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 }; 21 22 static int iopolicy = NVME_IOPOLICY_NUMA; 23 24 static int nvme_set_iopolicy(const char *val, const struct kernel_param *kp) 25 { 26 if (!val) 27 return -EINVAL; 28 if (!strncmp(val, "numa", 4)) 29 iopolicy = NVME_IOPOLICY_NUMA; 30 else if (!strncmp(val, "round-robin", 11)) 31 iopolicy = NVME_IOPOLICY_RR; 32 else 33 return -EINVAL; 34 35 return 0; 36 } 37 38 static int nvme_get_iopolicy(char *buf, const struct kernel_param *kp) 39 { 40 return sprintf(buf, "%s\n", nvme_iopolicy_names[iopolicy]); 41 } 42 43 module_param_call(iopolicy, nvme_set_iopolicy, nvme_get_iopolicy, 44 &iopolicy, 0644); 45 MODULE_PARM_DESC(iopolicy, 46 "Default multipath I/O policy; 'numa' (default) or 'round-robin'"); 47 48 void nvme_mpath_default_iopolicy(struct nvme_subsystem *subsys) 49 { 50 subsys->iopolicy = iopolicy; 51 } 52 53 void nvme_mpath_unfreeze(struct nvme_subsystem *subsys) 54 { 55 struct nvme_ns_head *h; 56 57 lockdep_assert_held(&subsys->lock); 58 list_for_each_entry(h, &subsys->nsheads, entry) 59 if (h->disk) 60 blk_mq_unfreeze_queue(h->disk->queue); 61 } 62 63 void nvme_mpath_wait_freeze(struct nvme_subsystem *subsys) 64 { 65 struct nvme_ns_head *h; 66 67 lockdep_assert_held(&subsys->lock); 68 list_for_each_entry(h, &subsys->nsheads, entry) 69 if (h->disk) 70 blk_mq_freeze_queue_wait(h->disk->queue); 71 } 72 73 void nvme_mpath_start_freeze(struct nvme_subsystem *subsys) 74 { 75 struct nvme_ns_head *h; 76 77 lockdep_assert_held(&subsys->lock); 78 list_for_each_entry(h, &subsys->nsheads, entry) 79 if (h->disk) 80 blk_freeze_queue_start(h->disk->queue); 81 } 82 83 void nvme_failover_req(struct request *req) 84 { 85 struct nvme_ns *ns = req->q->queuedata; 86 u16 status = nvme_req(req)->status & 0x7ff; 87 unsigned long flags; 88 struct bio *bio; 89 90 nvme_mpath_clear_current_path(ns); 91 92 /* 93 * If we got back an ANA error, we know the controller is alive but not 94 * ready to serve this namespace. Kick of a re-read of the ANA 95 * information page, and just try any other available path for now. 96 */ 97 if (nvme_is_ana_error(status) && ns->ctrl->ana_log_buf) { 98 set_bit(NVME_NS_ANA_PENDING, &ns->flags); 99 queue_work(nvme_wq, &ns->ctrl->ana_work); 100 } 101 102 spin_lock_irqsave(&ns->head->requeue_lock, flags); 103 for (bio = req->bio; bio; bio = bio->bi_next) { 104 bio_set_dev(bio, ns->head->disk->part0); 105 if (bio->bi_opf & REQ_POLLED) { 106 bio->bi_opf &= ~REQ_POLLED; 107 bio->bi_cookie = BLK_QC_T_NONE; 108 } 109 /* 110 * The alternate request queue that we may end up submitting 111 * the bio to may be frozen temporarily, in this case REQ_NOWAIT 112 * will fail the I/O immediately with EAGAIN to the issuer. 113 * We are not in the issuer context which cannot block. Clear 114 * the flag to avoid spurious EAGAIN I/O failures. 115 */ 116 bio->bi_opf &= ~REQ_NOWAIT; 117 } 118 blk_steal_bios(&ns->head->requeue_list, req); 119 spin_unlock_irqrestore(&ns->head->requeue_lock, flags); 120 121 blk_mq_end_request(req, 0); 122 kblockd_schedule_work(&ns->head->requeue_work); 123 } 124 125 void nvme_mpath_start_request(struct request *rq) 126 { 127 struct nvme_ns *ns = rq->q->queuedata; 128 struct gendisk *disk = ns->head->disk; 129 130 if (!blk_queue_io_stat(disk->queue) || blk_rq_is_passthrough(rq)) 131 return; 132 133 nvme_req(rq)->flags |= NVME_MPATH_IO_STATS; 134 nvme_req(rq)->start_time = bdev_start_io_acct(disk->part0, req_op(rq), 135 jiffies); 136 } 137 EXPORT_SYMBOL_GPL(nvme_mpath_start_request); 138 139 void nvme_mpath_end_request(struct request *rq) 140 { 141 struct nvme_ns *ns = rq->q->queuedata; 142 143 if (!