1 /* 2 * Copyright (C) 2001, 2002 Sistina Software (UK) Limited. 3 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved. 4 * 5 * This file is released under the GPL. 6 */ 7 8 #include "dm-core.h" 9 #include "dm-rq.h" 10 #include "dm-uevent.h" 11 12 #include <linux/init.h> 13 #include <linux/module.h> 14 #include <linux/mutex.h> 15 #include <linux/sched/mm.h> 16 #include <linux/sched/signal.h> 17 #include <linux/blkpg.h> 18 #include <linux/bio.h> 19 #include <linux/mempool.h> 20 #include <linux/dax.h> 21 #include <linux/slab.h> 22 #include <linux/idr.h> 23 #include <linux/uio.h> 24 #include <linux/hdreg.h> 25 #include <linux/delay.h> 26 #include <linux/wait.h> 27 #include <linux/pr.h> 28 #include <linux/refcount.h> 29 #include <linux/part_stat.h> 30 #include <linux/blk-crypto.h> 31 32 #define DM_MSG_PREFIX "core" 33 34 /* 35 * Cookies are numeric values sent with CHANGE and REMOVE 36 * uevents while resuming, removing or renaming the device. 37 */ 38 #define DM_COOKIE_ENV_VAR_NAME "DM_COOKIE" 39 #define DM_COOKIE_LENGTH 24 40 41 static const char *_name = DM_NAME; 42 43 static unsigned int major = 0; 44 static unsigned int _major = 0; 45 46 static DEFINE_IDR(_minor_idr); 47 48 static DEFINE_SPINLOCK(_minor_lock); 49 50 static void do_deferred_remove(struct work_struct *w); 51 52 static DECLARE_WORK(deferred_remove_work, do_deferred_remove); 53 54 static struct workqueue_struct *deferred_remove_workqueue; 55 56 atomic_t dm_global_event_nr = ATOMIC_INIT(0); 57 DECLARE_WAIT_QUEUE_HEAD(dm_global_eventq); 58 59 void dm_issue_global_event(void) 60 { 61 atomic_inc(&dm_global_event_nr); 62 wake_up(&dm_global_eventq); 63 } 64 65 /* 66 * One of these is allocated (on-stack) per original bio. 67 */ 68 struct clone_info { 69 struct dm_table *map; 70 struct bio *bio; 71 struct dm_io *io; 72 sector_t sector; 73 unsigned sector_count; 74 }; 75 76 /* 77 * One of these is allocated per clone bio. 78 */ 79 #define DM_TIO_MAGIC 7282014 80 struct dm_target_io { 81 unsigned magic; 82 struct dm_io *io; 83 struct dm_target *ti; 84 unsigned target_bio_nr; 85 unsigned *len_ptr; 86 bool inside_dm_io; 87 struct bio clone; 88 }; 89 90 /* 91 * One of these is allocated per original bio. 92 * It contains the first clone used for that original. 93 */ 94 #define DM_IO_MAGIC 5191977 95 struct dm_io { 96 unsigned magic; 97 struct mapped_device *md; 98 blk_status_t status; 99 atomic_t io_count; 100 struct bio *orig_bio; 101 unsigned long start_time; 102 spinlock_t endio_lock; 103 struct dm_stats_aux stats_aux; 104 /* last member of dm_target_io is 'struct bio' */ 105 struct dm_target_io tio; 106 }; 107 108 void *dm_per_bio_data(struct bio *bio, size_t data_size) 109 { 110 struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone); 111 if (!tio->inside_dm_io) 112 return (char *)bio - offsetof(struct dm_target_io, clone) - data_size; 113 return (char *)bio - offsetof(struct dm_target_io, clone) - offsetof(struct dm_io, tio) - data_size; 114 } 115 EXPORT_SYMBOL_GPL(dm_per_bio_data); 116 117 struct bio *dm_bio_from_per_bio_data(void *data, size_t data_size) 118 { 119 struct dm_io *io = (struct dm_io *)((char *)data + data_size); 120 if (io->magic == DM_IO_MAGIC) 121 return (struct bio *)((char *)io + offsetof(struct dm_io, tio) + offsetof(struct dm_target_io, clone)); 122 BUG_ON(io->magic != DM_TIO_MAGIC); 123 return (struct bio *)((char *)io + offsetof(struct dm_target_io, clone)); 124 } 125 EXPORT_SYMBOL_GPL(dm_bio_from_per_bio_data); 126 127 unsigned dm_bio_get_target_bio_nr(const struct bio *bio) 128 { 129 return container_of(bio, struct dm_target_io, clone)->target_bio_nr; 130 } 131 EXPORT_SYMBOL_GPL(dm_bio_get_target_bio_nr); 132 133 #define MINOR_ALLOCED ((void *)-1) 134 135 /* 136 * Bits for the md->flags field. 