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                 fallthrough;
  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 u16 nvmet_report_invalid_opcode(struct nvmet_req *req)
  86 {
  87         pr_debug("unhandled cmd %d on qid %d\n", req->cmd->common.opcode,
  88                  req->sq->qid);
  89
  90         req->error_loc = offsetof(struct nvme_common_command, opcode);
  91         return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
  92 }
  93
  94 static struct nvmet_subsys *nvmet_find_get_subsys(struct nvmet_port *port,
  95                 const char *subsysnqn);
  96
  97 u16 nvmet_copy_to_sgl(struct nvmet_req *req, off_t off, const void *buf,
  98                 size_t len)
  99 {
 100         if (sg_pcopy_from_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_copy_from_sgl(struct nvmet_req *req, off_t off, void *buf, size_t len)
 108 {
 109         if (sg_pcopy_to_buffer(req->sg, req->sg_cnt, buf, 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 u16 nvmet_zero_sgl(struct nvmet_req *req, off_t off, size_t len)
 117 {
 118         if (sg_zero_buffer(req->sg, req->sg_cnt, len, off) != len) {
 119                 req->error_loc = offsetof(struct nvme_common_command, dptr);
 120                 return NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR;
 121         }
 122         return 0;
 123 }
 124
 125 static unsigned int nvmet_max_nsid(struct nvmet_subsys *subsys)
 126 {
 127         unsigned long nsid = 0;
 128         struct nvmet_ns *cur;
 129         unsigned long idx;
 130
 131         xa_for_each(&subsys->namespaces, idx, cur)
 132                 nsid = cur->nsid;
 133
 134         return nsid;
 135 }
 136
 137 static u32 nvmet_async_event_result(struct nvmet_async_event *aen)
 138 {
 139         return aen->event_type | (aen->event_info << 8) | (aen->log_page << 16);
 140 }
 141
 142 static void nvmet_async_events_failall(struct nvmet_ctrl *ctrl)
 143 {
 144         u16 status = NVME_SC_INTERNAL | NVME_SC_DNR;
 145         struct nvmet_req *req;
 146
 147         mutex_lock(&ctrl->lock);
 148         while (ctrl->nr_async_event_cmds) {
 149                 req = ctrl->async_event_cmds[--ctrl->nr_async_event_cmds];
 150                 mutex_unlock(&ctrl->lock);
 151                 nvmet_req_complete(req, status);
 152                 mutex_lock(&ctrl->lock);
 153         }
 154         mutex_unlock(&ctrl->lock);
 155 }
 156
 157 static void nvmet_async_events_process(struct nvmet_ctrl *ctrl)
 158 {
 159         struct nvmet_async_event *aen;
 160         struct nvmet_req *req;
 161
 162         mutex_lock(&ctrl->lock);
 163         while (ctrl->nr_async_event_cmds && !list_empty(&ctrl->async_events)) {
 164                 aen = list_first_entry(&ctrl->async_events,
 165                                        struct nvmet_async_event, entry);
 166                 req = ctrl->async_event_cmds[--ctrl->nr_async_event_cmds];
 167                 nvmet_set_result(req, nvmet_async_event_result(aen));
 168
 169                 list_del(&aen->entry);
 170                 kfree(aen);
 171
 172                 mutex_unlock(&ctrl->lock);
 173                 trace_nvmet_async_event(ctrl, req->cqe->result.u32);
 174                 nvmet_req_complete(req, 0);
 175                 mutex_lock(&ctrl->lock);
 176         }
 177         mutex_unlock(&ctrl->lock);
 178 }
 179
 180 static void nvmet_async_events_free(struct nvmet_ctrl *ctrl)
 181 {
 182         struct nvmet_async_event *aen, *tmp;
 183
 184         mutex_lock(&ctrl->lock);
 185         list_for_each_entry_safe(aen, tmp, &ctrl->async_events, entry) {
 186                 list_del(&aen->entry);
 187                 kfree(aen);
 188         }
 189         mutex_unlock(&ctrl->lock);
 190 }
 191
 192 static void nvmet_async_event_work(struct work_struct *work)
 193 {
 194         struct nvmet_ctrl *ctrl =
 195                 container_of(work, struct nvmet_ctrl, async_event_work);
 196
 197         nvmet_async_events_process(ctrl);
 198 }
 199
 200 void nvmet_add_async_event(struct nvmet_ctrl *ctrl, u8 event_type,
 201                 u8 event_info, u8 log_page)
 202 {
 203         struct nvmet_async_event *aen;
 204
 205         aen = kmalloc(sizeof(*aen), GFP_KERNEL);
 206         if (!aen)
 207                 return;
 208
 209         aen->event_type = event_type;
 210         aen->event_info = event_info;
 211         aen->log_page = log_page;
 212
 213         mutex_lock(&ctrl->lock);
 214         list_add_tail(&aen->entry, &ctrl->async_events);
 215         mutex_unlock(&ctrl->lock);
 216
 217         schedule_work(&ctrl->async_event_work);
 218 }
 219
 220 static void nvmet_add_to_changed_ns_log(struct nvmet_ctrl *ctrl, __le32 nsid)
 221 {
 222         u32 i;
 223
 224         mutex_lock(&ctrl->lock);
 225         if (ctrl->nr_changed_ns > NVME_MAX_CHANGED_NAMESPACES)
 226                 goto out_unlock;
 227
 228         for (i = 0; i < ctrl->nr_changed_ns; i++) {
 229                 if (ctrl->changed_ns_list[i] == nsid)
 230                         goto out_unlock;
 231         }
 232
 233         if (ctrl->nr_changed_ns == NVME_MAX_CHANGED_NAMESPACES) {
 234                 ctrl->changed_ns_list[0] = cpu_to_le32(0xffffffff);
 235                 ctrl->nr_changed_ns = U32_MAX;
 236                 goto out_unlock;
 237         }
 238
 239         ctrl->changed_ns_list[ctrl->nr_changed_ns++] = nsid;
 240 out_unlock:
 241         mutex_unlock(&ctrl->lock);
 242 }
 243
 244 void nvmet_ns_changed(struct nvmet_subsys *subsys, u32 nsid)
 245 {
 246         struct nvmet_ctrl *ctrl;
 247
 248         lockdep_assert_held(&subsys->lock);
 249
 250         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
 251                 nvmet_add_to_changed_ns_log(ctrl, cpu_to_le32(nsid));
 252                 if (nvmet_aen_bit_disabled(ctrl, NVME_AEN_BIT_NS_ATTR))
 253                         continue;
 254                 nvmet_add_async_event(ctrl, NVME_AER_TYPE_NOTICE,
 255                                 NVME_AER_NOTICE_NS_CHANGED,
 256                                 NVME_LOG_CHANGED_NS);
 257         }
 258 }
 259
 260 void nvmet_send_ana_event(struct nvmet_subsys *subsys,
 261                 struct nvmet_port *port)
 262 {
 263         struct nvmet_ctrl *ctrl;
 264
 265         mutex_lock(&subsys->lock);
 266         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
 267                 if (port && ctrl->port != port)
 268                         continue;
 269                 if (nvmet_aen_bit_disabled(ctrl, NVME_AEN_BIT_ANA_CHANGE))
 270                         continue;
 271                 nvmet_add_async_event(ctrl, NVME_AER_TYPE_NOTICE,
 272                                 NVME_AER_NOTICE_ANA, NVME_LOG_ANA);
 273         }
 274         mutex_unlock(&subsys->lock);
 275 }
 276
 277 void nvmet_port_send_ana_event(struct nvmet_port *port)
 278 {
 279         struct nvmet_subsys_link *p;
 280
 281         down_read(&nvmet_config_sem);
 282         list_for_each_entry(p, &port->subsystems, entry)
