock;
 210         }
 211
 212         ctrl->changed_ns_list[ctrl->nr_changed_ns++] = nsid;
 213 out_unlock:
 214         mutex_unlock(&ctrl->lock);
 215 }
 216
 217 void nvmet_ns_changed(struct nvmet_subsys *subsys, u32 nsid)
 218 {
 219         struct nvmet_ctrl *ctrl;
 220
 221         lockdep_assert_held(&subsys->lock);
 222
 223         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
 224                 nvmet_add_to_changed_ns_log(ctrl, cpu_to_le32(nsid));
 225                 if (nvmet_aen_bit_disabled(ctrl, NVME_AEN_BIT_NS_ATTR))
 226                         continue;
 227                 nvmet_add_async_event(ctrl, NVME_AER_TYPE_NOTICE,
 228                                 NVME_AER_NOTICE_NS_CHANGED,
 229                                 NVME_LOG_CHANGED_NS);
 230         }
 231 }
 232
 233 void nvmet_send_ana_event(struct nvmet_subsys *subsys,
 234                 struct nvmet_port *port)
 235 {
 236         struct nvmet_ctrl *ctrl;
 237
 238         mutex_lock(&subsys->lock);
 239         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
 240                 if (port && ctrl->port != port)
 241                         continue;
 242                 if (nvmet_aen_bit_disabled(ctrl, NVME_AEN_BIT_ANA_CHANGE))
 243                         continue;
 244                 nvmet_add_async_event(ctrl, NVME_AER_TYPE_NOTICE,
 245                                 NVME_AER_NOTICE_ANA, NVME_LOG_ANA);
 246         }
 247         mutex_unlock(&subsys->lock);
 248 }
 249
 250 void nvmet_port_send_ana_event(struct nvmet_port *port)
 251 {
 252         struct nvmet_subsys_link *p;
 253
 254         down_read(&nvmet_config_sem);
 255         list_for_each_entry(p, &port->subsystems, entry)
 256                 nvmet_send_ana_event(p->subsys, port);
 257         up_read(&nvmet_config_sem);
 258 }
 259
 260 int nvmet_register_transport(const struct nvmet_fabrics_ops *ops)
 261 {
 262         int ret = 0;
 263
 264         down_write(&nvmet_config_sem);
 265         if (nvmet_transports[ops->type])
 266                 ret = -EINVAL;
 267         else
 268                 nvmet_transports[ops->type] = ops;
 269         up_write(&nvmet_config_sem);
 270
 271         return ret;
 272 }
 273 EXPORT_SYMBOL_GPL(nvmet_register_transport);
 274
 275 void nvmet_unregister_transport(const struct nvmet_fabrics_ops *ops)
 276 {
 277         down_write(&nvmet_config_sem);
 278         nvmet_transports[ops->type] = NULL;
 279         up_write(&nvmet_config_sem);
 280 }
 281 EXPORT_SYMBOL_GPL(nvmet_unregister_transport);
 282
 283 int nvmet_enable_port(struct nvmet_port *port)
 284 {
 285         const struct nvmet_fabrics_ops *ops;
 286         int ret;
 287
 288         lockdep_assert_held(&nvmet_config_sem);
 289
 290         ops = nvmet_transports[port->disc_addr.trtype];
 291         if (!ops) {
 292                 up_write(&nvmet_config_sem);
 293                 request_module("nvmet-transport-%d", port->disc_addr.trtype);
 294                 down_write(&nvmet_config_sem);
 295                 ops = nvmet_transports[port->disc_addr.trtype];
 296                 if (!ops) {
 297                         pr_err("transport type %d not supported\n",
 298                                 port->disc_addr.trtype);
 299                         return -EINVAL;
 300                 }
 301         }
 302
 303         if (!try_module_get(ops->owner))
 304                 return -EINVAL;
 305
 306         ret = ops->add_port(port);
 307         if (ret) {
 308                 module_put(ops->owner);
 309                 return ret;
 310         }
 311
 312         /* If the transport didn't set inline_data_size, then disable it. */
 313         if (port->inline_data_size < 0)
 314                 port->inline_data_size = 0;
 315
 316         port->enabled = true;
 317         port->tr_ops = ops;
 318         return 0;
 319 }
 320
 321 void nvmet_disable_port(struct nvmet_port *port)
 322 {
 323         const struct nvmet_fabrics_ops *ops;
 324
 325         lockdep_assert_held(&nvmet_config_sem);
 326
 327         port->enabled = false;
 328         port->tr_ops = NULL;
 329
 330         ops = nvmet_transports[port->disc_addr.trtype];
 331         ops->remove_port(port);
 332         module_put(ops->owner);
 333 }
 334
 335 static void nvmet_keep_alive_timer(struct work_struct *work)
 336 {
 337         struct nvmet_ctrl *ctrl = container_of(to_delayed_work(work),
 338                         struct nvmet_ctrl, ka_work);
 339         bool cmd_seen = ctrl->cmd_seen;
 340
 341         ctrl->cmd_seen = false;
 342         if (cmd_seen) {
 343                 pr_debug("ctrl %d reschedule traffic based keep-alive timer\n",
 344                         ctrl->cntlid);
 345                 schedule_delayed_work(&ctrl->ka_work, ctrl->kato * HZ);
 346                 return;
 347         }
 348
 349         pr_err("ctrl %d keep-alive timer (%d seconds) expired!\n",
 350                 ctrl->cntlid, ctrl->kato);
 351
 352         nvmet_ctrl_fatal_error(ctrl);
 353 }
 354
 355 static void nvmet_start_keep_alive_timer(struct nvmet_ctrl *ctrl)
 356 {
 357         pr_debug("ctrl %d start keep-alive timer for %d secs\n",
 358                 ctrl->cntlid, ctrl->kato);
 359
 360         INIT_DELAYED_WORK(&ctrl->ka_work, nvmet_keep_alive_timer);
 361         schedule_delayed_work(&ctrl->ka_work, ctrl->kato * HZ);
 362 }
 363
 364 static void nvmet_stop_keep_alive_timer(struct nvmet_ctrl *ctrl)
 365 {
 366         pr_debug("ctrl %d stop keep-alive\n", ctrl->cntlid);
 367
 368         cancel_delayed_work_sync(&ctrl->ka_work);
 369 }
 370