(nvme_req(rq)->flags & NVME_MPATH_IO_STATS)) 144 return; 145 bdev_end_io_acct(ns->head->disk->part0, req_op(rq), 146 blk_rq_bytes(rq) >> SECTOR_SHIFT, 147 nvme_req(rq)->start_time); 148 } 149 150 void nvme_kick_requeue_lists(struct nvme_ctrl *ctrl) 151 { 152 struct nvme_ns *ns; 153 154 down_read(&ctrl->namespaces_rwsem); 155 list_for_each_entry(ns, &ctrl->namespaces, list) { 156 if (!ns->head->disk) 157 continue; 158 kblockd_schedule_work(&ns->head->requeue_work); 159 if (ctrl->state == NVME_CTRL_LIVE) 160 disk_uevent(ns->head->disk, KOBJ_CHANGE); 161 } 162 up_read(&ctrl->namespaces_rwsem); 163 } 164 165 static const char *nvme_ana_state_names[] = { 166 [0] = "invalid state", 167 [NVME_ANA_OPTIMIZED] = "optimized", 168 [NVME_ANA_NONOPTIMIZED] = "non-optimized", 169 [NVME_ANA_INACCESSIBLE] = "inaccessible", 170 [NVME_ANA_PERSISTENT_LOSS] = "persistent-loss", 171 [NVME_ANA_CHANGE] = "change", 172 }; 173 174 bool nvme_mpath_clear_current_path(struct nvme_ns *ns) 175 { 176 struct nvme_ns_head *head = ns->head; 177 bool changed = false; 178 int node; 179 180 if (!head) 181 goto out; 182 183 for_each_node(node) { 184 if (ns == rcu_access_pointer(head->current_path[node])) { 185 rcu_assign_pointer(head->current_path[node], NULL); 186 changed = true; 187 } 188 } 189 out: 190 return changed; 191 } 192 193 void nvme_mpath_clear_ctrl_paths(struct nvme_ctrl *ctrl) 194 { 195 struct nvme_ns *ns; 196 197 down_read(&ctrl->namespaces_rwsem); 198 list_for_each_entry(ns, &ctrl->namespaces, list) { 199 nvme_mpath_clear_current_path(ns); 200 kblockd_schedule_work(&ns->head->requeue_work); 201 } 202 up_read(&ctrl->namespaces_rwsem); 203 } 204 205 void nvme_mpath_revalidate_paths(struct nvme_ns *ns) 206 { 207 struct nvme_ns_head *head = ns->head; 208 sector_t capacity = get_capacity(head->disk); 209 int node; 210 int srcu_idx; 211 212 srcu_idx = srcu_read_lock(&head->srcu); 213 list_for_each_entry_rcu(ns, &head->list, siblings) { 214 if (capacity != get_capacity(ns->disk)) 215 clear_bit(NVME_NS_READY, &ns->flags); 216 } 217 srcu_read_unlock(&head->srcu, srcu_idx); 218 219 for_each_node(node) 220 rcu_assign_pointer(head->current_path[node], NULL); 221 kblockd_schedule_work(&head->requeue_work); 222 } 223 224 static bool nvme_path_is_disabled(struct nvme_ns *ns) 225 { 226 /* 227 * We don't treat NVME_CTRL_DELETING as a disabled path as I/O should 228 * still be able to complete assuming that the controller is connected. 229 * Otherwise it will fail immediately and return to the requeue list. 230 */ 231 if (ns->ctrl->state != NVME_CTRL_LIVE && 232 ns->ctrl->state != NVME_CTRL_DELETING) 233 return true; 234 if (test_bit(NVME_NS_ANA_PENDING, &ns->flags) || 235 !test_bit(NVME_NS_READY, &ns->flags)) 236 return true; 237 return false; 238 } 239 240 static struct nvme_ns *__nvme_find_path(struct nvme_ns_head *head, int node) 241 { 242 int found_distance = INT_MAX, fallback_distance = INT_MAX, distance; 243 struct nvme_ns *found = NULL, *fallback = NULL, *ns; 244 245 list_for_each_entry_rcu(ns, &head->list, siblings) { 246 if (nvme_path_is_disabled(ns)) 247 continue; 248 249 if (READ_ONCE(head->subsys->iopolicy) == NVME_IOPOLICY_NUMA) 250 distance = node_distance(node, ns->ctrl->numa_node); 251 else 252 distance = LOCAL_DISTANCE; 253 254 switch (ns->ana_state) { 