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 0:
  50                 status = NVME_SC_SUCCESS;
  51                 break;
  52         case -ENOSPC:
  53                 req->error_loc = offsetof(struct nvme_rw_command, length);
  54                 status = NVME_SC_CAP_EXCEEDED | NVME_SC_DNR;
  55                 break;
  56         case -EREMOTEIO:
  57                 req->error_loc = offsetof(struct nvme_rw_command, slba);
  58                 status = NVME_SC_LBA_RANGE | NVME_SC_DNR;
  59                 break;
  60         case -EOPNOTSUPP:
  61                 req->error_loc = offsetof(struct nvme_common_command, opcode);
  62                 switch (req->cmd->common.opcode) {
  63                 case nvme_cmd_dsm:
  64                 case nvme_cmd_write_zeroes:
  65                         status = NVME_SC_ONCS_NOT_SUPPORTED | NVME_SC_DNR;
  66                         break;
  67                 default:
  68                         status = NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
  69                 }
  70                 break;
  71         case -ENODATA:
  72                 req->error_loc = offsetof(struct nvme_rw_command, nsid);
  73                 status = NVME_SC_ACCESS_DENIED;
  74                 break;
  75         case -EIO:
  76                 /* FALLTHRU */
  77         default:
  78                 req->error_loc = offsetof(struct nvme_common_command, opcode);
  79                 status = NVME_SC_INTERNAL | NVME_SC_DNR;
  80         }
  81
  82         return status;
  83 }
  84
  85 static struct nvmet_subsys *nvmet_find_get_subsys(struct nvmet_port *port,
  86                 const char *subsysnqn);
  87
  88 u16 nvmet_copy_to_sgl(struct nvmet_req *req, off_t off, const void *buf,
  89                 size_t len)
  90 {
  91         if (sg_pcopy_from_buffer(req->sg, req->sg_cnt, buf, len, off) != len) {
  92                 req->error_loc = offsetof(struct nvme_common_command, dptr);
  93                 return NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR;
  94         }
  95         return 0;
  96 }
  97
  98 u16 nvmet_copy_from_sgl(struct nvmet_req *req, off_t off, void *buf, size_t len)
  99 {
 100         if (sg_pcopy_to_buffer(req->sg, req->sg_cnt, buf, len, off) != len) {
 101                 req->error_loc = offsetof(struct nvme_common_command, dptr);
 102                 return NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR;
 103         }
 104         return 0;
 105 }
 106
 107 u16 nvmet_zero_sgl(struct nvmet_req *req, off_t off, size_t len)
 108 {
 109         if (sg_zero_buffer(req->sg, req->sg_cnt, len, off) != len) {
 110                 req->error_loc = offsetof(struct nvme_common_command, dptr);
 111                 return NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR;
 112         }
 113         return 0;
 114 }
 115
 116 static unsigned int nvmet_max_nsid(struct nvmet_subsys *subsys)
 117 {
 118         struct nvmet_ns *ns;
 119
 120         if (list_empty(&subsys->namespaces))
 121                 return 0;
 122
 123         ns = list_last_entry(&subsys->namespaces, struct nvmet_ns, dev_link);
 124         return ns->nsid;
 125 }
 126
 127 static u32 nvmet_async_event_result(struct nvmet_async_event *aen)
 128 {
 129         return aen->event_type | (aen->event_info << 8) | (aen->log_page << 16);
 130 }
 131
 132 static void nvmet_async_events_failall(struct nvmet_ctrl *ctrl)
 133 {
 134         u16 status = NVME_SC_INTERNAL | NVME_SC_DNR;
 135         struct nvmet_req *req;
 136
 137         mutex_lock(&ctrl->lock);
 138         while (ctrl->nr_async_event_cmds) {
 139                 req = ctrl->async_event_cmds[--ctrl->nr_async_event_cmds];
 140                 mutex_unlock(&ctrl->lock);
 141                 nvmet_req_complete(req, status);
 142                 mutex_lock(&ctrl->lock);
 143         }
 144         mutex_unlock(&ctrl->lock);
 145 }
 146
 147 static void nvmet_async_events_process(struct nvmet_ctrl *ctrl)
 148 {
 149         struct nvmet_async_event *aen;
 150         struct nvmet_req *req;
 151
 152         mutex_lock(&ctrl->lock);
 153         while (ctrl->nr_async_event_cmds && !list_empty(&ctrl->async_events)) {
 154                 aen = list_first_entry(&ctrl->async_events,
 155                                        struct nvmet_async_event, entry);
 156                 req = ctrl->async_event_cmds[--ctrl->nr_async_event_cmds];
 157                 nvmet_set_result(req, nvmet_async_event_result(aen));
 158
 159                 list_del(&aen->entry);
 160                 kfree(aen);
 161
 162                 mutex_unlock(&ctrl->lock);
 163                 trace_nvmet_async_event(ctrl, req->cqe->result.u32);
 164                 nvmet_req_complete(req, 0);
 165                 mutex_lock(&ctrl->lock);
 166         }
 167         mutex_unlock(&ctrl->lock);
 168 }
 169
 170 static void nvmet_async_events_free(struct nvmet_ctrl *ctrl)
 171 {
 172         struct nvmet_async_event *aen, *tmp;
 173
 174         mutex_lock(&ctrl->lock);
 175         list_for_each_entry_safe(aen, tmp, &ctrl->async_events, entry) {
 176                 list_del(&aen->entry);
 177                 kfree(aen);
 178         }
 179         mutex_unlock(&ctrl->lock);
 180 }
 181
 182 static void nvmet_async_event_work(struct work_struct *work)
 183 {
 184         struct nvmet_ctrl *ctrl =
 185                 container_of(work, struct nvmet_ctrl, async_event_work);
 186
 187         nvmet_async_events_process(ctrl);
 188 }
 189
 190 void nvmet_add_async_event(struct nvmet_ctrl *ctrl, u8 event_type,
 191                 u8 event_info, u8 log_page)
 192 {
 193         struct nvmet_async_event *aen;
 194
 195         aen = kmalloc(sizeof(*aen), GFP_KERNEL);
 196         if (!aen)
 197                 return;
 198
 199         aen->event_type = event_type;
 200         aen->event_info = event_info;
 201         aen->log_page = log_page;
 202
 203         mutex_lock(&ctrl->lock);
 204         list_add_tail(&aen->entry, &ctrl->async_events);
 205         mutex_unlock(&ctrl->lock);
 206
 207         schedule_work(&ctrl->async_event_work);
 208 }
 209
 210 static void nvmet_add_to_changed_ns_log(struct nvmet_ctrl *ctrl, __le32 nsid)
 211 {
 212         u32 i;
 213
 214         mutex_lock(&ctrl->lock);
 215         if (ctrl->nr_changed_ns > NVME_MAX_CHANGED_NAMESPACES)
 216                 goto out_unlock;
 217
 218         for (i = 0; i < ctrl->nr_changed_ns; i++) {
 219                 if (ctrl->changed_ns_list[i] == nsid)
 220                         goto out_unlock;
 221         }
 222
 223         if (ctrl->nr_changed_ns == NVME_MAX_CHANGED_NAMESPACES) {
 224                 ctrl->changed_ns_list[0] = cpu_to_le32(0xffffffff);
 225                 ctrl->nr_changed_ns = U32_MAX;
 226                 goto out_unlock;
 227         }
 228
 229         ctrl->changed_ns_list[ctrl->nr_changed_ns++] = nsid;
 230 out_unlock:
 231         mutex_unlock(&ctrl->lock);
 232 }
 233
 234 void nvmet_ns_changed(struct nvmet_subsys *subsys, u32 nsid)
 235 {
 236         struct nvmet_ctrl *ctrl;
 237
 238         lockdep_assert_held(&subsys->lock);
 239
 240         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
 241                 nvmet_add_to_changed_ns_log(ctrl, cpu_to_le32(nsid));
 242                 if (nvmet_aen_bit_disabled(ctrl, NVME_AEN_BIT_NS_ATTR))
 243                         continue;
 244                 nvmet_add_async_event(ctrl, NVME_AER_TYPE_NOTICE,
 245                                 NVME_AER_NOTICE_NS_CHANGED,
 246                                 NVME_LOG_CHANGED_NS);
 247         }
 248 }
 249
 250 void nvmet_send_ana_event(struct nvmet_subsys *subsys,
 251                 struct nvmet_port *port)
 252 {
 253         struct nvmet_ctrl *ctrl;
 254
 255         mutex_lock(&subsys->lock);