 283                 nvmet_send_ana_event(p->subsys, port);
 284         up_read(&nvmet_config_sem);
 285 }
 286
 287 int nvmet_register_transport(const struct nvmet_fabrics_ops *ops)
 288 {
 289         int ret = 0;
 290
 291         down_write(&nvmet_config_sem);
 292         if (nvmet_transports[ops->type])
 293                 ret = -EINVAL;
 294         else
 295                 nvmet_transports[ops->type] = ops;
 296         up_write(&nvmet_config_sem);
 297
 298         return ret;
 299 }
 300 EXPORT_SYMBOL_GPL(nvmet_register_transport);
 301
 302 void nvmet_unregister_transport(const struct nvmet_fabrics_ops *ops)
 303 {
 304         down_write(&nvmet_config_sem);
 305         nvmet_transports[ops->type] = NULL;
 306         up_write(&nvmet_config_sem);
 307 }
 308 EXPORT_SYMBOL_GPL(nvmet_unregister_transport);
 309
 310 void nvmet_port_del_ctrls(struct nvmet_port *port, struct nvmet_subsys *subsys)
 311 {
 312         struct nvmet_ctrl *ctrl;
 313
 314         mutex_lock(&subsys->lock);
 315         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
 316                 if (ctrl->port == port)
 317                         ctrl->ops->delete_ctrl(ctrl);
 318         }
 319         mutex_unlock(&subsys->lock);
 320 }
 321
 322 int nvmet_enable_port(struct nvmet_port *port)
 323 {
 324         const struct nvmet_fabrics_ops *ops;
 325         int ret;
 326
 327         lockdep_assert_held(&nvmet_config_sem);
 328
 329         ops = nvmet_transports[port->disc_addr.trtype];
 330         if (!ops) {
 331                 up_write(&nvmet_config_sem);
 332                 request_module("nvmet-transport-%d", port->disc_addr.trtype);
 333                 down_write(&nvmet_config_sem);
 334                 ops = nvmet_transports[port->disc_addr.trtype];
 335                 if (!ops) {
 336                         pr_err("transport type %d not supported\n",
 337                                 port->disc_addr.trtype);
 338                         return -EINVAL;
 339                 }
 340         }
 341
 342         if (!try_module_get(ops->owner))
 343                 return -EINVAL;
 344
 345         /*
 346          * If the user requested PI support and the transport isn't pi capable,
 347          * don't enable the port.
 348          */
 349         if (port->pi_enable && !(ops->flags & NVMF_METADATA_SUPPORTED)) {
 350                 pr_err("T10-PI is not supported by transport type %d\n",
 351                        port->disc_addr.trtype);
 352                 ret = -EINVAL;
 353                 goto out_put;
 354         }
 355
 356         ret = ops->add_port(port);
 357         if (ret)
 358                 goto out_put;
 359
 360         /* If the transport didn't set inline_data_size, then disable it. */
 361         if (port->inline_data_size < 0)
 362                 port->inline_data_size = 0;
 363
 364         port->enabled = true;
 365         port->tr_ops = ops;
 366         return 0;
 367
 368 out_put:
 369         module_put(ops->owner);
 370         return ret;
 371 }
 372
 373 void nvmet_disable_port(struct nvmet_port *port)
 374 {
 375         const struct nvmet_fabrics_ops *ops;
 376
 377         lockdep_assert_held(&nvmet_config_sem);
 378
 379         port->enabled = false;
 380         port->tr_ops = NULL;
 381
 382         ops = nvmet_transports[port->disc_addr.trtype];
 383         ops->remove_port(port);
 384         module_put(ops->owner);
 385 }
 386
 387 static void nvmet_keep_alive_timer(struct work_struct *work)
 388 {
 389         struct nvmet_ctrl *ctrl = container_of(to_delayed_work(work),
 390                         struct nvmet_ctrl, ka_work);
 391         bool reset_tbkas = ctrl->reset_tbkas;
 392
 393         ctrl->reset_tbkas = false;
 394         if (reset_tbkas) {
 395                 pr_debug("ctrl %d reschedule traffic based keep-alive timer\n",
 396                         ctrl->cntlid);
 397                 schedule_delayed_work(&ctrl->ka_work, ctrl->kato * HZ);
 398                 return;
 399         }
 400
 401         pr_err("ctrl %d keep-alive timer (%d seconds) expired!\n",
 402                 ctrl->cntlid, ctrl->kato);
 403
 404         nvmet_ctrl_fatal_error(ctrl);
 405 }
 406
 407 void nvmet_start_keep_alive_timer(struct nvmet_ctrl *ctrl)
 408 {
 409         if (unlikely(ctrl->kato == 0))
 410                 return;
 411
 412         pr_debug("ctrl %d start keep-alive timer for %d secs\n",
 413                 ctrl->cntlid, ctrl->kato);
 414
 415         INIT_DELAYED_WORK(&ctrl->ka_work, nvmet_keep_alive_timer);
 416         schedule_delayed_work(&ctrl->ka_work, ctrl->kato * HZ);
 417 }
 418
 419 void nvmet_stop_keep_alive_timer(struct nvmet_ctrl *ctrl)
 420 {
 421         if (unlikely(ctrl->kato == 0))
 422                 return;
 423
 424         pr_debug("ctrl %d stop keep-alive\n", ctrl->cntlid);
 425
 426         cancel_delayed_work_sync(&ctrl->ka_work);
 427 }
 428
 429 u16 nvmet_req_find_ns(struct nvmet_req *req)
 430 {
 431         u32 nsid = le32_to_cpu(req->cmd->common.nsid);
 432
 433         req->ns = xa_load(&nvmet_req_subsys(req)->namespaces, nsid);
 434         if (unlikely(!req->ns)) {
 435                 req->error_loc = offsetof(struct nvme_common_command, nsid);
 436                 return NVME_SC_INVALID_NS | NVME_SC_DNR;
 437         }
 438
 439         percpu_ref_get(&req->ns->ref);
 440         return NVME_SC_SUCCESS;
 441 }
 442
 443 static void nvmet_destroy_namespace(struct percpu_ref *ref)
 444 {
 445         struct nvmet_ns *ns = container_of(ref, struct nvmet_ns, ref);
 446
 447         complete(&ns->disable_done);
 448 }
 449
 450 void nvmet_put_namespace(struct nvmet_ns *ns)
 451 {
 452         percpu_ref_put(&ns->ref);
 453 }
 454
 455 static void nvmet_ns_dev_disable(struct nvmet_ns *ns)
 456 {
 457         nvmet_bdev_ns_disable(ns);
 458         nvmet_file_ns_disable(ns);
 459 }
 460
 461 static int nvmet_p2pmem_ns_enable(struct nvmet_ns *ns)
 462 {
 463         int ret;
 464         struct pci_dev *p2p_dev;
 465
 466         if (!ns->use_p2pmem)
 467                 return 0;
 468
 469         if (!ns->bdev) {
 470                 pr_err("peer-to-peer DMA is not supported by non-block device namespaces\n");
 471                 return -EINVAL;
 472         }
 473
 474         if (!blk_queue_pci_p2pdma(ns->bdev->bd_disk->queue)) {
 475                 pr_err("peer-to-peer DMA is not supported by the driver of %s\n",
 476                        ns->device_path);
 477                 return -EINVAL;
 478         }
 479
 480         if (ns->p2p_dev) {
 481                 ret = pci_p2pdma_distance(ns->p2p_dev, nvmet_ns_dev(ns), true);
 482                 if (ret < 0)
 483                         return -EINVAL;
 484         } else {
 485                 /*
 486                  * Right now we just check that there is p2pmem available so
 487                  * we can report an error to the user right away if there
 488                  * is not. We'll find the actual device to use once we
 489                  * setup the controller when the port's device is available.
