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 static const char *nvme_iopolicy_names[] = { 17 [NVME_IOPOLICY_NUMA] = "numa", 18 [NVME_IOPOLICY_RR] = "round-robin", 19 }; 20 21 static int iopolicy = NVME_IOPOLICY_NUMA; 22 23 static int nvme_set_iopolicy(const char *val, const struct kernel_param *kp) 24 { 25 if (!val) 26 return -EINVAL; 27 if (!strncmp(val, "numa", 4)) 28 iopolicy = NVME_IOPOLICY_NUMA; 29 else if (!strncmp(val, "round-robin", 11)) 30 iopolicy = NVME_IOPOLICY_RR; 31 else 32 return -EINVAL; 33 34 return 0; 35 } 36 37 static int nvme_get_iopolicy(char *buf, const struct kernel_param *kp) 38 { 39 return sprintf(buf, "%s\n", nvme_iopolicy_names[iopolicy]); 40 } 41 42 module_param_call(iopolicy, nvme_set_iopolicy, nvme_get_iopolicy, 43 &iopolicy, 0644); 44 MODULE_PARM_DESC(iopolicy, 45 "Default multipath I/O policy; 'numa' (default) or 'round-robin'"); 46 47 void nvme_mpath_default_iopolicy(struct nvme_subsystem *subsys) 48 { 49 subsys->iopolicy = iopolicy; 50 } 51 52 void nvme_mpath_unfreeze(struct nvme_subsystem *subsys) 53 { 54 struct nvme_ns_head *h; 55 56 lockdep_assert_held(&subsys->lock); 57 list_for_each_entry(h, &subsys->nsheads, entry) 58 if (h->disk) 59 blk_mq_unfreeze_queue(h->disk->queue); 60 } 61 62 void nvme_mpath_wait_freeze(struct nvme_subsystem *subsys) 63 { 64 struct nvme_ns_head *h; 65 66 lockdep_assert_held(&subsys->lock); 67 list_for_each_entry(h, &subsys->nsheads, entry) 68 if (h->disk) 69 blk_mq_freeze_queue_wait(h->disk->queue); 70 } 71 72 void nvme_mpath_start_freeze(struct nvme_subsystem *subsys) 73 { 74 struct nvme_ns_head *h; 75 76 lockdep_assert_held(&subsys->lock); 77 list_for_each_entry(h, &subsys->nsheads, entry) 78 if (h->disk) 79 blk_freeze_queue_start(h->disk->queue); 80 } 81 82 /* 83 * If multipathing is enabled we need to always use the subsystem instance 84 * number for numbering our devices to avoid conflicts between subsystems that 85 * have multiple controllers and thus use the multipath-aware subsystem node 86 * and those that have a single controller and use the controller node 87 * directly. 88 */ 89 bool nvme_mpath_set_disk_name(struct nvme_ns *ns, char *disk_name, int *flags) 90 { 91 if (!multipath) 92 return false; 93 if (!ns->head->disk) { 94 sprintf(disk_name, "nvme%dn%d", ns->ctrl->subsys->instance, 95 ns->head->instance); 96 return true; 97 } 98 sprintf(disk_name, "nvme%dc%dn%d", ns->ctrl->subsys->instance, 99 ns->ctrl->instance, ns->head->instance); 100 *flags = GENHD_FL_HIDDEN; 101 return true; 102 } 103 104 void nvme_failover_req(struct request *req) 105 { 106 struct nvme_ns *ns = req->q->queuedata; 107 u16 status = nvme_req(req)->status & 0x7ff; 108 unsigned long flags; 109 struct bio *bio; 110 111 nvme_mpath_clear_current_path(ns); 112 113 /* 114 * If we got back an ANA error, we know the controller is alive but not 115 * ready to serve this namespace. Kick of a re-read of the ANA 116 * information page, and just try any other available path for now. 117 */ 118 if (nvme_is_ana_error(status) && ns->ctrl->ana_log_buf) { 119 set_bit(NVME_NS_ANA_PENDING, &ns->flags); 120 queue_work(nvme_wq, &ns->ctrl->ana_work); 121 } 122 123 spin_lock_irqsave(&ns->head->requeue_lock, flags); 124 for (bio = req->bio; bio; bio = bio->bi_next) { 125 bio_set_dev(bio, ns->head->disk->part0); 