 256         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
 257                 if (port && ctrl->port != port)
 258                         continue;
 259                 if (nvmet_aen_bit_disabled(ctrl, NVME_AEN_BIT_ANA_CHANGE))
 260                         continue;
 261                 nvmet_add_async_event(ctrl, NVME_AER_TYPE_NOTICE,
 262                                 NVME_AER_NOTICE_ANA, NVME_LOG_ANA);
 263         }
 264         mutex_unlock(&subsys->lock);
 265 }
 266
 267 void nvmet_port_send_ana_event(struct nvmet_port *port)
 268 {
 269         struct nvmet_subsys_link *p;
 270
 271         down_read(&nvmet_config_sem);
 272         list_for_each_entry(p, &port->subsystems, entry)
 273                 nvmet_send_ana_event(p->subsys, port);
 274         up_read(&nvmet_config_sem);
 275 }
 276
 277 int nvmet_register_transport(const struct nvmet_fabrics_ops *ops)
 278 {
 279         int ret = 0;
 280
 281         down_write(&nvmet_config_sem);
 282         if (nvmet_transports[ops->type])
 283                 ret = -EINVAL;
 284         else
 285                 nvmet_transports[ops->type] = ops;
 286         up_write(&nvmet_config_sem);
 287
 288         return ret;
 289 }
 290 EXPORT_SYMBOL_GPL(nvmet_register_transport);
 291
 292 void nvmet_unregister_transport(const struct nvmet_fabrics_ops *ops)
 293 {
 294         down_write(&nvmet_config_sem);
 295         nvmet_transports[ops->type] = NULL;
 296         up_write(&nvmet_config_sem);
 297 }
 298 EXPORT_SYMBOL_GPL(nvmet_unregister_transport);
 299
 300 void nvmet_port_del_ctrls(struct nvmet_port *port, struct nvmet_subsys *subsys)
 301 {
 302         struct nvmet_ctrl *ctrl;
 303
 304         mutex_lock(&subsys->lock);
 305         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
 306                 if (ctrl->port == port)
 307                         ctrl->ops->delete_ctrl(ctrl);
 308         }
 309         mutex_unlock(&subsys->lock);
 310 }
 311
 312 int nvmet_enable_port(struct nvmet_port *port)
 313 {
 314         const struct nvmet_fabrics_ops *ops;
 315         int ret;
 316
 317         lockdep_assert_held(&nvmet_config_sem);
 318
 319         ops = nvmet_transports[port->disc_addr.trtype];
 320         if (!ops) {
 321                 up_write(&nvmet_config_sem);
 322                 request_module("nvmet-transport-%d", port->disc_addr.trtype);
 323                 down_write(&nvmet_config_sem);
 324                 ops = nvmet_transports[port->disc_addr.trtype];
 325                 if (!ops) {
 326                         pr_err("transport type %d not supported\n",
 327                                 port->disc_addr.trtype);
 328                         return -EINVAL;
 329                 }
 330         }
 331
 332         if (!try_module_get(ops->owner))
 333                 return -EINVAL;
 334
 335         /*
 336          * If the user requested PI support and the transport isn't pi capable,
 337          * don't enable the port.
 338          */
 339         if (port->pi_enable && !ops->metadata_support) {
 340                 pr_err("T10-PI is not supported by transport type %d\n",
 341                        port->disc_addr.trtype);
 342                 ret = -EINVAL;
 343                 goto out_put;
 344         }
 345
 346         ret = ops->add_port(port);
 347         if (ret)
 348                 goto out_put;
 349
 350         /* If the transport didn't set inline_data_size, then disable it. */
 351         if (port->inline_data_size < 0)
 352                 port->inline_data_size = 0;
 353
 354         port->enabled = true;
 355         port->tr_ops = ops;
 356         return 0;
 357
 358 out_put:
 359         module_put(ops->owner);
 360         return ret;
 361 }
 362
 363 void nvmet_disable_port(struct nvmet_port *port)
 364 {
 365         const struct nvmet_fabrics_ops *ops;
 366
 367         lockdep_assert_held(&nvmet_config_sem);
 368
 369         port->enabled = false;
 370         port->tr_ops = NULL;
 371
 372         ops = nvmet_transports[port->disc_addr.trtype];
 373         ops->remove_port(port);
 374         module_put(ops->owner);
 375 }
 376
 377 static void nvmet_keep_alive_timer(struct work_struct *work)
 378 {
 379         struct nvmet_ctrl *ctrl = container_of(to_delayed_work(work),
 380                         struct nvmet_ctrl, ka_work);
 381         bool cmd_seen = ctrl->cmd_seen;
 382
 383         ctrl->cmd_seen = false;
 384         if (cmd_seen) {
 385                 pr_debug("ctrl %d reschedule traffic based keep-alive timer\n",
 386                         ctrl->cntlid);
 387                 schedule_delayed_work(&ctrl->ka_work, ctrl->kato * HZ);
 388                 return;
 389         }
 390
 391         pr_err("ctrl %d keep-alive timer (%d seconds) expired!\n",
 392                 ctrl->cntlid, ctrl->kato);
 393
 394         nvmet_ctrl_fatal_error(ctrl);
 395 }
 396
 397 static void nvmet_start_keep_alive_timer(struct nvmet_ctrl *ctrl)
 398 {
 399         pr_debug("ctrl %d start keep-alive timer for %d secs\n",
 400                 ctrl->cntlid, ctrl->kato);
 401
 402         INIT_DELAYED_WORK(&ctrl->ka_work, nvmet_keep_alive_timer);
 403         schedule_delayed_work(&ctrl->ka_work, ctrl->kato * HZ);
 404 }
 405
 406 static void nvmet_stop_keep_alive_timer(struct nvmet_ctrl *ctrl)
 407 {
 408         pr_debug("ctrl %d stop keep-alive\n", ctrl->cntlid);
 409
 410         cancel_delayed_work_sync(&ctrl->ka_work);
 411 }
 412
 413 static struct nvmet_ns *__nvmet_find_namespace(struct nvmet_ctrl *ctrl,
 414                 __le32 nsid)
 415 {
 416         struct nvmet_ns *ns;
 417
 418         list_for_each_entry_rcu(ns, &ctrl->subsys->namespaces, dev_link) {
 419                 if (ns->nsid == le32_to_cpu(nsid))
 420                         return ns;
 421         }
 422
 423         return NULL;
 424 }
 425
 426 struct nvmet_ns *nvmet_find_namespace(struct nvmet_ctrl *ctrl, __le32 nsid)
 427 {
 428         struct nvmet_ns *ns;
 429
 430         rcu_read_lock();
 431         ns = __nvmet_find_namespace(ctrl, nsid);
 432         if (ns)
 433                 percpu_ref_get(&ns->ref);
 434         rcu_read_unlock();
 435
 436         return ns;
 437 }
 438
 439 static void nvmet_destroy_namespace(struct percpu_ref *ref)
 440 {
 441         struct nvmet_ns *ns = container_of(ref, struct nvmet_ns, ref);
 442
 443         complete(&ns->disable_done);
 444 }
 445
 446 void nvmet_put_namespace(struct nvmet_ns *ns)
 447 {
 448         percpu_ref_put(&ns->ref);
 449 }
 450
 451 static void nvmet_ns_dev_disable(struct nvmet_ns *ns)
 452 {
 453         nvmet_bdev_ns_disable(ns);
 454         nvmet_file_ns_disable(ns);
 455 }
 456
 457 static int nvmet_p2pmem_ns_enable(struct nvmet_ns *ns)
 458 {
 459         int ret;
 460         struct pci_dev *p2p_dev;
 461
 462         if (!ns->use_p2pmem)
 463                 return 0;
 464
 465         if (!ns->bdev) {
 466                 pr_err("peer-to-peer DMA is not supported by non-block device namespaces\n");
 467                 return -EINVAL;
 468         }
 469
 470         if (!blk_queue_pci_p2pdma(ns->bdev->bd_queue)) {
 471                 pr_err("peer-to-peer DMA is not supported by the driver of %s\n",
 472                        ns->device_path);
 473                 return -EINVAL;
 474         }
 475
 476         if (ns->p2p_dev) {
 477                 ret = pci_p2pdma_distance(ns->p2p_dev, nvmet_ns_dev(ns), true);
 478                 if (ret < 0)
 479                         return -EINVAL;
 480         } else {
 481                 /*
 482                  * Right now we just check that there is p2pmem available so
 483                  * we can report an error to the user right away if there
 484                  * is not. We'll find the actual device to use once we
 485                  * setup the controller when the port's device is available.
