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 cmd_seen = ctrl->cmd_seen;
 392
 393         ctrl->cmd_seen = false;
 394         if (cmd_seen) {
 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         schedule_delayed_work(&ctrl->ka_work, ctrl->kato * HZ);
 416 }
 417
 418 void nvmet_stop_keep_alive_timer(struct nvmet_ctrl *ctrl)
 419 {
 420         if (unlikely(ctrl->kato == 0))
 421                 return;
 422
 423         pr_debug("ctrl %d stop keep-alive\n", ctrl->cntlid);
 424
 425         cancel_delayed_work_sync(&ctrl->ka_work);
 426 }
 427
 428 u16 nvmet_req_find_ns(struct nvmet_req *req)
 429 {
 430         u32 nsid = le32_to_cpu(req->cmd->common.nsid);
 431
 432         req->ns = xa_load(&nvmet_req_subsys(req)->namespaces, nsid);
 433         if (unlikely(!req->ns)) {
 434                 req->error_loc = offsetof(struct nvme_common_command, nsid);
 435                 return NVME_SC_INVALID_NS | NVME_SC_DNR;
 436         }
 437
 438         percpu_ref_get(&req->ns->ref);
 439         return NVME_SC_SUCCESS;
 440 }
 441
 442 static void nvmet_destroy_namespace(struct percpu_ref *ref)
 443 {
 444         struct nvmet_ns *ns = container_of(ref, struct nvmet_ns, ref);
 445
 446         complete(&ns->disable_done);
 447 }
 448
 449 void nvmet_put_namespace(struct nvmet_ns *ns)
 450 {
 451         percpu_ref_put(&ns->ref);
 452 }
 453
 454 static void nvmet_ns_dev_disable(struct nvmet_ns *ns)
 455 {
 456         nvmet_bdev_ns_disable(ns);
 457         nvmet_file_ns_disable(ns);
 458 }
 459
 460 static int nvmet_p2pmem_ns_enable(struct nvmet_ns *ns)
 461 {
 462         int ret;
 463         struct pci_dev *p2p_dev;
 464
 465         if (!ns->use_p2pmem)
 466                 return 0;
 467
 468         if (!ns->bdev) {
 469                 pr_err("peer-to-peer DMA is not supported by non-block device namespaces\n");
 470                 return -EINVAL;
 471         }
 472
 473         if (!blk_queue_pci_p2pdma(ns->bdev->bd_disk->queue)) {
 474                 pr_err("peer-to-peer DMA is not supported by the driver of %s\n",
 475                        ns->device_path);
 476                 return -EINVAL;
 477         }
 478
 479         if (ns->p2p_dev) {
 480                 ret = pci_p2pdma_distance(ns->p2p_dev, nvmet_ns_dev(ns), true);
 481                 if (ret < 0)
 482                         return -EINVAL;
 483         } else {
 484                 /*
 485                  * Right now we just check that there is p2pmem available so
 486                  * we can report an error to the user right away if there
 487                  * is not. We'll find the actual device to use once we
 488                  * setup the controller when the port's device is available.
 489                  */
 490
 491                 p2p_dev = pci_p2pmem_find(nvmet_ns_dev(ns));
 492                 if (!p2p_dev) {
 493                         pr_err("no peer-to-peer memory is available for %s\n",
 494                                ns->device_path);
 495                         return -EINVAL;
 496                 }
 497
 498                 pci_dev_put(p2p_dev);
 499         }
 500
 501         return 0;
 502 }
 503
 504 /*
 505  * Note: ctrl->subsys->lock should be held when calling this function
 506  */
 507 static void nvmet_p2pmem_ns_add_p2p(struct nvmet_ctrl *ctrl,
 508                                     struct nvmet_ns *ns)
 509 {
 510         struct device *clients[2];
 511         struct pci_dev *p2p_dev;
 512         int ret;
 513
 514         if (!ctrl->p2p_client || !ns->use_p2pmem)
 515                 return;
 516
 517         if (ns->p2p_dev) {
 518                 ret = pci_p2pdma_distance(ns->p2p_dev, ctrl->p2p_client, true);
 519                 if (ret < 0)
 520                         return;
 521
 522                 p2p_dev = pci_dev_get(ns->p2p_dev);
 523         } else {
 524                 clients[0] = ctrl->p2p_client;
 525                 clients[1] = nvmet_ns_dev(ns);
 526
 527                 p2p_dev = pci_p2pmem_find_many(clients, ARRAY_SIZE(clients));
 528                 if (!p2p_dev) {
 529                         pr_err("no peer-to-peer memory is available that's supported by %s and %s\n",
 530                                dev_name(ctrl->p2p_client), ns->device_path);
 531                         return;
 532                 }
 533         }
 534
 535         ret = radix_tree_insert(&ctrl->p2p_ns_map, ns->nsid, p2p_dev);
 536         if (ret < 0)
 537                 pci_dev_put(p2p_dev);
 538
 539         pr_info("using p2pmem on %s for nsid %d\n", pci_name(p2p_dev),
 540                 ns->nsid);
 541 }
 542
 543 void nvmet_ns_revalidate(struct nvmet_ns *ns)
 544 {
 545         loff_t oldsize = ns->size;
 546
 547         if (ns->bdev)
 548                 nvmet_bdev_ns_revalidate(ns);
 549         else
 550                 nvmet_file_ns_revalidate(ns);
 551
 552         if (oldsize != ns->size)
 553                 nvmet_ns_changed(ns->subsys, ns->nsid);
 554 }
 555
 556 int nvmet_ns_enable(struct nvmet_ns *ns)
