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.max_zone_append_sectors = 0; 621 622 head->disk = blk_alloc_disk(&lim, ctrl->numa_node); 623 if (IS_ERR(head->disk)) 624 return PTR_ERR(head->disk); 625 head->disk->fops = &nvme_ns_head_ops; 626 head->disk->private_data = head; 627 sprintf(head->disk->disk_name, "nvme%dn%d", 628 ctrl->subsys->instance, head->instance); 629 return 0; 630 } 631 632 static void nvme_mpath_set_live(struct nvme_ns *ns) 633 { 634 struct nvme_ns_head *head = ns->head; 635 int rc; 636 637 if (!head->disk) 638 return; 639 640 /* 641 * test_and_set_bit() is used because it is protecting against two nvme 642 * paths simultaneously calling device_add_disk() on the same namespace 643 * head. 644 */ 645 if (!test_and_set_bit(NVME_NSHEAD_DISK_LIVE, &head->flags)) { 646 rc = device_add_disk(&head->subsys->dev, head->disk, 647 nvme_ns_attr_groups); 648 if (rc) { 649 clear_bit(NVME_NSHEAD_DISK_LIVE, &ns->flags); 650 return; 651 } 652 nvme_add_ns_head_cdev(head); 653 } 654 655 mutex_lock(&head->lock); 656 if (nvme_path_is_optimized(ns)) { 657 int node, srcu_idx; 658 659 srcu_idx = srcu_read_lock(&head->srcu); 660 for_each_online_node(node) 661 __nvme_find_path(head, node); 662 srcu_read_unlock(&head->srcu, srcu_idx); 663 } 664 mutex_unlock(&head->lock); 665 666 synchronize_srcu(&head->srcu); 667 kblockd_schedule_work(&head->requeue_work); 668 } 669 670 static int nvme_parse_ana_log(struct nvme_ctrl *ctrl, void *data, 671 int (*cb)(struct nvme_ctrl *ctrl, struct nvme_ana_group_desc *, 672 void *)) 673 { 674 void *base = ctrl->ana_log_buf; 675 size_t offset = sizeof(struct nvme_ana_rsp_hdr); 676 int error, i; 677 678 lockdep_assert_held(&ctrl->ana_lock); 679 680 for (i = 0; i < le16_to_cpu(ctrl->ana_log_buf->ngrps); i++) { 681 struct nvme_ana_group_desc *desc = base + offset; 682 u32 nr_nsids; 683 size_t nsid_buf_size; 684 685 if (WARN_ON_ONCE(offset > ctrl->ana_log_size - sizeof(*desc))) 686 return -EINVAL; 687 688 nr_nsids = le32_to_cpu(desc->nnsids); 689 nsid_buf_size = flex_array_size(desc, nsids, nr_nsids); 690 691 if (WARN_ON_ONCE(desc->grpid == 0)) 692 return -EINVAL; 693 if (WARN_ON_ONCE(le32_to_cpu(desc->grpid) > ctrl->anagrpmax)) 694 return -EINVAL; 695 if (WARN_ON_ONCE(desc->state == 0)) 696 return -EINVAL; 697 if (WARN_ON_ONCE(desc->state > NVME_ANA_CHANGE)) 698 return -EINVAL; 699 700 offset += sizeof(*desc); 701 if (WARN_ON_ONCE(offset > ctrl->ana_log_size - nsid_buf_size)) 702 return -EINVAL; 703 704 error = cb(ctrl, desc, data); 705 if (error) 706 return error; 707 708 offset += nsid_buf_size; 709 } 710 711 return 0; 712 } 713 714 static inline bool nvme_state_is_live(enum nvme_ana_state state) 715 { 716 return state == NVME_ANA_OPTIMIZED || state == NVME_ANA_NONOPTIMIZED; 717 } 718 719 static void nvme_update_ns_ana_state(struct nvme_ana_group_desc *desc, 720 struct nvme_ns *ns) 721 { 722 ns->ana_grpid = le32_to_cpu(desc->grpid); 723 ns->ana_state = desc->state; 724 clear_bit(NVME_NS_ANA_PENDING, &ns->flags); 725 /* 726 * nvme_mpath_set_live() will trigger I/O to the multipath path device 727 * and in turn to this path device. However we cannot accept this I/O 728 * if the controller is not live. This may deadlock if called from 729 * nvme_mpath_init_identify() and the ctrl will never complete 730 * initialization, preventing I/O from completing. For this case we 731 * will reprocess the ANA log page in nvme_mpath_update() once the 732 * controller is ready. 