126 if (bio->bi_opf & REQ_POLLED) { 127 bio->bi_opf &= ~REQ_POLLED; 128 bio->bi_cookie = BLK_QC_T_NONE; 129 } 130 } 131 blk_steal_bios(&ns->head->requeue_list, req); 132 spin_unlock_irqrestore(&ns->head->requeue_lock, flags); 133 134 blk_mq_end_request(req, 0); 135 kblockd_schedule_work(&ns->head->requeue_work); 136 } 137 138 void nvme_kick_requeue_lists(struct nvme_ctrl *ctrl) 139 { 140 struct nvme_ns *ns; 141 142 down_read(&ctrl->namespaces_rwsem); 143 list_for_each_entry(ns, &ctrl->namespaces, list) { 144 if (!ns->head->disk) 145 continue; 146 kblockd_schedule_work(&ns->head->requeue_work); 147 if (ctrl->state == NVME_CTRL_LIVE) 148 disk_uevent(ns->head->disk, KOBJ_CHANGE); 149 } 150 up_read(&ctrl->namespaces_rwsem); 151 } 152 153 static const char *nvme_ana_state_names[] = { 154 [0] = "invalid state", 155 [NVME_ANA_OPTIMIZED] = "optimized", 156 [NVME_ANA_NONOPTIMIZED] = "non-optimized", 157 [NVME_ANA_INACCESSIBLE] = "inaccessible", 158 [NVME_ANA_PERSISTENT_LOSS] = "persistent-loss", 159 [NVME_ANA_CHANGE] = "change", 160 }; 161 162 bool nvme_mpath_clear_current_path(struct nvme_ns *ns) 163 { 164 struct nvme_ns_head *head = ns->head; 165 bool changed = false; 166 int node; 167 168 if (!head) 169 goto out; 170 171 for_each_node(node) { 172 if (ns == rcu_access_pointer(head->current_path[node])) { 173 rcu_assign_pointer(head->current_path[node], NULL); 174 changed = true; 175 } 176 } 177 out: 178 return changed; 179 } 180 181 void nvme_mpath_clear_ctrl_paths(struct nvme_ctrl *ctrl) 182 { 183 struct nvme_ns *ns; 184 185 down_read(&ctrl->namespaces_rwsem); 186 list_for_each_entry(ns, &ctrl->namespaces, list) { 187 nvme_mpath_clear_current_path(ns); 188 kblockd_schedule_work(&ns->head->requeue_work); 189 } 190 up_read(&ctrl->namespaces_rwsem); 191 } 192 193 void nvme_mpath_revalidate_paths(struct nvme_ns *ns) 194 { 195 struct nvme_ns_head *head = ns->head; 196 sector_t capacity = get_capacity(head->disk); 197 int node; 198 199 list_for_each_entry_rcu(ns, &head->list, siblings) { 200 if (capacity != get_capacity(ns->disk)) 201 clear_bit(NVME_NS_READY, &ns->flags); 202 } 203 204 for_each_node(node) 205 rcu_assign_pointer(head->current_path[node], NULL); 206 } 207 208 static bool nvme_path_is_disabled(struct nvme_ns *ns) 209 { 210 /* 211 * We don't treat NVME_CTRL_DELETING as a disabled path as I/O should 212 * still be able to complete assuming that the controller is connected. 213 * Otherwise it will fail immediately and return to the requeue list. 214 */ 215 if (ns->ctrl->state != NVME_CTRL_LIVE && 216 ns->ctrl->state != NVME_CTRL_DELETING) 217 return true; 218 if (test_bit(NVME_NS_ANA_PENDING, &ns->flags) || 219 !test_bit(NVME_NS_READY, &ns->flags)) 220 return true; 221 return false; 222 } 223 224 static struct nvme_ns *__nvme_find_path(struct nvme_ns_head *head, int node) 225 { 226 int found_distance = INT_MAX, fallback_distance = INT_MAX, distance; 227 struct nvme_ns *found = NULL, *fallback = NULL, *ns; 228 229 list_for_each_entry_rcu(ns, &head->list, siblings) { 230 if (nvme_path_is_disabled(ns)) 231 continue; 232 233 if (READ_ONCE(head->subsys->iopolicy) == NVME_IOPOLICY_NUMA) 234 distance = node_distance(node, ns->ctrl->numa_node); 235 else 236 distance = LOCAL_DISTANCE; 237 238 switch (ns->ana_state) { 239 case