drivers/nvme/host/multipath.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2017-2018 Christoph Hellwig.
   4  */
   5
   6 #include <linux/backing-dev.h>
   7 #include <linux/moduleparam.h>
   8 #include <trace/events/block.h>
   9 #include "nvme.h"
  10
  11 static bool multipath = true;
  12 module_param(multipath, bool, 0444);
  13 MODULE_PARM_DESC(multipath,
  14         "turn on native support for multiple controllers per subsystem");
  15
  16 void nvme_mpath_unfreeze(struct nvme_subsystem *subsys)
  17 {
  18         struct nvme_ns_head *h;
  19
  20         lockdep_assert_held(&subsys->lock);
  21         list_for_each_entry(h, &subsys->nsheads, entry)
  22                 if (h->disk)
  23                         blk_mq_unfreeze_queue(h->disk->queue);
  24 }
  25
  26 void nvme_mpath_wait_freeze(struct nvme_subsystem *subsys)
  27 {
  28         struct nvme_ns_head *h;
  29
  30         lockdep_assert_held(&subsys->lock);
  31         list_for_each_entry(h, &subsys->nsheads, entry)
  32                 if (h->disk)
  33                         blk_mq_freeze_queue_wait(h->disk->queue);
  34 }
  35
  36 void nvme_mpath_start_freeze(struct nvme_subsystem *subsys)
  37 {
  38         struct nvme_ns_head *h;
  39
  40         lockdep_assert_held(&subsys->lock);
  41         list_for_each_entry(h, &subsys->nsheads, entry)
  42                 if (h->disk)
  43                         blk_freeze_queue_start(h->disk->queue);
  44 }
  45
  46 /*
  47  * If multipathing is enabled we need to always use the subsystem instance
  48  * number for numbering our devices to avoid conflicts between subsystems that
  49  * have multiple controllers and thus use the multipath-aware subsystem node
  50  * and those that have a single controller and use the controller node
  51  * directly.
  52  */
  53 bool nvme_mpath_set_disk_name(struct nvme_ns *ns, char *disk_name, int *flags)
  54 {
  55         if (!multipath)
  56                 return false;
  57         if (!ns->head->disk) {
  58                 sprintf(disk_name, "nvme%dn%d", ns->ctrl->subsys->instance,
  59                         ns->head->instance);
  60                 return true;
  61         }
  62         sprintf(disk_name, "nvme%dc%dn%d", ns->ctrl->subsys->instance,
  63                 ns->ctrl->instance, ns->head->instance);
  64         *flags = GENHD_FL_HIDDEN;
  65         return true;
  66 }
  67
  68 void nvme_failover_req(struct request *req)
  69 {
  70         struct nvme_ns *ns = req->q->queuedata;
  71         u16 status = nvme_req(req)->status & 0x7ff;
  72         unsigned long flags;
  73         struct bio *bio;
  74
  75         nvme_mpath_clear_current_path(ns);
  76
  77         /*
  78          * If we got back an ANA error, we know the controller is alive but not
  79          * ready to serve this namespace.  Kick of a re-read of the ANA
  80          * information page, and just try any other available path for now.
  81          */
  82         if (nvme_is_ana_error(status) && ns->ctrl->ana_log_buf) {
  83                 set_bit(NVME_NS_ANA_PENDING, &ns->flags);
  84                 queue_work(nvme_wq, &ns->ctrl->ana_work);
  85         }
  86
  87         spin_lock_irqsave(&ns->head->requeue_lock, flags);
  88         for (bio = req->bio; bio; bio = bio->bi_next)
  89                 bio_set_dev(bio, ns->head->disk->part0);
  90         blk_steal_bios(&ns->head->requeue_list, req);
  91         spin_unlock_irqrestore(&ns->head->requeue_lock, flags);
  92
  93         blk_mq_end_request(req, 0);
  94         kblockd_schedule_work(&ns->head->requeue_work);
  95 }
  96
  97 void nvme_kick_requeue_lists(struct nvme_ctrl *ctrl)
  98 {
  99         struct nvme_ns *ns;
 100
 101         down_read(&ctrl->namespaces_rwsem);
 102         list_for_each_entry(ns, &ctrl->namespaces, list) {
 103                 if (ns->head->disk)
 104                         kblockd_schedule_work(&ns->head->requeue_work);
 105         }
 106         up_read(&ctrl->namespaces_rwsem);
 107 }
 108
 109 static const char *nvme_ana_state_names[] = {
 110         [0]                             = "invalid state",
 111         [NVME_ANA_OPTIMIZED]            = "optimized",
 112         [NVME_ANA_NONOPTIMIZED]         = "non-optimized",
 113         [NVME_ANA_INACCESSIBLE]         = "inaccessible",
 114         [NVME_ANA_PERSISTENT_LOSS]      = "persistent-loss",
 115         [NVME_ANA_CHANGE]               = "change",
 116 };
 117
 118 bool nvme_mpath_clear_current_path(struct nvme_ns *ns)
 119 {
 120         struct nvme_ns_head *head = ns->head;
 121         bool changed = false;
 122         int node;
 123
 124         if (!head)
 125                 goto out;
 126
 127         for_each_node(node) {
 128                 if (ns == rcu_access_pointer(head->current_path[node])) {
 129                         rcu_assign_pointer(head->current_path[node], NULL);
