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 if (!test_bit(NVME_NSHEAD_DISK_LIVE, &head->flags)) 425 return NULL; 426 427 list_for_each_entry_rcu(ns, &head->list, siblings) { 428 if (test_bit(NVME_CTRL_FAILFAST_EXPIRED, &ns->ctrl->flags)) 429 continue; 430 switch (nvme_ctrl_state(ns->ctrl)) { 431 case NVME_CTRL_LIVE: 432 case NVME_CTRL_RESETTING: 433 case NVME_CTRL_CONNECTING: 434 return true; 435 default: 436 break; 437 } 438 } 439 return false; 440 } 441 442 static void nvme_ns_head_submit_bio(struct bio *bio) 443 { 444 struct nvme_ns_head *head = bio->bi_bdev->bd_disk->private_data; 445 struct device *dev = disk_to_dev(head->disk); 446 struct nvme_ns *ns; 447 int srcu_idx; 448 449 /* 450 * The namespace might be going away and the bio might be moved to a 451 * different queue via blk_steal_bios(), so we need to use the bio_split 452 * pool from the original queue to allocate the bvecs from. 453 */ 454 bio = bio_split_to_limits(bio); 455 if (!bio) 456 return; 457 458 srcu_idx = srcu_read_lock(&head->srcu); 459 ns = nvme_find_path(head); 460 if (likely(ns)) { 461 bio_set_dev(bio, ns->disk->part0); 462 bio->bi_opf |= REQ_NVME_MPATH; 463 trace_block_bio_remap(bio, disk_devt(ns->head->disk), 464 bio->bi_iter.bi_sector); 465 submit_bio_noacct(bio); 466 } else if (nvme_available_path(head)) { 467 dev_warn_ratelimited(dev, "no usable path - requeuing I/O\n"); 468 469 spin_lock_irq(&head->requeue_lock); 470 bio_list_add(&head->requeue_list, bio); 471 spin_unlock_irq(&head->requeue_lock); 472 } else { 473 dev_warn_ratelimited(dev, "no available path - failing I/O\n"); 474 475 bio_io_error(bio); 476 } 477 478 srcu_read_unlock(&head->srcu, srcu_idx); 479 } 480 481 static int nvme_ns_head_open(struct gendisk *disk, blk_mode_t mode) 482 { 483 if (!nvme_tryget_ns_head(disk->private_data)) 484 return -ENXIO; 485 return 0; 486 } 487 488 static void nvme_ns_head_release(struct gendisk *disk) 489 { 490 nvme_put_ns_head(disk->private_data); 491 } 492 493 static int nvme_ns_head_get_unique_id(struct gendisk *disk, u8 id[16], 494 enum blk_unique_id type) 495 { 496 struct nvme_ns_head *head = disk->private_data; 497 struct nvme_ns *ns; 498 int srcu_idx, ret = -EWOULDBLOCK; 499 500 srcu_idx = srcu_read_lock(&head->srcu); 501 ns = nvme_find_path(head); 502 if (ns) 503 ret = nvme_ns_get_unique_id(ns, id, type); 504 srcu_read_unlock(&head->srcu, srcu_idx); 505 return ret; 506 } 507 508 #ifdef CONFIG_BLK_DEV_ZONED 509 static int nvme_ns_head_report_zones(struct gendisk *disk, sector_t sector, 510 unsigned int nr_zones, report_zones_cb cb, void *data) 511 { 512 struct nvme_ns_head *head = disk->private_data; 513 struct nvme_ns *ns; 514 int srcu_idx, ret = -EWOULDBLOCK; 515 516 srcu_idx = srcu_read_lock(&head->srcu); 517 ns = nvme_find_path(head); 518 if (ns) 519 ret = nvme_ns_report_zones(ns, sector, nr_zones, cb, data); 520 srcu_read_unlock(&head->srcu, srcu_idx); 521 return ret; 522 } 523 #else 524 #define nvme_ns_head_report_zones NULL 525 #endif /* CONFIG_BLK_DEV_ZONED */ 526 527 const struct block_device_operations nvme_ns_head_ops = { 528 .owner = THIS_MODULE, 529 .submit_bio = nvme_ns_head_submit_bio, 530 .open = nvme_ns_head_open, 531 .release = nvme_ns_head_release, 532 .ioctl = nvme_ns_head_ioctl, 533 .compat_ioctl = blkdev_compat_ptr_ioctl, 534 .getgeo = nvme_getgeo, 535 .get_unique_id = nvme_ns_head_get_unique_id, 536 .report_zones = nvme_ns_head_report_zones, 537 .pr_ops = &nvme_pr_ops, 538 }; 539 540 static inline struct nvme_ns_head *cdev_to_ns_head(struct cdev *cdev) 541 { 542 return container_of(cdev, struct nvme_ns_head, cdev); 543 } 544 545 static int nvme_ns_head_chr_open(struct inode *inode, struct file *file) 546 { 547 if (!nvme_tryget_ns_head(cdev_to_ns_head(inode->i_cdev))) 548 return -ENXIO; 549 return 0; 550 } 551 552 static int nvme_ns_head_chr_release(struct inode *inode, struct file *file) 553 { 554 nvme_put_ns_head(cdev_to_ns_head(inode->i_cdev)); 555 return 0; 556 } 557 558 static const struct file_operations nvme_ns_head_chr_fops = { 559 .owner = THIS_MODULE, 560 .open = nvme_ns_head_chr_open, 561 .release = nvme_ns_head_chr_release, 562 .unlocked_ioctl = nvme_ns_head_chr_ioctl, 563 .compat_ioctl = compat_ptr_ioctl, 564 .uring_cmd = nvme_ns_head_chr_uring_cmd, 565 .uring_cmd_iopoll = nvme_ns_chr_uring_cmd_iopoll, 566 }; 567 568 static int nvme_add_ns_head_cdev(struct nvme_ns_head *head) 569 { 570 int ret; 571 572 head->cdev_device.parent = &head->subsys->dev; 573 ret = dev_set_name(&head->cdev_device, "ng%dn%d", 574 head->subsys->instance, head->instance); 575 if (ret) 576 return ret; 577 ret = nvme_cdev_add(&head->cdev, &head->cdev_device, 578 &nvme_ns_head_chr_fops, THIS_MODULE); 579 return ret; 580 } 581 582 static void nvme_partition_scan_work(struct work_struct *work) 583 { 584 struct nvme_ns_head *head = 585 container_of(work, struct nvme_ns_head, partition_scan_work); 586 587 if (WARN_ON_ONCE(!test_and_clear_bit(GD_SUPPRESS_PART_SCAN, 588 &head->disk->state))) 589 return; 590 591 mutex_lock(&head->disk->open_mutex); 592 bdev_disk_changed(head->disk, false); 593 mutex_unlock(&head->disk->open_mutex); 594 } 595 596 static void nvme_requeue_work(struct work_struct *work) 597 { 598 struct nvme_ns_head *head = 599 container_of(work, struct nvme_ns_head, requeue_work); 600 struct bio *bio, *next; 601 602 spin_lock_irq(&head->requeue_lock); 603 next = bio_list_get(&head->requeue_list); 604 spin_unlock_irq(&head->requeue_lock); 605 606 while ((bio = next) != NULL) { 607 next = bio->bi_next; 608 bio->bi_next = NULL; 609 610 submit_bio_noacct(bio); 611 } 612 } 613 614 int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head) 615 { 616 struct queue_limits lim; 617 618 mutex_init(&head->lock); 619 bio_list_init(&head->requeue_list); 620 spin_lock_init(&head->requeue_lock); 621 INIT_WORK(&head->requeue_work, nvme_requeue_work); 622 INIT_WORK(&head->partition_scan_work, nvme_partition_scan_work); 623 624 /* 625 * Add a multipath node if the subsystems supports multiple controllers. 626 * We also do this for private namespaces as the namespace sharing flag 627 * could change after a rescan. 628 */ 629 if (!(ctrl->subsys->cmic & NVME_CTRL_CMIC_MULTI_CTRL) || 630 !nvme_is_unique_nsid(ctrl, head) || !multipath) 631 return 0; 632 633 blk_set_stacking_limits(&lim); 634 lim.dma_alignment = 3; 635 lim.features |= BLK_FEAT_IO_STAT | BLK_FEAT_NOWAIT | BLK_FEAT_POLL; 636 if (head->ids.csi == NVME_CSI_ZNS) 637 lim.features |= BLK_FEAT_ZONED; 638 639 head->disk = blk_alloc_disk(&lim, ctrl->numa_node); 640 if (IS_ERR(head->disk)) 641 return PTR_ERR(head->disk); 642 head->disk->fops = &nvme_ns_head_ops; 643 head->disk->private_data = head; 644 645 /* 646 * We need to suppress the partition scan from occuring within the 647 * controller's scan_work context. If a path error occurs here, the IO 648 * will wait until a path becomes available or all paths are torn down, 649 * but that action also occurs within scan_work, so it would deadlock. 