 371 static struct nvmet_ns *__nvmet_find_namespace(struct nvmet_ctrl *ctrl,
 372                 __le32 nsid)
 373 {
 374         struct nvmet_ns *ns;
 375
 376         list_for_each_entry_rcu(ns, &ctrl->subsys->namespaces, dev_link) {
 377                 if (ns->nsid == le32_to_cpu(nsid))
 378                         return ns;
 379         }
 380
 381         return NULL;
 382 }
 383
 384 struct nvmet_ns *nvmet_find_namespace(struct nvmet_ctrl *ctrl, __le32 nsid)
 385 {
 386         struct nvmet_ns *ns;
 387
 388         rcu_read_lock();
 389         ns = __nvmet_find_namespace(ctrl, nsid);
 390         if (ns)
 391                 percpu_ref_get(&ns->ref);
 392         rcu_read_unlock();
 393
 394         return ns;
 395 }
 396
 397 static void nvmet_destroy_namespace(struct percpu_ref *ref)
 398 {
 399         struct nvmet_ns *ns = container_of(ref, struct nvmet_ns, ref);
 400
 401         complete(&ns->disable_done);
 402 }
 403
 404 void nvmet_put_namespace(struct nvmet_ns *ns)
 405 {
 406         percpu_ref_put(&ns->ref);
 407 }
 408
 409 static void nvmet_ns_dev_disable(struct nvmet_ns *ns)
 410 {
 411         nvmet_bdev_ns_disable(ns);
 412         nvmet_file_ns_disable(ns);
 413 }
 414
 415 static int nvmet_p2pmem_ns_enable(struct nvmet_ns *ns)
 416 {
 417         int ret;
 418         struct pci_dev *p2p_dev;
 419
 420         if (!ns->use_p2pmem)
 421                 return 0;
 422
 423         if (!ns->bdev) {
 424                 pr_err("peer-to-peer DMA is not supported by non-block device namespaces\n");
 425                 return -EINVAL;
 426         }
 427
 428         if (!blk_queue_pci_p2pdma(ns->bdev->bd_queue)) {
 429                 pr_err("peer-to-peer DMA is not supported by the driver of %s\n",
 430                        ns->device_path);
 431                 return -EINVAL;
 432         }
 433
 434         if (ns->p2p_dev) {
 435                 ret = pci_p2pdma_distance(ns->p2p_dev, nvmet_ns_dev(ns), true);
 436                 if (ret < 0)
 437                         return -EINVAL;
 438         } else {
 439                 /*
 440                  * Right now we just check that there is p2pmem available so
 441                  * we can report an error to the user right away if there
 442                  * is not. We'll find the actual device to use once we
 443                  * setup the controller when the port's device is available.
 444                  */
 445
 446                 p2p_dev = pci_p2pmem_find(nvmet_ns_dev(ns));
 447                 if (!p2p_dev) {
 448                         pr_err("no peer-to-peer memory is available for %s\n",
 449                                ns->device_path);
 450                         return -EINVAL;
 451                 }
 452
 453                 pci_dev_put(p2p_dev);
 454         }
 455
 456         return 0;
 457 }
 458
 459 /*
 460  * Note: ctrl->subsys->lock should be held when calling this function
 461  */
 462 static void nvmet_p2pmem_ns_add_p2p(struct nvmet_ctrl *ctrl,
 463                                     struct nvmet_ns *ns)
 464 {
 465         struct device *clients[2];
 466         struct pci_dev *p2p_dev;
 467         int ret;
 468
 469         if (!ctrl->p2p_client || !ns->use_p2pmem)
 470                 return;
 471
 472         if (ns->p2p_dev) {
 473                 ret = pci_p2pdma_distance(ns->p2p_dev, ctrl->p2p_client, true);
 474                 if (ret < 0)
 475                         return;
 476
 477                 p2p_dev = pci_dev_get(ns->p2p_dev);
 478         } else {
 479                 clients[0] = ctrl->p2p_client;
 480                 clients[1] = nvmet_ns_dev(ns);
 481
 482                 p2p_dev = pci_p2pmem_find_many(clients, ARRAY_SIZE(clients));
 483                 if (!p2p_dev) {
 484                         pr_err("no peer-to-peer memory is available that's supported by %s and %s\n",
 485                                dev_name(ctrl->p2p_client), ns->device_path);
 486                         return;
 487                 }
 488         }
 489
 490         ret = radix_tree_insert(&ctrl->p2p_ns_map, ns->nsid, p2p_dev);
 491         if (ret < 0)
 492                 pci_dev_put(p2p_dev);
 493
 494         pr_info("using p2pmem on %s for nsid %d\n", pci_name(p2p_dev),
 495                 ns->nsid);
 496 }
 497
 498 int nvmet_ns_enable(struct nvmet_ns *ns)
 499 {
 500         struct nvmet_subsys *subsys = ns->subsys;
 501         struct nvmet_ctrl *ctrl;
 502         int ret;
 503
 504         mutex_lock(&subsys->lock);
 505         ret = 0;
 506         if (ns->enabled)
 507                 goto out_unlock;
 508
 509         ret = -EMFILE;
 510         if (subsys->nr_namespaces == NVMET_MAX_NAMESPACES)
 511                 goto out_unlock;
 512
 513         ret = nvmet_bdev_ns_enable(ns);
 514         if (ret == -ENOTBLK)
 515                 ret = nvmet_file_ns_enable(ns);
 516         if (ret)
 517                 goto out_unlock;
 518
 519         ret = nvmet_p2pmem_ns_enable(ns);
 520         if (ret)
 521                 goto out_dev_disable;
 522
 523         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry)
 524                 nvmet_p2pmem_ns_add_p2p(ctrl, ns);
 525
 526         ret = percpu_ref_init(&ns->ref, nvmet_destroy_namespace,
 527                                 0, GFP_KERNEL);
 528         if (ret)
 529                 goto out_dev_put;
 530
 531         if (ns->nsid > subsys->max_nsid)
 532                 subsys->max_nsid = ns->nsid;
 533
 534         /*
 535          * The namespaces list needs to be sorted to simplify the implementation
 536          * of the Identify Namepace List subcommand.