NVME_ANA_OPTIMIZED: 240 if (distance < found_distance) { 241 found_distance = distance; 242 found = ns; 243 } 244 break; 245 case NVME_ANA_NONOPTIMIZED: 246 if (distance < fallback_distance) { 247 fallback_distance = distance; 248 fallback = ns; 249 } 250 break; 251 default: 252 break; 253 } 254 } 255 256 if (!found) 257 found = fallback; 258 if (found) 259 rcu_assign_pointer(head->current_path[node], found); 260 return found; 261 } 262 263 static struct nvme_ns *nvme_next_ns(struct nvme_ns_head *head, 264 struct nvme_ns *ns) 265 { 266 ns = list_next_or_null_rcu(&head->list, &ns->siblings, struct nvme_ns, 267 siblings); 268 if (ns) 269 return ns; 270 return list_first_or_null_rcu(&head->list, struct nvme_ns, siblings); 271 } 272 273 static struct nvme_ns *nvme_round_robin_path(struct nvme_ns_head *head, 274 int node, struct nvme_ns *old) 275 { 276 struct nvme_ns *ns, *found = NULL; 277 278 if (list_is_singular(&head->list)) { 279 if (nvme_path_is_disabled(old)) 280 return NULL; 281 return old; 282 } 283 284 for (ns = nvme_next_ns(head, old); 285 ns && ns != old; 286 ns = nvme_next_ns(head, ns)) { 287 if (nvme_path_is_disabled(ns)) 288 continue; 289 290 if (ns->ana_state == NVME_ANA_OPTIMIZED) { 291 found = ns; 292 goto out; 293 } 294 if (ns->ana_state == NVME_ANA_NONOPTIMIZED) 295 found = ns; 296 } 297 298 /* 299 * The loop above skips the current path for round-robin semantics. 300 * Fall back to the current path if either: 301 * - no other optimized path found and current is optimized, 302 * - no other usable path found and current is usable. 303 */ 304 if (!nvme_path_is_disabled(old) && 305 (old->ana_state == NVME_ANA_OPTIMIZED || 306 (!found && old->ana_state == NVME_ANA_NONOPTIMIZED))) 307 return old; 308 309 if (!found) 310 return NULL; 311 out: 312 rcu_assign_pointer(head->current_path[node], found); 313 return found; 314 } 315 316 static inline bool nvme_path_is_optimized(struct nvme_ns *ns) 317 { 318 return ns->ctrl->state == NVME_CTRL_LIVE && 319 ns->ana_state == NVME_ANA_OPTIMIZED; 320 } 321 322 inline struct nvme_ns *nvme_find_path(struct nvme_ns_head *head) 323 { 324 int node = numa_node_id(); 325 struct nvme_ns *ns; 326 327 ns = srcu_dereference(head->current_path[node], &head->srcu); 328 if (unlikely(!ns)) 329 return __nvme_find_path(head, node); 330 331 if (READ_ONCE(head->subsys->iopolicy) == NVME_IOPOLICY_RR) 332 return nvme_round_robin_path(head, node, ns); 333 if (unlikely(!nvme_path_is_optimized(ns))) 334 return __nvme_find_path(head, node); 335 return ns; 336 } 337 338 static bool nvme_available_path(struct nvme_ns_head *head) 339 { 340 struct nvme_ns *ns; 341 342 list_for_each_entry_rcu(ns, &head->list, siblings) { 343 if (test_bit(NVME_CTRL_FAILFAST_EXPIRED, &ns->ctrl->flags)) 344 continue; 345 switch (ns->ctrl->state) { 346 case NVME_CTRL_LIVE: 347 case NVME_CTRL_RESETTING: 348 case NVME_CTRL_CONNECTING: 349 /* fallthru */ 350 return true; 351 default: 352 break; 353 } 354 } 355 return false; 356 } 357 358 static void nvme_ns_head_submit_bio(struct bio *bio) 359 { 360 struct nvme_ns_head *head = bio->bi_bdev->bd_disk->private_data; 361 struct device *dev = disk_to_dev(head->disk); 362 struct nvme_ns *ns; 363 int srcu_idx; 364 365 /* 366 * The namespace might be going away and the bio might be moved to a 367 * different