137 */ 138 #define DMF_BLOCK_IO_FOR_SUSPEND 0 139 #define DMF_SUSPENDED 1 140 #define DMF_FROZEN 2 141 #define DMF_FREEING 3 142 #define DMF_DELETING 4 143 #define DMF_NOFLUSH_SUSPENDING 5 144 #define DMF_DEFERRED_REMOVE 6 145 #define DMF_SUSPENDED_INTERNALLY 7 146 #define DMF_POST_SUSPENDING 8 147 148 #define DM_NUMA_NODE NUMA_NO_NODE 149 static int dm_numa_node = DM_NUMA_NODE; 150 151 /* 152 * For mempools pre-allocation at the table loading time. 153 */ 154 struct dm_md_mempools { 155 struct bio_set bs; 156 struct bio_set io_bs; 157 }; 158 159 struct table_device { 160 struct list_head list; 161 refcount_t count; 162 struct dm_dev dm_dev; 163 }; 164 165 /* 166 * Bio-based DM's mempools' reserved IOs set by the user. 167 */ 168 #define RESERVED_BIO_BASED_IOS 16 169 static unsigned reserved_bio_based_ios = RESERVED_BIO_BASED_IOS; 170 171 static int __dm_get_module_param_int(int *module_param, int min, int max) 172 { 173 int param = READ_ONCE(*module_param); 174 int modified_param = 0; 175 bool modified = true; 176 177 if (param < min) 178 modified_param = min; 179 else if (param > max) 180 modified_param = max; 181 else 182 modified = false; 183 184 if (modified) { 185 (void)cmpxchg(module_param, param, modified_param); 186 param = modified_param; 187 } 188 189 return param; 190 } 191 192 unsigned __dm_get_module_param(unsigned *module_param, 193 unsigned def, unsigned max) 194 { 195 unsigned param = READ_ONCE(*module_param); 196 unsigned modified_param = 0; 197 198 if (!param) 199 modified_param = def; 200 else if (param > max) 201 modified_param = max; 202 203 if (modified_param) { 204 (void)cmpxchg(module_param, param, modified_param); 205 param = modified_param; 206 } 207 208 return param; 209 } 210 211 unsigned dm_get_reserved_bio_based_ios(void) 212 { 213 return __dm_get_module_param(&reserved_bio_based_ios, 214 RESERVED_BIO_BASED_IOS, DM_RESERVED_MAX_IOS); 215 } 216 EXPORT_SYMBOL_GPL(dm_get_reserved_bio_based_ios); 217 218 static unsigned dm_get_numa_node(void) 219 { 220 return __dm_get_module_param_int(&dm_numa_node, 221 DM_NUMA_NODE, num_online_nodes() - 1); 222 } 223 224 static int __init local_init(void) 225 { 226 int r; 227 228 r = dm_uevent_init(); 229 if (r) 230 return r; 231 232 deferred_remove_workqueue = alloc_workqueue("kdmremove", WQ_UNBOUND, 1); 233 if (!deferred_remove_workqueue) { 234 r = -ENOMEM; 235 goto out_uevent_exit; 236 } 237 238 _major = major; 239 r = register_blkdev(_major, _name); 240 if (r < 0) 241 goto out_free_workqueue; 242 243 if (!_major) 244 _major = r; 245 246 return 0; 247 248 out_free_workqueue: 249 destroy_workqueue(deferred_remove_workqueue); 250 out_uevent_exit: 251 dm_uevent_exit(); 252 253 return r; 254 } 255 256 static void local_exit(void) 257 { 258 flush_scheduled_work(); 259 destroy_workqueue(deferred_remove_workqueue); 260 261 unregister_blkdev(_major, _name); 262 dm_uevent_exit(); 263 264 _major = 0; 265 266 DMINFO("cleaned up"); 267 } 268 269 static int (*_inits[])(void) __initdata = { 270 local_init, 271 dm_target_init, 272 dm_linear_init, 273 dm_stripe_init, 274 dm_io_init, 275 dm_kcopyd_init, 276 dm_interface_init, 277 dm_statistics_init, 278 }; 279 280 static void (*_exits[])(void) = { 281 local_exit, 282 dm_target_exit, 283 