 557 {
 558         struct nvmet_subsys *subsys = ns->subsys;
 559         struct nvmet_ctrl *ctrl;
 560         int ret;
 561
 562         mutex_lock(&subsys->lock);
 563         ret = 0;
 564
 565         if (nvmet_passthru_ctrl(subsys)) {
 566                 pr_info("cannot enable both passthru and regular namespaces for a single subsystem");
 567                 goto out_unlock;
 568         }
 569
 570         if (ns->enabled)
 571                 goto out_unlock;
 572
 573         ret = -EMFILE;
 574         if (subsys->nr_namespaces == NVMET_MAX_NAMESPACES)
 575                 goto out_unlock;
 576
 577         ret = nvmet_bdev_ns_enable(ns);
 578         if (ret == -ENOTBLK)
 579                 ret = nvmet_file_ns_enable(ns);
 580         if (ret)
 581                 goto out_unlock;
 582
 583         ret = nvmet_p2pmem_ns_enable(ns);
 584         if (ret)
 585                 goto out_dev_disable;
 586
 587         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry)
 588                 nvmet_p2pmem_ns_add_p2p(ctrl, ns);
 589
 590         ret = percpu_ref_init(&ns->ref, nvmet_destroy_namespace,
 591                                 0, GFP_KERNEL);
 592         if (ret)
 593                 goto out_dev_put;
 594
 595         if (ns->nsid > subsys->max_nsid)
 596                 subsys->max_nsid = ns->nsid;
 597
 598         ret = xa_insert(&subsys->namespaces, ns->nsid, ns, GFP_KERNEL);
 599         if (ret)
 600                 goto out_restore_subsys_maxnsid;
 601
 602         subsys->nr_namespaces++;
 603
 604         nvmet_ns_changed(subsys, ns->nsid);
 605         ns->enabled = true;
 606         ret = 0;
 607 out_unlock:
 608         mutex_unlock(&subsys->lock);
 609         return ret;
 610
 611 out_restore_subsys_maxnsid:
 612         subsys->max_nsid = nvmet_max_nsid(subsys);
 613         percpu_ref_exit(&ns->ref);
 614 out_dev_put:
 615         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry)
 616                 pci_dev_put(radix_tree_delete(&ctrl->p2p_ns_map, ns->nsid));
 617 out_dev_disable:
 618         nvmet_ns_dev_disable(ns);
 619         goto out_unlock;
 620 }
 621
 622 void nvmet_ns_disable(struct nvmet_ns *ns)
 623 {
 624         struct nvmet_subsys *subsys = ns->subsys;
 625         struct nvmet_ctrl *ctrl;
 626
 627         mutex_lock(&subsys->lock);
 628         if (!ns->enabled)
 629                 goto out_unlock;
 630
 631         ns->enabled = false;
 632         xa_erase(&ns->subsys->namespaces, ns->nsid);
 633         if (ns->nsid == subsys->max_nsid)
 634                 subsys->max_nsid = nvmet_max_nsid(subsys);
 635
 636         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry)
 637                 pci_dev_put(radix_tree_delete(&ctrl->p2p_ns_map, ns->nsid));
 638
 639         mutex_unlock(&subsys->lock);
 640
 641         /*
 642          * Now that we removed the namespaces from the lookup list, we
 643          * can kill the per_cpu ref and wait for any remaining references
 644          * to be dropped, as well as a RCU grace period for anyone only
 645          * using the namepace under rcu_read_lock().  Note that we can't
 646          * use call_rcu here as we need to ensure the namespaces have
 647          * been fully destroyed before unloading the module.
 648          */
 649         percpu_ref_kill(&ns->ref);
 650         synchronize_rcu();
 651         wait_for_completion(&ns->disable_done);
 652         percpu_ref_exit(&ns->ref);
 653
 654         mutex_lock(&subsys->lock);
 655
 656         subsys->nr_namespaces--;
 657         nvmet_ns_changed(subsys, ns->nsid);
 658         nvmet_ns_dev_disable(ns);
 659 out_unlock:
 660         mutex_unlock(&subsys->lock);
 661 }
 662
 663 void nvmet_ns_free(struct nvmet_ns *ns)
 664 {
 665         nvmet_ns_disable(ns);
 666
 667         down_write(&nvmet_ana_sem);
 668         nvmet_ana_group_enabled[ns->anagrpid]--;
 669         up_write(&nvmet_ana_sem);
 670
 671         kfree(ns->device_path);
 672         kfree(ns);
 673 }
 674
 675 struct nvmet_ns *nvmet_ns_alloc(struct nvmet_subsys *subsys, u32 nsid)
 676 {
 677         struct nvmet_ns *ns;
 678
 679         ns = kzalloc(sizeof(*ns), GFP_KERNEL);
 680         if (!ns)
 681                 return NULL;
 682
 683         init_completion(&ns->disable_done);
 684
 685         ns->nsid = nsid;
 686         ns->subsys = subsys;
 687
 688         down_write(&nvmet_ana_sem);
 689         ns->anagrpid = NVMET_DEFAULT_ANA_GRPID;
 690         nvmet_ana_group_enabled[ns->anagrpid]++;
 691         up_write(&nvmet_ana_sem);
 692
 693         uuid_gen(&ns->uuid);
 694         ns->buffered_io = false;
 695
 696         return ns;
 697 }
 698
 699 static void nvmet_update_sq_head(struct nvmet_req *req)
 700 {
 701         if (req->sq->size) {
 702                 u32 old_sqhd, new_sqhd;
 703
 704                 do {
 705                         old_sqhd = req->sq->sqhd;
 706                         new_sqhd = (old_sqhd + 1) % req->sq->size;
 707                 } while (cmpxchg(&req->sq->sqhd, old_sqhd, new_sqhd) !=