queue via blk_steal_bios(), so we need to use the bio_split 368 * pool from the original queue to allocate the bvecs from. 369 */ 370 blk_queue_split(&bio); 371 372 srcu_idx = srcu_read_lock(&head->srcu); 373 ns = nvme_find_path(head); 374 if (likely(ns)) { 375 bio_set_dev(bio, ns->disk->part0); 376 bio->bi_opf |= REQ_NVME_MPATH; 377 trace_block_bio_remap(bio, disk_devt(ns->head->disk), 378 bio->bi_iter.bi_sector); 379 submit_bio_noacct(bio); 380 } else if (nvme_available_path(head)) { 381 dev_warn_ratelimited(dev, "no usable path - requeuing I/O\n"); 382 383 spin_lock_irq(&head->requeue_lock); 384 bio_list_add(&head->requeue_list, bio); 385 spin_unlock_irq(&head->requeue_lock); 386 } else { 387 dev_warn_ratelimited(dev, "no available path - failing I/O\n"); 388 389 bio->bi_status = BLK_STS_IOERR; 390 bio_endio(bio); 391 } 392 393 srcu_read_unlock(&head->srcu, srcu_idx); 394 } 395 396 static int nvme_ns_head_open(struct block_device *bdev, fmode_t mode) 397 { 398 if (!nvme_tryget_ns_head(bdev->bd_disk->private_data)) 399 return -ENXIO; 400 return 0; 401 } 402 403 static void nvme_ns_head_release(struct gendisk *disk, fmode_t mode) 404 { 405 nvme_put_ns_head(disk->private_data); 406 } 407 408 #ifdef CONFIG_BLK_DEV_ZONED 409 static int nvme_ns_head_report_zones(struct gendisk *disk, sector_t sector, 410 unsigned int nr_zones, report_zones_cb cb, void *data) 411 { 412 struct nvme_ns_head *head = disk->private_data; 413 struct nvme_ns *ns; 414 int srcu_idx, ret = -EWOULDBLOCK; 415 416 srcu_idx = srcu_read_lock(&head->srcu); 417 ns = nvme_find_path(head); 418 if (ns) 419 ret = nvme_ns_report_zones(ns, sector, nr_zones, cb, data); 420 srcu_read_unlock(&head->srcu, srcu_idx); 421 return ret; 422 } 423 #else 424 #define nvme_ns_head_report_zones NULL 425 #endif /* CONFIG_BLK_DEV_ZONED */ 426 427 const struct block_device_operations nvme_ns_head_ops = { 428 .owner = THIS_MODULE, 429 .submit_bio = nvme_ns_head_submit_bio, 430 .open = nvme_ns_head_open, 431 .release = nvme_ns_head_release, 432 .ioctl = nvme_ns_head_ioctl, 433 .getgeo = nvme_getgeo, 434 .report_zones = nvme_ns_head_report_zones, 435 .pr_ops = &nvme_pr_ops, 436 }; 437 438 static inline struct nvme_ns_head *cdev_to_ns_head(struct cdev *cdev) 439 { 440 return container_of(cdev, struct nvme_ns_head, cdev); 441 } 442 443 static int nvme_ns_head_chr_open(struct inode *inode, struct file *file) 444 { 445 if (!nvme_tryget_ns_head(cdev_to_ns_head(inode->i_cdev))) 446 return -ENXIO; 447 return 0; 448 } 449 450 static int nvme_ns_head_chr_release(struct inode *inode, struct file *file) 451 { 452 nvme_put_ns_head(cdev_to_ns_head(inode->i_cdev)); 453 return 0; 454 } 455 456 static const struct file_operations nvme_ns_head_chr_fops = { 457 .owner = THIS_MODULE, 458 .open = nvme_ns_head_chr_open, 459 .release = nvme_ns_head_chr_release, 460 .unlocked_ioctl = nvme_ns_head_chr_ioctl, 461 .compat_ioctl = compat_ptr_ioctl, 462 }; 463 464 static int nvme_add_ns_head_cdev(struct nvme_ns_head *head) 465 { 466 int ret; 467 468 head->cdev_device.parent = &head->subsys->dev; 469 ret = dev_set_name(&head->cdev_device, "ng%dn%d", 470 head->subsys->instance, head->instance); 471 if (ret) 472 return ret; 473 ret = nvme_cdev_add(&head->cdev, &head->cdev_device, 474 &nvme_ns_head_chr_fops, THIS_MODULE); 