255 case NVME_ANA_OPTIMIZED: 256 if (distance < found_distance) { 257 found_distance = distance; 258 found = ns; 259 } 260 break; 261 case NVME_ANA_NONOPTIMIZED: 262 if (distance < fallback_distance) { 263 fallback_distance = distance; 264 fallback = ns; 265 } 266 break; 267 default: 268 break; 269 } 270 } 271 272 if (!found) 273 found = fallback; 274 if (found) 275 rcu_assign_pointer(head->current_path[node], found); 276 return found; 277 } 278 279 static struct nvme_ns *nvme_next_ns(struct nvme_ns_head *head, 280 struct nvme_ns *ns) 281 { 282 ns = list_next_or_null_rcu(&head->list, &ns->siblings, struct nvme_ns, 283 siblings); 284 if (ns) 285 return ns; 286 return list_first_or_null_rcu(&head->list, struct nvme_ns, siblings); 287 } 288 289 static struct nvme_ns *nvme_round_robin_path(struct nvme_ns_head *head, 290 int node, struct nvme_ns *old) 291 { 292 struct nvme_ns *ns, *found = NULL; 293 294 if (list_is_singular(&head->list)) { 295 if (nvme_path_is_disabled(old)) 296 return NULL; 297 return old; 298 } 299 300 for (ns = nvme_next_ns(head, old); 301 ns && ns != old; 302 ns = nvme_next_ns(head, ns)) { 303 if (nvme_path_is_disabled(ns)) 304 continue; 305 306 if (ns->ana_state == NVME_ANA_OPTIMIZED) { 307 found = ns; 308 goto out; 309 } 310 if (ns->ana_state == NVME_ANA_NONOPTIMIZED) 311 found = ns; 312 } 313 314 /* 315 * The loop above skips the current path for round-robin semantics. 316 * Fall back to the current path if either: 317 * - no other optimized path found and current is optimized, 318 * - no other usable path found and current is usable. 319 */ 320 if (!nvme_path_is_disabled(old) && 321 (old->ana_state == NVME_ANA_OPTIMIZED || 322 (!found && old->ana_state == NVME_ANA_NONOPTIMIZED))) 323 return old; 324 325 if (!found) 326 return NULL; 327 out: 328 rcu_assign_pointer(head->current_path[node], found); 329 return found; 330 } 331 332 static inline bool nvme_path_is_optimized(struct nvme_ns *ns) 333 { 334 return ns->ctrl->state == NVME_CTRL_LIVE && 335 ns->ana_state == NVME_ANA_OPTIMIZED; 336 } 337 338 inline struct nvme_ns *nvme_find_path(struct nvme_ns_head *head) 339 { 340 int node = numa_node_id(); 341 struct nvme_ns *ns; 342 343 ns = srcu_dereference(head->current_path[node], &head->srcu); 344 if (unlikely(!ns)) 345 return __nvme_find_path(head, node); 346 347 if (READ_ONCE(head->subsys->iopolicy) == NVME_IOPOLICY_RR) 348 return nvme_round_robin_path(head, node, ns); 349 if (unlikely(!nvme_path_is_optimized(ns))) 350 return __nvme_find_path(head, node); 351 return ns; 352 } 353 354 static bool nvme_available_path(struct nvme_ns_head *head) 355 { 356 struct nvme_ns *ns; 357 358 list_for_each_entry_rcu(ns, &head->list, siblings) { 359 if (test_bit(NVME_CTRL_FAILFAST_EXPIRED, &ns->ctrl->flags)) 360 continue; 361 switch (ns->ctrl->state) { 362 case NVME_CTRL_LIVE: 363 case NVME_CTRL_RESETTING: 364 case NVME_CTRL_CONNECTING: 365 /* fallthru */ 366 return true; 367 default: 368 break; 369 } 370 } 371 return false; 372 } 373 374 static void nvme_ns_head_submit_bio(struct bio *bio) 375 { 376 struct nvme_ns_head *head = bio->bi_bdev->bd_disk->private_data; 377 struct device *dev = disk_to_dev(head->disk); 378 struct nvme_ns *ns; 379 int srcu_idx; 380 381 /* 382 * The namespace might be going away and the bio might be moved to a 383 * different queue via blk_steal_bios(), so we need to use the bio_split 384 * pool from the original queue to allocate the bvecs from. 385 */ 386 bio = bio_split_to_limits(bio); 387 if (!bio) 388 return; 389 390 srcu_idx = srcu_read_lock(&head->srcu); 391 ns = nvme_find_path(head); 392 if (likely(ns)) { 393 bio_set_dev(bio, ns->disk->part0); 394 bio->bi_opf |= REQ_NVME_MPATH; 395 trace_block_bio_remap(bio, disk_devt(ns->head->disk), 396 bio->bi_iter.bi_sector); 397 submit_bio_noacct(bio); 398 } else if (nvme_available_path(head)) { 399 dev_warn_ratelimited(dev, "no usable path - requeuing I/O\n"); 400 401 spin_lock_irq(&head->requeue_lock); 402 bio_list_add(&head->requeue_list, bio); 403 spin_unlock_irq(&head->requeue_lock); 404 } else { 405 dev_warn_ratelimited(dev, "no available path - failing I/O\n"); 406 407 bio_io_error(bio); 408 } 409 410 srcu_read_unlock(&head->srcu, srcu_idx); 411 } 412 413 static int nvme_ns_head_open(struct gendisk *disk, blk_mode_t mode) 414 { 415 if (!nvme_tryget_ns_head(disk->private_data)) 416 return -ENXIO; 417 return 0; 418 } 419 420 static void nvme_ns_head_release(struct gendisk *disk) 421 { 422 nvme_put_ns_head(disk->private_data); 423 } 424 425 #ifdef CONFIG_BLK_DEV_ZONED 426 static int nvme_ns_head_report_zones(struct gendisk *disk, sector_t sector, 427 unsigned int nr_zones, report_zones_cb cb, void *data) 428 { 429 struct nvme_ns_head *head = disk->private_data; 430 struct nvme_ns *ns; 431 int srcu_idx, ret = -EWOULDBLOCK; 432 433 srcu_idx = srcu_read_lock(&head->srcu); 434 ns = nvme_find_path(head); 435 if (ns) 436 ret = nvme_ns_report_zones(ns, sector, nr_zones, cb, data); 437 srcu_read_unlock(&head->srcu, srcu_idx); 438 return ret; 439 } 440 #else 441 #define nvme_ns_head_report_zones NULL 442 #endif /* CONFIG_BLK_DEV_ZONED */ 443 444 const struct block_device_operations nvme_ns_head_ops = { 445 .owner = THIS_MODULE, 446 .submit_bio = nvme_ns_head_submit_bio, 447 .open = nvme_ns_head_open, 448 .release = nvme_ns_head_release, 449 .ioctl = nvme_ns_head_ioctl, 450 .compat_ioctl = blkdev_compat_ptr_ioctl, 451 .getgeo = nvme_getgeo, 452 .report_zones = nvme_ns_head_report_zones, 453 .pr_ops = &nvme_pr_ops, 454 }; 455 456 static inline struct nvme_ns_head *cdev_to_ns_head(struct cdev *cdev) 457 { 458 return container_of(cdev, struct nvme_ns_head, cdev); 459 } 460 461 static int nvme_ns_head_chr_open(struct inode *inode, struct file *file) 462 { 463 if (!nvme_tryget_ns_head(cdev_to_ns_head(inode->i_cdev))) 464 return -ENXIO; 465 return 0; 466 } 467 468 static int nvme_ns_head_chr_release(struct inode *inode, struct file *file) 469 { 470 nvme_put_ns_head(cdev_to_ns_head(inode->i_cdev)); 471 return 0; 472 } 473 474 static const struct file_operations nvme_ns_head_chr_fops = { 475 .owner = THIS_MODULE, 476 .open = nvme_ns_head_chr_open, 477 .release = nvme_ns_head_chr_release, 478 .unlocked_ioctl = nvme_ns_head_chr_ioctl, 479 .compat_ioctl = compat_ptr_ioctl, 480 .uring_cmd = nvme_ns_head_chr_uring_cmd, 481 .uring_cmd_iopoll = nvme_ns_chr_uring_cmd_iopoll, 482 }; 483 484 static int nvme_add_ns_head_cdev(struct nvme_ns_head *head) 485 { 486 int ret; 487 488 head->cdev_device.parent = &head->subsys->dev; 489 ret = dev_set_name(&head->cdev_device, "ng%dn%d", 490 head->subsys->instance, head->instance); 491 if (ret) 492 return ret; 493 ret = nvme_cdev_add(&head->cdev, &head->cdev_device, 494 &nvme_ns_head_chr_fops, THIS_MODULE); 495 return ret; 496 } 497 498 static void nvme_requeue_work(struct work_struct *work) 499 { 500 struct nvme_ns_head *head = 501 container_of(work, struct nvme_ns_head, requeue_work); 502 struct