733 */ 734 if (nvme_state_is_live(ns->ana_state) && 735 nvme_ctrl_state(ns->ctrl) == NVME_CTRL_LIVE) 736 nvme_mpath_set_live(ns); 737 } 738 739 static int nvme_update_ana_state(struct nvme_ctrl *ctrl, 740 struct nvme_ana_group_desc *desc, void *data) 741 { 742 u32 nr_nsids = le32_to_cpu(desc->nnsids), n = 0; 743 unsigned *nr_change_groups = data; 744 struct nvme_ns *ns; 745 int srcu_idx; 746 747 dev_dbg(ctrl->device, "ANA group %d: %s.\n", 748 le32_to_cpu(desc->grpid), 749 nvme_ana_state_names[desc->state]); 750 751 if (desc->state == NVME_ANA_CHANGE) 752 (*nr_change_groups)++; 753 754 if (!nr_nsids) 755 return 0; 756 757 srcu_idx = srcu_read_lock(&ctrl->srcu); 758 list_for_each_entry_rcu(ns, &ctrl->namespaces, list) { 759 unsigned nsid; 760 again: 761 nsid = le32_to_cpu(desc->nsids[n]); 762 if (ns->head->ns_id < nsid) 763 continue; 764 if (ns->head->ns_id == nsid) 765 nvme_update_ns_ana_state(desc, ns); 766 if (++n == nr_nsids) 767 break; 768 if (ns->head->ns_id > nsid) 769 goto again; 770 } 771 srcu_read_unlock(&ctrl->srcu, srcu_idx); 772 return 0; 773 } 774 775 static int nvme_read_ana_log(struct nvme_ctrl *ctrl) 776 { 777 u32 nr_change_groups = 0; 778 int error; 779 780 mutex_lock(&ctrl->ana_lock); 781 error = nvme_get_log(ctrl, NVME_NSID_ALL, NVME_LOG_ANA, 0, NVME_CSI_NVM, 782 ctrl->ana_log_buf, ctrl->ana_log_size, 0); 783 if (error) { 784 dev_warn(ctrl->device, "Failed to get ANA log: %d\n", error); 785 goto out_unlock; 786 } 787 788 error = nvme_parse_ana_log(ctrl, &nr_change_groups, 789 nvme_update_ana_state); 790 if (error) 791 goto out_unlock; 792 793 /* 794 * In theory we should have an ANATT timer per group as they might enter 795 * the change state at different times. But that is a lot of overhead 796 * just to protect against a target that keeps entering new changes 797 * states while never finishing previous ones. But we'll still 798 * eventually time out once all groups are in change state, so this 799 * isn't a big deal. 800 * 801 * We also double the ANATT value to provide some slack for transports 802 * or AEN processing overhead. 803 */ 804 if (nr_change_groups) 805 mod_timer(&ctrl->anatt_timer, ctrl->anatt * HZ * 2 + jiffies); 806 else 807 del_timer_sync(&ctrl->anatt_timer); 808 out_unlock: 809 mutex_unlock(&ctrl->ana_lock); 810 return error; 811 } 812 813 static void nvme_ana_work(struct work_struct *work) 814 { 815 struct nvme_ctrl *ctrl = container_of(work, struct nvme_ctrl, ana_work); 816 817 if (nvme_ctrl_state(ctrl) != NVME_CTRL_LIVE) 818 return; 819 820 nvme_read_ana_log(ctrl); 821 } 822 823 void nvme_mpath_update(struct nvme_ctrl *ctrl) 824 { 825 u32 nr_change_groups = 0; 826 827 if (!ctrl->ana_log_buf) 828 return; 829 830 mutex_lock(&ctrl->ana_lock); 831 nvme_parse_ana_log(ctrl, &nr_change_groups, nvme_update_ana_state); 832 mutex_unlock(&ctrl->ana_lock); 833 } 834 835 static void nvme_anatt_timeout(struct timer_list *t) 836 { 837 struct nvme_ctrl *ctrl = from_timer(ctrl, t, anatt_timer); 838 839 dev_info(ctrl->device, "ANATT timeout, resetting controller.