 537          */
 538         if (list_empty(&subsys->namespaces)) {
 539                 list_add_tail_rcu(&ns->dev_link, &subsys->namespaces);
 540         } else {
 541                 struct nvmet_ns *old;
 542
 543                 list_for_each_entry_rcu(old, &subsys->namespaces, dev_link) {
 544                         BUG_ON(ns->nsid == old->nsid);
 545                         if (ns->nsid < old->nsid)
 546                                 break;
 547                 }
 548
 549                 list_add_tail_rcu(&ns->dev_link, &old->dev_link);
 550         }
 551         subsys->nr_namespaces++;
 552
 553         nvmet_ns_changed(subsys, ns->nsid);
 554         ns->enabled = true;
 555         ret = 0;
 556 out_unlock:
 557         mutex_unlock(&subsys->lock);
 558         return ret;
 559 out_dev_put:
 560         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry)
 561                 pci_dev_put(radix_tree_delete(&ctrl->p2p_ns_map, ns->nsid));
 562 out_dev_disable:
 563         nvmet_ns_dev_disable(ns);
 564         goto out_unlock;
 565 }
 566
 567 void nvmet_ns_disable(struct nvmet_ns *ns)
 568 {
 569         struct nvmet_subsys *subsys = ns->subsys;
 570         struct nvmet_ctrl *ctrl;
 571
 572         mutex_lock(&subsys->lock);
 573         if (!ns->enabled)
 574                 goto out_unlock;
 575
 576         ns->enabled = false;
 577         list_del_rcu(&ns->dev_link);
 578         if (ns->nsid == subsys->max_nsid)
 579                 subsys->max_nsid = nvmet_max_nsid(subsys);
 580
 581         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry)
 582                 pci_dev_put(radix_tree_delete(&ctrl->p2p_ns_map, ns->nsid));
 583
 584         mutex_unlock(&subsys->lock);
 585
 586         /*
 587          * Now that we removed the namespaces from the lookup list, we
 588          * can kill the per_cpu ref and wait for any remaining references
 589          * to be dropped, as well as a RCU grace period for anyone only
 590          * using the namepace under rcu_read_lock().  Note that we can't
 591          * use call_rcu here as we need to ensure the namespaces have
 592          * been fully destroyed before unloading the module.
 593          */
 594         percpu_ref_kill(&ns->ref);
 595         synchronize_rcu();
 596         wait_for_completion(&ns->disable_done);
 597         percpu_ref_exit(&ns->ref);
 598
 599         mutex_lock(&subsys->lock);
 600
 601         subsys->nr_namespaces--;
 602         nvmet_ns_changed(subsys, ns->nsid);
 603         nvmet_ns_dev_disable(ns);
 604 out_unlock:
 605         mutex_unlock(&subsys->lock);
 606 }
 607
 608 void nvmet_ns_free(struct nvmet_ns *ns)
 609 {
 610         nvmet_ns_disable(ns);
 611
 612         down_write(&nvmet_ana_sem);
 613         nvmet_ana_group_enabled[ns->anagrpid]--;
 614         up_write(&nvmet_ana_sem);
 615
 616         kfree(ns->device_path);
 617         kfree(ns);
 618 }
 619
 620 struct nvmet_ns *nvmet_ns_alloc(struct nvmet_subsys *subsys, u32 nsid)
 621 {
 622         struct nvmet_ns *ns;
 623
 624         ns = kzalloc(sizeof(*ns), GFP_KERNEL);
 625         if (!ns)
 626                 return NULL;
 627
 628         INIT_LIST_HEAD(&ns->dev_link);
 629         init_completion(&ns->disable_done);
 630
 631         ns->nsid = nsid;
 632         ns->subsys = subsys;
 633
 634         down_write(&nvmet_ana_sem);
 635         ns->anagrpid = NVMET_DEFAULT_ANA_GRPID;
 636         nvmet_ana_group_enabled[ns->anagrpid]++;
 637         up_write(&nvmet_ana_sem);
 638
 639         uuid_gen(&ns->uuid);
 640         ns->buffered_io = false;
 641
 642         return ns;
 643 }
 644
 645 static void nvmet_update_sq_head(struct nvmet_req *req)
 646 {
 647         if (req->sq->size) {
 648                 u32 old_sqhd, new_sqhd;
 649
 650                 do {
 651                         old_sqhd = req->sq->sqhd;
 652                         new_sqhd = (old_sqhd + 1) % req->sq->size;
 653                 } while (cmpxchg(&req->sq->sqhd, old_sqhd, new_sqhd) !=
 654                                         old_sqhd);
 655         }
 656         req->cqe->sq_head = cpu_to_le16(req->sq->sqhd & 0x0000FFFF);
 657 }
 658
 659 static void nvmet_set_error(struct nvmet_req *req, u16 status)
 660 {
 661         struct nvmet_ctrl *ctrl = req->sq->ctrl;
 662         struct nvme_error_slot *new_error_slot;
 663         unsigned long flags;
 664
 665         req->cqe->status = cpu_to_le16(status << 1);
 666
 667         if (!ctrl || req->error_loc == NVMET_NO_ERROR_LOC)
 668                 return;
 669
 670         spin_lock_irqsave(&ctrl->error_lock, flags);
 671         ctrl->err_counter++;
 672         new_error_slot =
 673                 &ctrl->slots[ctrl->err_counter % NVMET_ERROR_LOG_SLOTS];
 674
 675         new_error_slot->error_count = cpu_to_le64(ctrl->err_counter);
 676         new_error_slot->sqid = cpu_to_le16(req->sq->qid);
 677         new_error_slot->cmdid = cpu_to_le16(req->cmd->common.command_id);
 678         new_error_slot->status_field = cpu_to_le16(status << 1);
 679         new_error_slot->param_error_location = cpu_to_le16(req->error_loc);
 680         new_error_slot->lba = cpu_to_le64(req->error_slba);
 681         new_error_slot->nsid = req->cmd->common.nsid;
 682         spin_unlock_irqrestore(&ctrl->error_lock, flags);
 683
 684         /* set the more bit for this request */
 685         req->cqe->status |= cpu_to_le16(1 << 14);
 686 }
 687
 688 static void __nvmet_req_complete(struct nvmet_req *req, u16 status)
 689 {
 690         if (!req->sq->sqhd_disabled)
 691                 nvmet_update_sq_head(req);
 692         req->cqe->sq_id = cpu_to_le16(req->sq->qid);
 693         req->cqe->command_id = req->cmd->common.command_id;
 694
 695         if (unlikely(status))
 696                 nvmet_set_error(req, status);
 697
 698         trace_nvmet_req_complete(req);
 699
 700         if (req->ns)
 701                 nvmet_put_namespace(req->ns);
 702         req->ops->queue_response(req);
 703 }
 704
 705 void nvmet_req_complete(struct nvmet_req *req, u16 status)
 706 {
 707         __nvmet_req_complete(req, status);
 708         percpu_ref_put(&req->sq->ref);
 709 }
 710 EXPORT_SYMBOL_GPL(nvmet_req_complete);
 711
 712 void nvmet_cq_setup(struct nvmet_ctrl *ctrl, struct nvmet_cq *cq,
 713                 u16 qid, u16 size)
 714 {
 715         cq->qid = qid;
 716         cq->size = size;
 717
 718         ctrl->cqs[qid] = cq;
 719 }
 720
 721 void nvmet_sq_setup(struct nvmet_ctrl *ctrl, struct nvmet_sq *sq,
 722                 u16 qid, u16 size)
 723 {
 724         sq->sqhd = 0;
 725         sq->qid = qid;
 726         sq->size = size;
 727
 728         ctrl->sqs[qid] = sq;
 729 }
 730
 731 static void nvmet_confirm_sq(struct percpu_ref *ref)
 732 {
 733         struct nvmet_sq *sq = container_of(ref, struct nvmet_sq, ref);
 734
 735         complete(&sq->confirm_done);
 736 }
 737
 738 void nvmet_sq_destroy(struct nvmet_sq *sq)
 739 {
 740         /*
 741          * If this is the admin queue, complete all AERs so that our
 742          * queue doesn't have outstanding requests on it.