 130                         changed = true;
 131                 }
 132         }
 133 out:
 134         return changed;
 135 }
 136
 137 void nvme_mpath_clear_ctrl_paths(struct nvme_ctrl *ctrl)
 138 {
 139         struct nvme_ns *ns;
 140
 141         mutex_lock(&ctrl->scan_lock);
 142         down_read(&ctrl->namespaces_rwsem);
 143         list_for_each_entry(ns, &ctrl->namespaces, list)
 144                 if (nvme_mpath_clear_current_path(ns))
 145                         kblockd_schedule_work(&ns->head->requeue_work);
 146         up_read(&ctrl->namespaces_rwsem);
 147         mutex_unlock(&ctrl->scan_lock);
 148 }
 149
 150 void nvme_mpath_revalidate_paths(struct nvme_ns *ns)
 151 {
 152         struct nvme_ns_head *head = ns->head;
 153         sector_t capacity = get_capacity(head->disk);
 154         int node;
 155
 156         list_for_each_entry_rcu(ns, &head->list, siblings) {
 157                 if (capacity != get_capacity(ns->disk))
 158                         clear_bit(NVME_NS_READY, &ns->flags);
 159         }
 160
 161         for_each_node(node)
 162                 rcu_assign_pointer(head->current_path[node], NULL);
 163 }
 164
 165 static bool nvme_path_is_disabled(struct nvme_ns *ns)
 166 {
 167         /*
 168          * We don't treat NVME_CTRL_DELETING as a disabled path as I/O should
 169          * still be able to complete assuming that the controller is connected.
 170          * Otherwise it will fail immediately and return to the requeue list.
 171          */
 172         if (ns->ctrl->state != NVME_CTRL_LIVE &&
 173             ns->ctrl->state != NVME_CTRL_DELETING)
 174                 return true;
 175         if (test_bit(NVME_NS_ANA_PENDING, &ns->flags) ||
 176             !test_bit(NVME_NS_READY, &ns->flags))
 177                 return true;
 178         return false;
 179 }
 180
 181 static struct nvme_ns *__nvme_find_path(struct nvme_ns_head *head, int node)
 182 {
 183         int found_distance = INT_MAX, fallback_distance = INT_MAX, distance;
 184         struct nvme_ns *found = NULL, *fallback = NULL, *ns;
 185
 186         list_for_each_entry_rcu(ns, &head->list, siblings) {
 187                 if (nvme_path_is_disabled(ns))
 188                         continue;
 189
 190                 if (READ_ONCE(head->subsys->iopolicy) == NVME_IOPOLICY_NUMA)
 191                         distance = node_distance(node, ns->ctrl->numa_node);
 192                 else
 193                         distance = LOCAL_DISTANCE;
 194
 195                 switch (ns->ana_state) {
 196                 case NVME_ANA_OPTIMIZED:
 197                         if (distance < found_distance) {
 198                                 found_distance = distance;
 199                                 found = ns;
 200                         }
 201                         break;
 202                 case NVME_ANA_NONOPTIMIZED:
 203                         if (distance < fallback_distance) {
 204                                 fallback_distance = distance;
 205                                 fallback = ns;
 206                         }
 207                         break;
 208                 default:
 209                         break;
 210                 }
 211         }
 212
 213         if (!found)
 214                 found = fallback;
 215         if (found)
 216                 rcu_assign_pointer(head->current_path[node], found);
 217         return found;
 218 }
 219
 220 static struct nvme_ns *nvme_next_ns(struct nvme_ns_head *head,
 221                 struct nvme_ns *ns)
 222 {
 223         ns = list_next_or_null_rcu(&head->list, &ns->siblings, struct nvme_ns,
 224                         siblings);
 225         if (ns)
 226                 return ns;
 227         return list_first_or_null_rcu(&head->list, struct nvme_ns, siblings);
 228 }
 229
 230 static struct nvme_ns *nvme_round_robin_path(struct nvme_ns_head *head,
 231                 int node, struct nvme_ns *old)
 232 {
 233         struct nvme_ns *ns, *found = NULL;
 234
 235         if (list_is_singular(&head->list)) {
 236                 if (nvme_path_is_disabled(old))
 237                         return NULL;
 238                 return old;
 239         }
 240
 241         for (ns = nvme_next_ns(head, old);
 242              ns && ns != old;
 243              ns = nvme_next_ns(head, ns)) {
 244                 if (nvme_path_is_disabled(ns))
 245                         continue;
 246
 247                 if (ns->ana_state == NVME_ANA_OPTIMIZED) {
 248                         found = ns;
 249                         goto out;
 250                 }
 251                 if (ns->ana_state == NVME_ANA_NONOPTIMIZED)
 252                         found = ns;
 253         }
 254
 255         /*
 256          * The loop above skips the current path for round-robin semantics.
