drivers/nvme/target/core.c

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