650 * Defer the partion scan to a different context that does not block 651 * scan_work. 652 */ 653 set_bit(GD_SUPPRESS_PART_SCAN, &head->disk->state); 654 sprintf(head->disk->disk_name, "nvme%dn%d", 655 ctrl->subsys->instance, head->instance); 656 return 0; 657 } 658 659 static void nvme_mpath_set_live(struct nvme_ns *ns) 660 { 661 struct nvme_ns_head *head = ns->head; 662 int rc; 663 664 if (!head->disk) 665 return; 666 667 /* 668 * test_and_set_bit() is used because it is protecting against two nvme 669 * paths simultaneously calling device_add_disk() on the same namespace 670 * head. 671 */ 672 if (!test_and_set_bit(NVME_NSHEAD_DISK_LIVE, &head->flags)) { 673 rc = device_add_disk(&head->subsys->dev, head->disk, 674 nvme_ns_attr_groups); 675 if (rc) { 676 clear_bit(NVME_NSHEAD_DISK_LIVE, &head->flags); 677 return; 678 } 679 nvme_add_ns_head_cdev(head); 680 kblockd_schedule_work(&head->partition_scan_work); 681 } 682 683 mutex_lock(&head->lock); 684 if (nvme_path_is_optimized(ns)) { 685 int node, srcu_idx; 686 687 srcu_idx = srcu_read_lock(&head->srcu); 688 for_each_online_node(node) 689 __nvme_find_path(head, node); 690 srcu_read_unlock(&head->srcu, srcu_idx); 691 } 692 mutex_unlock(&head->lock); 693 694 synchronize_srcu(&head->srcu); 695 kblockd_schedule_work(&head->requeue_work); 696 } 697 698 static int nvme_parse_ana_log(struct nvme_ctrl *ctrl, void *data, 699 int (*cb)(struct nvme_ctrl *ctrl, struct nvme_ana_group_desc *, 700 void *)) 701 { 702 void *base = ctrl->ana_log_buf; 703 size_t offset = sizeof(struct nvme_ana_rsp_hdr); 704 int error, i; 705 706 lockdep_assert_held(&ctrl->ana_lock); 707 708 for (i = 0; i < le16_to_cpu(ctrl->ana_log_buf->ngrps); i++) { 709 struct nvme_ana_group_desc *desc = base + offset; 710 u32 nr_nsids; 711 size_t nsid_buf_size; 712 713 if (WARN_ON_ONCE(offset > ctrl->ana_log_size - sizeof(*desc))) 714 return -EINVAL; 715 716 nr_nsids = le32_to_cpu(desc->nnsids); 717 nsid_buf_size = flex_array_size(desc, nsids, nr_nsids); 718 719 if (WARN_ON_ONCE(desc->grpid == 0)) 720 return -EINVAL; 721 if (WARN_ON_ONCE(le32_to_cpu(desc->grpid) > ctrl->anagrpmax)) 722 return -EINVAL; 723 if (WARN_ON_ONCE(desc->state == 0)) 724 return -EINVAL; 725 if (WARN_ON_ONCE(desc->state > NVME_ANA_CHANGE)) 726 return -EINVAL; 727 728 offset += sizeof(*desc); 729 if (WARN_ON_ONCE(offset > ctrl->ana_log_size - nsid_buf_size)) 730 return -EINVAL; 731 732 error = cb(ctrl, desc, data); 733 if (error) 734 return error; 735 736 offset += nsid_buf_size; 737 } 738 739 return 0; 740 } 741 742 static inline bool nvme_state_is_live(enum nvme_ana_state state) 743 { 744 return state == NVME_ANA_OPTIMIZED || state == NVME_ANA_NONOPTIMIZED; 745 } 746 747 static void nvme_update_ns_ana_state(struct nvme_ana_group_desc *desc, 748 struct nvme_ns *ns) 749 { 750 ns->ana_grpid = le32_to_cpu(desc->grpid); 751 ns->ana_state = desc->state; 752 clear_bit(NVME_NS_ANA_PENDING, &ns->flags); 753 /* 754 * nvme_mpath_set_live() will trigger I/O to the multipath path device 755 * and in turn to this path device. However we cannot accept this I/O 756 * if the controller is not live. This may deadlock if called from 757 * nvme_mpath_init_identify() and the ctrl will never complete 758 * initialization, preventing I/O from completing. For this case we 759 * will reprocess the ANA log page in nvme_mpath_update() once the 760 * controller is ready. 