 743          */
 744         if (sq->ctrl && sq->ctrl->sqs && sq->ctrl->sqs[0] == sq)
 745                 nvmet_async_events_free(sq->ctrl);
 746         percpu_ref_kill_and_confirm(&sq->ref, nvmet_confirm_sq);
 747         wait_for_completion(&sq->confirm_done);
 748         wait_for_completion(&sq->free_done);
 749         percpu_ref_exit(&sq->ref);
 750
 751         if (sq->ctrl) {
 752                 nvmet_ctrl_put(sq->ctrl);
 753                 sq->ctrl = NULL; /* allows reusing the queue later */
 754         }
 755 }
 756 EXPORT_SYMBOL_GPL(nvmet_sq_destroy);
 757
 758 static void nvmet_sq_free(struct percpu_ref *ref)
 759 {
 760         struct nvmet_sq *sq = container_of(ref, struct nvmet_sq, ref);
 761
 762         complete(&sq->free_done);
 763 }
 764
 765 int nvmet_sq_init(struct nvmet_sq *sq)
 766 {
 767         int ret;
 768
 769         ret = percpu_ref_init(&sq->ref, nvmet_sq_free, 0, GFP_KERNEL);
 770         if (ret) {
 771                 pr_err("percpu_ref init failed!\n");
 772                 return ret;
 773         }
 774         init_completion(&sq->free_done);
 775         init_completion(&sq->confirm_done);
 776
 777         return 0;
 778 }
 779 EXPORT_SYMBOL_GPL(nvmet_sq_init);
 780
 781 static inline u16 nvmet_check_ana_state(struct nvmet_port *port,
 782                 struct nvmet_ns *ns)
 783 {
 784         enum nvme_ana_state state = port->ana_state[ns->anagrpid];
 785
 786         if (unlikely(state == NVME_ANA_INACCESSIBLE))
 787                 return NVME_SC_ANA_INACCESSIBLE;
 788         if (unlikely(state == NVME_ANA_PERSISTENT_LOSS))
 789                 return NVME_SC_ANA_PERSISTENT_LOSS;
 790         if (unlikely(state == NVME_ANA_CHANGE))
 791                 return NVME_SC_ANA_TRANSITION;
 792         return 0;
 793 }
 794
 795 static inline u16 nvmet_io_cmd_check_access(struct nvmet_req *req)
 796 {
 797         if (unlikely(req->ns->readonly)) {
 798                 switch (req->cmd->common.opcode) {
 799                 case nvme_cmd_read:
 800                 case nvme_cmd_flush:
 801                         break;
 802                 default:
 803                         return NVME_SC_NS_WRITE_PROTECTED;
 804                 }
 805         }
 806
 807         return 0;
 808 }
 809
 810 static u16 nvmet_parse_io_cmd(struct nvmet_req *req)
 811 {
 812         struct nvme_command *cmd = req->cmd;
 813         u16 ret;
 814
 815         ret = nvmet_check_ctrl_status(req, cmd);
 816         if (unlikely(ret))
 817                 return ret;
 818
 819         req->ns = nvmet_find_namespace(req->sq->ctrl, cmd->rw.nsid);
 820         if (unlikely(!req->ns)) {
 821                 req->error_loc = offsetof(struct nvme_common_command, nsid);
 822                 return NVME_SC_INVALID_NS | NVME_SC_DNR;
 823         }
 824         ret = nvmet_check_ana_state(req->port, req->ns);
 825         if (unlikely(ret)) {
 826                 req->error_loc = offsetof(struct nvme_common_command, nsid);
 827                 return ret;
 828         }
 829         ret = nvmet_io_cmd_check_access(req);
 830         if (unlikely(ret)) {
 831                 req->error_loc = offsetof(struct nvme_common_command, nsid);
 832                 return ret;
 833         }
 834
 835         if (req->ns->file)
 836                 return nvmet_file_parse_io_cmd(req);
 837         else
 838                 return nvmet_bdev_parse_io_cmd(req);
 839 }
 840
 841 bool nvmet_req_init(struct nvmet_req *req, struct nvmet_cq *cq,
 842                 struct nvmet_sq *sq, const struct nvmet_fabrics_ops *ops)
 843 {
 844         u8 flags = req->cmd->common.flags;
 845         u16 status;
 846
 847         req->cq = cq;
 848         req->sq = sq;
 849         req->ops = ops;
 850         req->sg = NULL;
 851         req->sg_cnt = 0;
 852         req->transfer_len = 0;
 853         req->cqe->status = 0;
 854         req->cqe->sq_head = 0;
 855         req->ns = NULL;
 856         req->error_loc = NVMET_NO_ERROR_LOC;
 857         req->error_slba = 0;
 858
 859         trace_nvmet_req_init(req, req->cmd);
 860
 861         /* no support for fused commands yet */
 862         if (unlikely(flags & (NVME_CMD_FUSE_FIRST | NVME_CMD_FUSE_SECOND))) {
 863                 req->error_loc = offsetof(struct nvme_common_command, flags);
 864                 status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 865                 goto fail;
 866         }
 867
 868         /*
 869          * For fabrics, PSDT field shall describe metadata pointer (MPTR) that
 870          * contains an address of a single contiguous physical buffer that is
 871          * byte aligned.