dm_linear_exit, 284 dm_stripe_exit, 285 dm_io_exit, 286 dm_kcopyd_exit, 287 dm_interface_exit, 288 dm_statistics_exit, 289 }; 290 291 static int __init dm_init(void) 292 { 293 const int count = ARRAY_SIZE(_inits); 294 295 int r, i; 296 297 for (i = 0; i < count; i++) { 298 r = _inits[i](); 299 if (r) 300 goto bad; 301 } 302 303 return 0; 304 305 bad: 306 while (i--) 307 _exits[i](); 308 309 return r; 310 } 311 312 static void __exit dm_exit(void) 313 { 314 int i = ARRAY_SIZE(_exits); 315 316 while (i--) 317 _exits[i](); 318 319 /* 320 * Should be empty by this point. 321 */ 322 idr_destroy(&_minor_idr); 323 } 324 325 /* 326 * Block device functions 327 */ 328 int dm_deleting_md(struct mapped_device *md) 329 { 330 return test_bit(DMF_DELETING, &md->flags); 331 } 332 333 static int dm_blk_open(struct block_device *bdev, fmode_t mode) 334 { 335 struct mapped_device *md; 336 337 spin_lock(&_minor_lock); 338 339 md = bdev->bd_disk->private_data; 340 if (!md) 341 goto out; 342 343 if (test_bit(DMF_FREEING, &md->flags) || 344 dm_deleting_md(md)) { 345 md = NULL; 346 goto out; 347 } 348 349 dm_get(md); 350 atomic_inc(&md->open_count); 351 out: 352 spin_unlock(&_minor_lock); 353 354 return md ? 0 : -ENXIO; 355 } 356 357 static void dm_blk_close(struct gendisk *disk, fmode_t mode) 358 { 359 struct mapped_device *md; 360 361 spin_lock(&_minor_lock); 362 363 md = disk->private_data; 364 if (WARN_ON(!md)) 365 goto out; 366 367 if (atomic_dec_and_test(&md->open_count) && 368 (test_bit(DMF_DEFERRED_REMOVE, &md->flags))) 369 queue_work(deferred_remove_workqueue, &deferred_remove_work); 370 371 dm_put(md); 372 out: 373 spin_unlock(&_minor_lock); 374 } 375 376 int dm_open_count(struct mapped_device *md) 377 { 378 return atomic_read(&md->open_count); 379 } 380 381 /* 382 * Guarantees nothing is using the device before it's deleted. 383 */ 384 int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred) 385 { 386 int r = 0; 387 388 spin_lock(&_minor_lock); 389 390 if (dm_open_count(md)) { 391 r = -EBUSY; 392 if (mark_deferred) 393 set_bit(DMF_DEFERRED_REMOVE, &md->flags); 394 } else if (only_deferred && !test_bit(DMF_DEFERRED_REMOVE, &md->flags)) 395 r = -EEXIST; 396 else 397 set_bit(DMF_DELETING, &md->flags); 398 399 spin_unlock(&_minor_lock); 400 401 return r; 402 } 403 404 int dm_cancel_deferred_remove(struct mapped_device *md) 405 { 406 int r = 0; 407 408 spin_lock(&_minor_lock); 409 410 if (test_bit(DMF_DELETING, &md->flags)) 411 r = -EBUSY; 412 else 413 clear_bit(DMF_DEFERRED_REMOVE, &md->flags); 414 415 spin_unlock(&_minor_lock); 416 417 return r; 418 } 419 420 static void do_deferred_remove(struct work_struct *w) 421 { 422 dm_deferred_remove(); 423 } 424 425 sector_t dm_get_size(struct mapped_device *md) 426 { 427 return get_capacity(md->disk); 428 } 429 430 struct request_queue *dm_get_md_queue(struct mapped_device *md) 431 { 432 return md->queue; 433 } 434 435 struct dm_stats *dm_get_stats(struct mapped_device *md) 436 { 437 return &md->stats; 438 } 439 440 static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo) 441 { 442 struct mapped_device *md = bdev->bd_disk->private_data; 443 444 return dm_get_geometry(md, geo); 445 } 446 447 #ifdef CONFIG_BLK_DEV_ZONED 448 int dm_report_zones_cb(struct blk_zone *zone, unsigned int idx, void *data) 449 { 450 struct dm_report_zones_args *args = data; 451 sector_t sector_diff = args->tgt->begin - args->start; 452 453 /* 454 * Ignore zones beyond the target range. 