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 <linux/vmalloc.h> 9 #include <trace/events/block.h> 10 #include "nvme.h" 11 12 bool multipath = true; 13 module_param(multipath, bool, 0444); 14 MODULE_PARM_DESC(multipath, 15 "turn on native support for multiple controllers per subsystem"); 16 17 static const char *nvme_iopolicy_names[] = { 18 [NVME_IOPOLICY_NUMA] = "numa", 19 [NVME_IOPOLICY_RR] = "round-robin", 20 [NVME_IOPOLICY_QD] = "queue-depth", 21 }; 22 23 static int iopolicy = NVME_IOPOLICY_NUMA; 24 25 static int nvme_set_iopolicy(const char *val, const struct kernel_param *kp) 26 { 27 if (!val) 28 return -EINVAL; 29 if (!strncmp(val, "numa", 4)) 30 iopolicy = NVME_IOPOLICY_NUMA; 31 else if (!strncmp(val, "round-robin", 11)) 32 iopolicy = NVME_IOPOLICY_RR; 33 else if (!strncmp(val, "queue-depth", 11)) 34 iopolicy = NVME_IOPOLICY_QD; 35 else 36 return -EINVAL; 37 38 return 0; 39 } 40 41 static int nvme_get_iopolicy(char *buf, const struct kernel_param *kp) 42 { 43 return sprintf(buf, "%s\n", nvme_iopolicy_names[iopolicy]); 44 } 45 46 module_param_call(iopolicy, nvme_set_iopolicy, nvme_get_iopolicy, 47 &iopolicy, 0644); 48 MODULE_PARM_DESC(iopolicy, 49 "Default multipath I/O policy; 'numa' (default), 'round-robin' or 'queue-depth'"); 50 51 void nvme_mpath_default_iopolicy(struct nvme_subsystem *subsys) 52 { 53 subsys->iopolicy = iopolicy; 54 } 55 56 void nvme_mpath_unfreeze(struct nvme_subsystem *subsys) 57 { 58 struct nvme_ns_head *h; 59 60 lockdep_assert_held(&subsys->lock); 61 list_for_each_entry(h, &subsys->nsheads, entry) 62 if (h->disk) 63 blk_mq_unfreeze_queue(h->disk->queue); 64 } 65 66 void nvme_mpath_wait_freeze(struct nvme_subsystem *subsys) 67 { 68 struct nvme_ns_head *h; 69 70 lockdep_assert_held(&subsys->lock); 71 list_for_each_entry(h, &subsys->nsheads, entry) 72 if (h->disk) 73 blk_mq_freeze_queue_wait(h->disk->queue); 74 } 75 76 void nvme_mpath_start_freeze(struct nvme_subsystem *subsys) 77 { 78 struct nvme_ns_head *h; 79 80 lockdep_assert_held(&subsys->lock); 81 list_for_each_entry(h, &subsys->nsheads, entry) 82 if (h->disk) 83 blk_freeze_queue_start(h->disk->queue); 84 } 85 86 void nvme_failover_req(struct request *req) 87 { 88 struct nvme_ns *ns = req->q->queuedata; 89 u16 status = nvme_req(req)->status & NVME_SCT_SC_MASK; 90 unsigned long flags; 91 struct bio *bio; 92 93 nvme_mpath_clear_current_path(ns); 94 95 /* 96 * If we got back an ANA error, we know the controller is alive but not 97 * ready to serve this namespace. Kick of a re-read of the ANA 98 * information page, and just try any other available path for now. 99 */ 100 if (nvme_is_ana_error(status) && ns->ctrl->ana_log_buf) { 101 set_bit(NVME_NS_ANA_PENDING, &ns->flags); 102 queue_work(nvme_wq, &ns->ctrl->ana_work); 103 } 104 105 spin_lock_irqsave(&ns->head->requeue_lock, flags); 106 for (bio = req->bio; bio; bio = bio->bi_next) { 107 bio_set_dev(bio, ns->head->disk->part0); 108 if (bio->bi_opf & REQ_POLLED) { 109 bio->bi_opf &= ~REQ_POLLED; 110 bio->bi_cookie = BLK_QC_T_NONE; 111 } 112 /* 113 * The alternate request queue that we may end up submitting 114 * the bio to may be frozen temporarily, in this case REQ_NOWAIT 115 * will fail the I/O immediately with EAGAIN to the issuer. 116 * We are not in the issuer context which cannot block. Clear 117 * the flag to avoid spurious EAGAIN I/O failures. 