 872          */
 873         if (unlikely((flags & NVME_CMD_SGL_ALL) != NVME_CMD_SGL_METABUF)) {
 874                 req->error_loc = offsetof(struct nvme_common_command, flags);
 875                 status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 876                 goto fail;
 877         }
 878
 879         if (unlikely(!req->sq->ctrl))
 880                 /* will return an error for any Non-connect command: */
 881                 status = nvmet_parse_connect_cmd(req);
 882         else if (likely(req->sq->qid != 0))
 883                 status = nvmet_parse_io_cmd(req);
 884         else if (nvme_is_fabrics(req->cmd))
 885                 status = nvmet_parse_fabrics_cmd(req);
 886         else if (req->sq->ctrl->subsys->type == NVME_NQN_DISC)
 887                 status = nvmet_parse_discovery_cmd(req);
 888         else
 889                 status = nvmet_parse_admin_cmd(req);
 890
 891         if (status)
 892                 goto fail;
 893
 894         if (unlikely(!percpu_ref_tryget_live(&sq->ref))) {
 895                 status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 896                 goto fail;
 897         }
 898
 899         if (sq->ctrl)
 900                 sq->ctrl->cmd_seen = true;
 901
 902         return true;
 903
 904 fail:
 905         __nvmet_req_complete(req, status);
 906         return false;
 907 }
 908 EXPORT_SYMBOL_GPL(nvmet_req_init);
 909
 910 void nvmet_req_uninit(struct nvmet_req *req)
 911 {
 912         percpu_ref_put(&req->sq->ref);
 913         if (req->ns)
 914                 nvmet_put_namespace(req->ns);
 915 }
 916 EXPORT_SYMBOL_GPL(nvmet_req_uninit);
 917
 918 void nvmet_req_execute(struct nvmet_req *req)
 919 {
 920         if (unlikely(req->data_len != req->transfer_len)) {
 921                 req->error_loc = offsetof(struct nvme_common_command, dptr);
 922                 nvmet_req_complete(req, NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR);
 923         } else
 924                 req->execute(req);
 925 }
 926 EXPORT_SYMBOL_GPL(nvmet_req_execute);
 927
 928 int nvmet_req_alloc_sgl(struct nvmet_req *req)
 929 {
 930         struct pci_dev *p2p_dev = NULL;
 931
 932         if (IS_ENABLED(CONFIG_PCI_P2PDMA)) {
 933                 if (req->sq->ctrl && req->ns)
 934                         p2p_dev = radix_tree_lookup(&req->sq->ctrl->p2p_ns_map,
 935                                                     req->ns->nsid);
 936
 937                 req->p2p_dev = NULL;
 938                 if (req->sq->qid && p2p_dev) {
 939                         req->sg = pci_p2pmem_alloc_sgl(p2p_dev, &req->sg_cnt,
 940                                                        req->transfer_len);
 941                         if (req->sg) {
 942                                 req->p2p_dev = p2p_dev;
 943                                 return 0;
 944                         }
 945                 }
 946
 947                 /*
 948                  * If no P2P memory was available we fallback to using
 949                  * regular memory
 950                  */
 951         }
 952
 953         req->sg = sgl_alloc(req->transfer_len, GFP_KERNEL, &req->sg_cnt);
 954         if (!req->sg)
 955                 return -ENOMEM;
 956
 957         return 0;
 958 }
 959 EXPORT_SYMBOL_GPL(nvmet_req_alloc_sgl);
 960
 961 void nvmet_req_free_sgl(struct nvmet_req *req)
 962 {
 963         if (req->p2p_dev)
 964                 pci_p2pmem_free_sgl(req->p2p_dev, req->sg);
 965         else
 966                 sgl_free(req->sg);
 967
 968         req->sg = NULL;
 969         req->sg_cnt = 0;
 970 }
 971 EXPORT_SYMBOL_GPL(nvmet_req_free_sgl);
 972
 973 static inline bool nvmet_cc_en(u32 cc)
 974 {
 975         return (cc >> NVME_CC_EN_SHIFT) & 0x1;
 976 }
 977
 978 static inline u8 nvmet_cc_css(u32 cc)
 979 {
 980         return (cc >> NVME_CC_CSS_SHIFT) & 0x7;
 981 }
 982
 983 static inline u8 nvmet_cc_mps(u32 cc)
 984 {
 985         return (cc >> NVME_CC_MPS_SHIFT) & 0xf;
 986 }
 987
 988 static inline u8 nvmet_cc_ams(u32 cc)
 989 {
 990         return (cc >> NVME_CC_AMS_SHIFT) & 0x7;
 991 }
 992
 993 static inline u8 nvmet_cc_shn(u32 cc)
 994 {
 995         return (cc >> NVME_CC_SHN_SHIFT) & 0x3;
 996 }
 997
 998 static inline u8 nvmet_cc_iosqes(u32 cc)
 999 {
1000         return (cc >> NVME_CC_IOSQES_SHIFT) & 0xf;
1001 }
1002
1003 static inline u8 nvmet_cc_iocqes(u32 cc)
1004 {
1005         return (cc >> NVME_CC_IOCQES_SHIFT) & 0xf;
1006 }
1007
1008 static void nvmet_start_ctrl(struct nvmet_ctrl *ctrl)
1009 {
1010         lockdep_assert_held(&ctrl->lock);
1011
1012         if (nvmet_cc_iosqes(ctrl->cc) != NVME_NVM_IOSQES ||
1013             nvmet_cc_iocqes(ctrl->cc) != NVME_NVM_IOCQES ||
1014             nvmet_cc_mps(ctrl->cc) != 0 ||
1015             nvmet_cc_ams(ctrl->cc) != 0 ||
1016             nvmet_cc_css(ctrl->cc) != 0) {
1017                 ctrl->csts = NVME_CSTS_CFS;
1018                 return;
1019         }
1020
1021         ctrl->csts = NVME_CSTS_RDY;
1022
1023         /*
1024          * Controllers that are not yet enabled should not really enforce the
1025          * keep alive timeout, but we still want to track a timeout and cleanup
1026          * in case a host died before it enabled the controller.  Hence, simply
1027          * reset the keep alive timer when the controller is enabled.