 708                                         old_sqhd);
 709         }
 710         req->cqe->sq_head = cpu_to_le16(req->sq->sqhd & 0x0000FFFF);
 711 }
 712
 713 static void nvmet_set_error(struct nvmet_req *req, u16 status)
 714 {
 715         struct nvmet_ctrl *ctrl = req->sq->ctrl;
 716         struct nvme_error_slot *new_error_slot;
 717         unsigned long flags;
 718
 719         req->cqe->status = cpu_to_le16(status << 1);
 720
 721         if (!ctrl || req->error_loc == NVMET_NO_ERROR_LOC)
 722                 return;
 723
 724         spin_lock_irqsave(&ctrl->error_lock, flags);
 725         ctrl->err_counter++;
 726         new_error_slot =
 727                 &ctrl->slots[ctrl->err_counter % NVMET_ERROR_LOG_SLOTS];
 728
 729         new_error_slot->error_count = cpu_to_le64(ctrl->err_counter);
 730         new_error_slot->sqid = cpu_to_le16(req->sq->qid);
 731         new_error_slot->cmdid = cpu_to_le16(req->cmd->common.command_id);
 732         new_error_slot->status_field = cpu_to_le16(status << 1);
 733         new_error_slot->param_error_location = cpu_to_le16(req->error_loc);
 734         new_error_slot->lba = cpu_to_le64(req->error_slba);
 735         new_error_slot->nsid = req->cmd->common.nsid;
 736         spin_unlock_irqrestore(&ctrl->error_lock, flags);
 737
 738         /* set the more bit for this request */
 739         req->cqe->status |= cpu_to_le16(1 << 14);
 740 }
 741
 742 static void __nvmet_req_complete(struct nvmet_req *req, u16 status)
 743 {
 744         if (!req->sq->sqhd_disabled)
 745                 nvmet_update_sq_head(req);
 746         req->cqe->sq_id = cpu_to_le16(req->sq->qid);
 747         req->cqe->command_id = req->cmd->common.command_id;
 748
 749         if (unlikely(status))
 750                 nvmet_set_error(req, status);
 751
 752         trace_nvmet_req_complete(req);
 753
 754         if (req->ns)
 755                 nvmet_put_namespace(req->ns);
 756         req->ops->queue_response(req);
 757 }
 758
 759 void nvmet_req_complete(struct nvmet_req *req, u16 status)
 760 {
 761         __nvmet_req_complete(req, status);
 762         percpu_ref_put(&req->sq->ref);
 763 }
 764 EXPORT_SYMBOL_GPL(nvmet_req_complete);
 765
 766 void nvmet_cq_setup(struct nvmet_ctrl *ctrl, struct nvmet_cq *cq,
 767                 u16 qid, u16 size)
 768 {
 769         cq->qid = qid;
 770         cq->size = size;
 771 }
 772
 773 void nvmet_sq_setup(struct nvmet_ctrl *ctrl, struct nvmet_sq *sq,
 774                 u16 qid, u16 size)
 775 {
 776         sq->sqhd = 0;
 777         sq->qid = qid;
 778         sq->size = size;
 779
 780         ctrl->sqs[qid] = sq;
 781 }
 782
 783 static void nvmet_confirm_sq(struct percpu_ref *ref)
 784 {
 785         struct nvmet_sq *sq = container_of(ref, struct nvmet_sq, ref);
 786
 787         complete(&sq->confirm_done);
 788 }
 789
 790 void nvmet_sq_destroy(struct nvmet_sq *sq)
 791 {
 792         struct nvmet_ctrl *ctrl = sq->ctrl;
 793
 794         /*
 795          * If this is the admin queue, complete all AERs so that our
 796          * queue doesn't have outstanding requests on it.
 797          */
 798         if (ctrl && ctrl->sqs && ctrl->sqs[0] == sq)
 799                 nvmet_async_events_failall(ctrl);
 800         percpu_ref_kill_and_confirm(&sq->ref, nvmet_confirm_sq);
 801         wait_for_completion(&sq->confirm_done);
 802         wait_for_completion(&sq->free_done);
 803         percpu_ref_exit(&sq->ref);
 804
 805         if (ctrl) {
 806                 nvmet_ctrl_put(ctrl);
 807                 sq->ctrl = NULL; /* allows reusing the queue later */
 808         }
 809 }
 810 EXPORT_SYMBOL_GPL(nvmet_sq_destroy);
 811
 812 static void nvmet_sq_free(struct percpu_ref *ref)
 813 {
 814         struct nvmet_sq *sq = container_of(ref, struct nvmet_sq, ref);
 815
 816         complete(&sq->free_done);
 817 }
 818
 819 int nvmet_sq_init(struct nvmet_sq *sq)
 820 {
 821         int ret;
 822
 823         ret = percpu_ref_init(&sq->ref, nvmet_sq_free, 0, GFP_KERNEL);
 824         if (ret) {
 825                 pr_err("percpu_ref init failed!\n");
 826                 return ret;
 827         }
 828         init_completion(&sq->free_done);
 829         init_completion(&sq->confirm_done);
 830
 831         return 0;
 832 }
 833 EXPORT_SYMBOL_GPL(nvmet_sq_init);
 834
 835 static inline u16 nvmet_check_ana_state(struct nvmet_port *port,
 836                 struct nvmet_ns *ns)
 837 {
 838         enum nvme_ana_state state = port->ana_state[ns->anagrpid];
 839
 840         if (unlikely(state == NVME_ANA_INACCESSIBLE))
 841                 return NVME_SC_ANA_INACCESSIBLE;
 842         if (unlikely(state == NVME_ANA_PERSISTENT_LOSS))
 843                 return NVME_SC_ANA_PERSISTENT_LOSS;
 844         if (unlikely(state == NVME_ANA_CHANGE))
 845                 return NVME_SC_ANA_TRANSITION;
 846         return 0;
 847 }
 848
 849 static inline u16 nvmet_io_cmd_check_access(struct nvmet_req *req)
 850 {
 851         if (unlikely(req->ns->readonly)) {