118 */ 119 bio->bi_opf &= ~REQ_NOWAIT; 120 } 121 blk_steal_bios(&ns->head->requeue_list, req); 122 spin_unlock_irqrestore(&ns->head->requeue_lock, flags); 123 124 nvme_req(req)->status = 0; 125 nvme_end_req(req); 126 kblockd_schedule_work(&ns->head->requeue_work); 127 } 128 129 void nvme_mpath_start_request(struct request *rq) 130 { 131 struct nvme_ns *ns = rq->q->queuedata; 132 struct gendisk *disk = ns->head->disk; 133 134 if (READ_ONCE(ns->head->subsys->iopolicy) == NVME_IOPOLICY_QD) { 135 atomic_inc(&ns->ctrl->nr_active); 136 nvme_req(rq)->flags |= NVME_MPATH_CNT_ACTIVE; 137 } 138 139 if (!blk_queue_io_stat(disk->queue) || blk_rq_is_passthrough(rq)) 140 return; 141 142 nvme_req(rq)->flags |= NVME_MPATH_IO_STATS; 143 nvme_req(rq)->start_time = bdev_start_io_acct(disk->part0, req_op(rq), 144 jiffies); 145 } 146 EXPORT_SYMBOL_GPL(nvme_mpath_start_request); 147 148 void nvme_mpath_end_request(struct request *rq) 149 { 150 struct nvme_ns *ns = rq->q->queuedata; 151 152 if (nvme_req(rq)->flags & NVME_MPATH_CNT_ACTIVE) 153 atomic_dec_if_positive(&ns->ctrl->nr_active); 154 155 if (!(nvme_req(rq)->flags & NVME_MPATH_IO_STATS)) 156 return; 157 bdev_end_io_acct(ns->head->disk->part0, req_op(rq), 158 blk_rq_bytes(rq) >> SECTOR_SHIFT, 159 nvme_req(rq)->start_time); 160 } 161 162 void nvme_kick_requeue_lists(struct nvme_ctrl *ctrl) 163 { 164 struct nvme_ns *ns; 165 int srcu_idx; 166 167 srcu_idx = srcu_read_lock(&ctrl->srcu); 168 list_for_each_entry_rcu(ns, &ctrl->namespaces, list) { 169 if (!ns->head->disk) 170 continue; 171 kblockd_schedule_work(&ns->head->requeue_work); 172 if (nvme_ctrl_state(ns->ctrl) == NVME_CTRL_LIVE) 173 disk_uevent(ns->head->disk, KOBJ_CHANGE); 174 } 175 srcu_read_unlock(&ctrl->srcu, srcu_idx); 176 } 177 178 static const char *nvme_ana_state_names[] = { 179 [0] = "invalid state", 180 [NVME_ANA_OPTIMIZED] = "optimized", 181 [NVME_ANA_NONOPTIMIZED] = "non-optimized", 182 [NVME_ANA_INACCESSIBLE] = "inaccessible", 183 [NVME_ANA_PERSISTENT_LOSS] = "persistent-loss", 184 [NVME_ANA_CHANGE] = "change", 185 }; 186 187 bool nvme_mpath_clear_current_path(struct nvme_ns *ns) 188 { 189 struct nvme_ns_head *head = ns->head; 190 bool changed = false; 191 int node; 192 193 if (!head) 194 goto out; 195 196 for_each_node(node) { 197 if (ns == rcu_access_pointer(head->current_path[node])) { 198 rcu_assign_pointer(head->current_path[node], NULL); 199 changed = true; 200 } 201 } 202 out: 203 return changed; 204 } 205 206 void nvme_mpath_clear_ctrl_paths(struct nvme_ctrl *ctrl) 207 { 208 struct nvme_ns *ns; 209 int srcu_idx; 210 211 srcu_idx = srcu_read_lock(&ctrl->srcu); 212 list_for_each_entry_rcu(ns, &ctrl->namespaces, list) { 213 nvme_mpath_clear_current_path(ns); 214 kblockd_schedule_work(&ns->head->requeue_work); 215 } 216 srcu_read_unlock(&ctrl->srcu, srcu_idx); 217 } 218 219 void nvme_mpath_revalidate_paths(struct nvme_ns *ns) 220 { 221 struct nvme_ns_head *head = ns->head; 222 sector_t capacity = get_capacity(head->disk); 223 int node; 224 int srcu_idx; 225 226 srcu_idx = srcu_read_lock(&head->srcu); 227 list_for_each_entry_rcu(ns, &head->list, siblings) { 228 if (capacity != get_capacity(ns->disk)) 229 clear_bit(NVME_NS_READY, &ns->flags); 230 } 231 srcu_read_unlock(&head->srcu, srcu_idx); 232 233 for_each_node(node) 234 rcu_assign_pointer(head->current_path[node], NULL); 235 kblockd_schedule_work(&head->requeue_work); 236 } 237 238 static bool nvme_path_is_disabled(struct nvme_ns *ns) 239 { 240 enum nvme_ctrl_state state = nvme_ctrl_state(ns->ctrl); 241 242 /* 243 * We don't treat NVME_CTRL_DELETING as a disabled path as I/O should 244 * still be able to complete assuming that the controller is connected. 245 * Otherwise it will fail immediately and return to the requeue list. 246 */ 247 if (state != NVME_CTRL_LIVE && state != NVME_CTRL_DELETING) 248 return true; 249 if (test_bit(NVME_NS_ANA_PENDING, &ns->flags) || 250 !test_bit(NVME_NS_READY, &ns->flags)) 251 return true; 252 return false; 253 } 254 255 static struct nvme_ns *__nvme_find_path(struct nvme_ns_head *head, int node) 256 { 257 int found_distance = INT_MAX, fallback_distance = INT_MAX, distance; 258 struct nvme_ns *found = NULL, *fallback = NULL, *ns; 259 260 list_for_each_entry_rcu(ns, &head->list, siblings) { 