 490                  */
 491
 492                 p2p_dev = pci_p2pmem_find(nvmet_ns_dev(ns));
 493                 if (!p2p_dev) {
 494                         pr_err("no peer-to-peer memory is available for %s\n",
 495                                ns->device_path);
 496                         return -EINVAL;
 497                 }
 498
 499                 pci_dev_put(p2p_dev);
 500         }
 501
 502         return 0;
 503 }
 504
 505 /*
 506  * Note: ctrl->subsys->lock should be held when calling this function
 507  */
 508 static void nvmet_p2pmem_ns_add_p2p(struct nvmet_ctrl *ctrl,
 509                                     struct nvmet_ns *ns)
 510 {
 511         struct device *clients[2];
 512         struct pci_dev *p2p_dev;
 513         int ret;
 514
 515         if (!ctrl->p2p_client || !ns->use_p2pmem)
 516                 return;
 517
 518         if (ns->p2p_dev) {
 519                 ret = pci_p2pdma_distance(ns->p2p_dev, ctrl->p2p_client, true);
 520                 if (ret < 0)
 521                         return;
 522
 523                 p2p_dev = pci_dev_get(ns->p2p_dev);
 524         } else {
 525                 clients[0] = ctrl->p2p_client;
 526                 clients[1] = nvmet_ns_dev(ns);
 527
 528                 p2p_dev = pci_p2pmem_find_many(clients, ARRAY_SIZE(clients));
 529                 if (!p2p_dev) {
 530                         pr_err("no peer-to-peer memory is available that's supported by %s and %s\n",
 531                                dev_name(ctrl->p2p_client), ns->device_path);
 532                         return;
 533                 }
 534         }
 535
 536         ret = radix_tree_insert(&ctrl->p2p_ns_map, ns->nsid, p2p_dev);
 537         if (ret < 0)
 538                 pci_dev_put(p2p_dev);
 539
 540         pr_info("using p2pmem on %s for nsid %d\n", pci_name(p2p_dev),
 541                 ns->nsid);
 542 }
 543
 544 void nvmet_ns_revalidate(struct nvmet_ns *ns)
 545 {
 546         loff_t oldsize = ns->size;
 547
 548         if (ns->bdev)
 549                 nvmet_bdev_ns_revalidate(ns);
 550         else
 551                 nvmet_file_ns_revalidate(ns);
 552
 553         if (oldsize != ns->size)
 554                 nvmet_ns_changed(ns->subsys, ns->nsid);
 555 }
 556
 557 int nvmet_ns_enable(struct nvmet_ns *ns)
 558 {
 559         struct nvmet_subsys *subsys = ns->subsys;
 560         struct nvmet_ctrl *ctrl;
 561         int ret;
 562
 563         mutex_lock(&subsys->lock);
 564         ret = 0;
 565
 566         if (nvmet_passthru_ctrl(subsys)) {
 567                 pr_info("cannot enable both passthru and regular namespaces for a single subsystem");
 568                 goto out_unlock;
 569         }
 570
 571         if (ns->enabled)
 572                 goto out_unlock;
 573
 574         ret = -EMFILE;
 575         if (subsys->nr_namespaces == NVMET_MAX_NAMESPACES)
 576                 goto out_unlock;
 577
 578         ret = nvmet_bdev_ns_enable(ns);
 579         if (ret == -ENOTBLK)
 580                 ret = nvmet_file_ns_enable(ns);
 581         if (ret)
 582                 goto out_unlock;
 583
 584         ret = nvmet_p2pmem_ns_enable(ns);
 585         if (ret)
 586                 goto out_dev_disable;
 587
 588         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry)
 589                 nvmet_p2pmem_ns_add_p2p(ctrl, ns);
 590
 591         ret = percpu_ref_init(&ns->ref, nvmet_destroy_namespace,
 592                                 0, GFP_KERNEL);
 593         if (ret)
 594                 goto out_dev_put;
 595
 596         if (ns->nsid > subsys->max_nsid)
 597                 subsys->max_nsid = ns->nsid;
 598
 599         ret = xa_insert(&subsys->namespaces, ns->nsid, ns, GFP_KERNEL);
 600         if (ret)
 601                 goto out_restore_subsys_maxnsid;
 602
 603         subsys->nr_namespaces++;
 604
 605         nvmet_ns_changed(subsys, ns->nsid);
 606         ns->enabled = true;
 607         ret = 0;
 608 out_unlock:
 609         mutex_unlock(&subsys->lock);
 610         return ret;
 611
 612 out_restore_subsys_maxnsid:
 613         subsys->max_nsid = nvmet_max_nsid(subsys);
 614         percpu_ref_exit(&ns->ref);
 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         xa_erase(&ns->subsys->namespaces, ns->nsid);
 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_completion(&ns->disable_done);
 685
 686         ns->nsid = nsid;
 687         ns->subsys = subsys;
 688
 689         down_write(&nvmet_ana_sem);
 690         ns->anagrpid = NVMET_DEFAULT_ANA_GRPID;
 691         nvmet_ana_group_enabled[ns->anagrpid]++;
 692         up_write(&nvmet_ana_sem);
 693
 694         uuid_gen(&ns->uuid);
 695         ns->buffered_io = false;
 696
 697         return ns;
 698 }
 699
 700 static void nvmet_update_sq_head(struct nvmet_req *req)
 701 {
 702         if (req->sq->size) {
 703                 u32 old_sqhd, new_sqhd;
 704
 705                 do {
 706                         old_sqhd = req->sq->sqhd;
 707                         new_sqhd = (old_sqhd + 1) % req->sq->size;
 708                 } while (cmpxchg(&req->sq->sqhd, old_sqhd, new_sqhd) !=
 709                                         old_sqhd);
 710         }
 711         req->cqe->sq_head = cpu_to_le16(req->sq->sqhd & 0x0000FFFF);
 712 }
 713
 714 static void nvmet_set_error(struct nvmet_req *req, u16 status)
 715 {
 716         struct nvmet_ctrl *ctrl = req->sq->ctrl;
 717         struct nvme_error_slot *new_error_slot;
 718         unsigned long flags;
 719
 720         req->cqe->status = cpu_to_le16(status << 1);
 721
 722         if (!ctrl || req->error_loc == NVMET_NO_ERROR_LOC)
 723                 return;
 724
 725         spin_lock_irqsave(&ctrl->error_lock, flags);
 726         ctrl->err_counter++;
 727         new_error_slot =
 728                 &ctrl->slots[ctrl->err_counter % NVMET_ERROR_LOG_SLOTS];
 729
 730         new_error_slot->error_count = cpu_to_le64(ctrl->err_counter);
 731         new_error_slot->sqid = cpu_to_le16(req->sq->qid);
 732         new_error_slot->cmdid = cpu_to_le16(req->cmd->common.command_id);
 733         new_error_slot->status_field = cpu_to_le16(status << 1);
 734         new_error_slot->param_error_location = cpu_to_le16(req->error_loc);
 735         new_error_slot->lba = cpu_to_le64(req->error_slba);
 736         new_error_slot->nsid = req->cmd->common.nsid;
 737         spin_unlock_irqrestore(&ctrl->error_lock, flags);
 738
 739         /* set the more bit for this request */
 740         req->cqe->status |= cpu_to_le16(1 << 14);
 741 }
 742
 743 static void __nvmet_req_complete(struct nvmet_req *req, u16 status)