\n"); 840 nvme_reset_ctrl(ctrl); 841 } 842 843 void nvme_mpath_stop(struct nvme_ctrl *ctrl) 844 { 845 if (!nvme_ctrl_use_ana(ctrl)) 846 return; 847 del_timer_sync(&ctrl->anatt_timer); 848 cancel_work_sync(&ctrl->ana_work); 849 } 850 851 #define SUBSYS_ATTR_RW(_name, _mode, _show, _store) \ 852 struct device_attribute subsys_attr_##_name = \ 853 __ATTR(_name, _mode, _show, _store) 854 855 static ssize_t nvme_subsys_iopolicy_show(struct device *dev, 856 struct device_attribute *attr, char *buf) 857 { 858 struct nvme_subsystem *subsys = 859 container_of(dev, struct nvme_subsystem, dev); 860 861 return sysfs_emit(buf, "%s\n", 862 nvme_iopolicy_names[READ_ONCE(subsys->iopolicy)]); 863 } 864 865 static void nvme_subsys_iopolicy_update(struct nvme_subsystem *subsys, 866 int iopolicy) 867 { 868 struct nvme_ctrl *ctrl; 869 int old_iopolicy = READ_ONCE(subsys->iopolicy); 870 871 if (old_iopolicy == iopolicy) 872 return; 873 874 WRITE_ONCE(subsys->iopolicy, iopolicy); 875 876 /* iopolicy changes clear the mpath by design */ 877 mutex_lock(&nvme_subsystems_lock); 878 list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) 879 nvme_mpath_clear_ctrl_paths(ctrl); 880 mutex_unlock(&nvme_subsystems_lock); 881 882 pr_notice("subsysnqn %s iopolicy changed from %s to %s\n", 883 subsys->subnqn, 884 nvme_iopolicy_names[old_iopolicy], 885 nvme_iopolicy_names[iopolicy]); 886 } 887 888 static ssize_t nvme_subsys_iopolicy_store(struct device *dev, 889 struct device_attribute *attr, const char *buf, size_t count) 890 { 891 struct nvme_subsystem *subsys = 892 container_of(dev, struct nvme_subsystem, dev); 893 int i; 894 895 for (i = 0; i < ARRAY_SIZE(nvme_iopolicy_names); i++) { 896 if (sysfs_streq(buf, nvme_iopolicy_names[i])) { 897 nvme_subsys_iopolicy_update(subsys, i); 898 return count; 899 } 900 } 901 902 return -EINVAL; 903 } 904 SUBSYS_ATTR_RW(iopolicy, S_IRUGO | S_IWUSR, 905 nvme_subsys_iopolicy_show, nvme_subsys_iopolicy_store); 906 907 static ssize_t ana_grpid_show(struct device *dev, struct device_attribute *attr, 908 char *buf) 909 { 910 return sysfs_emit(buf, "%d\n", nvme_get_ns_from_dev(dev)->ana_grpid); 911 } 912 DEVICE_ATTR_RO(ana_grpid); 913 914 static ssize_t ana_state_show(struct device *dev, struct device_attribute *attr, 915 char *buf) 916 { 917 struct nvme_ns *ns = nvme_get_ns_from_dev(dev); 918 919 return sysfs_emit(buf, "%s\n", nvme_ana_state_names[ns->ana_state]); 920 } 921 DEVICE_ATTR_RO(ana_state); 922 923 static int nvme_lookup_ana_group_desc(struct nvme_ctrl *ctrl, 924 struct nvme_ana_group_desc *desc, void *data) 925 { 926 struct nvme_ana_group_desc *dst = data; 927 928 if (desc->grpid != dst->grpid) 929 return 0; 930 931 *dst = *desc; 932 return -ENXIO; /* just break out of the loop */ 933 } 934 935 void nvme_mpath_add_disk(struct nvme_ns *ns, __le32 anagrpid) 936 { 937 if (nvme_ctrl_use_ana(ns->ctrl)) { 938 struct nvme_ana_group_desc desc = { 939 .grpid = anagrpid, 940 .state = 0, 941 }; 942 943 mutex_lock(&ns->ctrl->ana_lock); 944 ns->ana_grpid = le32_to_cpu(anagrpid); 945 nvme_parse_ana_log(ns->ctrl, &desc, nvme_lookup_ana_group_desc); 946 