261 if (nvme_path_is_disabled(ns)) 262 continue; 263 264 if (ns->ctrl->numa_node != NUMA_NO_NODE && 265 READ_ONCE(head->subsys->iopolicy) == NVME_IOPOLICY_NUMA) 266 distance = node_distance(node, ns->ctrl->numa_node); 267 else 268 distance = LOCAL_DISTANCE; 269 270 switch (ns->ana_state) { 271 case NVME_ANA_OPTIMIZED: 272 if (distance < found_distance) { 273 found_distance = distance; 274 found = ns; 275 } 276 break; 277 case NVME_ANA_NONOPTIMIZED: 278 if (distance < fallback_distance) { 279 fallback_distance = distance; 280 fallback = ns; 281 } 282 break; 283 default: 284 break; 285 } 286 } 287 288 if (!found) 289 found = fallback; 290 if (found) 291 rcu_assign_pointer(head->current_path[node], found); 292 return found; 293 } 294 295 static struct nvme_ns *nvme_next_ns(struct nvme_ns_head *head, 296 struct nvme_ns *ns) 297 { 298 ns = list_next_or_null_rcu(&head->list, &ns->siblings, struct nvme_ns, 299 siblings); 300 if (ns) 301 return ns; 302 return list_first_or_null_rcu(&head->list, struct nvme_ns, siblings); 303 } 304 305 static struct nvme_ns *nvme_round_robin_path(struct nvme_ns_head *head) 306 { 307 struct nvme_ns *ns, *found = NULL; 308 int node = numa_node_id(); 309 struct nvme_ns *old = srcu_dereference(head->current_path[node], 310 &head->srcu); 311 312 if (unlikely(!old)) 313 return __nvme_find_path(head, node); 314 315 if (list_is_singular(&head->list)) { 316 if (nvme_path_is_disabled(old)) 317 return NULL; 318 return old; 319 } 320 321 for (ns = nvme_next_ns(head, old); 322 ns && ns != old; 323 ns = nvme_next_ns(head, ns)) { 324 if (nvme_path_is_disabled(ns)) 325 continue; 326 327 if (ns->ana_state == NVME_ANA_OPTIMIZED) { 328 found = ns; 329 goto out; 330 } 331 if (ns->ana_state == NVME_ANA_NONOPTIMIZED) 332 found = ns; 333 } 334 335 /* 336 * The loop above skips the current path for round-robin semantics. 337 * Fall back to the current path if either: 338 * - no other optimized path found and current is optimized, 339 * - no other usable path found and current is usable. 340 */ 341 if (!nvme_path_is_disabled(old) && 342 (old->ana_state == NVME_ANA_OPTIMIZED || 343 (!found && old->ana_state == NVME_ANA_NONOPTIMIZED))) 344 return old; 345 346 if (!found) 347 return NULL; 348 out: 349 rcu_assign_pointer(head->current_path[node], found); 350 return found; 351 } 352 353 static struct nvme_ns *nvme_queue_depth_path(struct nvme_ns_head *head) 354 { 355 struct nvme_ns *best_opt = NULL, *best_nonopt = NULL, *ns; 356 unsigned int min_depth_opt = UINT_MAX, min_depth_nonopt = UINT_MAX; 357 unsigned int depth; 358 359 list_for_each_entry_rcu(ns, &head->list, siblings) { 360 if (nvme_path_is_disabled(ns)) 361 continue; 362 363 depth = atomic_read(&ns->ctrl->nr_active); 364 365 switch (ns->ana_state) { 366 case NVME_ANA_OPTIMIZED: 367 if (depth < min_depth_opt) { 368 min_depth_opt = depth; 369 best_opt = ns; 370 } 371 break; 372 case NVME_ANA_NONOPTIMIZED: 373 if (depth < min_depth_nonopt) { 374 min_depth_nonopt = depth; 375 best_nonopt = ns; 376 } 377 break; 378 default: 379 break; 380 } 381 382 if (min_depth_opt == 0) 383 return best_opt; 384 } 385 386 return best_opt ? best_opt : best_nonopt; 387 } 388 389 static inline bool nvme_path_is_optimized(struct nvme_ns *ns) 390 { 391 return nvme_ctrl_state(ns->ctrl) == NVME_CTRL_LIVE && 392 ns->ana_state == NVME_ANA_OPTIMIZED; 393 } 394 395 static struct nvme_ns *nvme_numa_path(struct nvme_ns_head *head) 396 { 397 int node = numa_node_id(); 398 struct nvme_ns *ns; 399 400 ns = srcu_dereference(head->current_path[node], &head->srcu); 401 if (unlikely(!ns)) 402 return __nvme_find_path(head, node); 403 if (unlikely(!nvme_path_is_optimized(ns))) 404 return __nvme_find_path(head, node); 405 return ns; 406 } 407 408 inline struct nvme_ns *nvme_find_path(struct nvme_ns_head *head) 409 { 410 switch (READ_ONCE(head->subsys->iopolicy)) { 411 case NVME_IOPOLICY_QD: 412 return nvme_queue_depth_path(head); 413 case NVME_IOPOLICY_RR: 414 return nvme_round_robin_path(head); 415 default: 416 return nvme_numa_path(head); 417 } 418 } 419 420 static bool nvme_available_path(struct nvme_ns_head *head) 421 { 422 struct nvme_ns *ns; 423 424 list_for_each_entry_rcu(ns, &head->list, siblings) { 425 if (test_bit(NVME_CTRL_FAILFAST_EXPIRED, &ns->ctrl->flags)) 426 continue; 427 switch (nvme_ctrl_state(ns->ctrl)) { 428 case NVME_CTRL_LIVE: 429 case NVME_CTRL_RESETTING: 430 case NVME_CTRL_CONNECTING: 431 /* fallthru */ 432 return true; 433 default: 434 break; 435 } 436 } 437 return false; 438 } 439 440 static void nvme_ns_head_submit_bio(struct bio *bio) 441 { 442 struct nvme_ns_head *head = bio->bi_bdev->bd_disk->private_data; 443 struct device *dev = disk_to_dev(head->disk); 444 struct nvme_ns *ns; 445 int srcu_idx; 446 447 /* 448 * The namespace might be going away and the bio might be moved to a 449 * different queue via blk_steal_bios(), so we need to use the bio_split 450 * pool from the original queue to allocate the bvecs from. 451 */ 452 bio = bio_split_to_limits(bio); 453 if (!bio) 454 return; 455 456 srcu_idx = srcu_read_lock(&head->srcu); 457 ns = nvme_find_path(head); 458 if (likely(ns)) { 459 bio_set_dev(bio, ns->disk->part0); 460 bio->bi_opf |= REQ_NVME_MPATH; 461 trace_block_bio_remap(bio, disk_devt(ns->head->disk), 462 bio->bi_iter.bi_sector); 463 submit_bio_noacct(bio); 464 } else if (nvme_available_path(head)) { 465 dev_warn_ratelimited(dev, "no usable path - requeuing I/O\n"); 466 467 spin_lock_irq(&head->requeue_lock); 468 bio_list_add(&head->requeue_list, bio); 469 spin_unlock_irq(&head->requeue_lock); 470 } else { 471 dev_warn_ratelimited(dev, "no available path - failing I/O\n"); 472 473 bio_io_error(bio); 474 } 475 476 srcu_read_unlock(&head->srcu, srcu_idx); 477 } 478 479 static int nvme_ns_head_open(struct gendisk *disk, blk_mode_t mode) 480 { 481 if (!nvme_tryget_ns_head(disk->private_data)) 482 return -ENXIO; 483 return 0; 484 } 485 486 static void nvme_ns_head_release(struct gendisk *disk) 487 { 488 nvme_put_ns_head(disk->private_data); 489 } 490 491 static int nvme_ns_head_get_unique_id(struct gendisk *disk, u8 id[16], 492 enum blk_unique_id type) 493 { 494 struct nvme_ns_head *head = disk->private_data; 495 struct nvme_ns *ns; 496 int srcu_idx, ret = -EWOULDBLOCK; 497 498 srcu_idx = srcu_read_lock(&head->srcu); 499 ns = nvme_find_path(head); 500 if (ns) 501 ret = nvme_ns_get_unique_id(ns, id, type); 502 srcu_read_unlock(&head->srcu, srcu_idx); 503 return ret; 504 } 505 506 #ifdef CONFIG_BLK_DEV_ZONED 507 static int nvme_ns_head_report_zones(struct gendisk *disk, sector_t sector, 508 unsigned int nr_zones, report_zones_cb cb, void *data) 509 { 510 struct nvme_ns_head *head = disk->private_data; 511 struct nvme_ns *ns; 512 int srcu_idx, ret = -EWOULDBLOCK; 513 514 srcu_idx = srcu_read_lock(&head->srcu); 515 ns = nvme_find_path(head); 516 if (ns) 517 ret = nvme_ns_report_zones(ns, sector, nr_zones, cb, data); 518 srcu_read_unlock(&head->srcu, srcu_idx); 519 return ret; 520 } 521 #else 522 #define nvme_ns_head_report_zones NULL 523 #endif /* CONFIG_BLK_DEV_ZONED */ 524 525 const struct block_device_operations nvme_ns_head_ops = { 526 .owner = THIS_MODULE, 527 .submit_bio = nvme_ns_head_submit_bio, 528 .open = nvme_ns_head_open, 529 .release = nvme_ns_head_release, 530 .ioctl = nvme_ns_head_ioctl, 531 .compat_ioctl = blkdev_compat_ptr_ioctl, 532 .getgeo = nvme_getgeo, 533 .get_unique_id = nvme_ns_head_get_unique_id, 534 .report_zones = nvme_ns_head_report_zones, 535 .pr_ops = &nvme_pr_ops, 536 }; 537 538 static inline struct nvme_ns_head *cdev_to_ns_head(struct cdev *cdev) 539 { 540 return container_of(cdev, struct