 744 {
 745         if (!req->sq->sqhd_disabled)
 746                 nvmet_update_sq_head(req);
 747         req->cqe->sq_id = cpu_to_le16(req->sq->qid);
 748         req->cqe->command_id = req->cmd->common.command_id;
 749
 750         if (unlikely(status))
 751                 nvmet_set_error(req, status);
 752
 753         trace_nvmet_req_complete(req);
 754
 755         if (req->ns)
 756                 nvmet_put_namespace(req->ns);
 757         req->ops->queue_response(req);
 758 }
 759
 760 void nvmet_req_complete(struct nvmet_req *req, u16 status)
 761 {
 762         __nvmet_req_complete(req, status);
 763         percpu_ref_put(&req->sq->ref);
 764 }
 765 EXPORT_SYMBOL_GPL(nvmet_req_complete);
 766
 767 void nvmet_cq_setup(struct nvmet_ctrl *ctrl, struct nvmet_cq *cq,
 768                 u16 qid, u16 size)
 769 {
 770         cq->qid = qid;
 771         cq->size = size;
 772 }
 773
 774 void nvmet_sq_setup(struct nvmet_ctrl *ctrl, struct nvmet_sq *sq,
 775                 u16 qid, u16 size)
 776 {
 777         sq->sqhd = 0;
 778         sq->qid = qid;
 779         sq->size = size;
 780
 781         ctrl->sqs[qid] = sq;
 782 }
 783
 784 static void nvmet_confirm_sq(struct percpu_ref *ref)
 785 {
 786         struct nvmet_sq *sq = container_of(ref, struct nvmet_sq, ref);
 787
 788         complete(&sq->confirm_done);
 789 }
 790
 791 void nvmet_sq_destroy(struct nvmet_sq *sq)
 792 {
 793         struct nvmet_ctrl *ctrl = sq->ctrl;
 794
 795         /*
 796          * If this is the admin queue, complete all AERs so that our
 797          * queue doesn't have outstanding requests on it.
 798          */
 799         if (ctrl && ctrl->sqs && ctrl->sqs[0] == sq)
 800                 nvmet_async_events_failall(ctrl);
 801         percpu_ref_kill_and_confirm(&sq->ref, nvmet_confirm_sq);
 802         wait_for_completion(&sq->confirm_done);
 803         wait_for_completion(&sq->free_done);
 804         percpu_ref_exit(&sq->ref);
 805
 806         if (ctrl) {
 807                 /*
 808                  * The teardown flow may take some time, and the host may not
 809                  * send us keep-alive during this period, hence reset the
 810                  * traffic based keep-alive timer so we don't trigger a
 811                  * controller teardown as a result of a keep-alive expiration.
 812                  */
 813                 ctrl->reset_tbkas = true;
 814                 nvmet_ctrl_put(ctrl);
 815                 sq->ctrl = NULL; /* allows reusing the queue later */
 816         }
 817 }
 818 EXPORT_SYMBOL_GPL(nvmet_sq_destroy);
 819
 820 static void nvmet_sq_free(struct percpu_ref *ref)
 821 {
 822         struct nvmet_sq *sq = container_of(ref, struct nvmet_sq, ref);
 823
 824         complete(&sq->free_done);
 825 }
 826
 827 int nvmet_sq_init(struct nvmet_sq *sq)
 828 {
 829         int ret;
 830
 831         ret = percpu_ref_init(&sq->ref, nvmet_sq_free, 0, GFP_KERNEL);
 832         if (ret) {
 833                 pr_err("percpu_ref init failed!\n");
 834                 return ret;
 835         }
 836         init_completion(&sq->free_done);
 837         init_completion(&sq->confirm_done);
 838
 839         return 0;
 840 }
 841 EXPORT_SYMBOL_GPL(nvmet_sq_init);
 842
 843 static inline u16 nvmet_check_ana_state(struct nvmet_port *port,
 844                 struct nvmet_ns *ns)
 845 {
 846         enum nvme_ana_state state = port->ana_state[ns->anagrpid];
 847
 848         if (unlikely(state == NVME_ANA_INACCESSIBLE))
 849                 return NVME_SC_ANA_INACCESSIBLE;
 850         if (unlikely(state == NVME_ANA_PERSISTENT_LOSS))
 851                 return NVME_SC_ANA_PERSISTENT_LOSS;
 852         if (unlikely(state == NVME_ANA_CHANGE))
 853                 return NVME_SC_ANA_TRANSITION;
 854         return 0;
 855 }
 856
 857 static inline u16 nvmet_io_cmd_check_access(struct nvmet_req *req)
 858 {
 859         if (unlikely(req->ns->readonly)) {
 860                 switch (req->cmd->common.opcode) {
 861                 case nvme_cmd_read:
 862                 case nvme_cmd_flush:
 863                         break;
 864                 default:
 865                         return NVME_SC_NS_WRITE_PROTECTED;
 866                 }
 867         }
 868
 869         return 0;
 870 }
 871
 872 static u16 nvmet_parse_io_cmd(struct nvmet_req *req)
 873 {
 874         u16 ret;
 875
 876         ret = nvmet_check_ctrl_status(req);
 877         if (unlikely(ret))
 878                 return ret;
 879
 880         if (nvmet_req_passthru_ctrl(req))
 881                 return nvmet_parse_passthru_io_cmd(req);
 882
 883         ret = nvmet_req_find_ns(req);
 884         if (unlikely(ret))
 885                 return ret;
 886
 887         ret = nvmet_check_ana_state(req->port, req->ns);
 888         if (unlikely(ret)) {
 889                 req->error_loc = offsetof(struct nvme_common_command, nsid);
 890                 return ret;
 891         }
 892         ret = nvmet_io_cmd_check_access(req);
 893         if (unlikely(ret)) {
 894                 req->error_loc = offsetof(struct nvme_common_command, nsid);
 895                 return ret;
 896         }
 897
 898         if (req->ns->file)
 899                 return nvmet_file_parse_io_cmd(req);
 900
 901         return nvmet_bdev_parse_io_cmd(req);
 902 }
 903
 904 bool nvmet_req_init(struct nvmet_req *req, struct nvmet_cq *cq,
 905                 struct nvmet_sq *sq, const struct nvmet_fabrics_ops *ops)
 906 {
 907         u8 flags = req->cmd->common.flags;
 908         u16 status;
 909
 910         req->cq = cq;
 911         req->sq = sq;
 912         req->ops = ops;
 913         req->sg = NULL;
 914         req->metadata_sg = NULL;
 915         req->sg_cnt = 0;
 916         req->metadata_sg_cnt = 0;
 917         req->transfer_len = 0;
 918         req->metadata_len = 0;
 919         req->cqe->status = 0;
 920         req->cqe->sq_head = 0;
 921         req->ns = NULL;
 922         req->error_loc = NVMET_NO_ERROR_LOC;
 923         req->error_slba = 0;
 924
 925         /* no support for fused commands yet */
 926         if (unlikely(flags & (NVME_CMD_FUSE_FIRST | NVME_CMD_FUSE_SECOND))) {
 927                 req->error_loc = offsetof(struct nvme_common_command, flags);
 928                 status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 929                 goto fail;
 930         }
 931
 932         /*
 933          * For fabrics, PSDT field shall describe metadata pointer (MPTR) that
 934          * contains an address of a single contiguous physical buffer that is
 935          * byte aligned.