1028          */
1029         mod_delayed_work(system_wq, &ctrl->ka_work, ctrl->kato * HZ);
1030 }
1031
1032 static void nvmet_clear_ctrl(struct nvmet_ctrl *ctrl)
1033 {
1034         lockdep_assert_held(&ctrl->lock);
1035
1036         /* XXX: tear down queues? */
1037         ctrl->csts &= ~NVME_CSTS_RDY;
1038         ctrl->cc = 0;
1039 }
1040
1041 void nvmet_update_cc(struct nvmet_ctrl *ctrl, u32 new)
1042 {
1043         u32 old;
1044
1045         mutex_lock(&ctrl->lock);
1046         old = ctrl->cc;
1047         ctrl->cc = new;
1048
1049         if (nvmet_cc_en(new) && !nvmet_cc_en(old))
1050                 nvmet_start_ctrl(ctrl);
1051         if (!nvmet_cc_en(new) && nvmet_cc_en(old))
1052                 nvmet_clear_ctrl(ctrl);
1053         if (nvmet_cc_shn(new) && !nvmet_cc_shn(old)) {
1054                 nvmet_clear_ctrl(ctrl);
1055                 ctrl->csts |= NVME_CSTS_SHST_CMPLT;
1056         }
1057         if (!nvmet_cc_shn(new) && nvmet_cc_shn(old))
1058                 ctrl->csts &= ~NVME_CSTS_SHST_CMPLT;
1059         mutex_unlock(&ctrl->lock);
1060 }
1061
1062 static void nvmet_init_cap(struct nvmet_ctrl *ctrl)
1063 {
1064         /* command sets supported: NVMe command set: */
1065         ctrl->cap = (1ULL << 37);
1066         /* CC.EN timeout in 500msec units: */
1067         ctrl->cap |= (15ULL << 24);
1068         /* maximum queue entries supported: */
1069         ctrl->cap |= NVMET_QUEUE_SIZE - 1;
1070 }
1071
1072 u16 nvmet_ctrl_find_get(const char *subsysnqn, const char *hostnqn, u16 cntlid,
1073                 struct nvmet_req *req, struct nvmet_ctrl **ret)
1074 {
1075         struct nvmet_subsys *subsys;
1076         struct nvmet_ctrl *ctrl;
1077         u16 status = 0;
1078
1079         subsys = nvmet_find_get_subsys(req->port, subsysnqn);
1080         if (!subsys) {
1081                 pr_warn("connect request for invalid subsystem %s!\n",
1082                         subsysnqn);
1083                 req->cqe->result.u32 = IPO_IATTR_CONNECT_DATA(subsysnqn);
1084                 return NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR;
1085         }
1086
1087         mutex_lock(&subsys->lock);
1088         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
1089                 if (ctrl->cntlid == cntlid) {
1090                         if (strncmp(hostnqn, ctrl->hostnqn, NVMF_NQN_SIZE)) {
1091                                 pr_warn("hostnqn mismatch.\n");
1092                                 continue;
1093                         }
1094                         if (!kref_get_unless_zero(&ctrl->ref))
1095                                 continue;
1096
1097                         *ret = ctrl;
1098                         goto out;
1099                 }
1100         }
1101
1102         pr_warn("could not find controller %d for subsys %s / host %s\n",
1103                 cntlid, subsysnqn, hostnqn);
1104         req->cqe->result.u32 = IPO_IATTR_CONNECT_DATA(cntlid);
1105         status = NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR;
1106
1107 out:
1108         mutex_unlock(&subsys->lock);
1109         nvmet_subsys_put(subsys);
1110         return status;
1111 }
1112
1113 u16 nvmet_check_ctrl_status(struct nvmet_req *req, struct nvme_command *cmd)
1114 {
1115         if (unlikely(!(req->sq->ctrl->cc & NVME_CC_ENABLE))) {
1116                 pr_err("got cmd %d while CC.EN == 0 on qid = %d\n",
1117                        cmd->common.opcode, req->sq->qid);
1118                 return NVME_SC_CMD_SEQ_ERROR | NVME_SC_DNR;
1119         }
1120
1121         if (unlikely(!(req->sq->ctrl->csts & NVME_CSTS_RDY))) {
1122                 pr_err("got cmd %d while CSTS.RDY == 0 on qid = %d\n",
1123                        cmd->common.opcode, req->sq->qid);
1124                 return NVME_SC_CMD_SEQ_ERROR | NVME_SC_DNR;
1125         }
1126         return 0;
1127 }
1128
1129 bool nvmet_host_allowed(struct nvmet_subsys *subsys, const char *hostnqn)
1130 {
1131         struct nvmet_host_link *p;
1132
1133         lockdep_assert_held(&nvmet_config_sem);
1134
1135         if (subsys->allow_any_host)
1136                 return true;
1137
1138         if (subsys->type == NVME_NQN_DISC) /* allow all access to disc subsys */
1139                 return true;
1140
1141         list_for_each_entry(p, &subsys->hosts, entry) {
1142                 if (!strcmp(nvmet_host_name(p->host), hostnqn))
1143                         return true;
1144         }
1145
1146         return false;
1147 }
1148
1149 /*
1150  * Note: ctrl->subsys->lock should be held when calling this function
1151  */
1152 static void nvmet_setup_p2p_ns_map(struct nvmet_ctrl *ctrl,
1153                 struct nvmet_req *req)
1154 {
1155         struct nvmet_ns *ns;
1156
1157         if (!req->p2p_client)
1158                 return;
1159
1160         ctrl->p2p_client = get_device(req->p2p_client);
1161
1162         list_for_each_entry_rcu(ns, &ctrl->subsys->namespaces, dev_link)
1163                 nvmet_p2pmem_ns_add_p2p(ctrl, ns);
1164 }
1165
1166 /*
1167  * Note: ctrl->subsys->lock should be held when calling this function
1168  */
1169 static void nvmet_release_p2p_ns_map(struct nvmet_ctrl *ctrl)
1170 {
1171         struct radix_tree_iter iter;
1172         void __rcu **slot;
1173
1174         radix_tree_for_each_slot(slot, &ctrl->p2p_ns_map, &iter, 0)
1175                 pci_dev_put(radix_tree_deref_slot(slot));