 257          * Fall back to the current path if either:
 258          *  - no other optimized path found and current is optimized,
 259          *  - no other usable path found and current is usable.
 260          */
 261         if (!nvme_path_is_disabled(old) &&
 262             (old->ana_state == NVME_ANA_OPTIMIZED ||
 263              (!found && old->ana_state == NVME_ANA_NONOPTIMIZED)))
 264                 return old;
 265
 266         if (!found)
 267                 return NULL;
 268 out:
 269         rcu_assign_pointer(head->current_path[node], found);
 270         return found;
 271 }
 272
 273 static inline bool nvme_path_is_optimized(struct nvme_ns *ns)
 274 {
 275         return ns->ctrl->state == NVME_CTRL_LIVE &&
 276                 ns->ana_state == NVME_ANA_OPTIMIZED;
 277 }
 278
 279 inline struct nvme_ns *nvme_find_path(struct nvme_ns_head *head)
 280 {
 281         int node = numa_node_id();
 282         struct nvme_ns *ns;
 283
 284         ns = srcu_dereference(head->current_path[node], &head->srcu);
 285         if (unlikely(!ns))
 286                 return __nvme_find_path(head, node);
 287
 288         if (READ_ONCE(head->subsys->iopolicy) == NVME_IOPOLICY_RR)
 289                 return nvme_round_robin_path(head, node, ns);
 290         if (unlikely(!nvme_path_is_optimized(ns)))
 291                 return __nvme_find_path(head, node);
 292         return ns;
 293 }
 294
 295 static bool nvme_available_path(struct nvme_ns_head *head)
 296 {
 297         struct nvme_ns *ns;
 298
 299         list_for_each_entry_rcu(ns, &head->list, siblings) {
 300                 if (test_bit(NVME_CTRL_FAILFAST_EXPIRED, &ns->ctrl->flags))
 301                         continue;
 302                 switch (ns->ctrl->state) {
 303                 case NVME_CTRL_LIVE:
 304                 case NVME_CTRL_RESETTING:
 305                 case NVME_CTRL_CONNECTING:
 306                         /* fallthru */
 307                         return true;
 308                 default:
 309                         break;
 310                 }
 311         }
 312         return false;
 313 }
 314
 315 static blk_qc_t nvme_ns_head_submit_bio(struct bio *bio)
 316 {
 317         struct nvme_ns_head *head = bio->bi_bdev->bd_disk->private_data;
 318         struct device *dev = disk_to_dev(head->disk);
 319         struct nvme_ns *ns;
 320         blk_qc_t ret = BLK_QC_T_NONE;
 321         int srcu_idx;
 322
 323         /*
 324          * The namespace might be going away and the bio might be moved to a
 325          * different queue via blk_steal_bios(), so we need to use the bio_split
 326          * pool from the original queue to allocate the bvecs from.