 936          */
 937         if (unlikely((flags & NVME_CMD_SGL_ALL) != NVME_CMD_SGL_METABUF)) {
 938                 req->error_loc = offsetof(struct nvme_common_command, flags);
 939                 status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 940                 goto fail;
 941         }
 942
 943         if (unlikely(!req->sq->ctrl))
 944                 /* will return an error for any non-connect command: */
 945                 status = nvmet_parse_connect_cmd(req);
 946         else if (likely(req->sq->qid != 0))
 947                 status = nvmet_parse_io_cmd(req);
 948         else
 949                 status = nvmet_parse_admin_cmd(req);
 950
 951         if (status)
 952                 goto fail;
 953
 954         trace_nvmet_req_init(req, req->cmd);
 955
 956         if (unlikely(!percpu_ref_tryget_live(&sq->ref))) {
 957                 status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 958                 goto fail;
 959         }
 960
 961         if (sq->ctrl)
 962                 sq->ctrl->reset_tbkas = true;
 963
 964         return true;
 965
 966 fail:
 967         __nvmet_req_complete(req, status);
 968         return false;
 969 }
 970 EXPORT_SYMBOL_GPL(nvmet_req_init);
 971
 972 void nvmet_req_uninit(struct nvmet_req *req)
 973 {
 974         percpu_ref_put(&req->sq->ref);
 975         if (req->ns)
 976                 nvmet_put_namespace(req->ns);
 977 }
 978 EXPORT_SYMBOL_GPL(nvmet_req_uninit);
 979
 980 bool nvmet_check_transfer_len(struct nvmet_req *req, size_t len)
 981 {
 982         if (unlikely(len != req->transfer_len)) {
 983                 req->error_loc = offsetof(struct nvme_common_command, dptr);
 984                 nvmet_req_complete(req, NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR);
 985                 return false;
 986         }
 987
 988         return true;
 989 }
 990 EXPORT_SYMBOL_GPL(nvmet_check_transfer_len);
 991
 992 bool nvmet_check_data_len_lte(struct nvmet_req *req, size_t data_len)
 993 {
 994         if (unlikely(data_len > req->transfer_len)) {
 995                 req->error_loc = offsetof(struct nvme_common_command, dptr);
 996                 nvmet_req_complete(req, NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR);
 997                 return false;
 998         }
 999
1000         return true;
1001 }
1002
1003 static unsigned int nvmet_data_transfer_len(struct nvmet_req *req)
1004 {
1005         return req->transfer_len - req->metadata_len;
1006 }
1007
1008 static int nvmet_req_alloc_p2pmem_sgls(struct pci_dev *p2p_dev,
1009                 struct nvmet_req *req)
1010 {
1011         req->sg = pci_p2pmem_alloc_sgl(p2p_dev, &req->sg_cnt,
1012                         nvmet_data_transfer_len(req));
1013         if (!req->sg)
1014                 goto out_err;
1015
1016         if (req->metadata_len) {
1017                 req->metadata_sg = pci_p2pmem_alloc_sgl(p2p_dev,
1018                                 &req->metadata_sg_cnt, req->metadata_len);
1019                 if (!req->metadata_sg)
1020                         goto out_free_sg;
1021         }
1022
1023         req->p2p_dev = p2p_dev;
1024
1025         return 0;
1026 out_free_sg:
1027         pci_p2pmem_free_sgl(req->p2p_dev, req->sg);
1028 out_err:
1029         return -ENOMEM;
1030 }
1031
1032 static struct pci_dev *nvmet_req_find_p2p_dev(struct nvmet_req *req)
1033 {
1034         if (!IS_ENABLED(CONFIG_PCI_P2PDMA) ||
1035             !req->sq->ctrl || !req->sq->qid || !req->ns)
1036                 return NULL;
1037         return radix_tree_lookup(&req->sq->ctrl->p2p_ns_map, req->ns->nsid);
1038 }
1039
1040 int nvmet_req_alloc_sgls(struct nvmet_req *req)
1041 {
1042         struct pci_dev *p2p_dev = nvmet_req_find_p2p_dev(req);
1043
1044         if (p2p_dev && !nvmet_req_alloc_p2pmem_sgls(p2p_dev, req))
1045                 return 0;
1046
1047         req->sg = sgl_alloc(nvmet_data_transfer_len(req), GFP_KERNEL,
1048                             &req->sg_cnt);
1049         if (unlikely(!req->sg))
1050                 goto out;
1051
1052         if (req->metadata_len) {
1053                 req->metadata_sg = sgl_alloc(req->metadata_len, GFP_KERNEL,
1054                                              &req->metadata_sg_cnt);
1055                 if (unlikely(!req->metadata_sg))
1056                         goto out_free;
1057         }
1058
1059         return 0;
1060 out_free:
1061         sgl_free(req->sg);
1062 out:
1063         return -ENOMEM;
1064 }
1065 EXPORT_SYMBOL_GPL(nvmet_req_alloc_sgls);
1066
1067 void nvmet_req_free_sgls(struct nvmet_req *req)
1068 {
1069         if (req->p2p_dev) {
1070                 pci_p2pmem_free_sgl(req->p2p_dev, req->sg);
1071                 if (req->metadata_sg)
1072                         pci_p2pmem_free_sgl(req->p2p_dev, req->metadata_sg);
1073                 req->p2p_dev = NULL;
1074         } else {
1075                 sgl_free(req->sg);
1076                 if (req->metadata_sg)
1077                         sgl_free(req->metadata_sg);
1078         }
1079
1080         req->sg = NULL;
1081         req->metadata_sg = NULL;
1082         req->sg_cnt = 0;
1083         req->metadata_sg_cnt = 0;
1084 }
1085 EXPORT_SYMBOL_GPL(nvmet_req_free_sgls);
1086
1087 static inline bool nvmet_cc_en(u32 cc)
1088 {
1089         return (cc >> NVME_CC_EN_SHIFT) & 0x1;
1090 }
1091
1092 static inline u8 nvmet_cc_css(u32 cc)
1093 {
1094         return (cc >> NVME_CC_CSS_SHIFT) & 0x7;
1095 }
1096
1097 static inline u8 nvmet_cc_mps(u32 cc)
1098 {
1099         return (cc >> NVME_CC_MPS_SHIFT) & 0xf;
1100 }
1101
1102 static inline u8 nvmet_cc_ams(u32 cc)
1103 {
1104         return (cc >> NVME_CC_AMS_SHIFT) & 0x7;
1105 }
1106
1107 static inline u8 nvmet_cc_shn(u32 cc)
1108 {
1109         return (cc >> NVME_CC_SHN_SHIFT) & 0x3;
1110 }
1111
1112 static inline u8 nvmet_cc_iosqes(u32 cc)
1113 {
1114         return (cc >> NVME_CC_IOSQES_SHIFT) & 0xf;
1115 }
1116
1117 static inline u8 nvmet_cc_iocqes(u32 cc)
1118 {
1119         return (cc >> NVME_CC_IOCQES_SHIFT) & 0xf;
1120 }
1121
1122 static void nvmet_start_ctrl(struct nvmet_ctrl *ctrl)
1123 {
1124         lockdep_assert_held(&ctrl->lock);
1125
1126         /*
1127          * Only I/O controllers should verify iosqes,iocqes.