1176
1177         put_device(ctrl->p2p_client);
1178 }
1179
1180 static void nvmet_fatal_error_handler(struct work_struct *work)
1181 {
1182         struct nvmet_ctrl *ctrl =
1183                         container_of(work, struct nvmet_ctrl, fatal_err_work);
1184
1185         pr_err("ctrl %d fatal error occurred!\n", ctrl->cntlid);
1186         ctrl->ops->delete_ctrl(ctrl);
1187 }
1188
1189 u16 nvmet_alloc_ctrl(const char *subsysnqn, const char *hostnqn,
1190                 struct nvmet_req *req, u32 kato, struct nvmet_ctrl **ctrlp)
1191 {
1192         struct nvmet_subsys *subsys;
1193         struct nvmet_ctrl *ctrl;
1194         int ret;
1195         u16 status;
1196
1197         status = NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR;
1198         subsys = nvmet_find_get_subsys(req->port, subsysnqn);
1199         if (!subsys) {
1200                 pr_warn("connect request for invalid subsystem %s!\n",
1201                         subsysnqn);
1202                 req->cqe->result.u32 = IPO_IATTR_CONNECT_DATA(subsysnqn);
1203                 goto out;
1204         }
1205
1206         status = NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR;
1207         down_read(&nvmet_config_sem);
1208         if (!nvmet_host_allowed(subsys, hostnqn)) {
1209                 pr_info("connect by host %s for subsystem %s not allowed\n",
1210                         hostnqn, subsysnqn);
1211                 req->cqe->result.u32 = IPO_IATTR_CONNECT_DATA(hostnqn);
1212                 up_read(&nvmet_config_sem);
1213                 status = NVME_SC_CONNECT_INVALID_HOST | NVME_SC_DNR;
1214                 goto out_put_subsystem;
1215         }
1216         up_read(&nvmet_config_sem);
1217
1218         status = NVME_SC_INTERNAL;
1219         ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
1220         if (!ctrl)
1221                 goto out_put_subsystem;
1222         mutex_init(&ctrl->lock);
1223
1224         nvmet_init_cap(ctrl);
1225
1226         ctrl->port = req->port;
1227
1228         INIT_WORK(&ctrl->async_event_work, nvmet_async_event_work);
1229         INIT_LIST_HEAD(&ctrl->async_events);
1230         INIT_RADIX_TREE(&ctrl->p2p_ns_map, GFP_KERNEL);
1231         INIT_WORK(&ctrl->fatal_err_work, nvmet_fatal_error_handler);
1232
1233         memcpy(ctrl->subsysnqn, subsysnqn, NVMF_NQN_SIZE);
1234         memcpy(ctrl->hostnqn, hostnqn, NVMF_NQN_SIZE);
1235
1236         kref_init(&ctrl->ref);
1237         ctrl->subsys = subsys;
1238         WRITE_ONCE(ctrl->aen_enabled, NVMET_AEN_CFG_OPTIONAL);
1239
1240         ctrl->changed_ns_list = kmalloc_array(NVME_MAX_CHANGED_NAMESPACES,
1241                         sizeof(__le32), GFP_KERNEL);
1242         if (!ctrl->changed_ns_list)
1243                 goto out_free_ctrl;
1244
1245         ctrl->cqs = kcalloc(subsys->max_qid + 1,
1246                         sizeof(struct nvmet_cq *),
1247                         GFP_KERNEL);
1248         if (!ctrl->cqs)
1249                 goto out_free_changed_ns_list;
1250
1251         ctrl->sqs = kcalloc(subsys->max_qid + 1,
1252                         sizeof(struct nvmet_sq *),
1253                         GFP_KERNEL);
1254         if (!ctrl->sqs)
1255                 goto out_free_cqs;
1256
1257         ret = ida_simple_get(&cntlid_ida,
1258                              NVME_CNTLID_MIN, NVME_CNTLID_MAX,
1259                              GFP_KERNEL);
1260         if (ret < 0) {
1261                 status = NVME_SC_CONNECT_CTRL_BUSY | NVME_SC_DNR;
1262                 goto out_free_sqs;
1263         }
1264         ctrl->cntlid = ret;
1265
1266         ctrl->ops = req->ops;
1267
1268         /*
1269          * Discovery controllers may use some arbitrary high value
1270          * in order to cleanup stale discovery sessions
1271          */
1272         if ((ctrl->subsys->type == NVME_NQN_DISC) && !kato)
1273                 kato = NVMET_DISC_KATO_MS;
1274
1275         /* keep-alive timeout in seconds */
1276         ctrl->kato = DIV_ROUND_UP(kato, 1000);
1277
1278         ctrl->err_counter = 0;
1279         spin_lock_init(&ctrl->error_lock);
1280
1281         nvmet_start_keep_alive_timer(ctrl);
1282
1283         mutex_lock(&subsys->lock);
1284         list_add_tail(&ctrl->subsys_entry, &subsys->ctrls);
1285         nvmet_setup_p2p_ns_map(ctrl, req);
1286         mutex_unlock(&subsys->lock);
1287
1288         *ctrlp = ctrl;
1289         return 0;
1290
1291 out_free_sqs:
1292         kfree(ctrl->sqs);
1293 out_free_cqs:
1294         kfree(ctrl->cqs);
1295 out_free_changed_ns_list:
1296         kfree(ctrl->changed_ns_list);
1297 out_free_ctrl:
1298         kfree(ctrl);
1299 out_put_subsystem:
1300         nvmet_subsys_put(subsys);
1301 out:
1302         return status;
1303 }
1304
1305 static void nvmet_ctrl_free(struct kref *ref)
1306 {
1307         struct nvmet_ctrl *ctrl = container_of(ref, struct nvmet_ctrl, ref);
1308         struct nvmet_subsys *subsys = ctrl->subsys;
1309
1310         mutex_lock(&subsys->lock);
1311         nvmet_release_p2p_ns_map(ctrl);
1312         list_del(&ctrl->subsys_entry);
1313         mutex_unlock(&subsys->lock);
1314
1315         nvmet_stop_keep_alive_timer(ctrl);
1316
1317         flush_work(&ctrl->async_event_work);
1318         cancel_work_sync(&ctrl->fatal_err_work);
1319
1320         ida_simple_remove(&cntlid_ida, ctrl->cntlid);