 852                 switch (req->cmd->common.opcode) {
 853                 case nvme_cmd_read:
 854                 case nvme_cmd_flush:
 855                         break;
 856                 default:
 857                         return NVME_SC_NS_WRITE_PROTECTED;
 858                 }
 859         }
 860
 861         return 0;
 862 }
 863
 864 static u16 nvmet_parse_io_cmd(struct nvmet_req *req)
 865 {
 866         u16 ret;
 867
 868         ret = nvmet_check_ctrl_status(req);
 869         if (unlikely(ret))
 870                 return ret;
 871
 872         if (nvmet_req_passthru_ctrl(req))
 873                 return nvmet_parse_passthru_io_cmd(req);
 874
 875         ret = nvmet_req_find_ns(req);
 876         if (unlikely(ret))
 877                 return ret;
 878
 879         ret = nvmet_check_ana_state(req->port, req->ns);
 880         if (unlikely(ret)) {
 881                 req->error_loc = offsetof(struct nvme_common_command, nsid);
 882                 return ret;
 883         }
 884         ret = nvmet_io_cmd_check_access(req);
 885         if (unlikely(ret)) {
 886                 req->error_loc = offsetof(struct nvme_common_command, nsid);
 887                 return ret;
 888         }
 889
 890         if (req->ns->file)
 891                 return nvmet_file_parse_io_cmd(req);
 892
 893         return nvmet_bdev_parse_io_cmd(req);
 894 }
 895
 896 bool nvmet_req_init(struct nvmet_req *req, struct nvmet_cq *cq,
 897                 struct nvmet_sq *sq, const struct nvmet_fabrics_ops *ops)
 898 {
 899         u8 flags = req->cmd->common.flags;
 900         u16 status;
 901
 902         req->cq = cq;
 903         req->sq = sq;
 904         req->ops = ops;
 905         req->sg = NULL;
 906         req->metadata_sg = NULL;
 907         req->sg_cnt = 0;
 908         req->metadata_sg_cnt = 0;
 909         req->transfer_len = 0;
 910         req->metadata_len = 0;
 911         req->cqe->status = 0;
 912         req->cqe->sq_head = 0;
 913         req->ns = NULL;
 914         req->error_loc = NVMET_NO_ERROR_LOC;
 915         req->error_slba = 0;
 916
 917         /* no support for fused commands yet */
 918         if (unlikely(flags & (NVME_CMD_FUSE_FIRST | NVME_CMD_FUSE_SECOND))) {
 919                 req->error_loc = offsetof(struct nvme_common_command, flags);
 920                 status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 921                 goto fail;
 922         }
 923
 924         /*
 925          * For fabrics, PSDT field shall describe metadata pointer (MPTR) that
 926          * contains an address of a single contiguous physical buffer that is
 927          * byte aligned.
 928          */
 929         if (unlikely((flags & NVME_CMD_SGL_ALL) != NVME_CMD_SGL_METABUF)) {
 930                 req->error_loc = offsetof(struct nvme_common_command, flags);
 931                 status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 932                 goto fail;
 933         }
 934
 935         if (unlikely(!req->sq->ctrl))
 936                 /* will return an error for any non-connect command: */
 937                 status = nvmet_parse_connect_cmd(req);
 938         else if (likely(req->sq->qid != 0))
 939                 status = nvmet_parse_io_cmd(req);
 940         else
 941                 status = nvmet_parse_admin_cmd(req);
 942
 943         if (status)
 944                 goto fail;
 945
 946         trace_nvmet_req_init(req, req->cmd);
 947
 948         if (unlikely(!percpu_ref_tryget_live(&sq->ref))) {
 949                 status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 950                 goto fail;
 951         }
 952
 953         if (sq->ctrl)
 954                 sq->ctrl->cmd_seen = true;
 955
 956         return true;
 957
 958 fail:
 959         __nvmet_req_complete(req, status);
 960         return false;
 961 }
 962 EXPORT_SYMBOL_GPL(nvmet_req_init);
 963
 964 void nvmet_req_uninit(struct nvmet_req *req)
 965 {
 966         percpu_ref_put(&req->sq->ref);
 967         if (req->ns)
 968                 nvmet_put_namespace(req->ns);
 969 }
 970 EXPORT_SYMBOL_GPL(nvmet_req_uninit);
 971
 972 bool nvmet_check_transfer_len(struct nvmet_req *req, size_t len)
 973 {
 974         if (unlikely(len != req->transfer_len)) {
 975                 req->error_loc = offsetof(struct nvme_common_command, dptr);
 976                 nvmet_req_complete(req, NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR);
 977                 return false;
 978         }
 979
 980         return true;
 981 }
 982 EXPORT_SYMBOL_GPL(nvmet_check_transfer_len);
 983
 984 bool nvmet_check_data_len_lte(struct nvmet_req *req, size_t data_len)
 985 {
 986         if (unlikely(data_len > req->transfer_len)) {
 987                 req->error_loc = offsetof(struct nvme_common_command, dptr);
 988                 nvmet_req_complete(req, NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR);
 989                 return false;
 990         }
 991
 992         return true;
 993 }
 994
 995 static unsigned int nvmet_data_transfer_len(struct nvmet_req *req)