1128          * Strictly speaking, the spec says a discovery controller
1129          * should verify iosqes,iocqes are zeroed, however that
1130          * would break backwards compatibility, so don't enforce it.
1131          */
1132         if (ctrl->subsys->type != NVME_NQN_DISC &&
1133             (nvmet_cc_iosqes(ctrl->cc) != NVME_NVM_IOSQES ||
1134              nvmet_cc_iocqes(ctrl->cc) != NVME_NVM_IOCQES)) {
1135                 ctrl->csts = NVME_CSTS_CFS;
1136                 return;
1137         }
1138
1139         if (nvmet_cc_mps(ctrl->cc) != 0 ||
1140             nvmet_cc_ams(ctrl->cc) != 0 ||
1141             nvmet_cc_css(ctrl->cc) != 0) {
1142                 ctrl->csts = NVME_CSTS_CFS;
1143                 return;
1144         }
1145
1146         ctrl->csts = NVME_CSTS_RDY;
1147
1148         /*
1149          * Controllers that are not yet enabled should not really enforce the
1150          * keep alive timeout, but we still want to track a timeout and cleanup
1151          * in case a host died before it enabled the controller.  Hence, simply
1152          * reset the keep alive timer when the controller is enabled.
1153          */
1154         if (ctrl->kato)
1155                 mod_delayed_work(system_wq, &ctrl->ka_work, ctrl->kato * HZ);
1156 }
1157
1158 static void nvmet_clear_ctrl(struct nvmet_ctrl *ctrl)
1159 {
1160         lockdep_assert_held(&ctrl->lock);
1161
1162         /* XXX: tear down queues? */
1163         ctrl->csts &= ~NVME_CSTS_RDY;
1164         ctrl->cc = 0;
1165 }
1166
1167 void nvmet_update_cc(struct nvmet_ctrl *ctrl, u32 new)
1168 {
1169         u32 old;
1170
1171         mutex_lock(&ctrl->lock);
1172         old = ctrl->cc;
1173         ctrl->cc = new;
1174
1175         if (nvmet_cc_en(new) && !nvmet_cc_en(old))
1176                 nvmet_start_ctrl(ctrl);
1177         if (!nvmet_cc_en(new) && nvmet_cc_en(old))
1178                 nvmet_clear_ctrl(ctrl);
1179         if (nvmet_cc_shn(new) && !nvmet_cc_shn(old)) {
1180                 nvmet_clear_ctrl(ctrl);
1181                 ctrl->csts |= NVME_CSTS_SHST_CMPLT;
1182         }
1183         if (!nvmet_cc_shn(new) && nvmet_cc_shn(old))
1184                 ctrl->csts &= ~NVME_CSTS_SHST_CMPLT;
1185         mutex_unlock(&ctrl->lock);
1186 }
1187
1188 static void nvmet_init_cap(struct nvmet_ctrl *ctrl)
1189 {
1190         /* command sets supported: NVMe command set: */
1191         ctrl->cap = (1ULL << 37);
1192         /* CC.EN timeout in 500msec units: */
1193         ctrl->cap |= (15ULL << 24);
1194         /* maximum queue entries supported: */
1195         ctrl->cap |= NVMET_QUEUE_SIZE - 1;
1196 }
1197
1198 struct nvmet_ctrl *nvmet_ctrl_find_get(const char *subsysnqn,
1199                                        const char *hostnqn, u16 cntlid,
1200                                        struct nvmet_req *req)
1201 {
1202         struct nvmet_ctrl *ctrl = NULL;
1203         struct nvmet_subsys *subsys;
1204
1205         subsys = nvmet_find_get_subsys(req->port, subsysnqn);
1206         if (!subsys) {
1207                 pr_warn("connect request for invalid subsystem %s!\n",
1208                         subsysnqn);
1209                 req->cqe->result.u32 = IPO_IATTR_CONNECT_DATA(subsysnqn);
1210                 goto out;
1211         }
1212
1213         mutex_lock(&subsys->lock);
1214         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
1215                 if (ctrl->cntlid == cntlid) {
1216                         if (strncmp(hostnqn, ctrl->hostnqn, NVMF_NQN_SIZE)) {
1217                                 pr_warn("hostnqn mismatch.\n");
1218                                 continue;
1219                         }
1220                         if (!kref_get_unless_zero(&ctrl->ref))
1221                                 continue;
1222
1223                         /* ctrl found */
1224                         goto found;
1225                 }
1226         }
1227
1228         ctrl = NULL; /* ctrl not found */
1229         pr_warn("could not find controller %d for subsys %s / host %s\n",
1230                 cntlid, subsysnqn, hostnqn);
1231         req->cqe->result.u32 = IPO_IATTR_CONNECT_DATA(cntlid);
1232
1233 found:
1234         mutex_unlock(&subsys->lock);
1235         nvmet_subsys_put(subsys);
1236 out:
1237         return ctrl;
1238 }
1239
1240 u16 nvmet_check_ctrl_status(struct nvmet_req *req)
1241 {
1242         if (unlikely(!(req->sq->ctrl->cc & NVME_CC_ENABLE))) {
1243                 pr_err("got cmd %d while CC.EN == 0 on qid = %d\n",
1244                        req->cmd->common.opcode, req->sq->qid);
1245                 return NVME_SC_CMD_SEQ_ERROR | NVME_SC_DNR;
1246         }
1247
1248         if (unlikely(!(req->sq->ctrl->csts & NVME_CSTS_RDY))) {
1249                 pr_err("got cmd %d while CSTS.RDY == 0 on qid = %d\n",
1250                        req->cmd->common.opcode, req->sq->qid);
1251                 return NVME_SC_CMD_SEQ_ERROR | NVME_SC_DNR;
1252         }
1253         return 0;
1254 }
1255
1256 bool nvmet_host_allowed(struct nvmet_subsys *subsys, const char *hostnqn)
1257 {
1258         struct nvmet_host_link *p;
1259
1260         lockdep_assert_held(&nvmet_config_sem);
1261
1262         if (subsys->allow_any_host)
1263                 return true;
1264
1265         if (subsys->type == NVME_NQN_DISC) /* allow all access to disc subsys */
1266                 return true;
1267
1268         list_for_each_entry(p, &subsys->hosts, entry) {
1269                 if (!strcmp(nvmet_host_name(p->host), hostnqn))
1270                         return true;
1271         }
1272
1273         return false;
1274 }
1275
1276 /*
1277  * Note: ctrl->subsys->lock should be held when calling this function
1278  */
1279 static void nvmet_setup_p2p_ns_map(struct nvmet_ctrl *ctrl,