761 */ 762 if (nvme_state_is_live(ns->ana_state) && 763 nvme_ctrl_state(ns->ctrl) == NVME_CTRL_LIVE) 764 nvme_mpath_set_live(ns); 765 } 766 767 static int nvme_update_ana_state(struct nvme_ctrl *ctrl, 768 struct nvme_ana_group_desc *desc, void *data) 769 { 770 u32 nr_nsids = le32_to_cpu(desc->nnsids), n = 0; 771 unsigned *nr_change_groups = data; 772 struct nvme_ns *ns; 773 int srcu_idx; 774 775 dev_dbg(ctrl->device, "ANA group %d: %s.\n", 776 le32_to_cpu(desc->grpid), 777 nvme_ana_state_names[desc->state]); 778 779 if (desc->state == NVME_ANA_CHANGE) 780 (*nr_change_groups)++; 781 782 if (!nr_nsids) 783 return 0; 784 785 srcu_idx = srcu_read_lock(&ctrl->srcu); 786 list_for_each_entry_rcu(ns, &ctrl->namespaces, list) { 787 unsigned nsid; 788 again: 789 nsid = le32_to_cpu(desc->nsids[n]); 790 if (ns->head->ns_id < nsid) 791 continue; 792 if (ns->head->ns_id == nsid) 793 nvme_update_ns_ana_state(desc, ns); 794 if (++n == nr_nsids) 795 break; 796 if (ns->head->ns_id > nsid) 797 goto again; 798 } 799 srcu_read_unlock(&ctrl->srcu, srcu_idx); 800 return 0; 801 } 802 803 static int nvme_read_ana_log(struct nvme_ctrl *ctrl) 804 { 805 u32 nr_change_groups = 0; 806 int error; 807 808 mutex_lock(&ctrl->ana_lock); 809 error = nvme_get_log(ctrl, NVME_NSID_ALL, NVME_LOG_ANA, 0, NVME_CSI_NVM, 810 ctrl->ana_log_buf, ctrl->ana_log_size, 0); 811 if (error) { 812 dev_warn(ctrl->device, "Failed to get ANA log: %d\n", error); 813 goto out_unlock; 814 } 815 816 error = nvme_parse_ana_log(ctrl, &nr_change_groups, 817 nvme_update_ana_state); 818 if (error) 819 goto out_unlock; 820 821 /* 822 * In theory we should have an ANATT timer per group as they might enter 823 * the change state at different times. But that is a lot of overhead 824 * just to protect against a target that keeps entering new changes 825 * states while never finishing previous ones. But we'll still 826 * eventually time out once all groups are in change state, so this 827 * isn't a big deal. 828 * 829 * We also double the ANATT value to provide some slack for transports 830 * or AEN processing overhead. 831 */ 832 if (nr_change_groups) 833 mod_timer(&ctrl->anatt_timer, ctrl->anatt * HZ * 2 + jiffies); 834 else 835 del_timer_sync(&ctrl->anatt_timer); 836 out_unlock: 837 mutex_unlock(&ctrl->ana_lock); 838 return error; 839 } 840 841 static void nvme_ana_work(struct work_struct *work) 842 { 843 struct nvme_ctrl *ctrl = container_of(work, struct nvme_ctrl, ana_work); 844 845 if (nvme_ctrl_state(ctrl) != NVME_CTRL_LIVE) 846 return; 847 848 nvme_read_ana_log(ctrl); 849 } 850 851 void nvme_mpath_update(struct nvme_ctrl *ctrl) 852 { 853 u32 nr_change_groups = 0; 854 855 if (!ctrl->ana_log_buf) 856 return; 857 858 mutex_lock(&ctrl->ana_lock); 859 nvme_parse_ana_log(ctrl, &nr_change_groups, nvme_update_ana_state); 860 mutex_unlock(&ctrl->ana_lock); 861 } 862 863 static void nvme_anatt_timeout(struct timer_list *t) 864 { 865 struct nvme_ctrl *ctrl = from_timer(ctrl, t, anatt_timer); 866 867 dev_info(ctrl->device, "ANATT timeout, resetting controller.