 996 {
 997         return req->transfer_len - req->metadata_len;
 998 }
 999
1000 static int nvmet_req_alloc_p2pmem_sgls(struct nvmet_req *req)
1001 {
1002         req->sg = pci_p2pmem_alloc_sgl(req->p2p_dev, &req->sg_cnt,
1003                         nvmet_data_transfer_len(req));
1004         if (!req->sg)
1005                 goto out_err;
1006
1007         if (req->metadata_len) {
1008                 req->metadata_sg = pci_p2pmem_alloc_sgl(req->p2p_dev,
1009                                 &req->metadata_sg_cnt, req->metadata_len);
1010                 if (!req->metadata_sg)
1011                         goto out_free_sg;
1012         }
1013         return 0;
1014 out_free_sg:
1015         pci_p2pmem_free_sgl(req->p2p_dev, req->sg);
1016 out_err:
1017         return -ENOMEM;
1018 }
1019
1020 static bool nvmet_req_find_p2p_dev(struct nvmet_req *req)
1021 {
1022         if (!IS_ENABLED(CONFIG_PCI_P2PDMA))
1023                 return false;
1024
1025         if (req->sq->ctrl && req->sq->qid && req->ns) {
1026                 req->p2p_dev = radix_tree_lookup(&req->sq->ctrl->p2p_ns_map,
1027                                                  req->ns->nsid);
1028                 if (req->p2p_dev)
1029                         return true;
1030         }
1031
1032         req->p2p_dev = NULL;
1033         return false;
1034 }
1035
1036 int nvmet_req_alloc_sgls(struct nvmet_req *req)
1037 {
1038         if (nvmet_req_find_p2p_dev(req) && !nvmet_req_alloc_p2pmem_sgls(req))
1039                 return 0;
1040
1041         req->sg = sgl_alloc(nvmet_data_transfer_len(req), GFP_KERNEL,
1042                             &req->sg_cnt);
1043         if (unlikely(!req->sg))
1044                 goto out;
1045
1046         if (req->metadata_len) {
1047                 req->metadata_sg = sgl_alloc(req->metadata_len, GFP_KERNEL,
1048                                              &req->metadata_sg_cnt);
1049                 if (unlikely(!req->metadata_sg))
1050                         goto out_free;
1051         }
1052
1053         return 0;
1054 out_free:
1055         sgl_free(req->sg);
1056 out:
1057         return -ENOMEM;
1058 }
1059 EXPORT_SYMBOL_GPL(nvmet_req_alloc_sgls);
1060
1061 void nvmet_req_free_sgls(struct nvmet_req *req)
1062 {
1063         if (req->p2p_dev) {
1064                 pci_p2pmem_free_sgl(req->p2p_dev, req->sg);
1065                 if (req->metadata_sg)
1066                         pci_p2pmem_free_sgl(req->p2p_dev, req->metadata_sg);
1067         } else {
1068                 sgl_free(req->sg);
1069                 if (req->metadata_sg)
1070                         sgl_free(req->metadata_sg);
1071         }
1072
1073         req->sg = NULL;
1074         req->metadata_sg = NULL;
1075         req->sg_cnt = 0;
1076         req->metadata_sg_cnt = 0;
1077 }
1078 EXPORT_SYMBOL_GPL(nvmet_req_free_sgls);
1079
1080 static inline bool nvmet_cc_en(u32 cc)
1081 {
1082         return (cc >> NVME_CC_EN_SHIFT) & 0x1;
1083 }
1084
1085 static inline u8 nvmet_cc_css(u32 cc)
1086 {
1087         return (cc >> NVME_CC_CSS_SHIFT) & 0x7;
1088 }
1089
1090 static inline u8 nvmet_cc_mps(u32 cc)
1091 {
1092         return (cc >> NVME_CC_MPS_SHIFT) & 0xf;
1093 }
1094
1095 static inline u8 nvmet_cc_ams(u32 cc)
1096 {
1097         return (cc >> NVME_CC_AMS_SHIFT) & 0x7;
1098 }
1099
1100 static inline u8 nvmet_cc_shn(u32 cc)
1101 {
1102         return (cc >> NVME_CC_SHN_SHIFT) & 0x3;
1103 }
1104
1105 static inline u8 nvmet_cc_iosqes(u32 cc)
1106 {
1107         return (cc >> NVME_CC_IOSQES_SHIFT) & 0xf;
1108 }
1109
1110 static inline u8 nvmet_cc_iocqes(u32 cc)
1111 {
1112         return (cc >> NVME_CC_IOCQES_SHIFT) & 0xf;
1113 }
1114
1115 static void nvmet_start_ctrl(struct nvmet_ctrl *ctrl)
1116 {
1117         lockdep_assert_held(&ctrl->lock);
1118
1119         /*
1120          * Only I/O controllers should verify iosqes,iocqes.
1121          * Strictly speaking, the spec says a discovery controller
1122          * should verify iosqes,iocqes are zeroed, however that
1123          * would break backwards compatibility, so don't enforce it.
1124          */
1125         if (ctrl->subsys->type != NVME_NQN_DISC &&
1126             (nvmet_cc_iosqes(ctrl->cc) != NVME_NVM_IOSQES ||
1127              nvmet_cc_iocqes(ctrl->cc) != NVME_NVM_IOCQES)) {
1128                 ctrl->csts = NVME_CSTS_CFS;
1129                 return;
1130         }
1131
1132         if (nvmet_cc_mps(ctrl->cc) != 0 ||
1133             nvmet_cc_ams(ctrl->cc) != 0 ||
1134             nvmet_cc_css(ctrl->cc) != 0) {
1135                 ctrl->csts = NVME_CSTS_CFS;
1136                 return;
1137         }
1138
1139         ctrl->csts = NVME_CSTS_RDY;
1140
1141         /*
1142          * Controllers that are not yet enabled should not really enforce the
1143          * keep alive timeout, but we still want to track a timeout and cleanup
1144          * in case a host died before it enabled the controller.  Hence, simply
1145          * reset the keep alive timer when the controller is enabled.