 327          */
 328         blk_queue_split(&bio);
 329
 330         srcu_idx = srcu_read_lock(&head->srcu);
 331         ns = nvme_find_path(head);
 332         if (likely(ns)) {
 333                 bio_set_dev(bio, ns->disk->part0);
 334                 bio->bi_opf |= REQ_NVME_MPATH;
 335                 trace_block_bio_remap(bio, disk_devt(ns->head->disk),
 336                                       bio->bi_iter.bi_sector);
 337                 ret = submit_bio_noacct(bio);
 338         } else if (nvme_available_path(head)) {
 339                 dev_warn_ratelimited(dev, "no usable path - requeuing I/O\n");
 340
 341                 spin_lock_irq(&head->requeue_lock);
 342                 bio_list_add(&head->requeue_list, bio);
 343                 spin_unlock_irq(&head->requeue_lock);
 344         } else {
 345                 dev_warn_ratelimited(dev, "no available path - failing I/O\n");
 346
 347                 bio->bi_status = BLK_STS_IOERR;
 348                 bio_endio(bio);
 349         }
 350
 351         srcu_read_unlock(&head->srcu, srcu_idx);
 352         return ret;
 353 }
 354
 355 static int nvme_ns_head_open(struct block_device *bdev, fmode_t mode)
 356 {
 357         if (!nvme_tryget_ns_head(bdev->bd_disk->private_data))
 358                 return -ENXIO;
 359         return 0;
 360 }
 361
 362 static void nvme_ns_head_release(struct gendisk *disk, fmode_t mode)
 363 {
 364         nvme_put_ns_head(disk->private_data);
 365 }
 366
 367 #ifdef CONFIG_BLK_DEV_ZONED
 368 static int nvme_ns_head_report_zones(struct gendisk *disk, sector_t sector,
 369                 unsigned int nr_zones, report_zones_cb cb, void *data)
 370 {
 371         struct nvme_ns_head *head = disk->private_data;
 372         struct nvme_ns *ns;
 373         int srcu_idx, ret = -EWOULDBLOCK;
 374
 375         srcu_idx = srcu_read_lock(&head->srcu);
 376         ns = nvme_find_path(head);
 377         if (ns)
 378                 ret = nvme_ns_report_zones(ns, sector, nr_zones, cb, data);
 379         srcu_read_unlock(&head->srcu, srcu_idx);
 380         return ret;
 381 }
 382 #else
 383 #define nvme_ns_head_report_zones       NULL
 384 #endif /* CONFIG_BLK_DEV_ZONED */
 385
 386 const struct block_device_operations nvme_ns_head_ops = {
 387         .owner          = THIS_MODULE,
 388         .submit_bio     = nvme_ns_head_submit_bio,
 389         .open           = nvme_ns_head_open,
 390         .release        = nvme_ns_head_release,
 391         .ioctl          = nvme_ns_head_ioctl,
 392         .getgeo         = nvme_getgeo,
 393         .report_zones   = nvme_ns_head_report_zones,
 394         .pr_ops         = &nvme_pr_ops,
 395 };
 396
 397 static inline struct nvme_ns_head *cdev_to_ns_head(struct cdev *cdev)
 398 {
 399         return container_of(cdev, struct nvme_ns_head, cdev);
 400 }
 401
 402 static int nvme_ns_head_chr_open(struct inode *inode, struct file *file)
 403 {
 404         if (!nvme_tryget_ns_head(cdev_to_ns_head(inode->i_cdev)))
 405                 return -ENXIO;
 406         return 0;
 407 }
 408
 409 static int nvme_ns_head_chr_release(struct inode *inode, struct file *file)
 410 {
 411         nvme_put_ns_head(cdev_to_ns_head(inode->i_cdev));
 412         return 0;
 413 }
 414
 415 static const struct file_operations nvme_ns_head_chr_fops = {
 416         .owner          = THIS_MODULE,
 417         .open           = nvme_ns_head_chr_open,
 418         .release        = nvme_ns_head_chr_release,
 419         .unlocked_ioctl = nvme_ns_head_chr_ioctl,
 420         .compat_ioctl   = compat_ptr_ioctl,
 421 };
 422
 423 static int nvme_add_ns_head_cdev(struct nvme_ns_head *head)
 424 {
 425         int ret;
 426
 427         head->cdev_device.parent = &head->subsys->dev;
 428         ret = dev_set_name(&head->cdev_device, "ng%dn%d",
 429                            head->subsys->instance, head->instance);
 430         if (ret)
 431                 return ret;
 432         ret = nvme_cdev_add(&head->cdev, &head->cdev_device,
 433                             &nvme_ns_head_chr_fops, THIS_MODULE);
 434         if (ret)
 435                 kfree_const(head->cdev_device.kobj.name);
 436         return ret;
 437 }
 438
 439 static void nvme_requeue_work(struct work_struct *work)
 440 {
 441         struct nvme_ns_head *head =
 442                 container_of(work, struct nvme_ns_head, requeue_work);
 443         struct bio *bio, *next;
 444
 445         spin_lock_irq(&head->requeue_lock);
 446         next = bio_list_get(&head->requeue_list);
 447         spin_unlock_irq(&head->requeue_lock);
 448
 449         while ((bio = next) != NULL) {
 450                 next = bio->bi_next;
 451                 bio->bi_next = NULL;
 452
 453                 submit_bio_noacct(bio);
 454         }
 455 }
 456
 457 int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head)
 458 {
 459         bool vwc = false;
 460
 461         mutex_init(&head->lock);
 462         bio_list_init(&head->requeue_list);
 463         spin_lock_init(&head->requeue_lock);
 464         INIT_WORK(&head->requeue_work, nvme_requeue_work);
 465
 466         /*
 467          * Add a multipath node if the subsystems supports multiple controllers.