\n"); 868 nvme_reset_ctrl(ctrl); 869 } 870 871 void nvme_mpath_stop(struct nvme_ctrl *ctrl) 872 { 873 if (!nvme_ctrl_use_ana(ctrl)) 874 return; 875 del_timer_sync(&ctrl->anatt_timer); 876 cancel_work_sync(&ctrl->ana_work); 877 } 878 879 #define SUBSYS_ATTR_RW(_name, _mode, _show, _store) \ 880 struct device_attribute subsys_attr_##_name = \ 881 __ATTR(_name, _mode, _show, _store) 882 883 static ssize_t nvme_subsys_iopolicy_show(struct device *dev, 884 struct device_attribute *attr, char *buf) 885 { 886 struct nvme_subsystem *subsys = 887 container_of(dev, struct nvme_subsystem, dev); 888 889 return sysfs_emit(buf, "%s\n", 890 nvme_iopolicy_names[READ_ONCE(subsys->iopolicy)]); 891 } 892 893 static void nvme_subsys_iopolicy_update(struct nvme_subsystem *subsys, 894 int iopolicy) 895 { 896 struct nvme_ctrl *ctrl; 897 int old_iopolicy = READ_ONCE(subsys->iopolicy); 898 899 if (old_iopolicy == iopolicy) 900 return; 901 902 WRITE_ONCE(subsys->iopolicy, iopolicy); 903 904 /* iopolicy changes clear the mpath by design */ 905 mutex_lock(&nvme_subsystems_lock); 906 list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) 907 nvme_mpath_clear_ctrl_paths(ctrl); 908 mutex_unlock(&nvme_subsystems_lock); 909 910 pr_notice("subsysnqn %s iopolicy changed from %s to %s\n", 911 subsys->subnqn, 912 nvme_iopolicy_names[old_iopolicy], 913 nvme_iopolicy_names[iopolicy]); 914 } 915 916 static ssize_t nvme_subsys_iopolicy_store(struct device *dev, 917 struct device_attribute *attr, const char *buf, size_t count) 918 { 919 struct nvme_subsystem *subsys = 920 container_of(dev, struct nvme_subsystem, dev); 921 int i; 922 923 for (i = 0; i < ARRAY_SIZE(nvme_iopolicy_names); i++) { 924 if (sysfs_streq(buf, nvme_iopolicy_names[i])) { 925 nvme_subsys_iopolicy_update(subsys, i); 926 return count; 927 } 928 } 929 930 return -EINVAL; 931 } 932 SUBSYS_ATTR_RW(iopolicy, S_IRUGO | S_IWUSR, 933 nvme_subsys_iopolicy_show, nvme_subsys_iopolicy_store); 934 935 static ssize_t ana_grpid_show(struct device *dev, struct device_attribute *attr, 936 char *buf) 937 { 938 return sysfs_emit(buf, "%d\n", nvme_get_ns_from_dev(dev)->ana_grpid); 939 } 940 DEVICE_ATTR_RO(ana_grpid); 941 942 static ssize_t ana_state_show(struct device *dev, struct device_attribute *attr, 943 char *buf) 944 { 945 struct nvme_ns *ns = nvme_get_ns_from_dev(dev); 946 947 return sysfs_emit(buf, "%s\n", nvme_ana_state_names[ns->ana_state]); 948 } 949 DEVICE_ATTR_RO(ana_state); 950 951 static int nvme_lookup_ana_group_desc(struct nvme_ctrl *ctrl, 952 struct nvme_ana_group_desc *desc, void *data) 953 { 954 struct nvme_ana_group_desc *dst = data; 955 956 if (desc->grpid != dst->grpid) 957 return 0; 958 959 *dst = *desc; 960 return -ENXIO; /* just break out of the loop */ 961 } 962 963 void nvme_mpath_add_disk(struct nvme_ns *ns, __le32 anagrpid) 964 { 965 if (nvme_ctrl_use_ana(ns->ctrl)) { 966 struct nvme_ana_group_desc desc = { 967 .grpid = anagrpid, 968 .state = 0, 969 }; 970 971 mutex_lock(&ns->ctrl->ana_lock); 972 ns->ana_grpid = le32_to_cpu(anagrpid); 973 nvme_parse_ana_log(ns->ctrl, &desc, nvme_lookup_ana_group_desc); 974 mutex_unlock(&ns->ctrl->ana_lock); 975 if (desc.state) { 976 /* found the group desc: update */ 977 nvme_update_ns_ana_state(&desc, ns); 