nvme_ns_head, cdev); 541 } 542 543 static int nvme_ns_head_chr_open(struct inode *inode, struct file *file) 544 { 545 if (!nvme_tryget_ns_head(cdev_to_ns_head(inode->i_cdev))) 546 return -ENXIO; 547 return 0; 548 } 549 550 static int nvme_ns_head_chr_release(struct inode *inode, struct file *file) 551 { 552 nvme_put_ns_head(cdev_to_ns_head(inode->i_cdev)); 553 return 0; 554 } 555 556 static const struct file_operations nvme_ns_head_chr_fops = { 557 .owner = THIS_MODULE, 558 .open = nvme_ns_head_chr_open, 559 .release = nvme_ns_head_chr_release, 560 .unlocked_ioctl = nvme_ns_head_chr_ioctl, 561 .compat_ioctl = compat_ptr_ioctl, 562 .uring_cmd = nvme_ns_head_chr_uring_cmd, 563 .uring_cmd_iopoll = nvme_ns_chr_uring_cmd_iopoll, 564 }; 565 566 static int nvme_add_ns_head_cdev(struct nvme_ns_head *head) 567 { 568 int ret; 569 570 head->cdev_device.parent = &head->subsys->dev; 571 ret = dev_set_name(&head->cdev_device, "ng%dn%d", 572 head->subsys->instance, head->instance); 573 if (ret) 574 return ret; 575 ret = nvme_cdev_add(&head->cdev, &head->cdev_device, 576 &nvme_ns_head_chr_fops, THIS_MODULE); 577 return ret; 578 } 579 580 static void nvme_requeue_work(struct work_struct *work) 581 { 582 struct nvme_ns_head *head = 583 container_of(work, struct nvme_ns_head, requeue_work); 584 struct bio *bio, *next; 585 586 spin_lock_irq(&head->requeue_lock); 587 next = bio_list_get(&head->requeue_list); 588 spin_unlock_irq(&head->requeue_lock); 589 590 while ((bio = next) != NULL) { 591 next = bio->bi_next; 592 bio->bi_next = NULL; 593 594 submit_bio_noacct(bio); 595 } 596 } 597 598 int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head) 599 { 600 struct queue_limits lim; 601 602 mutex_init(&head->lock); 603 bio_list_init(&head->requeue_list); 604 spin_lock_init(&head->requeue_lock); 605 INIT_WORK(&head->requeue_work, nvme_requeue_work); 606 607 /* 608 * Add a multipath node if the subsystems supports multiple controllers. 609 * We also do this for private namespaces as the namespace sharing flag 610 * could change after a rescan. 611 */ 612 if (!(ctrl->subsys->cmic & NVME_CTRL_CMIC_MULTI_CTRL) || 613 !nvme_is_unique_nsid(ctrl, head) || !multipath) 614 return 0; 615 616 blk_set_stacking_limits(&lim); 617 lim.dma_alignment = 3; 618 lim.features |= BLK_FEAT_IO_STAT | BLK_FEAT_NOWAIT | BLK_FEAT_POLL; 619 if (head->ids.csi == NVME_CSI_ZNS) 620 lim.features |= BLK_FEAT_ZONED; 621 else 622 lim.max_zone_append_sectors = 0; 623 624 head->disk = blk_alloc_disk(&lim, ctrl->numa_node); 625 if (IS_ERR(head->disk)) 626 return PTR_ERR(head->disk); 627 head->disk->fops = &nvme_ns_head_ops; 628 head->disk->private_data = head; 629 sprintf(head->disk->disk_name, "nvme%dn%d", 630 ctrl->subsys->instance, head->instance); 631 return 0; 632 } 633 634 static void nvme_mpath_set_live(struct nvme_ns *ns) 635 { 636 struct nvme_ns_head *head = ns->head; 637 int rc; 638 639 if (!head->disk) 640 return; 641 642 /* 643 * test_and_set_bit() is used because it is protecting against two nvme 644 * paths simultaneously calling device_add_disk() on the same namespace 645 * head. 646 */ 647 if (!test_and_set_bit(NVME_NSHEAD_DISK_LIVE, &head->flags)) { 648 rc = device_add_disk(&head->subsys->dev, head->disk, 649 nvme_ns_attr_groups); 650 if (rc) { 651 clear_bit(NVME_NSHEAD_DISK_LIVE, &ns->flags); 652 return; 653 } 654 nvme_add_ns_head_cdev(head); 655 } 656 657 mutex_lock(&head->lock); 658 if (nvme_path_is_optimized(ns)) { 659 int node, srcu_idx; 660 661 srcu_idx = srcu_read_lock(&head->srcu); 662 for_each_online_node(node) 663 __nvme_find_path(head, node); 664 srcu_read_unlock(&head->srcu, srcu_idx); 665 } 666 mutex_unlock(&head->lock); 667 668 synchronize_srcu(&head->srcu); 669 kblockd_schedule_work(&head->requeue_work); 670 } 671 672 static int nvme_parse_ana_log(struct