 486                  */
 487
 488                 p2p_dev = pci_p2pmem_find(nvmet_ns_dev(ns));
 489                 if (!p2p_dev) {
 490                         pr_err("no peer-to-peer memory is available for %s\n",
 491                                ns->device_path);
 492                         return -EINVAL;
 493                 }
 494
 495                 pci_dev_put(p2p_dev);
 496         }
 497
 498         return 0;
 499 }
 500
 501 /*
 502  * Note: ctrl->subsys->lock should be held when calling this function
 503  */
 504 static void nvmet_p2pmem_ns_add_p2p(struct nvmet_ctrl *ctrl,
 505                                     struct nvmet_ns *ns)
 506 {
 507         struct device *clients[2];
 508         struct pci_dev *p2p_dev;
 509         int ret;
 510
 511         if (!ctrl->p2p_client || !ns->use_p2pmem)
 512                 return;
 513
 514         if (ns->p2p_dev) {
 515                 ret = pci_p2pdma_distance(ns->p2p_dev, ctrl->p2p_client, true);
 516                 if (ret < 0)
 517                         return;
 518
 519                 p2p_dev = pci_dev_get(ns->p2p_dev);
 520         } else {
 521                 clients[0] = ctrl->p2p_client;
 522                 clients[1] = nvmet_ns_dev(ns);
 523
 524                 p2p_dev = pci_p2pmem_find_many(clients, ARRAY_SIZE(clients));
 525                 if (!p2p_dev) {
 526                         pr_err("no peer-to-peer memory is available that's supported by %s and %s\n",
 527                                dev_name(ctrl->p2p_client), ns->device_path);
 528                         return;
 529                 }
 530         }
 531
 532         ret = radix_tree_insert(&ctrl->p2p_ns_map, ns->nsid, p2p_dev);
 533         if (ret < 0)
 534                 pci_dev_put(p2p_dev);
 535
 536         pr_info("using p2pmem on %s for nsid %d\n", pci_name(p2p_dev),
 537                 ns->nsid);
 538 }
 539
 540 void nvmet_ns_revalidate(struct nvmet_ns *ns)
 541 {
 542         loff_t oldsize = ns->size;
 543
 544         if (ns->bdev)
 545                 nvmet_bdev_ns_revalidate(ns);
 546         else
 547                 nvmet_file_ns_revalidate(ns);
 548
 549         if (oldsize != ns->size)
 550                 nvmet_ns_changed(ns->subsys, ns->nsid);
 551 }
 552
 553 int nvmet_ns_enable(struct nvmet_ns *ns)
 554 {
 555         struct nvmet_subsys *subsys = ns->subsys;
 556         struct nvmet_ctrl *ctrl;
 557         int ret;
 558
 559         mutex_lock(&subsys->lock);
 560         ret = 0;
 561         if (ns->enabled)
 562                 goto out_unlock;
 563
 564         ret = -EMFILE;
 565         if (subsys->nr_namespaces == NVMET_MAX_NAMESPACES)
 566                 goto out_unlock;
 567
 568         ret = nvmet_bdev_ns_enable(ns);
 569         if (ret == -ENOTBLK)
 570                 ret = nvmet_file_ns_enable(ns);
 571         if (ret)
 572                 goto out_unlock;
 573
 574         ret = nvmet_p2pmem_ns_enable(ns);
 575         if (ret)
 576                 goto out_dev_disable;
 577
 578         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry)
 579                 nvmet_p2pmem_ns_add_p2p(ctrl, ns);
 580
 581         ret = percpu_ref_init(&ns->ref, nvmet_destroy_namespace,
 582                                 0, GFP_KERNEL);
 583         if (ret)
 584                 goto out_dev_put;
 585
 586         if (ns->nsid > subsys->max_nsid)
 587                 subsys->max_nsid = ns->nsid;
 588
 589         /*
 590          * The namespaces list needs to be sorted to simplify the implementation
 591          * of the Identify Namepace List subcommand.
 592          */
 593         if (list_empty(&subsys->namespaces)) {
 594                 list_add_tail_rcu(&ns->dev_link, &subsys->namespaces);
 595         } else {
 596                 struct nvmet_ns *old;
 597
 598                 list_for_each_entry_rcu(old, &subsys->namespaces, dev_link,
 599                                         lockdep_is_held(&subsys->lock)) {
 600                         BUG_ON(ns->nsid == old->nsid);
 601                         if (ns->nsid < old->nsid)
 602                                 break;
 603                 }
 604
 605                 list_add_tail_rcu(&ns->dev_link, &old->dev_link);
 606         }
 607         subsys->nr_namespaces++;
 608
 609         nvmet_ns_changed(subsys, ns->nsid);
 610         ns->enabled = true;
 611         ret = 0;
 612 out_unlock:
 613         mutex_unlock(&subsys->lock);
 614         return ret;
 615 out_dev_put:
 616         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry)
 617                 pci_dev_put(radix_tree_delete(&ctrl->p2p_ns_map, ns->nsid));
 618 out_dev_disable:
 619         nvmet_ns_dev_disable(ns);
 620         goto out_unlock;
 621 }
 622
 623 void nvmet_ns_disable(struct nvmet_ns *ns)
 624 {
 625         struct nvmet_subsys *subsys = ns->subsys;
 626         struct nvmet_ctrl *ctrl;
 627
 628         mutex_lock(&subsys->lock);
 629         if (!ns->enabled)
 630                 goto out_unlock;
 631
 632         ns->enabled = false;
 633         list_del_rcu(&ns->dev_link);
 634         if (ns->nsid == subsys->max_nsid)
 635                 subsys->max_nsid = nvmet_max_nsid(subsys);
 636
 637         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry)
 638                 pci_dev_put(radix_tree_delete(&ctrl->p2p_ns_map, ns->nsid));
 639
 640         mutex_unlock(&subsys->lock);
 641
 642         /*
 643          * Now that we removed the namespaces from the lookup list, we
 644          * can kill the per_cpu ref and wait for any remaining references
 645          * to be dropped, as well as a RCU grace period for anyone only
 646          * using the namepace under rcu_read_lock().  Note that we can't
 647          * use call_rcu here as we need to ensure the namespaces have
 648          * been fully destroyed before unloading the module.