455 */ 456 if (zone->start >= args->start + args->tgt->len) 457 return 0; 458 459 /* 460 * Remap the start sector and write pointer position of the zone 461 * to match its position in the target range. 462 */ 463 zone->start += sector_diff; 464 if (zone->type != BLK_ZONE_TYPE_CONVENTIONAL) { 465 if (zone->cond == BLK_ZONE_COND_FULL) 466 zone->wp = zone->start + zone->len; 467 else if (zone->cond == BLK_ZONE_COND_EMPTY) 468 zone->wp = zone->start; 469 else 470 zone->wp += sector_diff; 471 } 472 473 args->next_sector = zone->start + zone->len; 474 return args->orig_cb(zone, args->zone_idx++, args->orig_data); 475 } 476 EXPORT_SYMBOL_GPL(dm_report_zones_cb); 477 478 static int dm_blk_report_zones(struct gendisk *disk, sector_t sector, 479 unsigned int nr_zones, report_zones_cb cb, void *data) 480 { 481 struct mapped_device *md = disk->private_data; 482 struct dm_table *map; 483 int srcu_idx, ret; 484 struct dm_report_zones_args args = { 485 .next_sector = sector, 486 .orig_data = data, 487 .orig_cb = cb, 488 }; 489 490 if (dm_suspended_md(md)) 491 return -EAGAIN; 492 493 map = dm_get_live_table(md, &srcu_idx); 494 if (!map) 495 return -EIO; 496 497 do { 498 struct dm_target *tgt; 499 500 tgt = dm_table_find_target(map, args.next_sector); 501 if (WARN_ON_ONCE(!tgt->type->report_zones)) { 502 ret = -EIO; 503 goto out; 504 } 505 506 args.tgt = tgt; 507 ret = tgt->type->report_zones(tgt, &args, 508 nr_zones - args.zone_idx); 509 if (ret < 0) 510 goto out; 511 } while (args.zone_idx < nr_zones && 512 args.next_sector < get_capacity(disk)); 513 514 ret = args.zone_idx; 515 out: 516 dm_put_live_table(md, srcu_idx); 517 return ret; 518 } 519 #else 520 #define dm_blk_report_zones NULL 521 #endif /* CONFIG_BLK_DEV_ZONED */ 522 523 static int dm_prepare_ioctl(struct mapped_device *md, int *srcu_idx, 524 struct block_device **bdev) 525 __acquires(md->io_barrier) 526 { 527 struct dm_target *tgt; 528 struct dm_table *map; 529 int r; 530 531 retry: 532 r = -ENOTTY; 533 map = dm_get_live_table(md, srcu_idx); 534 if (!map || !dm_table_get_size(map)) 535 return r; 536 537 /* We only support devices that have a single target */ 538 if (dm_table_get_num_targets(map) != 1) 539 return r; 540 541 tgt = dm_table_get_target(map, 0); 542 if (!tgt->type->prepare_ioctl) 543 return r; 544 545 if (dm_suspended_md(md)) 546 return -EAGAIN; 547 548 r = tgt->type->prepare_ioctl(tgt, bdev); 549 if (r == -ENOTCONN && !fatal_signal_pending(current)) { 550 dm_put_live_table(md, *srcu_idx); 551 msleep(10); 552 goto retry; 553 } 554 555 return r; 556 } 557 558 static void dm_unprepare_ioctl(struct mapped_device *md, int srcu_idx) 559 __releases(md->io_barrier) 560 { 561 dm_put_live_table(md, srcu_idx); 562 } 563 564 static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode, 565 unsigned int cmd, unsigned long arg) 566 { 567 struct mapped_device *md = bdev->bd_disk->private_data; 568 int r, srcu_idx; 569 570 r = dm_prepare_ioctl(md, &srcu_idx, &bdev); 571 if (r < 0) 572 goto out; 573 574 if (r > 0) { 575 /* 576 * Target determined this ioctl is being issued against a 577 * subset of the parent bdev; require extra privileges. 