1321
1322         kfree(ctrl->sqs);
1323         kfree(ctrl->cqs);
1324         kfree(ctrl->changed_ns_list);
1325         kfree(ctrl);
1326
1327         nvmet_subsys_put(subsys);
1328 }
1329
1330 void nvmet_ctrl_put(struct nvmet_ctrl *ctrl)
1331 {
1332         kref_put(&ctrl->ref, nvmet_ctrl_free);
1333 }
1334
1335 void nvmet_ctrl_fatal_error(struct nvmet_ctrl *ctrl)
1336 {
1337         mutex_lock(&ctrl->lock);
1338         if (!(ctrl->csts & NVME_CSTS_CFS)) {
1339                 ctrl->csts |= NVME_CSTS_CFS;
1340                 schedule_work(&ctrl->fatal_err_work);
1341         }
1342         mutex_unlock(&ctrl->lock);
1343 }
1344 EXPORT_SYMBOL_GPL(nvmet_ctrl_fatal_error);
1345
1346 static struct nvmet_subsys *nvmet_find_get_subsys(struct nvmet_port *port,
1347                 const char *subsysnqn)
1348 {
1349         struct nvmet_subsys_link *p;
1350
1351         if (!port)
1352                 return NULL;
1353
1354         if (!strcmp(NVME_DISC_SUBSYS_NAME, subsysnqn)) {
1355                 if (!kref_get_unless_zero(&nvmet_disc_subsys->ref))
1356                         return NULL;
1357                 return nvmet_disc_subsys;
1358         }
1359
1360         down_read(&nvmet_config_sem);
1361         list_for_each_entry(p, &port->subsystems, entry) {
1362                 if (!strncmp(p->subsys->subsysnqn, subsysnqn,
1363                                 NVMF_NQN_SIZE)) {
1364                         if (!kref_get_unless_zero(&p->subsys->ref))
1365                                 break;
1366                         up_read(&nvmet_config_sem);
1367                         return p->subsys;
1368                 }
1369         }
1370         up_read(&nvmet_config_sem);
1371         return NULL;
1372 }
1373
1374 struct nvmet_subsys *nvmet_subsys_alloc(const char *subsysnqn,
1375                 enum nvme_subsys_type type)
1376 {
1377         struct nvmet_subsys *subsys;
1378
1379         subsys = kzalloc(sizeof(*subsys), GFP_KERNEL);
1380         if (!subsys)
1381                 return ERR_PTR(-ENOMEM);
1382
1383         subsys->ver = NVME_VS(1, 3, 0); /* NVMe 1.3.0 */
1384         /* generate a random serial number as our controllers are ephemeral: */
1385         get_random_bytes(&subsys->serial, sizeof(subsys->serial));
1386
1387         switch (type) {
1388         case NVME_NQN_NVME:
1389                 subsys->max_qid = NVMET_NR_QUEUES;
1390                 break;
1391         case NVME_NQN_DISC:
1392                 subsys->max_qid = 0;
1393                 break;
1394         default:
1395                 pr_err("%s: Unknown Subsystem type - %d\n", __func__, type);
1396                 kfree(subsys);
1397                 return ERR_PTR(-EINVAL);
1398         }
1399         subsys->type = type;
1400         subsys->subsysnqn = kstrndup(subsysnqn, NVMF_NQN_SIZE,
1401                         GFP_KERNEL);
1402         if (!subsys->subsysnqn) {
1403                 kfree(subsys);
1404                 return ERR_PTR(-ENOMEM);
1405         }
1406
1407         kref_init(&subsys->ref);
1408
1409         mutex_init(&subsys->lock);
1410         INIT_LIST_HEAD(&subsys->namespaces);
1411         INIT_LIST_HEAD(&subsys->ctrls);
1412         INIT_LIST_HEAD(&subsys->hosts);
1413
1414         return subsys;
1415 }
1416
1417 static void nvmet_subsys_free(struct kref *ref)
1418 {
1419         struct nvmet_subsys *subsys =
1420                 container_of(ref, struct nvmet_subsys, ref);
1421
1422         WARN_ON_ONCE(!list_empty(&subsys->namespaces));
1423
1424         kfree(subsys->subsysnqn);
1425         kfree(subsys);
1426 }
1427
1428 void nvmet_subsys_del_ctrls(struct nvmet_subsys *subsys)
1429 {
1430         struct nvmet_ctrl *ctrl;
1431
1432         mutex_lock(&subsys->lock);
1433         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry)
1434                 ctrl->ops->delete_ctrl(ctrl);
1435         mutex_unlock(&subsys->lock);
1436 }
1437
1438 void nvmet_subsys_put(struct nvmet_subsys *subsys)
1439 {
1440         kref_put(&subsys->ref, nvmet_subsys_free);
1441 }
1442
1443 static int __init nvmet_init(void)
1444 {
1445         int error;
1446
1447         nvmet_ana_group_enabled[NVMET_DEFAULT_ANA_GRPID] = 1;
1448
1449         buffered_io_wq = alloc_workqueue("nvmet-buffered-io-wq",
1450                         WQ_MEM_RECLAIM, 0);
1451         if (!buffered_io_wq) {
1452                 error = -ENOMEM;
1453                 goto out;
1454         }
1455
1456         error = nvmet_init_discovery();
1457         if (error)
1458                 goto out_free_work_queue;
1459
1460         error = nvmet_init_configfs();
1461         if (error)
1462                 goto out_exit_discovery;
1463         return 0;
1464
1465 out_exit_discovery:
1466         nvmet_exit_discovery();
1467 out_free_work_queue:
1468         destroy_workqueue(buffered_io_wq);
1469 out:
1470         return error;
1471 }
1472
1473 static void __exit nvmet_exit(void)
1474 {
1475         nvmet_exit_configfs();
1476         nvmet_exit_discovery();
1477         ida_destroy(&cntlid_ida);
1478         destroy_workqueue(buffered_io_wq);
1479
1480         BUILD_BUG_ON(sizeof(struct nvmf_disc_rsp_page_entry) != 1024);
1481         BUILD_BUG_ON(sizeof(struct nvmf_disc_rsp_page_hdr) != 1024);
1482 }
1483
1484 module_init(nvmet_init);
1485 module_exit(nvmet_exit);
1486
1487 MODULE_LICENSE("GPL v2");