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