1146          */
1147         if (ctrl->kato)
1148                 mod_delayed_work(system_wq, &ctrl->ka_work, ctrl->kato * HZ);
1149 }
1150
1151 static void nvmet_clear_ctrl(struct nvmet_ctrl *ctrl)
1152 {
1153         lockdep_assert_held(&ctrl->lock);
1154
1155         /* XXX: tear down queues? */
1156         ctrl->csts &= ~NVME_CSTS_RDY;
1157         ctrl->cc = 0;
1158 }
1159
1160 void nvmet_update_cc(struct nvmet_ctrl *ctrl, u32 new)
1161 {
1162         u32 old;
1163
1164         mutex_lock(&ctrl->lock);
1165         old = ctrl->cc;
1166         ctrl->cc = new;
1167
1168         if (nvmet_cc_en(new) && !nvmet_cc_en(old))
1169                 nvmet_start_ctrl(ctrl);
1170         if (!nvmet_cc_en(new) && nvmet_cc_en(old))
1171                 nvmet_clear_ctrl(ctrl);
1172         if (nvmet_cc_shn(new) && !nvmet_cc_shn(old)) {
1173                 nvmet_clear_ctrl(ctrl);
1174                 ctrl->csts |= NVME_CSTS_SHST_CMPLT;
1175         }
1176         if (!nvmet_cc_shn(new) && nvmet_cc_shn(old))
1177                 ctrl->csts &= ~NVME_CSTS_SHST_CMPLT;
1178         mutex_unlock(&ctrl->lock);
1179 }
1180
1181 static void nvmet_init_cap(struct nvmet_ctrl *ctrl)
1182 {
1183         /* command sets supported: NVMe command set: */
1184         ctrl->cap = (1ULL << 37);
1185         /* CC.EN timeout in 500msec units: */
1186         ctrl->cap |= (15ULL << 24);
1187         /* maximum queue entries supported: */
1188         ctrl->cap |= NVMET_QUEUE_SIZE - 1;
1189 }
1190
1191 struct nvmet_ctrl *nvmet_ctrl_find_get(const char *subsysnqn,
1192                                        const char *hostnqn, u16 cntlid,
1193                                        struct nvmet_req *req)
1194 {
1195         struct nvmet_ctrl *ctrl = NULL;
1196         struct nvmet_subsys *subsys;
1197
1198         subsys = nvmet_find_get_subsys(req->port, subsysnqn);
1199         if (!subsys) {
1200                 pr_warn("connect request for invalid subsystem %s!\n",
1201                         subsysnqn);
1202                 req->cqe->result.u32 = IPO_IATTR_CONNECT_DATA(subsysnqn);
1203                 goto out;
1204         }
1205
1206         mutex_lock(&subsys->lock);
1207         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
1208                 if (ctrl->cntlid == cntlid) {
1209                         if (strncmp(hostnqn, ctrl->hostnqn, NVMF_NQN_SIZE)) {
1210                                 pr_warn("hostnqn mismatch.\n");
1211                                 continue;
1212                         }
1213                         if (!kref_get_unless_zero(&ctrl->ref))
1214                                 continue;
1215
1216                         /* ctrl found */
1217                         goto found;
1218                 }
1219         }
1220
1221         ctrl = NULL; /* ctrl not found */
1222         pr_warn("could not find controller %d for subsys %s / host %s\n",
1223                 cntlid, subsysnqn, hostnqn);
1224         req->cqe->result.u32 = IPO_IATTR_CONNECT_DATA(cntlid);
1225
1226 found:
1227         mutex_unlock(&subsys->lock);
1228         nvmet_subsys_put(subsys);
1229 out:
1230         return ctrl;
1231 }
1232
1233 u16 nvmet_check_ctrl_status(struct nvmet_req *req)
1234 {
1235         if (unlikely(!(req->sq->ctrl->cc & NVME_CC_ENABLE))) {
1236                 pr_err("got cmd %d while CC.EN == 0 on qid = %d\n",
1237                        req->cmd->common.opcode, req->sq->qid);
1238                 return NVME_SC_CMD_SEQ_ERROR | NVME_SC_DNR;
1239         }
1240
1241         if (unlikely(!(req->sq->ctrl->csts & NVME_CSTS_RDY))) {
1242                 pr_err("got cmd %d while CSTS.RDY == 0 on qid = %d\n",
1243                        req->cmd->common.opcode, req->sq->qid);
1244                 return NVME_SC_CMD_SEQ_ERROR | NVME_SC_DNR;
1245         }
1246         return 0;
1247 }
1248
1249 bool nvmet_host_allowed(struct nvmet_subsys *subsys, const char *hostnqn)
1250 {
1251         struct nvmet_host_link *p;
1252
1253         lockdep_assert_held(&nvmet_config_sem);
1254
1255         if (subsys->allow_any_host)
1256                 return true;
1257
1258         if (subsys->type == NVME_NQN_DISC) /* allow all access to disc subsys */
1259                 return true;
1260
1261         list_for_each_entry(p, &subsys->hosts, entry) {
1262                 if (!strcmp(nvmet_host_name(p->host), hostnqn))
1263                         return true;
1264         }
1265
1266         return false;
1267 }
1268
1269 /*
1270  * Note: ctrl->subsys->lock should be held when calling this function
1271  */
1272 static void nvmet_setup_p2p_ns_map(struct nvmet_ctrl *ctrl,
1273                 struct nvmet_req *req)
1274 {
1275         struct nvmet_ns *ns;
1276         unsigned long idx;
1277
1278         if (!req->p2p_client)
1279                 return;
1280
1281         ctrl->p2p_client = get_device(req->p2p_client);
1282
1283         xa_for_each(&ctrl->subsys->namespaces, idx, ns)
1284                 nvmet_p2pmem_ns_add_p2p(ctrl, ns);
1285 }
1286
1287 /*
1288  * Note: ctrl->subsys->lock should be held when calling this function
1289  */
1290 static void nvmet_release_p2p_ns_map(struct nvmet_ctrl *ctrl)
1291 {
1292         struct radix_tree_iter iter;
1293         void __rcu **slot;
1294
1295         radix_tree_for_each_slot(slot, &ctrl->p2p_ns_map, &iter, 0)
1296                 pci_dev_put(radix_tree_deref_slot(slot));
1297
1298         put_device(ctrl->p2p_client);