 649          */
 650         percpu_ref_kill(&ns->ref);
 651         synchronize_rcu();
 652         wait_for_completion(&ns->disable_done);
 653         percpu_ref_exit(&ns->ref);
 654
 655         mutex_lock(&subsys->lock);
 656
 657         subsys->nr_namespaces--;
 658         nvmet_ns_changed(subsys, ns->nsid);
 659         nvmet_ns_dev_disable(ns);
 660 out_unlock:
 661         mutex_unlock(&subsys->lock);
 662 }
 663
 664 void nvmet_ns_free(struct nvmet_ns *ns)
 665 {
 666         nvmet_ns_disable(ns);
 667
 668         down_write(&nvmet_ana_sem);
 669         nvmet_ana_group_enabled[ns->anagrpid]--;
 670         up_write(&nvmet_ana_sem);
 671
 672         kfree(ns->device_path);
 673         kfree(ns);
 674 }
 675
 676 struct nvmet_ns *nvmet_ns_alloc(struct nvmet_subsys *subsys, u32 nsid)
 677 {
 678         struct nvmet_ns *ns;
 679
 680         ns = kzalloc(sizeof(*ns), GFP_KERNEL);
 681         if (!ns)
 682                 return NULL;
 683
 684         INIT_LIST_HEAD(&ns->dev_link);
 685         init_completion(&ns->disable_done);
 686
 687         ns->nsid = nsid;
 688         ns->subsys = subsys;
 689
 690         down_write(&nvmet_ana_sem);
 691         ns->anagrpid = NVMET_DEFAULT_ANA_GRPID;
 692         nvmet_ana_group_enabled[ns->anagrpid]++;
 693         up_write(&nvmet_ana_sem);
 694
 695         uuid_gen(&ns->uuid);
 696         ns->buffered_io = false;
 697
 698         return ns;
 699 }
 700
 701 static void nvmet_update_sq_head(struct nvmet_req *req)
 702 {
 703         if (req->sq->size) {
 704                 u32 old_sqhd, new_sqhd;
 705
 706                 do {
 707                         old_sqhd = req->sq->sqhd;
 708                         new_sqhd = (old_sqhd + 1) % req->sq->size;
 709                 } while (cmpxchg(&req->sq->sqhd, old_sqhd, new_sqhd) !=
 710                                         old_sqhd);
 711         }
 712         req->cqe->sq_head = cpu_to_le16(req->sq->sqhd & 0x0000FFFF);
 713 }
 714
 715 static void nvmet_set_error(struct nvmet_req *req, u16 status)
 716 {
 717         struct nvmet_ctrl *ctrl = req->sq->ctrl;
 718         struct nvme_error_slot *new_error_slot;
 719         unsigned long flags;
 720
 721         req->cqe->status = cpu_to_le16(status << 1);
 722
 723         if (!ctrl || req->error_loc == NVMET_NO_ERROR_LOC)
 724                 return;
 725
 726         spin_lock_irqsave(&ctrl->error_lock, flags);
 727         ctrl->err_counter++;
 728         new_error_slot =
 729                 &ctrl->slots[ctrl->err_counter % NVMET_ERROR_LOG_SLOTS];
 730
 731         new_error_slot->error_count = cpu_to_le64(ctrl->err_counter);
 732         new_error_slot->sqid = cpu_to_le16(req->sq->qid);
 733         new_error_slot->cmdid = cpu_to_le16(req->cmd->common.command_id);
 734         new_error_slot->status_field = cpu_to_le16(status << 1);
 735         new_error_slot->param_error_location = cpu_to_le16(req->error_loc);
 736         new_error_slot->lba = cpu_to_le64(req->error_slba);
 737         new_error_slot->nsid = req->cmd->common.nsid;
 738         spin_unlock_irqrestore(&ctrl->error_lock, flags);
 739
 740         /* set the more bit for this request */
 741         req->cqe->status |= cpu_to_le16(1 << 14);
 742 }
 743
 744 static void __nvmet_req_complete(struct nvmet_req *req, u16 status)
 745 {
 746         if (!req->sq->sqhd_disabled)
 747                 nvmet_update_sq_head(req);
 748         req->cqe->sq_id = cpu_to_le16(req->sq->qid);
 749         req->cqe->command_id = req->cmd->common.command_id;
 750
 751         if (unlikely(status))
 752                 nvmet_set_error(req, status);
 753
 754         trace_nvmet_req_complete(req);
 755
 756         if (req->ns)
 757                 nvmet_put_namespace(req->ns);
 758         req->ops->queue_response(req);
 759 }
 760
 761 void nvmet_req_complete(struct nvmet_req *req, u16 status)
 762 {
 763         __nvmet_req_complete(req, status);
 764         percpu_ref_put(&req->sq->ref);
 765 }
 766 EXPORT_SYMBOL_GPL(nvmet_req_complete);
 767
 768 void nvmet_cq_setup(struct nvmet_ctrl *ctrl, struct nvmet_cq *cq,
 769                 u16 qid, u16 size)
 770 {
 771         cq->qid = qid;
 772         cq->size = size;
 773
 774         ctrl->cqs[qid] = cq;
 775 }
 776
 777 void nvmet_sq_setup(struct nvmet_ctrl *ctrl, struct nvmet_sq *sq,
 778                 u16 qid, u16 size)
 779 {
 780         sq->sqhd = 0;
 781         sq->qid = qid;
 782         sq->size = size;
 783
 784         ctrl->sqs[qid] = sq;
 785 }
 786
 787 static void nvmet_confirm_sq(struct percpu_ref *ref)
 788 {
 789         struct nvmet_sq *sq = container_of(ref, struct nvmet_sq, ref);
 790
 791         complete(&sq->confirm_done);
 792 }
 793
 794 void nvmet_sq_destroy(struct nvmet_sq *sq)
 795 {
 796         struct nvmet_ctrl *ctrl = sq->ctrl;
 797
 798         /*
 799          * If this is the admin queue, complete all AERs so that our
 800          * queue doesn't have outstanding requests on it.