bio *bio, *next; 503 504 spin_lock_irq(&head->requeue_lock); 505 next = bio_list_get(&head->requeue_list); 506 spin_unlock_irq(&head->requeue_lock); 507 508 while ((bio = next) != NULL) { 509 next = bio->bi_next; 510 bio->bi_next = NULL; 511 512 submit_bio_noacct(bio); 513 } 514 } 515 516 int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head) 517 { 518 bool vwc = false; 519 520 mutex_init(&head->lock); 521 bio_list_init(&head->requeue_list); 522 spin_lock_init(&head->requeue_lock); 523 INIT_WORK(&head->requeue_work, nvme_requeue_work); 524 525 /* 526 * Add a multipath node if the subsystems supports multiple controllers. 527 * We also do this for private namespaces as the namespace sharing flag 528 * could change after a rescan. 529 */ 530 if (!(ctrl->subsys->cmic & NVME_CTRL_CMIC_MULTI_CTRL) || 531 !nvme_is_unique_nsid(ctrl, head) || !multipath) 532 return 0; 533 534 head->disk = blk_alloc_disk(ctrl->numa_node); 535 if (!head->disk) 536 return -ENOMEM; 537 head->disk->fops = &nvme_ns_head_ops; 538 head->disk->private_data = head; 539 sprintf(head->disk->disk_name, "nvme%dn%d", 540 ctrl->subsys->instance, head->instance); 541 542 blk_queue_flag_set(QUEUE_FLAG_NONROT, head->disk->queue); 543 blk_queue_flag_set(QUEUE_FLAG_NOWAIT, head->disk->queue); 544 blk_queue_flag_set(QUEUE_FLAG_IO_STAT, head->disk->queue); 545 /* 546 * This assumes all controllers that refer to a namespace either 547 * support poll queues or not. That is not a strict guarantee, 548 * but if the assumption is wrong the effect is only suboptimal 549 * performance but not correctness problem. 550 */ 551 if (ctrl->tagset->nr_maps > HCTX_TYPE_POLL && 552 ctrl->tagset->map[HCTX_TYPE_POLL].nr_queues) 553 blk_queue_flag_set(QUEUE_FLAG_POLL, head->disk->queue); 554 555 /* set to a default value of 512 until the disk is validated */ 556 blk_queue_logical_block_size(head->disk->queue, 512); 557 blk_set_stacking_limits(&head->disk->queue->limits); 558 blk_queue_dma_alignment(head->disk->queue, 3); 559 560 /* we need to propagate up the VMC settings */ 561 if (ctrl->vwc & NVME_CTRL_VWC_PRESENT) 562 vwc = true; 563 blk_queue_write_cache(head->disk->queue, vwc, vwc); 564 return 0; 565 } 566 567 static void nvme_mpath_set_live(struct nvme_ns *ns) 568 { 569 struct nvme_ns_head *head = ns->head; 570 int rc; 571 572 if (!head->disk) 573 return; 574 575 /* 576 * test_and_set_bit() is used because it is protecting against two nvme 577 * paths simultaneously calling device_add_disk() on the same namespace 578 * head. 579 */ 580 if (!test_and_set_bit(NVME_NSHEAD_DISK_LIVE, &head->flags)) { 581 rc = device_add_disk(&head->subsys->dev, head->disk, 582 nvme_ns_id_attr_groups); 583 if (rc) { 584 clear_bit(NVME_NSHEAD_DISK_LIVE, &ns->flags); 585 return; 586 } 587 nvme_add_ns_head_cdev(head); 588 } 589 590 mutex_lock(&head->lock); 591 if (nvme_path_is_optimized(ns)) { 592 int node, srcu_idx; 593 594 srcu_idx = srcu_read_lock(&head->srcu); 595 for_each_node(node) 596 __nvme_find_path(head, node); 597 srcu_read_unlock(&head->srcu, srcu_idx); 598 } 599 mutex_unlock(&head->lock); 600 601 synchronize_srcu(&head->srcu); 602 kblockd_schedule_work(&head->requeue_work); 603 } 604 605 static int nvme_parse_ana_log(struct nvme_ctrl *ctrl, void *data, 606 int (*cb)(struct nvme_ctrl *ctrl, struct nvme_ana_group_desc *, 607 void *)) 608 { 609 void *base = ctrl->ana_log_buf; 610 size_t offset = sizeof(struct nvme_ana_rsp_hdr); 611 int error, i; 612 613 