1299 }
1300
1301 static void nvmet_fatal_error_handler(struct work_struct *work)
1302 {
1303         struct nvmet_ctrl *ctrl =
1304                         container_of(work, struct nvmet_ctrl, fatal_err_work);
1305
1306         pr_err("ctrl %d fatal error occurred!\n", ctrl->cntlid);
1307         ctrl->ops->delete_ctrl(ctrl);
1308 }
1309
1310 u16 nvmet_alloc_ctrl(const char *subsysnqn, const char *hostnqn,
1311                 struct nvmet_req *req, u32 kato, struct nvmet_ctrl **ctrlp)
1312 {
1313         struct nvmet_subsys *subsys;
1314         struct nvmet_ctrl *ctrl;
1315         int ret;
1316         u16 status;
1317
1318         status = NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR;
1319         subsys = nvmet_find_get_subsys(req->port, subsysnqn);
1320         if (!subsys) {
1321                 pr_warn("connect request for invalid subsystem %s!\n",
1322                         subsysnqn);
1323                 req->cqe->result.u32 = IPO_IATTR_CONNECT_DATA(subsysnqn);
1324                 req->error_loc = offsetof(struct nvme_common_command, dptr);
1325                 goto out;
1326         }
1327
1328         down_read(&nvmet_config_sem);
1329         if (!nvmet_host_allowed(subsys, hostnqn)) {
1330                 pr_info("connect by host %s for subsystem %s not allowed\n",
1331                         hostnqn, subsysnqn);
1332                 req->cqe->result.u32 = IPO_IATTR_CONNECT_DATA(hostnqn);
1333                 up_read(&nvmet_config_sem);
1334                 status = NVME_SC_CONNECT_INVALID_HOST | NVME_SC_DNR;
1335                 req->error_loc = offsetof(struct nvme_common_command, dptr);
1336                 goto out_put_subsystem;
1337         }
1338         up_read(&nvmet_config_sem);
1339
1340         status = NVME_SC_INTERNAL;
1341         ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
1342         if (!ctrl)
1343                 goto out_put_subsystem;
1344         mutex_init(&ctrl->lock);
1345
1346         nvmet_init_cap(ctrl);
1347
1348         ctrl->port = req->port;
1349
1350         INIT_WORK(&ctrl->async_event_work, nvmet_async_event_work);
1351         INIT_LIST_HEAD(&ctrl->async_events);
1352         INIT_RADIX_TREE(&ctrl->p2p_ns_map, GFP_KERNEL);
1353         INIT_WORK(&ctrl->fatal_err_work, nvmet_fatal_error_handler);
1354         INIT_DELAYED_WORK(&ctrl->ka_work, nvmet_keep_alive_timer);
1355
1356         memcpy(ctrl->subsysnqn, subsysnqn, NVMF_NQN_SIZE);
1357         memcpy(ctrl->hostnqn, hostnqn, NVMF_NQN_SIZE);
1358
1359         kref_init(&ctrl->ref);
1360         ctrl->subsys = subsys;
1361         WRITE_ONCE(ctrl->aen_enabled, NVMET_AEN_CFG_OPTIONAL);
1362
1363         ctrl->changed_ns_list = kmalloc_array(NVME_MAX_CHANGED_NAMESPACES,
1364                         sizeof(__le32), GFP_KERNEL);
1365         if (!ctrl->changed_ns_list)
1366                 goto out_free_ctrl;
1367
1368         ctrl->sqs = kcalloc(subsys->max_qid + 1,
1369                         sizeof(struct nvmet_sq *),
1370                         GFP_KERNEL);
1371         if (!ctrl->sqs)
1372                 goto out_free_changed_ns_list;
1373
1374         if (subsys->cntlid_min > subsys->cntlid_max)
1375                 goto out_free_sqs;
1376
1377         ret = ida_simple_get(&cntlid_ida,
1378                              subsys->cntlid_min, subsys->cntlid_max,
1379                              GFP_KERNEL);
1380         if (ret < 0) {
1381                 status = NVME_SC_CONNECT_CTRL_BUSY | NVME_SC_DNR;
1382                 goto out_free_sqs;
1383         }
1384         ctrl->cntlid = ret;
1385
1386         ctrl->ops = req->ops;
1387
1388         /*
1389          * Discovery controllers may use some arbitrary high value
1390          * in order to cleanup stale discovery sessions
1391          */
1392         if ((ctrl->subsys->type == NVME_NQN_DISC) && !kato)
1393                 kato = NVMET_DISC_KATO_MS;
1394
1395         /* keep-alive timeout in seconds */
1396         ctrl->kato = DIV_ROUND_UP(kato, 1000);
1397
1398         ctrl->err_counter = 0;
1399         spin_lock_init(&ctrl->error_lock);
1400
1401         nvmet_start_keep_alive_timer(ctrl);
1402
1403         mutex_lock(&subsys->lock);
1404         list_add_tail(&ctrl->subsys_entry, &subsys->ctrls);
1405         nvmet_setup_p2p_ns_map(ctrl, req);
1406         mutex_unlock(&subsys->lock);
1407
1408         *ctrlp = ctrl;
1409         return 0;
1410
1411 out_free_sqs:
1412         kfree(ctrl->sqs);
1413 out_free_changed_ns_list:
1414         kfree(ctrl->changed_ns_list);
1415 out_free_ctrl:
1416         kfree(ctrl);
1417 out_put_subsystem:
1418         nvmet_subsys_put(subsys);
1419 out:
1420         return status;
1421 }
1422
1423 static void nvmet_ctrl_free(struct kref *ref)
1424 {
1425         struct nvmet_ctrl *ctrl = container_of(ref, struct nvmet_ctrl, ref);
1426         struct nvmet_subsys *subsys = ctrl->subsys;
1427
1428         mutex_lock(&subsys->lock);
1429         nvmet_release_p2p_ns_map(ctrl);
1430         list_del(&ctrl->subsys_entry);
1431         mutex_unlock(&subsys->lock);
1432
1433         nvmet_stop_keep_alive_timer(ctrl);
1434
1435         flush_work(&ctrl->async_event_work);
1436         cancel_work_sync(&ctrl->fatal_err_work);
1437
1438         ida_simple_remove(&cntlid_ida, ctrl->cntlid);
1439
1440         nvmet_async_events_free(ctrl);
1441         kfree(ctrl->sqs);
1442         kfree(ctrl->changed_ns_list);
1443         kfree(ctrl);