475 return ret; 476 } 477 478 static void nvme_requeue_work(struct work_struct *work) 479 { 480 struct nvme_ns_head *head = 481 container_of(work, struct nvme_ns_head, requeue_work); 482 struct bio *bio, *next; 483 484 spin_lock_irq(&head->requeue_lock); 485 next = bio_list_get(&head->requeue_list); 486 spin_unlock_irq(&head->requeue_lock); 487 488 while ((bio = next) != NULL) { 489 next = bio->bi_next; 490 bio->bi_next = NULL; 491 492 submit_bio_noacct(bio); 493 } 494 } 495 496 int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head) 497 { 498 bool vwc = false; 499 500 mutex_init(&head->lock); 501 bio_list_init(&head->requeue_list); 502 spin_lock_init(&head->requeue_lock); 503 INIT_WORK(&head->requeue_work, nvme_requeue_work); 504 505 /* 506 * Add a multipath node if the subsystems supports multiple controllers. 507 * We also do this for private namespaces as the namespace sharing data could 508 * change after a rescan. 509 */ 510 if (!(ctrl->subsys->cmic & NVME_CTRL_CMIC_MULTI_CTRL) || !multipath) 511 return 0; 512 513 head->disk = blk_alloc_disk(ctrl->numa_node); 514 if (!head->disk) 515 return -ENOMEM; 516 head->disk->fops = &nvme_ns_head_ops; 517 head->disk->private_data = head; 518 sprintf(head->disk->disk_name, "nvme%dn%d", 519 ctrl->subsys->instance, head->instance); 520 521 blk_queue_flag_set(QUEUE_FLAG_NONROT, head->disk->queue); 522 blk_queue_flag_set(QUEUE_FLAG_NOWAIT, head->disk->queue); 523 /* 524 * This assumes all controllers that refer to a namespace either 525 * support poll queues or not. That is not a strict guarantee, 526 * but if the assumption is wrong the effect is only suboptimal 527 * performance but not correctness problem. 528 */ 529 if (ctrl->tagset->nr_maps > HCTX_TYPE_POLL && 530 ctrl->tagset->map[HCTX_TYPE_POLL].nr_queues) 531 blk_queue_flag_set(QUEUE_FLAG_POLL, head->disk->queue); 532 533 /* set to a default value of 512 until the disk is validated */ 534 blk_queue_logical_block_size(head->disk->queue, 512); 535 blk_set_stacking_limits(&head->disk->queue->limits); 536 537 /* we need to propagate up the VMC settings */ 538 if (ctrl->vwc & NVME_CTRL_VWC_PRESENT) 539 vwc = true; 540 blk_queue_write_cache(head->disk->queue, vwc, vwc); 541 return 0; 542 } 543 544 static void nvme_mpath_set_live(struct nvme_ns *ns) 545 { 546 struct nvme_ns_head *head = ns->head; 547 int rc; 548 549 if (!head->disk) 550 return; 551 552 /* 553 * test_and_set_bit() is used because it is protecting against two nvme 554 * paths simultaneously calling device_add_disk() on the same namespace 555 * head. 556 */ 557 if (!test_and_set_bit(NVME_NSHEAD_DISK_LIVE, &head->flags)) { 558 rc = device_add_disk(&head->subsys->dev, head->disk, 559 nvme_ns_id_attr_groups); 560 if (rc) { 561 clear_bit(NVME_NSHEAD_DISK_LIVE, &ns->flags); 562 return; 563 } 564 nvme_add_ns_head_cdev(head); 565 } 566 567 mutex_lock(&head->lock); 568 if (nvme_path_is_optimized(ns)) { 569 int node, srcu_idx; 570 571 srcu_idx = srcu_read_lock(&head->srcu); 572 for_each_node(node) 573 __nvme_find_path(head, node); 574 srcu_read_unlock(&head->srcu, srcu_idx); 575 } 576 mutex_unlock(&head->lock); 577 578 synchronize_srcu(&head->srcu); 579 kblockd_schedule_work(&head->requeue_work); 580 } 581 582 static int nvme_parse_ana_log(struct nvme_ctrl *ctrl, void *data, 583 