nvme_ctrl *ctrl, void *data, 673 int (*cb)(struct nvme_ctrl *ctrl, struct nvme_ana_group_desc *, 674 void *)) 675 { 676 void *base = ctrl->ana_log_buf; 677 size_t offset = sizeof(struct nvme_ana_rsp_hdr); 678 int error, i; 679 680 lockdep_assert_held(&ctrl->ana_lock); 681 682 for (i = 0; i < le16_to_cpu(ctrl->ana_log_buf->ngrps); i++) { 683 struct nvme_ana_group_desc *desc = base + offset; 684 u32 nr_nsids; 685 size_t nsid_buf_size; 686 687 if (WARN_ON_ONCE(offset > ctrl->ana_log_size - sizeof(*desc))) 688 return -EINVAL; 689 690 nr_nsids = le32_to_cpu(desc->nnsids); 691 nsid_buf_size = flex_array_size(desc, nsids, nr_nsids); 692 693 if (WARN_ON_ONCE(desc->grpid == 0)) 694 return -EINVAL; 695 if (WARN_ON_ONCE(le32_to_cpu(desc->grpid) > ctrl->anagrpmax)) 696 return -EINVAL; 697 if (WARN_ON_ONCE(desc->state == 0)) 698 return -EINVAL; 699 if (WARN_ON_ONCE(desc->state > NVME_ANA_CHANGE)) 700 return -EINVAL; 701 702 offset += sizeof(*desc); 703 if (WARN_ON_ONCE(offset > ctrl->ana_log_size - nsid_buf_size)) 704 return -EINVAL; 705 706 error = cb(ctrl, desc, data); 707 if (error) 708 return error; 709 710 offset += nsid_buf_size; 711 } 712 713 return 0; 714 } 715 716 static inline bool nvme_state_is_live(enum nvme_ana_state state) 717 { 718 return state == NVME_ANA_OPTIMIZED || state == NVME_ANA_NONOPTIMIZED; 719 } 720 721 static void nvme_update_ns_ana_state(struct nvme_ana_group_desc *desc, 722 struct nvme_ns *ns) 723 { 724 ns->ana_grpid = le32_to_cpu(desc->grpid); 725 ns->ana_state = desc->state; 726 clear_bit(NVME_NS_ANA_PENDING, &ns->flags); 727 /* 728 * nvme_mpath_set_live() will trigger I/O to the multipath path device 729 * and in turn to this path device. However we cannot accept this I/O 730 * if the controller is not live. This may deadlock if called from 731 * nvme_mpath_init_identify() and the ctrl will never complete 732 * initialization, preventing I/O from completing. For this case we 733 * will reprocess the ANA log page in nvme_mpath_update() once the 734 * controller is ready. 735 */ 736 if (nvme_state_is_live(ns->ana_state) && 737 nvme_ctrl_state(ns->ctrl) == NVME_CTRL_LIVE) 738 nvme_mpath_set_live(ns); 739 } 740 741 static int nvme_update_ana_state(struct nvme_ctrl *ctrl, 742 struct nvme_ana_group_desc *desc, void *data) 743 { 744 u32 nr_nsids = le32_to_cpu(desc->nnsids), n = 0; 745 unsigned *nr_change_groups = data; 746 struct nvme_ns *ns; 747 int srcu_idx; 748 749 dev_dbg(ctrl->device, "ANA group %d: %s.\n", 750 le32_to_cpu(desc->grpid), 751 nvme_ana_state_names[desc->state]); 752 753 if (desc->state == NVME_ANA_CHANGE) 754 (*nr_change_groups)++; 755 756 if (!nr_nsids) 757 return 0; 758 759 srcu_idx = srcu_read_lock(&ctrl->srcu); 760 list_for_each_entry_rcu(ns, &ctrl->namespaces, list) { 761 unsigned nsid; 762 again: 763 nsid = le32_to_cpu(desc->nsids[n]); 764 if (ns->head->ns_id < nsid) 765 continue; 766 if (ns->head->ns_id == nsid) 767 nvme_update_ns_ana_state(desc, ns); 768 if (++n == nr_nsids) 769 break; 770 if (ns->head->ns_id > nsid) 771 goto again; 772 } 773 srcu_read_unlock(&ctrl->srcu, srcu_idx); 774 return 0; 775 } 776 777 static int nvme_read_ana_log(struct nvme_ctrl *ctrl) 778 { 779 u32 nr_change_groups = 0; 780 int error; 781 782 mutex_lock(&ctrl->ana_lock); 783 error = nvme_get_log(ctrl, NVME_NSID_ALL, NVME_LOG_ANA, 0, NVME_CSI_NVM, 784 ctrl->ana_log_buf, ctrl->ana_log_size, 0); 785 if (error) { 786 dev_warn(ctrl->device, "Failed to get ANA log: %d\n", error); 787 goto out_unlock; 788 } 789 790 error = nvme_parse_ana_log(ctrl, &nr_change_groups, 791 nvme_update_ana_state); 792 if (error) 793 goto out_unlock; 794 795 /* 796 * In theory we should have an ANATT timer per group as they might enter 797 * the change state at different times. But that is a lot of overhead 798 * just to protect against a target that keeps entering new changes 799 * states while never finishing previous ones. But we'll still 800 * eventually time out once all groups are in change state, so this 801 * isn't a big deal. 802 * 803 * We also double the ANATT value to provide some slack for transports 804 * or AEN processing overhead. 