 468          * We also do this for private namespaces as the namespace sharing data could
 469          * change after a rescan.
 470          */
 471         if (!(ctrl->subsys->cmic & NVME_CTRL_CMIC_MULTI_CTRL) || !multipath)
 472                 return 0;
 473
 474         head->disk = blk_alloc_disk(ctrl->numa_node);
 475         if (!head->disk)
 476                 return -ENOMEM;
 477         head->disk->fops = &nvme_ns_head_ops;
 478         head->disk->private_data = head;
 479         sprintf(head->disk->disk_name, "nvme%dn%d",
 480                         ctrl->subsys->instance, head->instance);
 481
 482         blk_queue_flag_set(QUEUE_FLAG_NONROT, head->disk->queue);
 483         blk_queue_flag_set(QUEUE_FLAG_NOWAIT, head->disk->queue);
 484
 485         /* set to a default value of 512 until the disk is validated */
 486         blk_queue_logical_block_size(head->disk->queue, 512);
 487         blk_set_stacking_limits(&head->disk->queue->limits);
 488
 489         /* we need to propagate up the VMC settings */
 490         if (ctrl->vwc & NVME_CTRL_VWC_PRESENT)
 491                 vwc = true;
 492         blk_queue_write_cache(head->disk->queue, vwc, vwc);
 493         return 0;
 494 }
 495
 496 static void nvme_mpath_set_live(struct nvme_ns *ns)
 497 {
 498         struct nvme_ns_head *head = ns->head;
 499
 500         if (!head->disk)
 501                 return;
 502
 503         if (!test_and_set_bit(NVME_NSHEAD_DISK_LIVE, &head->flags)) {
 504                 device_add_disk(&head->subsys->dev, head->disk,
 505                                 nvme_ns_id_attr_groups);
 506                 nvme_add_ns_head_cdev(head);
 507         }
 508
 509         mutex_lock(&head->lock);
 510         if (nvme_path_is_optimized(ns)) {
 511                 int node, srcu_idx;
 512
 513                 srcu_idx = srcu_read_lock(&head->srcu);
 514                 for_each_node(node)
 515                         __nvme_find_path(head, node);
 516                 srcu_read_unlock(&head->srcu, srcu_idx);
 517         }
 518         mutex_unlock(&head->lock);
 519
 520         synchronize_srcu(&head->srcu);
 521         kblockd_schedule_work(&head->requeue_work);
 522 }
 523
 524 static int nvme_parse_ana_log(struct nvme_ctrl *ctrl, void *data,
 525                 int (*cb)(struct nvme_ctrl *ctrl, struct nvme_ana_group_desc *,
 526                         void *))
 527 {
 528         void *base = ctrl->ana_log_buf;
 529         size_t offset = sizeof(struct nvme_ana_rsp_hdr);
 530         int error, i;
 531
 532         lockdep_assert_held(&ctrl->ana_lock);
 533
 534         for (i = 0; i < le16_to_cpu(ctrl->ana_log_buf->ngrps); i++) {
 535                 struct nvme_ana_group_desc *desc = base + offset;
 536                 u32 nr_nsids;
 537                 size_t nsid_buf_size;
 538
 539                 if (WARN_ON_ONCE(offset > ctrl->ana_log_size - sizeof(*desc)))
 540                         return -EINVAL;
 541
 542                 nr_nsids = le32_to_cpu(desc->nnsids);
 543                 nsid_buf_size = nr_nsids * sizeof(__le32);
 544
 545                 if (WARN_ON_ONCE(desc->grpid == 0))
 546                         return -EINVAL;
 547                 if (WARN_ON_ONCE(le32_to_cpu(desc->grpid) > ctrl->anagrpmax))
 548                         return -EINVAL;
 549                 if (WARN_ON_ONCE(desc->state == 0))
 550                         return -EINVAL;
 551                 if (WARN_ON_ONCE(desc->state > NVME_ANA_CHANGE))