lockdep_assert_held(&ctrl->ana_lock); 614 615 for (i = 0; i < le16_to_cpu(ctrl->ana_log_buf->ngrps); i++) { 616 struct nvme_ana_group_desc *desc = base + offset; 617 u32 nr_nsids; 618 size_t nsid_buf_size; 619 620 if (WARN_ON_ONCE(offset > ctrl->ana_log_size - sizeof(*desc))) 621 return -EINVAL; 622 623 nr_nsids = le32_to_cpu(desc->nnsids); 624 nsid_buf_size = flex_array_size(desc, nsids, nr_nsids); 625 626 if (WARN_ON_ONCE(desc->grpid == 0)) 627 return -EINVAL; 628 if (WARN_ON_ONCE(le32_to_cpu(desc->grpid) > ctrl->anagrpmax)) 629 return -EINVAL; 630 if (WARN_ON_ONCE(desc->state == 0)) 631 return -EINVAL; 632 if (WARN_ON_ONCE(desc->state > NVME_ANA_CHANGE)) 633 return -EINVAL; 634 635 offset += sizeof(*desc); 636 if (WARN_ON_ONCE(offset > ctrl->ana_log_size - nsid_buf_size)) 637 return -EINVAL; 638 639 error = cb(ctrl, desc, data); 640 if (error) 641 return error; 642 643 offset += nsid_buf_size; 644 } 645 646 return 0; 647 } 648 649 static inline bool nvme_state_is_live(enum nvme_ana_state state) 650 { 651 return state == NVME_ANA_OPTIMIZED || state == NVME_ANA_NONOPTIMIZED; 652 } 653 654 static void nvme_update_ns_ana_state(struct nvme_ana_group_desc *desc, 655 struct nvme_ns *ns) 656 { 657 ns->ana_grpid = le32_to_cpu(desc->grpid); 658 ns->ana_state = desc->state; 659 clear_bit(NVME_NS_ANA_PENDING, &ns->flags); 660 /* 661 * nvme_mpath_set_live() will trigger I/O to the multipath path device 662 * and in turn to this path device. However we cannot accept this I/O 663 * if the controller is not live. This may deadlock if called from 664 * nvme_mpath_init_identify() and the ctrl will never complete 665 * initialization, preventing I/O from completing. For this case we 666 * will reprocess the ANA log page in nvme_mpath_update() once the 667 * controller is ready. 668 */ 669 if (nvme_state_is_live(ns->ana_state) && 670 ns->ctrl->state == NVME_CTRL_LIVE) 671 nvme_mpath_set_live(ns); 672 } 673 674 static int nvme_update_ana_state(struct nvme_ctrl *ctrl, 675 struct nvme_ana_group_desc *desc, void *data) 676 { 677 u32 nr_nsids = le32_to_cpu(desc->nnsids), n = 0; 678 unsigned *nr_change_groups = data; 679 struct nvme_ns *ns; 680 681 dev_dbg(ctrl->device, "ANA group %d: %s.\n", 682 le32_to_cpu(desc->grpid), 683 nvme_ana_state_names[desc->state]); 684 685 if (desc->state == NVME_ANA_CHANGE) 686 (*nr_change_groups)++; 687 688 if (!nr_nsids) 689 return 0; 690 691 down_read(&ctrl->namespaces_rwsem); 692 list_for_each_entry(ns, &ctrl->namespaces, list) { 693 unsigned nsid; 694 again: 695 nsid = le32_to_cpu(desc->nsids[n]); 696 if (ns->head->ns_id < nsid) 697 continue; 698 if (ns->head->ns_id == nsid) 699 nvme_update_ns_ana_state(desc, ns); 700 if (++n == nr_nsids) 701 break; 702 if (ns->head->ns_id > nsid) 703 goto again; 704 } 705 up_read(&ctrl->namespaces_rwsem); 706 return 0; 707 } 708 709 static int nvme_read_ana_log(struct nvme_ctrl *ctrl) 710 { 711 u32 nr_change_groups = 0; 712 int error; 713 714 mutex_lock(&ctrl->ana_lock); 715 error = nvme_get_log(ctrl, NVME_NSID_ALL, NVME_LOG_ANA, 0, NVME_CSI_NVM, 716 ctrl->ana_log_buf, ctrl->ana_log_size, 0); 717 if (error) { 718 dev_warn(ctrl->device, "Failed to get ANA log: %d\n", error); 719 goto out_unlock; 720 } 721 722 error = nvme_parse_ana_log(ctrl, &nr_change_groups, 723 nvme_update_ana_state); 724 if (error) 725 goto out_unlock; 726 727 /* 728 * In theory we should have an ANATT timer per group as they might enter 729 * the change state at different times. But that is a lot of overhead 730 * just to protect against a target that keeps entering new changes 731 * states while never finishing previous ones. But we'll still 732 * eventually time out once all groups are in change state, so this 733 * isn't a big deal. 734 * 735 * We also double the ANATT value to provide some slack for transports 736 * or AEN processing overhead. 