578 */ 579 if (!capable(CAP_SYS_RAWIO)) { 580 DMWARN_LIMIT( 581 "%s: sending ioctl %x to DM device without required privilege.", 582 current->comm, cmd); 583 r = -ENOIOCTLCMD; 584 goto out; 585 } 586 } 587 588 r = __blkdev_driver_ioctl(bdev, mode, cmd, arg); 589 out: 590 dm_unprepare_ioctl(md, srcu_idx); 591 return r; 592 } 593 594 static void start_io_acct(struct dm_io *io); 595 596 static struct dm_io *alloc_io(struct mapped_device *md, struct bio *bio) 597 { 598 struct dm_io *io; 599 struct dm_target_io *tio; 600 struct bio *clone; 601 602 clone = bio_alloc_bioset(GFP_NOIO, 0, &md->io_bs); 603 if (!clone) 604 return NULL; 605 606 tio = container_of(clone, struct dm_target_io, clone); 607 tio->inside_dm_io = true; 608 tio->io = NULL; 609 610 io = container_of(tio, struct dm_io, tio); 611 io->magic = DM_IO_MAGIC; 612 io->status = 0; 613 atomic_set(&io->io_count, 1); 614 io->orig_bio = bio; 615 io->md = md; 616 spin_lock_init(&io->endio_lock); 617 618 start_io_acct(io); 619 620 return io; 621 } 622 623 static void free_io(struct mapped_device *md, struct dm_io *io) 624 { 625 bio_put(&io->tio.clone); 626 } 627 628 static struct dm_target_io *alloc_tio(struct clone_info *ci, struct dm_target *ti, 629 unsigned target_bio_nr, gfp_t gfp_mask) 630 { 631 struct dm_target_io *tio; 632 633 if (!ci->io->tio.io) { 634 /* the dm_target_io embedded in ci->io is available */ 635 tio = &ci->io->tio; 636 } else { 637 struct bio *clone = bio_alloc_bioset(gfp_mask, 0, &ci->io->md->bs); 638 if (!clone) 639 return NULL; 640 641 tio = container_of(clone, struct dm_target_io, clone); 642 tio->inside_dm_io = false; 643 } 644 645 tio->magic = DM_TIO_MAGIC; 646 tio->io = ci->io; 647 tio->ti = ti; 648 tio->target_bio_nr = target_bio_nr; 649 650 return tio; 651 } 652 653 static void free_tio(struct dm_target_io *tio) 654 { 655 if (tio->inside_dm_io) 656 return; 657 bio_put(&tio->clone); 658 } 659 660 u64 dm_start_time_ns_from_clone(struct bio *bio) 661 { 662 struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone); 663 struct dm_io *io = tio->io; 664 665 return jiffies_to_nsecs(io->start_time); 666 } 667 EXPORT_SYMBOL_GPL(dm_start_time_ns_from_clone); 668 669 static void start_io_acct(struct dm_io *io) 670 { 671 struct mapped_device *md = io->md; 672 struct bio *bio = io->orig_bio; 673 674 io->start_time = bio_start_io_acct(bio); 675 if (unlikely(dm_stats_used(&md->stats))) 676 dm_stats_account_io(&md->stats, bio_data_dir(bio), 677 bio->bi_iter.bi_sector, bio_sectors(bio), 678 false, 0, &io->stats_aux); 679 } 680 681 static void end_io_acct(struct dm_io *io) 682 { 683 struct mapped_device *md = io->md; 684 struct bio *bio = io->orig_bio; 685 unsigned long duration = jiffies - io->start_time; 686 687 bio_end_io_acct(bio, io->start_time); 688 689 if (unlikely(dm_stats_used(&md->stats))) 690 dm_stats_account_io(&md->stats, bio_data_dir(bio), 691 bio->bi_iter.bi_sector, bio_sectors(bio), 692 true, duration, &io->stats_aux); 693 694 /* nudge anyone waiting on suspend queue */ 695 if (unlikely(wq_has_sleeper(&md->wait))) 696 wake_up(&md->wait); 697 } 698 699 /* 700 * Add the bio to the list of deferred io. 701 */ 702 static void queue_io(struct mapped_device *md, struct bio *bio) 703 { 704 unsigned long flags; 705 706 spin_lock_irqsave(&md->deferred_lock, flags); 707 bio_list_add(&md->deferred, bio); 708 spin_unlock_irqrestore(&md->deferred_lock, flags); 709 queue_work(md->wq, &md->work); 710 } 711 712 /* 713 * Everyone (including functions in this file), should use this 714 * function to access the md->map field, and make sure they call 715 * dm_put_live_table() when finished. 