 552                         return -EINVAL;
 553
 554                 offset += sizeof(*desc);
 555                 if (WARN_ON_ONCE(offset > ctrl->ana_log_size - nsid_buf_size))
 556                         return -EINVAL;
 557
 558                 error = cb(ctrl, desc, data);
 559                 if (error)
 560                         return error;
 561
 562                 offset += nsid_buf_size;
 563         }
 564
 565         return 0;
 566 }
 567
 568 static inline bool nvme_state_is_live(enum nvme_ana_state state)
 569 {
 570         return state == NVME_ANA_OPTIMIZED || state == NVME_ANA_NONOPTIMIZED;
 571 }
 572
 573 static void nvme_update_ns_ana_state(struct nvme_ana_group_desc *desc,
 574                 struct nvme_ns *ns)
 575 {
 576         ns->ana_grpid = le32_to_cpu(desc->grpid);
 577         ns->ana_state = desc->state;
 578         clear_bit(NVME_NS_ANA_PENDING, &ns->flags);
 579
 580         if (nvme_state_is_live(ns->ana_state))
 581                 nvme_mpath_set_live(ns);
 582 }
 583
 584 static int nvme_update_ana_state(struct nvme_ctrl *ctrl,
 585                 struct nvme_ana_group_desc *desc, void *data)
 586 {
 587         u32 nr_nsids = le32_to_cpu(desc->nnsids), n = 0;
 588         unsigned *nr_change_groups = data;
 589         struct nvme_ns *ns;
 590
 591         dev_dbg(ctrl->device, "ANA group %d: %s.\n",
 592                         le32_to_cpu(desc->grpid),
 593                         nvme_ana_state_names[desc->state]);
 594
 595         if (desc->state == NVME_ANA_CHANGE)
 596                 (*nr_change_groups)++;
 597
 598         if (!nr_nsids)
 599                 return 0;
 600
 601         down_read(&ctrl->namespaces_rwsem);
 602         list_for_each_entry(ns, &ctrl->namespaces, list) {
 603                 unsigned nsid = le32_to_cpu(desc->nsids[n]);
 604
 605                 if (ns->head->ns_id < nsid)
 606                         continue;
 607                 if (ns->head->ns_id == nsid)
 608                         nvme_update_ns_ana_state(desc, ns);
 609                 if (++n == nr_nsids)
 610                         break;
 611         }
 612         up_read(&ctrl->namespaces_rwsem);
 613         return 0;
 614 }
 615
 616 static int nvme_read_ana_log(struct nvme_ctrl *ctrl)
 617 {
 618         u32 nr_change_groups = 0;
 619         int error;
 620
 621         mutex_lock(&ctrl->ana_lock);
 622         error = nvme_get_log(ctrl, NVME_NSID_ALL, NVME_LOG_ANA, 0, NVME_CSI_NVM,
 623                         ctrl->ana_log_buf, ctrl->ana_log_size, 0);
 624         if (error) {
 625                 dev_warn(ctrl->device, "Failed to get ANA log: %d\n", error);
 626                 goto out_unlock;
 627         }
 628
 629         error = nvme_parse_ana_log(ctrl, &nr_change_groups,
 630                         nvme_update_ana_state);
 631         if (error)
 632                 goto out_unlock;
 633
 634         /*
 635          * In theory we should have an ANATT timer per group as they might enter
 636          * the change state at different times.  But that is a lot of overhead
 637          * just to protect against a target that keeps entering new changes
 638          * states while never finishing previous ones.  But we'll still
 639          * eventually time out once all groups are in change state, so this
 640          * isn't a big deal.
 641          *
 642          * We also double the ANATT value to provide some slack for transports
 643          * or AEN processing overhead.