 801          */
 802         if (ctrl && ctrl->sqs && ctrl->sqs[0] == sq)
 803                 nvmet_async_events_failall(ctrl);
 804         percpu_ref_kill_and_confirm(&sq->ref, nvmet_confirm_sq);
 805         wait_for_completion(&sq->confirm_done);
 806         wait_for_completion(&sq->free_done);
 807         percpu_ref_exit(&sq->ref);
 808
 809         if (ctrl) {
 810                 nvmet_ctrl_put(ctrl);
 811                 sq->ctrl = NULL; /* allows reusing the queue later */
 812         }
 813 }
 814 EXPORT_SYMBOL_GPL(nvmet_sq_destroy);
 815
 816 static void nvmet_sq_free(struct percpu_ref *ref)
 817 {
 818         struct nvmet_sq *sq = container_of(ref, struct nvmet_sq, ref);
 819
 820         complete(&sq->free_done);
 821 }
 822
 823 int nvmet_sq_init(struct nvmet_sq *sq)
 824 {
 825         int ret;
 826
 827         ret = percpu_ref_init(&sq->ref, nvmet_sq_free, 0, GFP_KERNEL);
 828         if (ret) {
 829                 pr_err("percpu_ref init failed!\n");
 830                 return ret;
 831         }
 832         init_completion(&sq->free_done);
 833         init_completion(&sq->confirm_done);
 834
 835         return 0;
 836 }
 837 EXPORT_SYMBOL_GPL(nvmet_sq_init);
 838
 839 static inline u16 nvmet_check_ana_state(struct nvmet_port *port,
 840                 struct nvmet_ns *ns)
 841 {
 842         enum nvme_ana_state state = port->ana_state[ns->anagrpid];
 843
 844         if (unlikely(state == NVME_ANA_INACCESSIBLE))
 845                 return NVME_SC_ANA_INACCESSIBLE;
 846         if (unlikely(state == NVME_ANA_PERSISTENT_LOSS))
 847                 return NVME_SC_ANA_PERSISTENT_LOSS;
 848         if (unlikely(state == NVME_ANA_CHANGE))
 849                 return NVME_SC_ANA_TRANSITION;
 850         return 0;
 851 }
 852
 853 static inline u16 nvmet_io_cmd_check_access(struct nvmet_req *req)
 854 {
 855         if (unlikely(req->ns->readonly)) {
 856                 switch (req->cmd->common.opcode) {
 857                 case nvme_cmd_read:
 858                 case nvme_cmd_flush:
 859                         break;
 860                 default:
 861                         return NVME_SC_NS_WRITE_PROTECTED;
 862                 }
 863         }
 864
 865         return 0;
 866 }
 867
 868 static u16 nvmet_parse_io_cmd(struct nvmet_req *req)
 869 {
 870         struct nvme_command *cmd = req->cmd;
 871         u16 ret;
 872
 873         ret = nvmet_check_ctrl_status(req, cmd);
 874         if (unlikely(ret))
 875                 return ret;
 876
 877         req->ns = nvmet_find_namespace(req->sq->ctrl, cmd->rw.nsid);
 878         if (unlikely(!req->ns)) {
 879                 req->error_loc = offsetof(struct nvme_common_command, nsid);
 880                 return NVME_SC_INVALID_NS | NVME_SC_DNR;
 881         }
 882         ret = nvmet_check_ana_state(req->port, req->ns);
 883         if (unlikely(ret)) {
 884                 req->error_loc = offsetof(struct nvme_common_command, nsid);
 885                 return ret;
 886         }
 887         ret = nvmet_io_cmd_check_access(req);
 888         if (unlikely(ret)) {
 889                 req->error_loc = offsetof(struct nvme_common_command, nsid);
 890                 return ret;
 891         }
 892
 893         if (req->ns->file)
 894                 return nvmet_file_parse_io_cmd(req);
 895         else
 896                 return nvmet_bdev_parse_io_cmd(req);
 897 }
 898
 899 bool nvmet_req_init(struct nvmet_req *req, struct nvmet_cq *cq,
 900                 struct nvmet_sq *sq, const struct nvmet_fabrics_ops *ops)
 901 {
 902         u8 flags = req->cmd->common.flags;
 903         u16 status;
 904
 905         req->cq = cq;
 906         req->sq = sq;
 907         req->ops = ops;
 908         req->sg = NULL;
 909         req->metadata_sg = NULL;
 910         req->sg_cnt = 0;
 911         req->metadata_sg_cnt = 0;
 912         req->transfer_len = 0;
 913         req->metadata_len = 0;
 914         req->cqe->status = 0;
 915         req->cqe->sq_head = 0;
 916         req->ns = NULL;
 917         req->error_loc = NVMET_NO_ERROR_LOC;
 918         req->error_slba = 0;
 919
 920         trace_nvmet_req_init(req, req->cmd);
 921
 922         /* no support for fused commands yet */
 923         if (unlikely(flags & (NVME_CMD_FUSE_FIRST | NVME_CMD_FUSE_SECOND))) {
 924                 req->error_loc = offsetof(struct nvme_common_command, flags);
 925                 status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 926                 goto fail;
 927         }
 928
 929         /*
 930          * For fabrics, PSDT field shall describe metadata pointer (MPTR) that
 931          * contains an address of a single contiguous physical buffer that is
 932          * byte aligned.
 933          */
 934         if (unlikely((flags & NVME_CMD_SGL_ALL) != NVME_CMD_SGL_METABUF)) {
 935                 req->error_loc = offsetof(struct nvme_common_command, flags);
 936                 status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 937                 goto fail;
 938         }
 939
 940         if (unlikely(!req->sq->ctrl))
 941                 /* will return an error for any non-connect command: */
 942                 status = nvmet_parse_connect_cmd(req);
 943         else if (likely(req->sq->qid != 0))
 944                 status = nvmet_parse_io_cmd(req);
 945         else
 946                 status = nvmet_parse_admin_cmd(req);
 947
 948         if (status)
 949                 goto fail;
 950
 951         if (unlikely(!percpu_ref_tryget_live(&sq->ref))) {
 952                 status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 953                 goto fail;
 954         }
 955
 956         if (sq->ctrl)
 957                 sq->ctrl->cmd_seen = true;
 958
 959         return true;
 960
 961 fail:
 962         __nvmet_req_complete(req, status);
 963         return false;
 964 }
 965 EXPORT_SYMBOL_GPL(nvmet_req_init);
 966
 967 void nvmet_req_uninit(struct nvmet_req *req)
 968 {
 969         percpu_ref_put(&req->sq->ref);
 970         if (req->ns)
 971                 nvmet_put_namespace(req->ns);
 972 }
 973 EXPORT_SYMBOL_GPL(nvmet_req_uninit);
 974
 975 bool nvmet_check_transfer_len(struct nvmet_req *req, size_t len)
 976 {
 977         if (unlikely(len != req->transfer_len)) {
 978                 req->error_loc = offsetof(struct nvme_common_command, dptr);
 979                 nvmet_req_complete(req, NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR);
 980                 return false;
 981         }
 982
 983         return true;
 984 }
 985 EXPORT_SYMBOL_GPL(nvmet_check_transfer_len);
 986
 987 bool nvmet_check_data_len_lte(struct nvmet_req *req, size_t data_len)
 988 {
 989         if (unlikely(data_len > req->transfer_len)) {
 990                 req->error_loc = offsetof(struct nvme_common_command, dptr);
 991                 nvmet_req_complete(req, NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR);
 992                 return false;
 993         }
 994
 995         return true;
 996 }
 997