int (*cb)(struct nvme_ctrl *ctrl, struct nvme_ana_group_desc *, 584 void *)) 585 { 586 void *base = ctrl->ana_log_buf; 587 size_t offset = sizeof(struct nvme_ana_rsp_hdr); 588 int error, i; 589 590 lockdep_assert_held(&ctrl->ana_lock); 591 592 for (i = 0; i < le16_to_cpu(ctrl->ana_log_buf->ngrps); i++) { 593 struct nvme_ana_group_desc *desc = base + offset; 594 u32 nr_nsids; 595 size_t nsid_buf_size; 596 597 if (WARN_ON_ONCE(offset > ctrl->ana_log_size - sizeof(*desc))) 598 return -EINVAL; 599 600 nr_nsids = le32_to_cpu(desc->nnsids); 601 nsid_buf_size = flex_array_size(desc, nsids, nr_nsids); 602 603 if (WARN_ON_ONCE(desc->grpid == 0)) 604 return -EINVAL; 605 if (WARN_ON_ONCE(le32_to_cpu(desc->grpid) > ctrl->anagrpmax)) 606 return -EINVAL; 607 if (WARN_ON_ONCE(desc->state == 0)) 608 return -EINVAL; 609 if (WARN_ON_ONCE(desc->state > NVME_ANA_CHANGE)) 610 return -EINVAL; 611 612 offset += sizeof(*desc); 613 if (WARN_ON_ONCE(offset > ctrl->ana_log_size - nsid_buf_size)) 614 return -EINVAL; 615 616 error = cb(ctrl, desc, data); 617 if (error) 618 return error; 619 620 offset += nsid_buf_size; 621 } 622 623 return 0; 624 } 625 626 static inline bool nvme_state_is_live(enum nvme_ana_state state) 627 { 628 return state == NVME_ANA_OPTIMIZED || state == NVME_ANA_NONOPTIMIZED; 629 } 630 631 static void nvme_update_ns_ana_state(struct nvme_ana_group_desc *desc, 632 struct nvme_ns *ns) 633 { 634 ns->ana_grpid = le32_to_cpu(desc->grpid); 635 ns->ana_state = desc->state; 636 clear_bit(NVME_NS_ANA_PENDING, &ns->flags); 637 638 if (nvme_state_is_live(ns->ana_state)) 639 nvme_mpath_set_live(ns); 640 } 641 642 static int nvme_update_ana_state(struct nvme_ctrl *ctrl, 643 struct nvme_ana_group_desc *desc, void *data) 644 { 645 u32 nr_nsids = le32_to_cpu(desc->nnsids), n = 0; 646 unsigned *nr_change_groups = data; 647 struct nvme_ns *ns; 648 649 dev_dbg(ctrl->device, "ANA group %d: %s.\n", 650 le32_to_cpu(desc->grpid), 651 nvme_ana_state_names[desc->state]); 652 653 if (desc->state == NVME_ANA_CHANGE) 654 (*nr_change_groups)++; 655 656 if (!nr_nsids) 657 return 0; 658 659 down_read(&ctrl->namespaces_rwsem); 660 list_for_each_entry(ns, &ctrl->namespaces, list) { 661 unsigned nsid; 662 again: 663 nsid = le32_to_cpu(desc->nsids[n]); 664 if (ns->head->ns_id < nsid) 665 continue; 666 if (ns->head->ns_id == nsid) 667 nvme_update_ns_ana_state(desc, ns); 668 if (++n == nr_nsids) 669 break; 670 if (ns->head->ns_id > nsid) 671 goto again; 672 } 673 up_read(&ctrl->namespaces_rwsem); 674 return 0; 675 } 676 677 static int nvme_read_ana_log(struct nvme_ctrl *ctrl) 678 { 679 u32 nr_change_groups = 0; 680 int error; 681 682 mutex_lock(&ctrl->ana_lock); 683 error = nvme_get_log(ctrl, NVME_NSID_ALL, NVME_LOG_ANA, 0, NVME_CSI_NVM, 684 ctrl->ana_log_buf, ctrl->ana_log_size, 0); 685 if (error) { 686 dev_warn(ctrl->device, "Failed to get ANA log: %d\n", error); 687 goto out_unlock; 688 } 689 690 error = nvme_parse_ana_log(ctrl, &nr_change_groups, 691 nvme_update_ana_state); 692 if (error) 693 goto out_unlock; 694 695 /* 696 * In theory we should have an ANATT timer per group as they might enter 697 * the change state at different times. But that is a lot of overhead 698 * just to protect against a target that keeps entering new changes 699 * states while never finishing previous ones. But we'll still 700 * eventually time out once all groups are in change state, so this 701 * isn't a big deal. 702 * 703 * We also double the ANATT value to provide some slack for transports 704 * or AEN processing overhead. 