 644          */
 645         if (nr_change_groups)
 646                 mod_timer(&ctrl->anatt_timer, ctrl->anatt * HZ * 2 + jiffies);
 647         else
 648                 del_timer_sync(&ctrl->anatt_timer);
 649 out_unlock:
 650         mutex_unlock(&ctrl->ana_lock);
 651         return error;
 652 }
 653
 654 static void nvme_ana_work(struct work_struct *work)
 655 {
 656         struct nvme_ctrl *ctrl = container_of(work, struct nvme_ctrl, ana_work);
 657
 658         if (ctrl->state != NVME_CTRL_LIVE)
 659                 return;
 660
 661         nvme_read_ana_log(ctrl);
 662 }
 663
 664 static void nvme_anatt_timeout(struct timer_list *t)
 665 {
 666         struct nvme_ctrl *ctrl = from_timer(ctrl, t, anatt_timer);
 667
 668         dev_info(ctrl->device, "ANATT timeout, resetting controller.\n");
 669         nvme_reset_ctrl(ctrl);
 670 }
 671
 672 void nvme_mpath_stop(struct nvme_ctrl *ctrl)
 673 {
 674         if (!nvme_ctrl_use_ana(ctrl))
 675                 return;
 676         del_timer_sync(&ctrl->anatt_timer);
 677         cancel_work_sync(&ctrl->ana_work);
 678 }
 679
 680 #define SUBSYS_ATTR_RW(_name, _mode, _show, _store)  \
 681         struct device_attribute subsys_attr_##_name =   \
 682                 __ATTR(_name, _mode, _show, _store)
 683
 684 static const char *nvme_iopolicy_names[] = {
 685         [NVME_IOPOLICY_NUMA]    = "numa",
 686         [NVME_IOPOLICY_RR]      = "round-robin",
 687 };
 688
 689 static ssize_t nvme_subsys_iopolicy_show(struct device *dev,
 690                 struct device_attribute *attr, char *buf)
 691 {
 692         struct nvme_subsystem *subsys =
 693                 container_of(dev, struct nvme_subsystem, dev);
 694
 695         return sysfs_emit(buf, "%s\n",
 696                           nvme_iopolicy_names[READ_ONCE(subsys->iopolicy)]);
 697 }
 698
 699 static ssize_t nvme_subsys_iopolicy_store(struct device *dev,
 700                 struct device_attribute *attr, const char *buf, size_t count)
 701 {
 702         struct nvme_subsystem *subsys =
 703                 container_of(dev, struct nvme_subsystem, dev);
 704         int i;
 705
 706         for (i = 0; i < ARRAY_SIZE(nvme_iopolicy_names); i++) {
 707                 if (sysfs_streq(buf, nvme_iopolicy_names[i])) {
 708                         WRITE_ONCE(subsys->iopolicy, i);
 709                         return count;
 710                 }
 711         }
 712
 713         return -EINVAL;
 714 }
 715 SUBSYS_ATTR_RW(iopolicy, S_IRUGO | S_IWUSR,
 716                       nvme_subsys_iopolicy_show, nvme_subsys_iopolicy_store);
 717
 718 static ssize_t ana_grpid_show(struct device *dev, struct device_attribute *attr,
 719                 char *buf)
 720 {
 721         return sysfs_emit(buf, "%d\n", nvme_get_ns_from_dev(dev)->ana_grpid);
 722 }
 723 DEVICE_ATTR_RO(ana_grpid);
 724
 725 static ssize_t ana_state_show(struct device *dev, struct device_attribute *attr,
 726                 char *buf)
 727 {
 728         struct nvme_ns *ns = nvme_get_ns_from_dev(dev);
 729
 730         return sysfs_emit(buf, "%s\n", nvme_ana_state_names[ns->ana_state]);
 731 }
 732 DEVICE_ATTR_RO(ana_state);
 733
 734 static int nvme_lookup_ana_group_desc(struct nvme_ctrl *ctrl,
 735                 struct nvme_ana_group_desc *desc, void *data)
 736 {
 737         struct nvme_ana_group_desc *dst = data;
 738
 739         if (desc->grpid != dst->grpid)
 740                 return 0;
 741
 742         *dst = *desc;
 743         return -ENXIO; /* just break out of the loop */
 744 }
 745
 746 void nvme_mpath_add_disk(struct nvme_ns *ns, struct nvme_id_ns *id)
 747 {
 748         if (nvme_ctrl_use_ana(ns->ctrl)) {
 749                 struct nvme_ana_group_desc desc = {
 750                         .grpid = id->anagrpid,
 751                         .state = 0,
 752                 };
 753
 754                 mutex_lock(&ns->ctrl->ana_lock);
 755                 ns->ana_grpid = le32_to_cpu(id->anagrpid);
 756                 nvme_parse_ana_log(ns->ctrl, &desc, nvme_lookup_ana_group_desc);
 757                 mutex_unlock(&ns->ctrl->ana_lock);
 758                 if (desc.state) {
 759                         /* found the group desc: update */