 998 static unsigned int nvmet_data_transfer_len(struct nvmet_req *req)
 999 {
1000         return req->transfer_len - req->metadata_len;
1001 }
1002
1003 static int nvmet_req_alloc_p2pmem_sgls(struct nvmet_req *req)
1004 {
1005         req->sg = pci_p2pmem_alloc_sgl(req->p2p_dev, &req->sg_cnt,
1006                         nvmet_data_transfer_len(req));
1007         if (!req->sg)
1008                 goto out_err;
1009
1010         if (req->metadata_len) {
1011                 req->metadata_sg = pci_p2pmem_alloc_sgl(req->p2p_dev,
1012                                 &req->metadata_sg_cnt, req->metadata_len);
1013                 if (!req->metadata_sg)
1014                         goto out_free_sg;
1015         }
1016         return 0;
1017 out_free_sg:
1018         pci_p2pmem_free_sgl(req->p2p_dev, req->sg);
1019 out_err:
1020         return -ENOMEM;
1021 }
1022
1023 static bool nvmet_req_find_p2p_dev(struct nvmet_req *req)
1024 {
1025         if (!IS_ENABLED(CONFIG_PCI_P2PDMA))
1026                 return false;
1027
1028         if (req->sq->ctrl && req->sq->qid && req->ns) {
1029                 req->p2p_dev = radix_tree_lookup(&req->sq->ctrl->p2p_ns_map,
1030                                                  req->ns->nsid);
1031                 if (req->p2p_dev)
1032                         return true;
1033         }
1034
1035         req->p2p_dev = NULL;
1036         return false;
1037 }
1038
1039 int nvmet_req_alloc_sgls(struct nvmet_req *req)
1040 {
1041         if (nvmet_req_find_p2p_dev(req) && !nvmet_req_alloc_p2pmem_sgls(req))
1042                 return 0;
1043
1044         req->sg = sgl_alloc(nvmet_data_transfer_len(req), GFP_KERNEL,
1045                             &req->sg_cnt);
1046         if (unlikely(!req->sg))
1047                 goto out;
1048
1049         if (req->metadata_len) {
1050                 req->metadata_sg = sgl_alloc(req->metadata_len, GFP_KERNEL,
1051                                              &req->metadata_sg_cnt);
1052                 if (unlikely(!req->metadata_sg))
1053                         goto out_free;
1054         }
1055
1056         return 0;
1057 out_free:
1058         sgl_free(req->sg);
1059 out:
1060         return -ENOMEM;
1061 }
1062 EXPORT_SYMBOL_GPL(nvmet_req_alloc_sgls);
1063
1064 void nvmet_req_free_sgls(struct nvmet_req *req)
1065 {
1066         if (req->p2p_dev) {
1067                 pci_p2pmem_free_sgl(req->p2p_dev, req->sg);
1068                 if (req->metadata_sg)
1069                         pci_p2pmem_free_sgl(req->p2p_dev, req->metadata_sg);
1070         } else {
1071                 sgl_free(req->sg);
1072                 if (req->metadata_sg)
1073                         sgl_free(req->metadata_sg);
1074         }
1075
1076         req->sg = NULL;
1077         req->metadata_sg = NULL;
1078         req->sg_cnt = 0;
1079         req->metadata_sg_cnt = 0;
1080 }
1081 EXPORT_SYMBOL_GPL(nvmet_req_free_sgls);
1082
1083 static inline bool nvmet_cc_en(u32 cc)
1084 {
1085         return (cc >> NVME_CC_EN_SHIFT) & 0x1;
1086 }
1087
1088 static inline u8 nvmet_cc_css(u32 cc)
1089 {
1090         return (cc >> NVME_CC_CSS_SHIFT) & 0x7;
1091 }
1092
1093 static inline u8 nvmet_cc_mps(u32 cc)
1094 {
1095         return (cc >> NVME_CC_MPS_SHIFT) & 0xf;
1096 }
1097
1098 static inline u8 nvmet_cc_ams(u32 cc)
1099 {
1100         return (cc >> NVME_CC_AMS_SHIFT) & 0x7;
1101 }
1102
1103 static inline u8 nvmet_cc_shn(u32 cc)
1104 {
1105         return (cc >> NVME_CC_SHN_SHIFT) & 0x3;
1106 }
1107
1108 static inline u8 nvmet_cc_iosqes(u32 cc)
1109 {
1110         return (cc >> NVME_CC_IOSQES_SHIFT) & 0xf;
1111 }
1112
1113 static inline u8 nvmet_cc_iocqes(u32 cc)
1114 {
1115         return (cc >> NVME_CC_IOCQES_SHIFT) & 0xf;
1116 }
1117
1118 static void nvmet_start_ctrl(struct nvmet_ctrl *ctrl)
1119 {
1120         lockdep_assert_held(&ctrl->lock);
1121
1122         if (nvmet_cc_iosqes(ctrl->cc) != NVME_NVM_IOSQES ||
1123             nvmet_cc_iocqes(ctrl->cc) != NVME_NVM_IOCQES ||
1124             nvmet_cc_mps(ctrl->cc) != 0 ||
1125             nvmet_cc_ams(ctrl->cc) != 0 ||
1126             nvmet_cc_css(ctrl->cc) != 0) {
1127                 ctrl->csts = NVME_CSTS_CFS;
1128                 return;
1129         }
1130
1131         ctrl->csts = NVME_CSTS_RDY;
1132
1133         /*
1134          * Controllers that are not yet enabled should not really enforce the
1135          * keep alive timeout, but we still want to track a timeout and cleanup
1136          * in case a host died before it enabled the controller.  Hence, simply
1137          * reset the keep alive timer when the controller is enabled.
1138          */
1139         mod_delayed_work(system_wq, &ctrl->ka_work, ctrl->kato * HZ);
1140 }
1141
1142 static void nvmet_clear_ctrl(struct nvmet_ctrl *ctrl)
1143 {
1144         lockdep_assert_held(&ctrl->lock);
1145
1146         /* XXX: tear down queues? */
1147         ctrl->csts &= ~NVME_CSTS_RDY;
1148         ctrl->cc = 0;
1149 }
1150
1151 void nvmet_update_cc(struct nvmet_ctrl *ctrl, u32 new)
1152 {
1153         u32 old;
1154
1155         mutex_lock(&ctrl->lock);
1156         old = ctrl->cc;
1157         ctrl->cc = new;
1158
1159         if (nvmet_cc_en(new) && !nvmet_cc_en(old))
1160                 nvmet_start_ctrl(ctrl);
1161         if (!nvmet_cc_en(new) && nvmet_cc_en(old))
1162                 nvmet_clear_ctrl(ctrl);
1163         if (nvmet_cc_shn(new) && !nvmet_cc_shn(old)) {
1164                 nvmet_clear_ctrl(ctrl);
1165                 ctrl->csts |= NVME_CSTS_SHST_CMPLT;
1166         }
1167         if (!nvmet_cc_shn(new) && nvmet_cc_shn(old))
1168                 ctrl->csts &= ~NVME_CSTS_SHST_CMPLT;
1169         mutex_unlock(&ctrl->lock);
1170 }
1171
1172 static void nvmet_init_cap(struct nvmet_ctrl *ctrl)
1173 {
1174         /* command sets supported: NVMe command set: */
1175         ctrl->cap = (1ULL << 37);
1176         /* CC.EN timeout in 500msec units: */
1177         ctrl->cap |= (15ULL << 24);
1178         /* maximum queue entries supported: */
1179         ctrl->cap |= NVMET_QUEUE_SIZE - 1;
1180 }
1181
1182 u16 nvmet_ctrl_find_get(const char *subsysnqn, const char *hostnqn, u16 cntlid,
1183                 struct nvmet_req *req, struct nvmet_ctrl **ret)
1184 {
1185         struct nvmet_subsys *subsys;
1186         struct nvmet_ctrl *ctrl;
1187         u16 status = 0;
1188
1189         subsys = nvmet_find_get_subsys(req->port, subsysnqn);
1190         if (!subsys) {
1191                 pr_warn("connect request for invalid subsystem %s!\n",
1192                         subsysnqn);
1193                 req->cqe->result.u32 = IPO_IATTR_CONNECT_DATA(subsysnqn);
1194                 return NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR;
1195         }
1196
1197         mutex_lock(&subsys->lock);
1198         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
1199                 if (ctrl->cntlid == cntlid) {
1200                         if (strncmp(hostnqn, ctrl->hostnqn, NVMF_NQN_SIZE)) {
1201                                 pr_warn("hostnqn mismatch.\n");