805 */ 806 if (nr_change_groups) 807 mod_timer(&ctrl->anatt_timer, ctrl->anatt * HZ * 2 + jiffies); 808 else 809 del_timer_sync(&ctrl->anatt_timer); 810 out_unlock: 811 mutex_unlock(&ctrl->ana_lock); 812 return error; 813 } 814 815 static void nvme_ana_work(struct work_struct *work) 816 { 817 struct nvme_ctrl *ctrl = container_of(work, struct nvme_ctrl, ana_work); 818 819 if (nvme_ctrl_state(ctrl) != NVME_CTRL_LIVE) 820 return; 821 822 nvme_read_ana_log(ctrl); 823 } 824 825 void nvme_mpath_update(struct nvme_ctrl *ctrl) 826 { 827 u32 nr_change_groups = 0; 828 829 if (!ctrl->ana_log_buf) 830 return; 831 832 mutex_lock(&ctrl->ana_lock); 833 nvme_parse_ana_log(ctrl, &nr_change_groups, nvme_update_ana_state); 834 mutex_unlock(&ctrl->ana_lock); 835 } 836 837 static void nvme_anatt_timeout(struct timer_list *t) 838 { 839 struct nvme_ctrl *ctrl = from_timer(ctrl, t, anatt_timer); 840 841 dev_info(ctrl->device, "ANATT timeout, resetting controller.\n"); 842 nvme_reset_ctrl(ctrl); 843 } 844 845 void nvme_mpath_stop(struct nvme_ctrl *ctrl) 846 { 847 if (!nvme_ctrl_use_ana(ctrl)) 848 return; 849 del_timer_sync(&ctrl->anatt_timer); 850 cancel_work_sync(&ctrl->ana_work); 851 } 852 853 #define SUBSYS_ATTR_RW(_name, _mode, _show, _store) \ 854 struct device_attribute subsys_attr_##_name = \ 855 __ATTR(_name, _mode, _show, _store) 856 857 static ssize_t nvme_subsys_iopolicy_show(struct device *dev, 858 struct device_attribute *attr, char *buf) 859 { 860 struct nvme_subsystem *subsys = 861 container_of(dev, struct nvme_subsystem, dev); 862 863 return sysfs_emit(buf, "%s\n", 864 nvme_iopolicy_names[READ_ONCE(subsys->iopolicy)]); 865 } 866 867 static void nvme_subsys_iopolicy_update(struct nvme_subsystem *subsys, 868 int iopolicy) 869 { 870 struct nvme_ctrl *ctrl; 871 int old_iopolicy = READ_ONCE(subsys->iopolicy); 872 873 if (old_iopolicy == iopolicy) 874 return; 875 876 WRITE_ONCE(subsys->iopolicy, iopolicy); 877 878 /* iopolicy changes clear the mpath by design */ 879 mutex_lock(&nvme_subsystems_lock); 880 list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) 881 nvme_mpath_clear_ctrl_paths(ctrl); 882 mutex_unlock(&nvme_subsystems_lock); 883 884 pr_notice("subsysnqn %s iopolicy changed from %s to %s\n", 885 subsys->subnqn, 886 nvme_iopolicy_names[old_iopolicy], 887 nvme_iopolicy_names[iopolicy]); 888 } 889 890 static ssize_t nvme_subsys_iopolicy_store(struct device *dev, 891 struct device_attribute *attr, const char *buf, size_t count) 892 { 893 struct nvme_subsystem *subsys = 894 container_of(dev, struct nvme_subsystem, dev); 895 int i; 896 897 for (i = 0; i < ARRAY_SIZE(nvme_iopolicy_names); i++) { 898 if (sysfs_streq(buf, nvme_iopolicy_names[i])) { 899 nvme_subsys_iopolicy_update(subsys, i); 900 return count; 901 } 902 } 903 904 return -EINVAL; 905 } 906 SUBSYS_ATTR_RW(iopolicy, S_IRUGO | S_IWUSR, 907 nvme_subsys_iopolicy_show, nvme_subsys_iopolicy_store); 908 909 static ssize_t ana_grpid_show(struct device *dev, struct device_attribute *attr, 910 char *buf) 911 { 912 return sysfs_emit(buf, "%d\n", nvme_get_ns_from_dev(dev)->ana_grpid); 913 } 914 DEVICE_ATTR_RO(ana_grpid); 915 916 static ssize_t ana_state_show(struct device *dev, struct device_attribute *attr, 917 char *buf) 918 { 919 struct nvme_ns *ns = nvme_get_ns_from_dev(dev); 920 921 return sysfs_emit(buf, "%s\n", nvme_ana_state_names[ns->ana_state]); 922 } 923 DEVICE_ATTR_RO(ana_state); 924 925 static int nvme_lookup_ana_group_desc(struct nvme_ctrl *ctrl, 926 struct