1280                 struct nvmet_req *req)
1281 {
1282         struct nvmet_ns *ns;
1283         unsigned long idx;
1284
1285         if (!req->p2p_client)
1286                 return;
1287
1288         ctrl->p2p_client = get_device(req->p2p_client);
1289
1290         xa_for_each(&ctrl->subsys->namespaces, idx, ns)
1291                 nvmet_p2pmem_ns_add_p2p(ctrl, ns);
1292 }
1293
1294 /*
1295  * Note: ctrl->subsys->lock should be held when calling this function
1296  */
1297 static void nvmet_release_p2p_ns_map(struct nvmet_ctrl *ctrl)
1298 {
1299         struct radix_tree_iter iter;
1300         void __rcu **slot;
1301
1302         radix_tree_for_each_slot(slot, &ctrl->p2p_ns_map, &iter, 0)
1303                 pci_dev_put(radix_tree_deref_slot(slot));
1304
1305         put_device(ctrl->p2p_client);
1306 }
1307
1308 static void nvmet_fatal_error_handler(struct work_struct *work)
1309 {
1310         struct nvmet_ctrl *ctrl =
1311                         container_of(work, struct nvmet_ctrl, fatal_err_work);
1312
1313         pr_err("ctrl %d fatal error occurred!\n", ctrl->cntlid);
1314         ctrl->ops->delete_ctrl(ctrl);
1315 }
1316
1317 u16 nvmet_alloc_ctrl(const char *subsysnqn, const char *hostnqn,
1318                 struct nvmet_req *req, u32 kato, struct nvmet_ctrl **ctrlp)
1319 {
1320         struct nvmet_subsys *subsys;
1321         struct nvmet_ctrl *ctrl;
1322         int ret;
1323         u16 status;
1324
1325         status = NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR;
1326         subsys = nvmet_find_get_subsys(req->port, subsysnqn);
1327         if (!subsys) {
1328                 pr_warn("connect request for invalid subsystem %s!\n",
1329                         subsysnqn);
1330                 req->cqe->result.u32 = IPO_IATTR_CONNECT_DATA(subsysnqn);
1331                 req->error_loc = offsetof(struct nvme_common_command, dptr);
1332                 goto out;
1333         }
1334
1335         down_read(&nvmet_config_sem);
1336         if (!nvmet_host_allowed(subsys, hostnqn)) {
1337                 pr_info("connect by host %s for subsystem %s not allowed\n",
1338                         hostnqn, subsysnqn);
1339                 req->cqe->result.u32 = IPO_IATTR_CONNECT_DATA(hostnqn);
1340                 up_read(&nvmet_config_sem);
1341                 status = NVME_SC_CONNECT_INVALID_HOST | NVME_SC_DNR;
1342                 req->error_loc = offsetof(struct nvme_common_command, dptr);
1343                 goto out_put_subsystem;
1344         }
1345         up_read(&nvmet_config_sem);
1346
1347         status = NVME_SC_INTERNAL;
1348         ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
1349         if (!ctrl)
1350                 goto out_put_subsystem;
1351         mutex_init(&ctrl->lock);
1352
1353         nvmet_init_cap(ctrl);
1354
1355         ctrl->port = req->port;
1356
1357         INIT_WORK(&ctrl->async_event_work, nvmet_async_event_work);
1358         INIT_LIST_HEAD(&ctrl->async_events);
1359         INIT_RADIX_TREE(&ctrl->p2p_ns_map, GFP_KERNEL);
1360         INIT_WORK(&ctrl->fatal_err_work, nvmet_fatal_error_handler);
1361
1362         memcpy(ctrl->subsysnqn, subsysnqn, NVMF_NQN_SIZE);
1363         memcpy(ctrl->hostnqn, hostnqn, NVMF_NQN_SIZE);
1364
1365         kref_init(&ctrl->ref);
1366         ctrl->subsys = subsys;
1367         WRITE_ONCE(ctrl->aen_enabled, NVMET_AEN_CFG_OPTIONAL);
1368
1369         ctrl->changed_ns_list = kmalloc_array(NVME_MAX_CHANGED_NAMESPACES,
1370                         sizeof(__le32), GFP_KERNEL);
1371         if (!ctrl->changed_ns_list)
1372                 goto out_free_ctrl;
1373
1374         ctrl->sqs = kcalloc(subsys->max_qid + 1,
1375                         sizeof(struct nvmet_sq *),
1376                         GFP_KERNEL);
1377         if (!ctrl->sqs)
1378                 goto out_free_changed_ns_list;
1379
1380         if (subsys->cntlid_min > subsys->cntlid_max)
1381                 goto out_free_sqs;
1382
1383         ret = ida_simple_get(&cntlid_ida,
1384                              subsys->cntlid_min, subsys->cntlid_max,
1385                              GFP_KERNEL);
1386         if (ret < 0) {
1387                 status = NVME_SC_CONNECT_CTRL_BUSY | NVME_SC_DNR;
1388                 goto out_free_sqs;
1389         }
1390         ctrl->cntlid = ret;
1391
1392         ctrl->ops = req->ops;
1393
1394         /*
1395          * Discovery controllers may use some arbitrary high value
1396          * in order to cleanup stale discovery sessions
1397          */
1398         if ((ctrl->subsys->type == NVME_NQN_DISC) && !kato)
1399                 kato = NVMET_DISC_KATO_MS;
1400
1401         /* keep-alive timeout in seconds */
1402         ctrl->kato = DIV_ROUND_UP(kato, 1000);
1403
1404         ctrl->err_counter = 0;
1405         spin_lock_init(&ctrl->error_lock);
1406
1407         nvmet_start_keep_alive_timer(ctrl);
1408
1409         mutex_lock(&subsys->lock);
1410         list_add_tail(&ctrl->subsys_entry, &subsys->ctrls);
1411         nvmet_setup_p2p_ns_map(ctrl, req);
1412         mutex_unlock(&subsys->lock);
1413
1414         *ctrlp = ctrl;
1415         return 0;
1416
1417 out_free_sqs:
1418         kfree(ctrl->sqs);
1419 out_free_changed_ns_list:
1420         kfree(ctrl->changed_ns_list);
1421 out_free_ctrl:
1422         kfree(ctrl);
1423 out_put_subsystem:
1424         nvmet_subsys_put(subsys);
1425 out:
1426         return status;
1427 }
1428
1429 static void nvmet_ctrl_free(struct kref *ref)
1430 {
1431         struct nvmet_ctrl *ctrl = container_of(ref, struct nvmet_ctrl, ref);
1432         struct nvmet_subsys *subsys = ctrl->subsys;
1433
1434         mutex_lock(&subsys->lock);
1435         nvmet_release_p2p_ns_map(ctrl);
1436         list_del(&ctrl->subsys_entry);
1437         mutex_unlock(&subsys->lock);
1438