705 */ 706 if (nr_change_groups) 707 mod_timer(&ctrl->anatt_timer, ctrl->anatt * HZ * 2 + jiffies); 708 else 709 del_timer_sync(&ctrl->anatt_timer); 710 out_unlock: 711 mutex_unlock(&ctrl->ana_lock); 712 return error; 713 } 714 715 static void nvme_ana_work(struct work_struct *work) 716 { 717 struct nvme_ctrl *ctrl = container_of(work, struct nvme_ctrl, ana_work); 718 719 if (ctrl->state != NVME_CTRL_LIVE) 720 return; 721 722 nvme_read_ana_log(ctrl); 723 } 724 725 static void nvme_anatt_timeout(struct timer_list *t) 726 { 727 struct nvme_ctrl *ctrl = from_timer(ctrl, t, anatt_timer); 728 729 dev_info(ctrl->device, "ANATT timeout, resetting controller.\n"); 730 nvme_reset_ctrl(ctrl); 731 } 732 733 void nvme_mpath_stop(struct nvme_ctrl *ctrl) 734 { 735 if (!nvme_ctrl_use_ana(ctrl)) 736 return; 737 del_timer_sync(&ctrl->anatt_timer); 738 cancel_work_sync(&ctrl->ana_work); 739 } 740 741 #define SUBSYS_ATTR_RW(_name, _mode, _show, _store) \ 742 struct device_attribute subsys_attr_##_name = \ 743 __ATTR(_name, _mode, _show, _store) 744 745 static ssize_t nvme_subsys_iopolicy_show(struct device *dev, 746 struct device_attribute *attr, char *buf) 747 { 748 struct nvme_subsystem *subsys = 749 container_of(dev, struct nvme_subsystem, dev); 750 751 return sysfs_emit(buf, "%s\n", 752 nvme_iopolicy_names[READ_ONCE(subsys->iopolicy)]); 753 } 754 755 static ssize_t nvme_subsys_iopolicy_store(struct device *dev, 756 struct device_attribute *attr, const char *buf, size_t count) 757 { 758 struct nvme_subsystem *subsys = 759 container_of(dev, struct nvme_subsystem, dev); 760 int i; 761 762 for (i = 0; i < ARRAY_SIZE(nvme_iopolicy_names); i++) { 763 if (sysfs_streq(buf, nvme_iopolicy_names[i])) { 764 WRITE_ONCE(subsys->iopolicy, i); 765 return count; 766 } 767 } 768 769 return -EINVAL; 770 } 771 SUBSYS_ATTR_RW(iopolicy, S_IRUGO | S_IWUSR, 772 nvme_subsys_iopolicy_show, nvme_subsys_iopolicy_store); 773 774 static ssize_t ana_grpid_show(struct device *dev, struct device_attribute *attr, 775 char *buf) 776 { 777 return sysfs_emit(buf, "%d\n", nvme_get_ns_from_dev(dev)->ana_grpid); 778 } 779 DEVICE_ATTR_RO(ana_grpid); 780 781 static ssize_t ana_state_show(struct device *dev, struct device_attribute *attr, 782 char *buf) 783 { 784 struct nvme_ns *ns = nvme_get_ns_from_dev(dev); 785 786 return sysfs_emit(buf, "%s\n", nvme_ana_state_names[ns->ana_state]); 787 } 788 DEVICE_ATTR_RO(ana_state); 789 790 static int nvme_lookup_ana_group_desc(struct nvme_ctrl *ctrl, 791 struct nvme_ana_group_desc *desc, void *data) 792 { 793 struct nvme_ana_group_desc *dst = data; 794 795 if (desc->grpid != dst->grpid) 796 return 0; 797 798 *dst = *desc; 799 return -ENXIO; /* just break out of the loop */ 800 } 801 802 void nvme_mpath_add_disk(struct nvme_ns *ns, struct nvme_id_ns *id) 803 { 804 if (nvme_ctrl_use_ana(ns->ctrl)) { 805 struct nvme_ana_group_desc desc = { 806 .grpid = id->anagrpid, 807 .state = 0, 808 }; 809 810 mutex_lock(&ns->ctrl->ana_lock); 811 ns->ana_grpid = le32_to_cpu(id->anagrpid); 812 nvme_parse_ana_log(ns->ctrl, &desc, nvme_lookup_ana_group_desc); 