737 */ 738 if (nr_change_groups) 739 mod_timer(&ctrl->anatt_timer, ctrl->anatt * HZ * 2 + jiffies); 740 else 741 del_timer_sync(&ctrl->anatt_timer); 742 out_unlock: 743 mutex_unlock(&ctrl->ana_lock); 744 return error; 745 } 746 747 static void nvme_ana_work(struct work_struct *work) 748 { 749 struct nvme_ctrl *ctrl = container_of(work, struct nvme_ctrl, ana_work); 750 751 if (ctrl->state != NVME_CTRL_LIVE) 752 return; 753 754 nvme_read_ana_log(ctrl); 755 } 756 757 void nvme_mpath_update(struct nvme_ctrl *ctrl) 758 { 759 u32 nr_change_groups = 0; 760 761 if (!ctrl->ana_log_buf) 762 return; 763 764 mutex_lock(&ctrl->ana_lock); 765 nvme_parse_ana_log(ctrl, &nr_change_groups, nvme_update_ana_state); 766 mutex_unlock(&ctrl->ana_lock); 767 } 768 769 static void nvme_anatt_timeout(struct timer_list *t) 770 { 771 struct nvme_ctrl *ctrl = from_timer(ctrl, t, anatt_timer); 772 773 dev_info(ctrl->device, "ANATT timeout, resetting controller.\n"); 774 nvme_reset_ctrl(ctrl); 775 } 776 777 void nvme_mpath_stop(struct nvme_ctrl *ctrl) 778 { 779 if (!nvme_ctrl_use_ana(ctrl)) 780 return; 781 del_timer_sync(&ctrl->anatt_timer); 782 cancel_work_sync(&ctrl->ana_work); 783 } 784 785 #define SUBSYS_ATTR_RW(_name, _mode, _show, _store) \ 786 struct device_attribute subsys_attr_##_name = \ 787 __ATTR(_name, _mode, _show, _store) 788 789 static ssize_t nvme_subsys_iopolicy_show(struct device *dev, 790 struct device_attribute *attr, char *buf) 791 { 792 struct nvme_subsystem *subsys = 793 container_of(dev, struct nvme_subsystem, dev); 794 795 return sysfs_emit(buf, "%s\n", 796 nvme_iopolicy_names[READ_ONCE(subsys->iopolicy)]); 797 } 798 799 static ssize_t nvme_subsys_iopolicy_store(struct device *dev, 800 struct device_attribute *attr, const char *buf, size_t count) 801 { 802 struct nvme_subsystem *subsys = 803 container_of(dev, struct nvme_subsystem, dev); 804 int i; 805 806 for (i = 0; i < ARRAY_SIZE(nvme_iopolicy_names); i++) { 807 if (sysfs_streq(buf, nvme_iopolicy_names[i])) { 808 WRITE_ONCE(subsys->iopolicy, i); 809 return count; 810 } 811 } 812 813 return -EINVAL; 814 } 815 SUBSYS_ATTR_RW(iopolicy, S_IRUGO | S_IWUSR, 816 nvme_subsys_iopolicy_show, nvme_subsys_iopolicy_store); 817 818 static ssize_t ana_grpid_show(struct device *dev, struct device_attribute *attr, 819 char *buf) 820 { 821 return sysfs_emit(buf, "%d\n", nvme_get_ns_from_dev(dev)->ana_grpid); 822 } 823 DEVICE_ATTR_RO(ana_grpid); 824 825 static ssize_t ana_state_show(struct device *dev, struct device_attribute *attr, 826 char *buf) 827 { 828 struct nvme_ns *ns = nvme_get_ns_from_dev(dev); 829 830 return sysfs_emit(buf, "%s\n", nvme_ana_state_names[ns->ana_state]); 831 } 832 DEVICE_ATTR_RO(ana_state); 833 834 static int nvme_lookup_ana_group_desc(struct nvme_ctrl *ctrl, 835 struct nvme_ana_group_desc *desc, void *data) 836 { 837 struct nvme_ana_group_desc *dst = data; 838 839 if (desc->grpid != dst->grpid) 840 return 0; 841 842 *dst = *desc; 843 return -ENXIO; /* just break out of the loop */ 844 } 845 846 void nvme_mpath_add_disk(struct nvme_ns *ns, __le32 anagrpid) 847 { 848 if (nvme_ctrl_use_ana(ns->ctrl)) { 