1444
1445         nvmet_subsys_put(subsys);
1446 }
1447
1448 void nvmet_ctrl_put(struct nvmet_ctrl *ctrl)
1449 {
1450         kref_put(&ctrl->ref, nvmet_ctrl_free);
1451 }
1452
1453 void nvmet_ctrl_fatal_error(struct nvmet_ctrl *ctrl)
1454 {
1455         mutex_lock(&ctrl->lock);
1456         if (!(ctrl->csts & NVME_CSTS_CFS)) {
1457                 ctrl->csts |= NVME_CSTS_CFS;
1458                 schedule_work(&ctrl->fatal_err_work);
1459         }
1460         mutex_unlock(&ctrl->lock);
1461 }
1462 EXPORT_SYMBOL_GPL(nvmet_ctrl_fatal_error);
1463
1464 static struct nvmet_subsys *nvmet_find_get_subsys(struct nvmet_port *port,
1465                 const char *subsysnqn)
1466 {
1467         struct nvmet_subsys_link *p;
1468
1469         if (!port)
1470                 return NULL;
1471
1472         if (!strcmp(NVME_DISC_SUBSYS_NAME, subsysnqn)) {
1473                 if (!kref_get_unless_zero(&nvmet_disc_subsys->ref))
1474                         return NULL;
1475                 return nvmet_disc_subsys;
1476         }
1477
1478         down_read(&nvmet_config_sem);
1479         list_for_each_entry(p, &port->subsystems, entry) {
1480                 if (!strncmp(p->subsys->subsysnqn, subsysnqn,
1481                                 NVMF_NQN_SIZE)) {
1482                         if (!kref_get_unless_zero(&p->subsys->ref))
1483                                 break;
1484                         up_read(&nvmet_config_sem);
1485                         return p->subsys;
1486                 }
1487         }
1488         up_read(&nvmet_config_sem);
1489         return NULL;
1490 }
1491
1492 struct nvmet_subsys *nvmet_subsys_alloc(const char *subsysnqn,
1493                 enum nvme_subsys_type type)
1494 {
1495         struct nvmet_subsys *subsys;
1496
1497         subsys = kzalloc(sizeof(*subsys), GFP_KERNEL);
1498         if (!subsys)
1499                 return ERR_PTR(-ENOMEM);
1500
1501         subsys->ver = NVMET_DEFAULT_VS;
1502         /* generate a random serial number as our controllers are ephemeral: */
1503         get_random_bytes(&subsys->serial, sizeof(subsys->serial));
1504
1505         switch (type) {
1506         case NVME_NQN_NVME:
1507                 subsys->max_qid = NVMET_NR_QUEUES;
1508                 break;
1509         case NVME_NQN_DISC:
1510                 subsys->max_qid = 0;
1511                 break;
1512         default:
1513                 pr_err("%s: Unknown Subsystem type - %d\n", __func__, type);
1514                 kfree(subsys);
1515                 return ERR_PTR(-EINVAL);
1516         }
1517         subsys->type = type;
1518         subsys->subsysnqn = kstrndup(subsysnqn, NVMF_NQN_SIZE,
1519                         GFP_KERNEL);
1520         if (!subsys->subsysnqn) {
1521                 kfree(subsys);
1522                 return ERR_PTR(-ENOMEM);
1523         }
1524         subsys->cntlid_min = NVME_CNTLID_MIN;
1525         subsys->cntlid_max = NVME_CNTLID_MAX;
1526         kref_init(&subsys->ref);
1527
1528         mutex_init(&subsys->lock);
1529         xa_init(&subsys->namespaces);
1530         INIT_LIST_HEAD(&subsys->ctrls);
1531         INIT_LIST_HEAD(&subsys->hosts);
1532
1533         return subsys;
1534 }
1535
1536 static void nvmet_subsys_free(struct kref *ref)
1537 {
1538         struct nvmet_subsys *subsys =
1539                 container_of(ref, struct nvmet_subsys, ref);
1540
1541         WARN_ON_ONCE(!xa_empty(&subsys->namespaces));
1542
1543         xa_destroy(&subsys->namespaces);
1544         nvmet_passthru_subsys_free(subsys);
1545
1546         kfree(subsys->subsysnqn);
1547         kfree(subsys->model_number);
1548         kfree(subsys);
1549 }
1550
1551 void nvmet_subsys_del_ctrls(struct nvmet_subsys *subsys)
1552 {
1553         struct nvmet_ctrl *ctrl;
1554
1555         mutex_lock(&subsys->lock);
1556         list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry)
1557                 ctrl->ops->delete_ctrl(ctrl);
1558         mutex_unlock(&subsys->lock);
1559 }
1560
1561 void nvmet_subsys_put(struct nvmet_subsys *subsys)
1562 {
1563         kref_put(&subsys->ref, nvmet_subsys_free);
1564 }
1565
1566 static int __init nvmet_init(void)
1567 {
1568         int error;
1569
1570         nvmet_ana_group_enabled[NVMET_DEFAULT_ANA_GRPID] = 1;
1571
1572         buffered_io_wq = alloc_workqueue("nvmet-buffered-io-wq",
1573                         WQ_MEM_RECLAIM, 0);
1574         if (!buffered_io_wq) {
1575                 error = -ENOMEM;
1576                 goto out;
1577         }
1578
1579         error = nvmet_init_discovery();
1580         if (error)
1581                 goto out_free_work_queue;
1582
1583         error = nvmet_init_configfs();
1584         if (error)
1585                 goto out_exit_discovery;
1586         return 0;
1587
1588 out_exit_discovery:
1589         nvmet_exit_discovery();
1590 out_free_work_queue:
1591         destroy_workqueue(buffered_io_wq);
1592 out:
1593         return error;
1594 }
1595
1596 static void __exit nvmet_exit(void)
1597 {
1598         nvmet_exit_configfs();
1599         nvmet_exit_discovery();
1600         ida_destroy(&cntlid_ida);
1601         destroy_workqueue(buffered_io_wq);
1602
1603         BUILD_BUG_ON(sizeof(struct nvmf_disc_rsp_page_entry) != 1024);
1604         BUILD_BUG_ON(sizeof(struct nvmf_disc_rsp_page_hdr) != 1024);
1605 }
1606
1607 module_init(nvmet_init);
1608 module_exit(nvmet_exit);
1609
1610 MODULE_LICENSE("GPL v2");