813 mutex_unlock(&ns->ctrl->ana_lock); 814 if (desc.state) { 815 /* found the group desc: update */ 816 nvme_update_ns_ana_state(&desc, ns); 817 } else { 818 /* group desc not found: trigger a re-read */ 819 set_bit(NVME_NS_ANA_PENDING, &ns->flags); 820 queue_work(nvme_wq, &ns->ctrl->ana_work); 821 } 822 } else { 823 ns->ana_state = NVME_ANA_OPTIMIZED; 824 nvme_mpath_set_live(ns); 825 } 826 827 if (blk_queue_stable_writes(ns->queue) && ns->head->disk) 828 blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, 829 ns->head->disk->queue); 830 #ifdef CONFIG_BLK_DEV_ZONED 831 if (blk_queue_is_zoned(ns->queue) && ns->head->disk) 832 ns->head->disk->queue->nr_zones = ns->queue->nr_zones; 833 #endif 834 } 835 836 void nvme_mpath_shutdown_disk(struct nvme_ns_head *head) 837 { 838 if (!head->disk) 839 return; 840 kblockd_schedule_work(&head->requeue_work); 841 if (test_bit(NVME_NSHEAD_DISK_LIVE, &head->flags)) { 842 nvme_cdev_del(&head->cdev, &head->cdev_device); 843 del_gendisk(head->disk); 844 } 845 } 846 847 void nvme_mpath_remove_disk(struct nvme_ns_head *head) 848 { 849 if (!head->disk) 850 return; 851 blk_set_queue_dying(head->disk->queue); 852 /* make sure all pending bios are cleaned up */ 853 kblockd_schedule_work(&head->requeue_work); 854 flush_work(&head->requeue_work); 855 blk_cleanup_disk(head->disk); 856 } 857 858 void nvme_mpath_init_ctrl(struct nvme_ctrl *ctrl) 859 { 860 mutex_init(&ctrl->ana_lock); 861 timer_setup(&ctrl->anatt_timer, nvme_anatt_timeout, 0); 862 INIT_WORK(&ctrl->ana_work, nvme_ana_work); 863 } 864 865 int nvme_mpath_init_identify(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id) 866 { 867 size_t max_transfer_size = ctrl->max_hw_sectors << SECTOR_SHIFT; 868 size_t ana_log_size; 869 int error = 0; 870 871 /* check if multipath is enabled and we have the capability */ 872 if (!multipath || !ctrl->subsys || 873 !(ctrl->subsys->cmic & NVME_CTRL_CMIC_ANA)) 874 return 0; 875 876 if (!ctrl->max_namespaces || 877 ctrl->max_namespaces > le32_to_cpu(id->nn)) { 878 dev_err(ctrl->device, 879 "Invalid MNAN value %u\n", ctrl->max_namespaces); 880 return -EINVAL; 881 } 882 883 ctrl->anacap = id->anacap; 884 ctrl->anatt = id->anatt; 885 ctrl->nanagrpid = le32_to_cpu(id->nanagrpid); 886 ctrl->anagrpmax = le32_to_cpu(id->anagrpmax); 887 888 ana_log_size = sizeof(struct nvme_ana_rsp_hdr) + 889 ctrl->nanagrpid * sizeof(struct nvme_ana_group_desc) + 890 ctrl->max_namespaces * sizeof(__le32); 891 if (ana_log_size > max_transfer_size) { 892 dev_err(ctrl->device, 893 "ANA log page size (%zd) larger than MDTS (%zd).\n", 894 ana_log_size, max_transfer_size); 895 dev_err(ctrl->device, "disabling ANA support.\n"); 896 goto out_uninit; 897 } 898 if (ana_log_size > ctrl->ana_log_size) { 899 nvme_mpath_stop(ctrl); 900 nvme_mpath_uninit(ctrl); 901 ctrl->ana_log_buf = kmalloc(ana_log_size, GFP_KERNEL); 902 if (!ctrl->ana_log_buf) 903 return -ENOMEM; 904 } 905 ctrl->ana_log_size = ana_log_size; 906 error = nvme_read_ana_log(ctrl); 907 if (error) 908 goto out_uninit; 909 return 0; 910 911 out_uninit: 912 nvme_mpath_uninit(ctrl); 913 return error; 914 } 915 916 void nvme_mpath_uninit(struct nvme_ctrl *ctrl) 917 { 918 kfree(ctrl->ana_log_buf); 919 ctrl->ana_log_buf = NULL; 920 ctrl->ana_log_size = 0; 921 } 922