nvme_ana_group_desc *desc, void *data) 927 { 928 struct nvme_ana_group_desc *dst = data; 929 930 if (desc->grpid != dst->grpid) 931 return 0; 932 933 *dst = *desc; 934 return -ENXIO; /* just break out of the loop */ 935 } 936 937 void nvme_mpath_add_disk(struct nvme_ns *ns, __le32 anagrpid) 938 { 939 if (nvme_ctrl_use_ana(ns->ctrl)) { 940 struct nvme_ana_group_desc desc = { 941 .grpid = anagrpid, 942 .state = 0, 943 }; 944 945 mutex_lock(&ns->ctrl->ana_lock); 946 ns->ana_grpid = le32_to_cpu(anagrpid); 947 nvme_parse_ana_log(ns->ctrl, &desc, nvme_lookup_ana_group_desc); 948 mutex_unlock(&ns->ctrl->ana_lock); 949 if (desc.state) { 950 /* found the group desc: update */ 951 nvme_update_ns_ana_state(&desc, ns); 952 } else { 953 /* group desc not found: trigger a re-read */ 954 set_bit(NVME_NS_ANA_PENDING, &ns->flags); 955 queue_work(nvme_wq, &ns->ctrl->ana_work); 956 } 957 } else { 958 ns->ana_state = NVME_ANA_OPTIMIZED; 959 nvme_mpath_set_live(ns); 960 } 961 962 #ifdef CONFIG_BLK_DEV_ZONED 963 if (blk_queue_is_zoned(ns->queue) && ns->head->disk) 964 ns->head->disk->nr_zones = ns->disk->nr_zones; 965 #endif 966 } 967 968 void nvme_mpath_shutdown_disk(struct nvme_ns_head *head) 969 { 970 if (!head->disk) 971 return; 972 kblockd_schedule_work(&head->requeue_work); 973 if (test_bit(NVME_NSHEAD_DISK_LIVE, &head->flags)) { 974 nvme_cdev_del(&head->cdev, &head->cdev_device); 975 del_gendisk(head->disk); 976 } 977 } 978 979 void nvme_mpath_remove_disk(struct nvme_ns_head *head) 980 { 981 if (!head->disk) 982 return; 983 /* make sure all pending bios are cleaned up */ 984 kblockd_schedule_work(&head->requeue_work); 985 flush_work(&head->requeue_work); 986 put_disk(head->disk); 987 } 988 989 void nvme_mpath_init_ctrl(struct nvme_ctrl *ctrl) 990 { 991 mutex_init(&ctrl->ana_lock); 992 timer_setup(&ctrl->anatt_timer, nvme_anatt_timeout, 0); 993 INIT_WORK(&ctrl->ana_work, nvme_ana_work); 994 } 995 996 int nvme_mpath_init_identify(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id) 997 { 998 size_t max_transfer_size = ctrl->max_hw_sectors << SECTOR_SHIFT; 999 size_t ana_log_size; 1000 int error = 0; 1001 1002 /* check if multipath is enabled and we have the capability */ 1003 if (!multipath || !ctrl->subsys || 1004 !(ctrl->subsys->cmic & NVME_CTRL_CMIC_ANA)) 1005 return 0; 1006 1007 /* initialize this in the identify path to cover controller resets */ 1008 atomic_set(&ctrl->nr_active, 0); 1009 1010 if (!ctrl->max_namespaces || 1011 ctrl->max_namespaces > le32_to_cpu(id->nn)) { 1012 dev_err(ctrl->device, 1013 "Invalid MNAN value %u\n", ctrl->max_namespaces); 1014 return -EINVAL; 1015 } 1016 1017 ctrl->anacap = id->anacap; 1018 ctrl->anatt = id->anatt; 1019 ctrl->nanagrpid = le32_to_cpu(id->nanagrpid); 1020 ctrl->anagrpmax = le32_to_cpu(id->anagrpmax); 1021 1022 ana_log_size = sizeof(struct nvme_ana_rsp_hdr) + 1023 ctrl->nanagrpid * sizeof(struct nvme_ana_group_desc) + 1024 ctrl->max_namespaces * sizeof(__le32); 1025 if (ana_log_size > max_transfer_size) { 1026 dev_err(ctrl->device, 1027 "ANA log page size (%zd) larger than MDTS (%zd).\n", 1028 ana_log_size, max_transfer_size); 1029 dev_err(ctrl->device, "disabling ANA support.\n"); 1030 goto out_uninit; 1031 } 1032 if (ana_log_size > ctrl->ana_log_size) { 1033 nvme_mpath_stop(ctrl); 1034 nvme_mpath_uninit(ctrl); 1035 ctrl->ana_log_buf = kvmalloc(ana_log_size, GFP_KERNEL); 1036 if (!ctrl->ana_log_buf) 1037 return -ENOMEM; 1038 } 1039 ctrl->ana_log_size = ana_log_size; 1040 error = nvme_read_ana_log(ctrl); 1041 if (error) 1042 goto out_uninit; 1043 return 0; 1044 1045 out_uninit: 1046 nvme_mpath_uninit(ctrl); 1047 return error; 1048 } 1049 1050 void nvme_mpath_uninit(struct nvme_ctrl *ctrl) 1051 { 1052 kvfree(ctrl->ana_log_buf); 1053 ctrl->ana_log_buf = NULL; 1054 ctrl->ana_log_size = 0; 1055 } 1056