 760                         nvme_update_ns_ana_state(&desc, ns);
 761                 } else {
 762                         /* group desc not found: trigger a re-read */
 763                         set_bit(NVME_NS_ANA_PENDING, &ns->flags);
 764                         queue_work(nvme_wq, &ns->ctrl->ana_work);
 765                 }
 766         } else {
 767                 ns->ana_state = NVME_ANA_OPTIMIZED;
 768                 nvme_mpath_set_live(ns);
 769         }
 770
 771         if (blk_queue_stable_writes(ns->queue) && ns->head->disk)
 772                 blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES,
 773                                    ns->head->disk->queue);
 774 #ifdef CONFIG_BLK_DEV_ZONED
 775         if (blk_queue_is_zoned(ns->queue) && ns->head->disk)
 776                 ns->head->disk->queue->nr_zones = ns->queue->nr_zones;
 777 #endif
 778 }
 779
 780 void nvme_mpath_shutdown_disk(struct nvme_ns_head *head)
 781 {
 782         if (!head->disk)
 783                 return;
 784         kblockd_schedule_work(&head->requeue_work);
 785         if (test_bit(NVME_NSHEAD_DISK_LIVE, &head->flags)) {
 786                 nvme_cdev_del(&head->cdev, &head->cdev_device);
 787                 del_gendisk(head->disk);
 788         }
 789 }
 790
 791 void nvme_mpath_remove_disk(struct nvme_ns_head *head)
 792 {
 793         if (!head->disk)
 794                 return;
 795         blk_set_queue_dying(head->disk->queue);
 796         /* make sure all pending bios are cleaned up */
 797         kblockd_schedule_work(&head->requeue_work);
 798         flush_work(&head->requeue_work);
 799         blk_cleanup_disk(head->disk);
 800 }
 801
 802 void nvme_mpath_init_ctrl(struct nvme_ctrl *ctrl)
 803 {
 804         mutex_init(&ctrl->ana_lock);
 805         timer_setup(&ctrl->anatt_timer, nvme_anatt_timeout, 0);
 806         INIT_WORK(&ctrl->ana_work, nvme_ana_work);
 807 }
 808
 809 int nvme_mpath_init_identify(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id)
 810 {
 811         size_t max_transfer_size = ctrl->max_hw_sectors << SECTOR_SHIFT;
 812         size_t ana_log_size;
 813         int error = 0;
 814
 815         /* check if multipath is enabled and we have the capability */
 816         if (!multipath || !ctrl->subsys ||
 817             !(ctrl->subsys->cmic & NVME_CTRL_CMIC_ANA))
 818                 return 0;
 819
 820         if (!ctrl->max_namespaces ||
 821             ctrl->max_namespaces > le32_to_cpu(id->nn)) {
 822                 dev_err(ctrl->device,
 823                         "Invalid MNAN value %u\n", ctrl->max_namespaces);
 824                 return -EINVAL;
 825         }
 826
 827         ctrl->anacap = id->anacap;
 828         ctrl->anatt = id->anatt;
 829         ctrl->nanagrpid = le32_to_cpu(id->nanagrpid);
 830         ctrl->anagrpmax = le32_to_cpu(id->anagrpmax);
 831
 832         ana_log_size = sizeof(struct nvme_ana_rsp_hdr) +
 833                 ctrl->nanagrpid * sizeof(struct nvme_ana_group_desc) +
 834                 ctrl->max_namespaces * sizeof(__le32);
 835         if (ana_log_size > max_transfer_size) {
 836                 dev_err(ctrl->device,
 837                         "ANA log page size (%zd) larger than MDTS (%zd).\n",
 838                         ana_log_size, max_transfer_size);
 839                 dev_err(ctrl->device, "disabling ANA support.\n");
 840                 goto out_uninit;
 841         }
 842         if (ana_log_size > ctrl->ana_log_size) {
 843                 nvme_mpath_stop(ctrl);
 844                 kfree(ctrl->ana_log_buf);
 845                 ctrl->ana_log_buf = kmalloc(ana_log_size, GFP_KERNEL);
 846                 if (!ctrl->ana_log_buf)
 847                         return -ENOMEM;
 848         }
 849         ctrl->ana_log_size = ana_log_size;
 850         error = nvme_read_ana_log(ctrl);
 851         if (error)
 852                 goto out_uninit;
 853         return 0;
 854
 855 out_uninit:
 856         nvme_mpath_uninit(ctrl);
 857         return error;
 858 }
 859
 860 void nvme_mpath_uninit(struct nvme_ctrl *ctrl)
 861 {
 862         kfree(ctrl->ana_log_buf);
 863         ctrl->ana_log_buf = NULL;
 864 }