1202                                 continue;
1203                         }
1204                         if (!kref_get_unless_zero(&ctrl->ref))
1205                                 continue;
1206
1207                         *ret = ctrl;
1208                         goto out;
1209                 }
1210         }
1211
1212         pr_warn("could not find controller %d for subsys %s / host %s\n",
1213                 cntlid, subsysnqn, hostnqn);
1214         req->cqe->result.u32 = IPO_IATTR_CONNECT_DATA(cntlid);
1215         status = NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR;
1216
1217 out:
1218         mutex_unlock(&subsys->lock);
1219         nvmet_subsys_put(subsys);
1220         return status;
1221 }
1222
1223 u16 nvmet_check_ctrl_status(struct nvmet_req *req, struct nvme_command *cmd)
1224 {
1225         if (unlikely(!(req->sq->ctrl->cc & NVME_CC_ENABLE))) {
1226                 pr_err("got cmd %d while CC.EN == 0 on qid = %d\n",
1227                        cmd->common.opcode, req->sq->qid);
1228                 return NVME_SC_CMD_SEQ_ERROR | NVME_SC_DNR;
1229         }
1230
1231         if (unlikely(!(req->sq->ctrl->csts & NVME_CSTS_RDY))) {
1232                 pr_err("got cmd %d while CSTS.RDY == 0 on qid = %d\n",
1233                        cmd->common.opcode, req->sq->qid);
1234                 return NVME_SC_CMD_SEQ_ERROR | NVME_SC_DNR;
1235         }
1236         return 0;
1237 }
1238
1239 bool nvmet_host_allowed(struct nvmet_subsys *subsys, const char *hostnqn)
1240 {
1241         struct nvmet_host_link *p;
1242
1243         lockdep_assert_held(&nvmet_config_sem);
1244
1245         if (subsys->allow_any_host)
1246                 return true;
1247
1248         if (subsys->type == NVME_NQN_DISC) /* allow all access to disc subsys */
1249                 return true;
1250
1251         list_for_each_entry(p, &subsys->hosts, entry) {
1252                 if (!strcmp(nvmet_host_name(p->host), hostnqn))
1253                         return true;
1254         }
1255
1256         return false;
1257 }
1258
1259 /*
1260  * Note: ctrl->subsys->lock should be held when calling this function
1261  */
1262 static void nvmet_setup_p2p_ns_map(struct nvmet_ctrl *ctrl,
1263                 struct nvmet_req *req)
1264 {
1265         struct nvmet_ns *ns;
1266
1267         if (!req->p2p_client)
1268                 return;
1269
1270         ctrl->p2p_client = get_device(req->p2p_client);
1271
1272         list_for_each_entry_rcu(ns, &ctrl->subsys->namespaces, dev_link,
1273                                 lockdep_is_held(&ctrl->subsys->lock))
1274                 nvmet_p2pmem_ns_add_p2p(ctrl, ns);
1275 }
1276
1277 /*
1278  * Note: ctrl->subsys->lock should be held when calling this function
1279  */
1280 static void nvmet_release_p2p_ns_map(struct nvmet_ctrl *ctrl)
1281 {
1282         struct radix_tree_iter iter;
1283         void __rcu **slot;
1284
1285         radix_tree_for_each_slot(slot, &ctrl->p2p_ns_map, &iter, 0)
1286                 pci_dev_put(radix_tree_deref_slot(slot));
1287
1288         put_device(ctrl->p2p_client);
1289 }
1290
1291 static void nvmet_fatal_error_handler(struct work_struct *work)
1292 {
1293         struct nvmet_ctrl *ctrl =
1294                         container_of(work, struct nvmet_ctrl, fatal_err_work);
1295
1296         pr_err("ctrl %d fatal error occurred!\n", ctrl->cntlid);
1297         ctrl->ops->delete_ctrl(ctrl);
1298 }
1299
1300 u16 nvmet_alloc_ctrl(const char *subsysnqn, const char *hostnqn,
1301                 struct nvmet_req *req, u32 kato, struct nvmet_ctrl **ctrlp)
1302 {
1303         struct nvmet_subsys *subsys;
1304         struct nvmet_ctrl *ctrl;
1305         int ret;
1306         u16 status;
1307
1308         status = NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR;
1309         subsys = nvmet_find_get_subsys(req->port, subsysnqn);
1310         if (!subsys) {
1311                 pr_warn("connect request for invalid subsystem %s!\n",
1312                         subsysnqn);
1313                 req->cqe->result.u32 = IPO_IATTR_CONNECT_DATA(subsysnqn);
1314                 goto out;
1315         }
1316
1317         status = NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR;
1318         down_read(&nvmet_config_sem);
1319         if (!nvmet_host_allowed(subsys, hostnqn)) {
1320                 pr_info("connect by host %s for subsystem %s not allowed\n",
1321                         hostnqn, subsysnqn);
1322                 req->cqe->result.u32 = IPO_IATTR_CONNECT_DATA(hostnqn);
1323                 up_read(&nvmet_config_sem);
1324                 status = NVME_SC_CONNECT_INVALID_HOST | NVME_SC_DNR;
1325                 goto out_put_subsystem;
1326         }
1327         up_read(&nvmet_config_sem);
1328
1329         status = NVME_SC_INTERNAL;
1330         ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
1331         if (!ctrl)
1332                 goto out_put_subsystem;
1333         mutex_init(&ctrl->lock);
1334
1335         nvmet_init_cap(ctrl);
1336
1337         ctrl->port = req->port;
1338
1339         INIT_WORK(&ctrl->async_event_work, nvmet_async_event_work);
1340         INIT_LIST_HEAD(&ctrl->async_events);
1341         INIT_RADIX_TREE(&ctrl->p2p_ns_map, GFP_KERNEL);
1342         INIT_WORK(&ctrl->fatal_err_work, nvmet_fatal_error_handler);
1343
1344         memcpy(ctrl->subsysnqn, subsysnqn, NVMF_NQN_SIZE);
1345         memcpy(ctrl->hostnqn, hostnqn, NVMF_NQN_SIZE);
1346
1347         kref_init(&ctrl->ref);
1348         ctrl->subsys = subsys;
1349         WRITE_ONCE(ctrl->aen_enabled, NVMET_AEN_CFG_OPTIONAL);
1350
1351         ctrl->changed_ns_list = kmalloc_array(NVME_MAX_CHANGED_NAMESPACES,
1352                         sizeof(__le32), GFP_KERNEL);
1353         if (!ctrl->changed_ns_list)
1354                 goto out_free_ctrl;
1355
1356         ctrl->cqs = kcalloc(subsys->max_qid + 1,
1357                         sizeof(struct nvmet_cq *),
1358                         GFP_KERNEL);
1359         if (!ctrl->cqs)
1360                 goto out_free_changed_ns_list;
1361
1362         ctrl->sqs = kcalloc(subsys->max_qid + 1,
1363                         sizeof(struct nvmet_sq *),
1364                         GFP_KERNEL);
1365         if (!ctrl->sqs)
1366                 goto out_free_cqs;
1367
1368         if (subsys->cntlid_min > subsys->cntlid_max)
1369                 goto out_free_cqs;
1370
1371         ret = ida_simple_get(&cntlid_ida,
1372                              subsys->cntlid_min, subsys->cntlid_max,
1373                              GFP_KERNEL);
1374         if (ret < 0) {
1375                 status = NVME_SC_CONNECT_CTRL_BUSY | NVME_SC_DNR;
1376                 goto out_free_sqs;
1377         }
1378         ctrl->cntlid = ret;
1379
1380         ctrl->ops = req->ops;
1381
1382         /*
1383          * Discovery controllers may use some arbitrary high value
1384          * in order to cleanup stale discovery sessions
1385          */
1386         if ((ctrl->subsys->type == NVME_NQN_DISC) && !kato)