1439         nvmet_stop_keep_alive_timer(ctrl);
1440
1441         flush_work(&ctrl->async_event_work);
1442         cancel_work_sync(&ctrl->fatal_err_work);
1443
1444         ida_simple_remove(&cntlid_ida, ctrl->cntlid);
1445
1446         nvmet_async_events_free(ctrl);
1447         kfree(ctrl->sqs);
1448         kfree(ctrl->changed_ns_list);
1449         kfree(ctrl);
1450
1451         nvmet_subsys_put(subsys);
1452 }
1453
1454 void nvmet_ctrl_put(struct nvmet_ctrl *ctrl)
1455 {
1456         kref_put(&ctrl->ref, nvmet_ctrl_free);
1457 }
1458
1459 void nvmet_ctrl_fatal_error(struct nvmet_ctrl *ctrl)
1460 {
1461         mutex_lock(&ctrl->lock);
1462         if (!(ctrl->csts & NVME_CSTS_CFS)) {
1463                 ctrl->csts |= NVME_CSTS_CFS;
1464                 schedule_work(&ctrl->fatal_err_work);
1465         }
1466         mutex_unlock(&ctrl->lock);
1467 }
1468 EXPORT_SYMBOL_GPL(nvmet_ctrl_fatal_error);
1469
1470 static struct nvmet_subsys *nvmet_find_get_subsys(struct nvmet_port *port,
1471                 const char *subsysnqn)
1472 {
1473         struct nvmet_subsys_link *p;
1474
1475         if (!port)
1476                 return NULL;
1477
1478         if (!strcmp(NVME_DISC_SUBSYS_NAME, subsysnqn)) {
1479                 if (!kref_get_unless_zero(&nvmet_disc_subsys->ref))
1480                         return NULL;
1481                 return nvmet_disc_subsys;
1482         }
1483
1484         down_read(&nvmet_config_sem);
1485         list_for_each_entry(p, &port->subsystems, entry) {
1486                 if (!strncmp(p->subsys->subsysnqn, subsysnqn,
1487                                 NVMF_NQN_SIZE)) {
1488                         if (!kref_get_unless_zero(&p->subsys->ref))
1489                                 break;
1490                         up_read(&nvmet_config_sem);
1491                         return p->subsys;
1492                 }
1493         }
1494         up_read(&nvmet_config_sem);
1495         return NULL;
1496 }
1497
1498 struct nvmet_subsys *nvmet_subsys_alloc(const char *subsysnqn,
1499                 enum nvme_subsys_type type)
1500 {
1501         struct nvmet_subsys *subsys;
1502
1503         subsys = kzalloc(sizeof(*subsys), GFP_KERNEL);
1504         if (!subsys)
1505                 return ERR_PTR(-ENOMEM);
1506
1507         subsys->ver = NVMET_DEFAULT_VS;
1508         /* generate a random serial number as our controllers are ephemeral: */
1509         get_random_bytes(&subsys->serial, sizeof(subsys->serial));
1510
1511         switch (type) {
1512         case NVME_NQN_NVME:
1513                 subsys->max_qid = NVMET_NR_QUEUES;
1514                 break;
1515         case NVME_NQN_DISC:
1516                 subsys->max_qid = 0;
1517                 break;
1518         default:
1519                 pr_err("%s: Unknown Subsystem type - %d\n", __func__, type);
1520                 kfree(subsys);
1521                 return ERR_PTR(-EINVAL);
1522         }
1523         subsys->type = type;
1524         subsys->subsysnqn = kstrndup(subsysnqn, NVMF_NQN_SIZE,
1525                         GFP_KERNEL);
1526         if (!subsys->subsysnqn) {
1527                 kfree(subsys);
1528                 return ERR_PTR(-ENOMEM);
1529         }
1530         subsys->cntlid_min = NVME_CNTLID_MIN;
1531         subsys->cntlid_max = NVME_CNTLID_MAX;
1532         kref_init(&subsys->ref);
1533
1534         mutex_init(&subsys->lock);
1535         xa_init(&subsys->namespaces);
1536         INIT_LIST_HEAD(&subsys->ctrls);
1537         INIT_LIST_HEAD(&subsys->hosts);
1538
1539         return subsys;
1540 }
1541
1542 static void nvmet_subsys_free(struct kref *ref)
1543 {
1544         struct nvmet_subsys *subsys =
1545                 container_of(ref, struct nvmet_subsys, ref);
1546
1547         WARN_ON_ONCE(!xa_empty(&subsys->namespaces));
1548
1549         xa_destroy(&subsys->namespaces);
1550         nvmet_passthru_subsys_free(subsys);
1551
1552         kfree(subsys->subsysnqn);
1553         kfree(subsys->model_number);
1554         kfree(subsys);
1555 }
1556
1557 void nvmet_subsys_del_ctrls(struct nvmet_subsys *subsys)
1558 {
1559         struct nvmet_ctrl *ctrl;
1560
1561         mutex_lock(&subsys->lock);
1562         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry)
1563                 ctrl->ops->delete_ctrl(ctrl);
1564         mutex_unlock(&subsys->lock);
1565 }
1566
1567 void nvmet_subsys_put(struct nvmet_subsys *subsys)
1568 {
1569         kref_put(&subsys->ref, nvmet_subsys_free);
1570 }
1571
1572 static int __init nvmet_init(void)
1573 {
1574         int error;
1575
1576         nvmet_ana_group_enabled[NVMET_DEFAULT_ANA_GRPID] = 1;
1577
1578         buffered_io_wq = alloc_workqueue("nvmet-buffered-io-wq",
1579                         WQ_MEM_RECLAIM, 0);
1580         if (!buffered_io_wq) {
1581                 error = -ENOMEM;
1582                 goto out;
1583         }
1584
1585         error = nvmet_init_discovery();
1586         if (error)
1587                 goto out_free_work_queue;
1588
1589         error = nvmet_init_configfs();
1590         if (error)
1591                 goto out_exit_discovery;
1592         return 0;
1593
1594 out_exit_discovery:
1595         nvmet_exit_discovery();
1596 out_free_work_queue:
1597         destroy_workqueue(buffered_io_wq);
1598 out:
1599         return error;
1600 }
1601
1602 static void __exit nvmet_exit(void)
1603 {
1604         nvmet_exit_configfs();
1605         nvmet_exit_discovery();
1606         ida_destroy(&cntlid_ida);
1607         destroy_workqueue(buffered_io_wq);
1608
1609         BUILD_BUG_ON(sizeof(struct nvmf_disc_rsp_page_entry) != 1024);
1610         BUILD_BUG_ON(sizeof(struct nvmf_disc_rsp_page_hdr) != 1024);
1611 }
1612
1613 module_init(nvmet_init);
1614 module_exit(nvmet_exit);
1615
1616 MODULE_LICENSE("GPL v2");