978 } else { 979 /* group desc not found: trigger a re-read */ 980 set_bit(NVME_NS_ANA_PENDING, &ns->flags); 981 queue_work(nvme_wq, &ns->ctrl->ana_work); 982 } 983 } else { 984 ns->ana_state = NVME_ANA_OPTIMIZED; 985 nvme_mpath_set_live(ns); 986 } 987 988 #ifdef CONFIG_BLK_DEV_ZONED 989 if (blk_queue_is_zoned(ns->queue) && ns->head->disk) 990 ns->head->disk->nr_zones = ns->disk->nr_zones; 991 #endif 992 } 993 994 void nvme_mpath_shutdown_disk(struct nvme_ns_head *head) 995 { 996 if (!head->disk) 997 return; 998 if (test_and_clear_bit(NVME_NSHEAD_DISK_LIVE, &head->flags)) { 999 nvme_cdev_del(&head->cdev, &head->cdev_device); 1000 /* 1001 * requeue I/O after NVME_NSHEAD_DISK_LIVE has been cleared 1002 * to allow multipath to fail all I/O. 1003 */ 1004 synchronize_srcu(&head->srcu); 1005 kblockd_schedule_work(&head->requeue_work); 1006 del_gendisk(head->disk); 1007 } 1008 } 1009 1010 void nvme_mpath_remove_disk(struct nvme_ns_head *head) 1011 { 1012 if (!head->disk) 1013 return; 1014 /* make sure all pending bios are cleaned up */ 1015 kblockd_schedule_work(&head->requeue_work); 1016 flush_work(&head->requeue_work); 1017 flush_work(&head->partition_scan_work); 1018 put_disk(head->disk); 1019 } 1020 1021 void nvme_mpath_init_ctrl(struct nvme_ctrl *ctrl) 1022 { 1023 mutex_init(&ctrl->ana_lock); 1024 timer_setup(&ctrl->anatt_timer, nvme_anatt_timeout, 0); 1025 INIT_WORK(&ctrl->ana_work, nvme_ana_work); 1026 } 1027 1028 int nvme_mpath_init_identify(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id) 1029 { 1030 size_t max_transfer_size = ctrl->max_hw_sectors << SECTOR_SHIFT; 1031 size_t ana_log_size; 1032 int error = 0; 1033 1034 /* check if multipath is enabled and we have the capability */ 1035 if (!multipath || !ctrl->subsys || 1036 !(ctrl->subsys->cmic & NVME_CTRL_CMIC_ANA)) 1037 return 0; 1038 1039 /* initialize this in the identify path to cover controller resets */ 1040 atomic_set(&ctrl->nr_active, 0); 1041 1042 if (!ctrl->max_namespaces || 1043 ctrl->max_namespaces > le32_to_cpu(id->nn)) { 1044 dev_err(ctrl->device, 1045 "Invalid MNAN value %u\n", ctrl->max_namespaces); 1046 return -EINVAL; 1047 } 1048 1049 ctrl->anacap = id->anacap; 1050 ctrl->anatt = id->anatt; 1051 ctrl->nanagrpid = le32_to_cpu(id->nanagrpid); 1052 ctrl->anagrpmax = le32_to_cpu(id->anagrpmax); 1053 1054 ana_log_size = sizeof(struct nvme_ana_rsp_hdr) + 1055 ctrl->nanagrpid * sizeof(struct nvme_ana_group_desc) + 1056 ctrl->max_namespaces * sizeof(__le32); 1057 if (ana_log_size > max_transfer_size) { 1058 dev_err(ctrl->device, 1059 "ANA log page size (%zd) larger than MDTS (%zd).\n", 1060 ana_log_size, max_transfer_size); 1061 dev_err(ctrl->device, "disabling ANA support.\n"); 1062 goto out_uninit; 1063 } 1064 if (ana_log_size > ctrl->ana_log_size) { 1065 nvme_mpath_stop(ctrl); 1066 nvme_mpath_uninit(ctrl); 1067 ctrl->ana_log_buf = kvmalloc(ana_log_size, GFP_KERNEL); 1068 if (!ctrl->ana_log_buf) 1069 return -ENOMEM; 1070 } 1071 ctrl->ana_log_size = ana_log_size; 1072 error = nvme_read_ana_log(ctrl); 1073 if (error) 1074 goto out_uninit; 1075 return 0; 1076 1077 out_uninit: 1078 nvme_mpath_uninit(ctrl); 1079 return error; 1080 } 1081 1082 void nvme_mpath_uninit(struct nvme_ctrl *ctrl) 1083 { 1084 kvfree(ctrl->ana_log_buf); 1085 ctrl->ana_log_buf = NULL; 1086 ctrl->ana_log_size = 0; 1087 } 1088