1387                 kato = NVMET_DISC_KATO_MS;
1388
1389         /* keep-alive timeout in seconds */
1390         ctrl->kato = DIV_ROUND_UP(kato, 1000);
1391
1392         ctrl->err_counter = 0;
1393         spin_lock_init(&ctrl->error_lock);
1394
1395         nvmet_start_keep_alive_timer(ctrl);
1396
1397         mutex_lock(&subsys->lock);
1398         list_add_tail(&ctrl->subsys_entry, &subsys->ctrls);
1399         nvmet_setup_p2p_ns_map(ctrl, req);
1400         mutex_unlock(&subsys->lock);
1401
1402         *ctrlp = ctrl;
1403         return 0;
1404
1405 out_free_sqs:
1406         kfree(ctrl->sqs);
1407 out_free_cqs:
1408         kfree(ctrl->cqs);
1409 out_free_changed_ns_list:
1410         kfree(ctrl->changed_ns_list);
1411 out_free_ctrl:
1412         kfree(ctrl);
1413 out_put_subsystem:
1414         nvmet_subsys_put(subsys);
1415 out:
1416         return status;
1417 }
1418
1419 static void nvmet_ctrl_free(struct kref *ref)
1420 {
1421         struct nvmet_ctrl *ctrl = container_of(ref, struct nvmet_ctrl, ref);
1422         struct nvmet_subsys *subsys = ctrl->subsys;
1423
1424         mutex_lock(&subsys->lock);
1425         nvmet_release_p2p_ns_map(ctrl);
1426         list_del(&ctrl->subsys_entry);
1427         mutex_unlock(&subsys->lock);
1428
1429         nvmet_stop_keep_alive_timer(ctrl);
1430
1431         flush_work(&ctrl->async_event_work);
1432         cancel_work_sync(&ctrl->fatal_err_work);
1433
1434         ida_simple_remove(&cntlid_ida, ctrl->cntlid);
1435
1436         nvmet_async_events_free(ctrl);
1437         kfree(ctrl->sqs);
1438         kfree(ctrl->cqs);
1439         kfree(ctrl->changed_ns_list);
1440         kfree(ctrl);
1441
1442         nvmet_subsys_put(subsys);
1443 }
1444
1445 void nvmet_ctrl_put(struct nvmet_ctrl *ctrl)
1446 {
1447         kref_put(&ctrl->ref, nvmet_ctrl_free);
1448 }
1449
1450 void nvmet_ctrl_fatal_error(struct nvmet_ctrl *ctrl)
1451 {
1452         mutex_lock(&ctrl->lock);
1453         if (!(ctrl->csts & NVME_CSTS_CFS)) {
1454                 ctrl->csts |= NVME_CSTS_CFS;
1455                 schedule_work(&ctrl->fatal_err_work);
1456         }
1457         mutex_unlock(&ctrl->lock);
1458 }
1459 EXPORT_SYMBOL_GPL(nvmet_ctrl_fatal_error);
1460
1461 static struct nvmet_subsys *nvmet_find_get_subsys(struct nvmet_port *port,
1462                 const char *subsysnqn)
1463 {
1464         struct nvmet_subsys_link *p;
1465
1466         if (!port)
1467                 return NULL;
1468
1469         if (!strcmp(NVME_DISC_SUBSYS_NAME, subsysnqn)) {
1470                 if (!kref_get_unless_zero(&nvmet_disc_subsys->ref))
1471                         return NULL;
1472                 return nvmet_disc_subsys;
1473         }
1474
1475         down_read(&nvmet_config_sem);
1476         list_for_each_entry(p, &port->subsystems, entry) {
1477                 if (!strncmp(p->subsys->subsysnqn, subsysnqn,
1478                                 NVMF_NQN_SIZE)) {
1479                         if (!kref_get_unless_zero(&p->subsys->ref))
1480                                 break;
1481                         up_read(&nvmet_config_sem);
1482                         return p->subsys;
1483                 }
1484         }
1485         up_read(&nvmet_config_sem);
1486         return NULL;
1487 }
1488
1489 struct nvmet_subsys *nvmet_subsys_alloc(const char *subsysnqn,
1490                 enum nvme_subsys_type type)
1491 {
1492         struct nvmet_subsys *subsys;
1493
1494         subsys = kzalloc(sizeof(*subsys), GFP_KERNEL);
1495         if (!subsys)
1496                 return ERR_PTR(-ENOMEM);
1497
1498         subsys->ver = NVME_VS(1, 3, 0); /* NVMe 1.3.0 */
1499         /* generate a random serial number as our controllers are ephemeral: */
1500         get_random_bytes(&subsys->serial, sizeof(subsys->serial));
1501
1502         switch (type) {
1503         case NVME_NQN_NVME:
1504                 subsys->max_qid = NVMET_NR_QUEUES;
1505                 break;
1506         case NVME_NQN_DISC:
1507                 subsys->max_qid = 0;
1508                 break;
1509         default:
1510                 pr_err("%s: Unknown Subsystem type - %d\n", __func__, type);
1511                 kfree(subsys);
1512                 return ERR_PTR(-EINVAL);
1513         }
1514         subsys->type = type;
1515         subsys->subsysnqn = kstrndup(subsysnqn, NVMF_NQN_SIZE,
1516                         GFP_KERNEL);
1517         if (!subsys->subsysnqn) {
1518                 kfree(subsys);
1519                 return ERR_PTR(-ENOMEM);
1520         }
1521         subsys->cntlid_min = NVME_CNTLID_MIN;
1522         subsys->cntlid_max = NVME_CNTLID_MAX;
1523         kref_init(&subsys->ref);
1524
1525         mutex_init(&subsys->lock);
1526         INIT_LIST_HEAD(&subsys->namespaces);
1527         INIT_LIST_HEAD(&subsys->ctrls);
1528         INIT_LIST_HEAD(&subsys->hosts);
1529
1530         return subsys;
1531 }
1532
1533 static void nvmet_subsys_free(struct kref *ref)
1534 {
1535         struct nvmet_subsys *subsys =
1536                 container_of(ref, struct nvmet_subsys, ref);
1537
1538         WARN_ON_ONCE(!list_empty(&subsys->namespaces));
1539
1540         kfree(subsys->subsysnqn);
1541         kfree_rcu(subsys->model, rcuhead);
1542         kfree(subsys);
1543 }
1544
1545 void nvmet_subsys_del_ctrls(struct nvmet_subsys *subsys)
1546 {
1547         struct nvmet_ctrl *ctrl;
1548
1549         mutex_lock(&subsys->lock);
1550         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry)
1551                 ctrl->ops->delete_ctrl(ctrl);
1552         mutex_unlock(&subsys->lock);
1553 }
1554
1555 void nvmet_subsys_put(struct nvmet_subsys *subsys)
1556 {
1557         kref_put(&subsys->ref, nvmet_subsys_free);
1558 }
1559
1560 static int __init nvmet_init(void)
1561 {
1562         int error;
1563
1564         nvmet_ana_group_enabled[NVMET_DEFAULT_ANA_GRPID] = 1;
1565
1566         buffered_io_wq = alloc_workqueue("nvmet-buffered-io-wq",
1567                         WQ_MEM_RECLAIM, 0);
1568         if (!buffered_io_wq) {
1569                 error = -ENOMEM;
1570                 goto out;
1571         }
1572
1573         error = nvmet_init_discovery();
1574         if (error)
1575                 goto out_free_work_queue;
1576
1577         error = nvmet_init_configfs();
1578         if (error)
1579                 goto out_exit_discovery;
1580         return 0;
1581
1582 out_exit_discovery:
1583         nvmet_exit_discovery();
1584 out_free_work_queue:
1585         destroy_workqueue(buffered_io_wq);
1586 out:
1587         return error;
1588 }
1589
1590 static void __exit nvmet_exit(void)
1591 {
1592         nvmet_exit_configfs();
1593         nvmet_exit_discovery();
1594         ida_destroy(&cntlid_ida);
1595         destroy_workqueue(buffered_io_wq);
1596
1597         BUILD_BUG_ON(sizeof(struct nvmf_disc_rsp_page_entry) != 1024);
1598         BUILD_BUG_ON(sizeof(struct nvmf_disc_rsp_page_hdr) != 1024);
1599 }
1600
1601 module_init(nvmet_init);
1602 module_exit(nvmet_exit);
1603
1604 MODULE_LICENSE("GPL v2");