mutex_unlock(&ns->ctrl->ana_lock); 947 if (desc.state) { 948 /* found the group desc: update */ 949 nvme_update_ns_ana_state(&desc, ns); 950 } else { 951 /* group desc not found: trigger a re-read */ 952 set_bit(NVME_NS_ANA_PENDING, &ns->flags); 953 queue_work(nvme_wq, &ns->ctrl->ana_work); 954 } 955 } else { 956 ns->ana_state = NVME_ANA_OPTIMIZED; 957 nvme_mpath_set_live(ns); 958 } 959 960 #ifdef CONFIG_BLK_DEV_ZONED 961 if (blk_queue_is_zoned(ns->queue) && ns->head->disk) 962 ns->head->disk->nr_zones = ns->disk->nr_zones; 963 #endif 964 } 965 966 void nvme_mpath_shutdown_disk(struct nvme_ns_head *head) 967 { 968 if (!head->disk) 969 return; 970 kblockd_schedule_work(&head->requeue_work); 971 if (test_bit(NVME_NSHEAD_DISK_LIVE, &head->flags)) { 972 nvme_cdev_del(&head->cdev, &head->cdev_device); 973 del_gendisk(head->disk); 974 } 975 } 976 977 void nvme_mpath_remove_disk(struct nvme_ns_head *head) 978 { 979 if (!head->disk) 980 return; 981 /* make sure all pending bios are cleaned up */ 982 kblockd_schedule_work(&head->requeue_work); 983 flush_work(&head->requeue_work); 984 put_disk(head->disk); 985 } 986 987 void nvme_mpath_init_ctrl(struct nvme_ctrl *ctrl) 988 { 989 mutex_init(&ctrl->ana_lock); 990 timer_setup(&ctrl->anatt_timer, nvme_anatt_timeout, 0); 991 INIT_WORK(&ctrl->ana_work, nvme_ana_work); 992 } 993 994 int nvme_mpath_init_identify(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id) 995 { 996 size_t max_transfer_size = ctrl->max_hw_sectors << SECTOR_SHIFT; 997 size_t ana_log_size; 998 int error = 0; 999 1000 /* check if multipath is enabled and we have the capability */ 1001 if (!multipath || !ctrl->subsys || 1002 !(ctrl->subsys->cmic & NVME_CTRL_CMIC_ANA)) 1003 return 0; 1004 1005 /* initialize this in the identify path to cover controller resets */ 1006 atomic_set(&ctrl->nr_active, 0); 1007 1008 if (!ctrl->max_namespaces || 1009 ctrl->max_namespaces > le32_to_cpu(id->nn)) { 1010 dev_err(ctrl->device, 1011 "Invalid MNAN value %u\n", ctrl->max_namespaces); 1012 return -EINVAL; 1013 } 1014 1015 ctrl->anacap = id->anacap; 1016 ctrl->anatt = id->anatt; 1017 ctrl->nanagrpid = le32_to_cpu(id->nanagrpid); 1018 ctrl->anagrpmax = le32_to_cpu(id->anagrpmax); 1019 1020 ana_log_size = sizeof(struct nvme_ana_rsp_hdr) + 1021 ctrl->nanagrpid * sizeof(struct nvme_ana_group_desc) + 1022 ctrl->max_namespaces * sizeof(__le32); 1023 if (ana_log_size > max_transfer_size) { 1024 dev_err(ctrl->device, 1025 "ANA log page size (%zd) larger than MDTS (%zd).\n", 1026 ana_log_size, max_transfer_size); 1027 dev_err(ctrl->device, "disabling ANA support.\n"); 1028 goto out_uninit; 1029 } 1030 if (ana_log_size > ctrl->ana_log_size) { 1031 nvme_mpath_stop(ctrl); 1032 nvme_mpath_uninit(ctrl); 1033 ctrl->ana_log_buf = kvmalloc(ana_log_size, GFP_KERNEL); 1034 if (!ctrl->ana_log_buf) 1035 return -ENOMEM; 1036 } 1037 ctrl->ana_log_size = ana_log_size; 1038 error = nvme_read_ana_log(ctrl); 1039 if (error) 1040 goto out_uninit; 1041 return 0; 1042 1043 out_uninit: 1044 nvme_mpath_uninit(ctrl); 1045 return error; 1046 } 1047 1048 void nvme_mpath_uninit(struct nvme_ctrl *ctrl) 1049 { 1050 kvfree(ctrl->ana_log_buf); 1051 ctrl->ana_log_buf = NULL; 1052 ctrl->ana_log_size = 0; 1053 } 1054