849 struct nvme_ana_group_desc desc = { 850 .grpid = anagrpid, 851 .state = 0, 852 }; 853 854 mutex_lock(&ns->ctrl->ana_lock); 855 ns->ana_grpid = le32_to_cpu(anagrpid); 856 nvme_parse_ana_log(ns->ctrl, &desc, nvme_lookup_ana_group_desc); 857 mutex_unlock(&ns->ctrl->ana_lock); 858 if (desc.state) { 859 /* found the group desc: update */ 860 nvme_update_ns_ana_state(&desc, ns); 861 } else { 862 /* group desc not found: trigger a re-read */ 863 set_bit(NVME_NS_ANA_PENDING, &ns->flags); 864 queue_work(nvme_wq, &ns->ctrl->ana_work); 865 } 866 } else { 867 ns->ana_state = NVME_ANA_OPTIMIZED; 868 nvme_mpath_set_live(ns); 869 } 870 871 if (blk_queue_stable_writes(ns->queue) && ns->head->disk) 872 blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, 873 ns->head->disk->queue); 874 #ifdef CONFIG_BLK_DEV_ZONED 875 if (blk_queue_is_zoned(ns->queue) && ns->head->disk) 876 ns->head->disk->nr_zones = ns->disk->nr_zones; 877 #endif 878 } 879 880 void nvme_mpath_shutdown_disk(struct nvme_ns_head *head) 881 { 882 if (!head->disk) 883 return; 884 kblockd_schedule_work(&head->requeue_work); 885 if (test_bit(NVME_NSHEAD_DISK_LIVE, &head->flags)) { 886 nvme_cdev_del(&head->cdev, &head->cdev_device); 887 del_gendisk(head->disk); 888 } 889 } 890 891 void nvme_mpath_remove_disk(struct nvme_ns_head *head) 892 { 893 if (!head->disk) 894 return; 895 /* make sure all pending bios are cleaned up */ 896 kblockd_schedule_work(&head->requeue_work); 897 flush_work(&head->requeue_work); 898 put_disk(head->disk); 899 } 900 901 void nvme_mpath_init_ctrl(struct nvme_ctrl *ctrl) 902 { 903 mutex_init(&ctrl->ana_lock); 904 timer_setup(&ctrl->anatt_timer, nvme_anatt_timeout, 0); 905 INIT_WORK(&ctrl->ana_work, nvme_ana_work); 906 } 907 908 int nvme_mpath_init_identify(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id) 909 { 910 size_t max_transfer_size = ctrl->max_hw_sectors << SECTOR_SHIFT; 911 size_t ana_log_size; 912 int error = 0; 913 914 /* check if multipath is enabled and we have the capability */ 915 if (!multipath || !ctrl->subsys || 916 !(ctrl->subsys->cmic & NVME_CTRL_CMIC_ANA)) 917 return 0; 918 919 if (!ctrl->max_namespaces || 920 ctrl->max_namespaces > le32_to_cpu(id->nn)) { 921 dev_err(ctrl->device, 922 "Invalid MNAN value %u\n", ctrl->max_namespaces); 923 return -EINVAL; 924 } 925 926 ctrl->anacap = id->anacap; 927 ctrl->anatt = id->anatt; 928 ctrl->nanagrpid = le32_to_cpu(id->nanagrpid); 929 ctrl->anagrpmax = le32_to_cpu(id->anagrpmax); 930 931 ana_log_size = sizeof(struct nvme_ana_rsp_hdr) + 932 ctrl->nanagrpid * sizeof(struct nvme_ana_group_desc) + 933 ctrl->max_namespaces * sizeof(__le32); 934 if (ana_log_size > max_transfer_size) { 935 dev_err(ctrl->device, 936 "ANA log page size (%zd) larger than MDTS (%zd).\n", 937 ana_log_size, max_transfer_size); 938 dev_err(ctrl->device, "disabling ANA support.\n"); 939 goto out_uninit; 940 } 941 if (ana_log_size > ctrl->ana_log_size) { 942 nvme_mpath_stop(ctrl); 943 nvme_mpath_uninit(ctrl); 944 ctrl->ana_log_buf = kvmalloc(ana_log_size, GFP_KERNEL); 945 if (!ctrl->ana_log_buf) 946 return -ENOMEM; 947 } 948 ctrl->ana_log_size = ana_log_size; 949 error = nvme_read_ana_log(ctrl); 950 if (error) 951 goto out_uninit; 952 return 0; 953 954 out_uninit: 955 nvme_mpath_uninit(ctrl); 956 return error; 957 } 958 959 void nvme_mpath_uninit(struct nvme_ctrl *ctrl) 960 { 961 kvfree(ctrl->ana_log_buf); 962 ctrl->ana_log_buf = NULL; 963 ctrl->ana_log_size = 0; 964 } 965