716 */ 717 struct dm_table *dm_get_live_table(struct mapped_device *md, int *srcu_idx) __acquires(md->io_barrier) 718 { 719 *srcu_idx = srcu_read_lock(&md->io_barrier); 720 721 return srcu_dereference(md->map, &md->io_barrier); 722 } 723 724 void dm_put_live_table(struct mapped_device *md, int srcu_idx) __releases(md->io_barrier) 725 { 726 srcu_read_unlock(&md->io_barrier, srcu_idx); 727 } 728 729 void dm_sync_table(struct mapped_device *md) 730 { 731 synchronize_srcu(&md->io_barrier); 732 synchronize_rcu_expedited(); 733 } 734 735 /* 736 * A fast alternative to dm_get_live_table/dm_put_live_table. 737 * The caller must not block between these two functions. 738 */ 739 static struct dm_table *dm_get_live_table_fast(struct mapped_device *md) __acquires(RCU) 740 { 741 rcu_read_lock(); 742 return rcu_dereference(md->map); 743 } 744 745 static void dm_put_live_table_fast(struct mapped_device *md) __releases(RCU) 746 { 747 rcu_read_unlock(); 748 } 749 750 static char *_dm_claim_ptr = "I belong to device-mapper"; 751 752 /* 753 * Open a table device so we can use it as a map destination. 754 */ 755 static int open_table_device(struct table_device *td, dev_t dev, 756 struct mapped_device *md) 757 { 758 struct block_device *bdev; 759 760 int r; 761 762 BUG_ON(td->dm_dev.bdev); 763 764 bdev = blkdev_get_by_dev(dev, td->dm_dev.mode | FMODE_EXCL, _dm_claim_ptr); 765 if (IS_ERR(bdev)) 766 return PTR_ERR(bdev); 767 768 r = bd_link_disk_holder(bdev, dm_disk(md)); 769 if (r) { 770 blkdev_put(bdev, td->dm_dev.mode | FMODE_EXCL); 771 return r; 772 } 773 774 td->dm_dev.bdev = bdev; 775 td->dm_dev.dax_dev = dax_get_by_host(bdev->bd_disk->disk_name); 776 return 0; 777 } 778 779 /* 780 * Close a table device that we've been using. 781 */ 782 static void close_table_device(struct table_device *td, struct mapped_device *md) 783 { 784 if (!td->dm_dev.bdev) 785 return; 786 787 bd_unlink_disk_holder(td->dm_dev.bdev, dm_disk(md)); 788 blkdev_put(td->dm_dev.bdev, td->dm_dev.mode | FMODE_EXCL); 789 put_dax(td->dm_dev.dax_dev); 790 td->dm_dev.bdev = NULL; 791 td->dm_dev.dax_dev = NULL; 792 } 793 794 static struct table_device *find_table_device(struct list_head *l, dev_t dev, 795 fmode_t mode) 796 { 797 struct table_device *td; 798 799 list_for_each_entry(td, l, list) 800 if (td->dm_dev.bdev->bd_dev == dev && td->dm_dev.mode == mode) 801 return td; 802 803 return NULL; 804 } 805 806 int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode, 807 struct dm_dev **result) 808 { 809 int r; 810 struct table_device *td; 811 812 mutex_lock(&md->table_devices_lock); 813 td = find_table_device(&md->table_devices, dev, mode); 814 if (!td) { 815 td = kmalloc_node(sizeof(*td), GFP_KERNEL, md->numa_node_id); 816 if (!td) { 817 mutex_unlock(&md->table_devices_lock); 818 return -ENOMEM; 819 } 820 821 td->dm_dev.mode = mode; 822 td->dm_dev.bdev = NULL; 823 824 if ((r = open_table_device(td, dev, md))) { 825 mutex_unlock(&md->table_devices_lock); 826 kfree(td); 827 return r; 828 } 829 830 format_dev_t(td->dm_dev.name, dev); 831 832 refcount_set(&td->count, 1); 833 list_add(&td->list, &md->table_devices); 834 } else { 835 refcount_inc(&td->count); 836 } 837 mutex_unlock(&md->table_devices_lock); 838 839 *result = &td->dm_dev; 840 return 0; 841 } 842 EXPORT_SYMBOL_GPL(dm_get_table_device); 843 844 void dm_put_table_device(struct mapped_device *md, struct dm_dev *d) 845 { 846 struct table_device *td = container_of(d, struct table_device, dm_dev); 847 848 mutex_lock(&md->table_devices_lock); 849 if (refcount_dec_and_test(&td->count)) { 850 close_table_device(td, md); 851 list_del(&td->list); 852 kfree(td); 853 } 854 mutex_unlock(&md->table_devices_lock); 855 } 856 EXPORT_SYMBOL(dm_put_table_device); 857 858 static void free_table_devices(struct list_head *devices) 859 { 860 struct list_head *tmp, *next; 861 862 list_for_each_safe(tmp, next, devices) { 863 struct table_device *td = list_entry(tmp, struct table_device, list); 864 865 DMWARN("dm_destroy: %s still exists with %d references", 866 td->dm_dev.name, refcount_read(&td->count)); 867 kfree(td); 868 } 869 } 870 871 /* 872 * Get the geometry associated with a dm device 873 */ 874 int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo) 875 { 876 *geo = md->geometry; 877 878 return 0; 879 } 880 881 /* 882 * Set the geometry of a device. 883 */ 884 int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo) 885 { 886 sector_t sz = (sector_t)geo->cylinders * geo->heads * geo->sectors; 887 888 if (geo->start > sz) { 889 DMWARN("Start sector is beyond the geometry limits."); 890 return -EINVAL; 891 } 892 893 md->geometry = *geo; 894 895 return 0; 896 } 897 898 static int __noflush_suspending(struct mapped_device *md) 899 { 900 return test_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); 901 } 902 903 /* 904 * Decrements the number of outstanding ios that a bio has been 905 * cloned into, completing the original io if necc. 906 */ 907 static void dec_pending(struct dm_io *io, blk_status_t error) 908 { 909 unsigned long flags; 910 blk_status_t io_error; 911 struct bio *bio; 912 struct mapped_device *md = io->md; 913 914 /* Push-back supersedes any I/O errors */ 915 if (unlikely(error)) { 916 spin_lock_irqsave(&io->endio_lock, flags); 917 if (!(io->status == BLK_STS_DM_REQUEUE && __noflush_suspending(md))) 918 io->status = error; 919 spin_unlock_irqrestore(&io->endio_lock, flags); 920 } 921 922 if (atomic_dec_and_test(&io->io_count)) { 923 if (io->status == BLK_STS_DM_REQUEUE) { 924 /* 925 * Target requested pushing back the I/O. 926 */ 927 spin_lock_irqsave(&md->deferred_lock, flags); 928 if (__noflush_suspending(md)) 929 /* NOTE early return due to BLK_STS_DM_REQUEUE below */ 930 bio_list_add_head(&md->deferred, io->orig_bio); 931 else 932 /* noflush suspend was interrupted. */ 933 io->status = BLK_STS_IOERR; 934 spin_unlock_irqrestore(&md->deferred_lock, flags); 935 } 936 937 io_error = io->status; 938 bio = io->orig_bio; 939 end_io_acct(io); 940 free_io(md, io); 941 942 if (io_error == BLK_STS_DM_REQUEUE) 943 return; 944 945 if ((bio->bi_opf & REQ_PREFLUSH) && bio->bi_iter.bi_size) { 946 /* 947 * Preflush done for flush with data, reissue 948 * without REQ_PREFLUSH. 949 */ 950 bio->bi_opf &= ~REQ_PREFLUSH; 951 queue_io(md, bio); 952 } else { 953 /* done with normal IO or empty flush */ 954 if (io_error) 955 bio->bi_status = io_error; 956 bio_endio(bio); 957 } 958 } 959 } 960 961 void disable_discard(struct mapped_device *md) 962 { 963 struct queue_limits *limits = dm_get_queue_limits(md); 964 965 /* device doesn't really support DISCARD, disable it */ 966 limits->max_discard_sectors = 0; 967 blk_queue_flag_clear(QUEUE_FLAG_DISCARD, md->queue); 968 } 969 970 void disable_write_same(struct mapped_device *md) 971 { 972 struct queue_limits *limits = dm_get_queue_limits(md); 973 974 /* device doesn't really support WRITE SAME, disable it */ 975 limits->max_write_same_sectors = 0; 976 } 977 978 void disable_write_zeroes(struct mapped_device *md) 979 { 980 struct queue_limits *limits = dm_get_queue_limits(md); 981 982 /* device doesn't really support WRITE ZEROES, disable it */ 983 limits->max_write_zeroes_sectors = 0; 984 } 985 986 static void clone_endio(struct bio *bio) 987 { 988 blk_status_t error = bio->bi_status; 989 struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone); 990 struct dm_io *io = tio->io; 991 struct mapped_device *md = tio->io->md; 992 dm_endio_fn endio = tio->ti->type->end_io; 993 struct bio *orig_bio = io->orig_bio; 994 995 if (unlikely(error == BLK_STS_TARGET) && md->type != DM_TYPE_NVME_BIO_BASED) { 996 if (bio_op(bio) == REQ_OP_DISCARD && 997 !bio->bi_disk->queue->limits.max_discard_sectors) 998 disable_discard(md); 999 else if (bio_op(bio) == REQ_OP_WRITE_SAME && 1000 !bio->bi_disk->queue->limits.max_write_same_sectors) 1001 disable_write_same(md); 1002 else if (bio_op(bio) == REQ_OP_WRITE_ZEROES && 1003 !bio->bi_disk->queue->limits.max_write_zeroes_sectors) 1004 disable_write_zeroes(md); 1005 } 1006 1007 /* 1008 * For zone-append bios get offset in zone of the written 1009 * sector and add that to the original bio sector pos. 1010 */ 1011 if (bio_op(orig_bio) == REQ_OP_ZONE_APPEND) { 1012 sector_t written_sector = bio->bi_iter.bi_sector; 1013 struct request_queue *q = orig_bio->bi_disk->queue; 1014 u64 mask = (u64)blk_queue_zone_sectors(q) - 1; 1015 1016 orig_bio->bi_iter.bi_sector += written_sector & mask; 1017 } 1018 1019 if (endio) { 1020 int r = endio(tio->ti, bio, &error); 1021 switch (r) { 1022 case DM_ENDIO_REQUEUE: 1023 error = BLK_STS_DM_REQUEUE; 1024 fallthrough; 1025 case DM_ENDIO_DONE: 1026 break; 1027 case DM_ENDIO_INCOMPLETE: 1028 /* The target will handle the io */ 1029 return; 1030 default: 1031 DMWARN("unimplemented target endio return value: %d", r); 1032 BUG(); 1033 } 1034 } 1035 1036 free_tio(tio); 1037 dec_pending(io, error); 1038 } 1039 1040 /* 1041 * Return maximum size of I/O possible at the supplied sector up to the current 1042 * target boundary. 1043 */ 1044 static sector_t max_io_len_target_boundary(sector_t sector, struct dm_target *ti) 1045 { 1046 sector_t target_offset = dm_target_offset(ti, sector); 1047 1048 return ti->len - target_offset; 1049 } 1050 1051 static sector_t max_io_len(sector_t sector, struct dm_target *ti) 1052 { 1053 sector_t len = max_io_len_target_boundary(sector, ti); 1054 sector_t offset, max_len; 1055 1056 /* 1057 * Does the target need to split even further? 1058 */ 1059 if (ti->max_io_len) { 1060 offset = dm_target_offset(ti, sector); 1061 if (unlikely(ti->max_io_len & (ti->max_io_len - 1))) 1062 max_len = sector_div(offset, ti->max_io_len); 1063 else 1064 max_len = offset & (ti->max_io_len - 1); 1065 max_len = ti->max_io_len - max_len; 1066 1067 if (len > max_len) 1068 len = max_len; 1069 } 1070 1071 return len; 1072 } 1073 1074 int dm_set_target_max_io_len(struct dm_target *ti, sector_t len) 1075 { 1076 if (len > UINT_MAX) { 1077 DMERR("Specified maximum size of target IO (%llu) exceeds limit (%u)", 1078 (unsigned long long)len, UINT_MAX); 1079 ti->error = "Maximum size of target IO is too large"; 1080 return -EINVAL; 1081 } 1082 1083 ti->max_io_len = (uint32_t) len; 1084 1085 return 0; 1086 } 1087 EXPORT_SYMBOL_GPL(dm_set_target_max_io_len); 1088 1089 static struct dm_target *dm_dax_get_live_target(struct mapped_device *md, 1090 sector_t sector, int *srcu_idx) 1091 __acquires(md->io_barrier) 1092 { 1093 struct dm_table *map; 1094 struct dm_target *ti; 1095 1096 map = dm_get_live_table(md, srcu_idx); 1097 if (!map) 1098 return NULL; 1099 1100 ti = dm_table_find_target(map, sector); 1101 if (!ti) 1102 return NULL; 1103 1104 return ti; 1105 } 1106 1107 static long dm_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, 1108 long nr_pages, void **kaddr, pfn_t *pfn) 1109 { 1110 struct mapped_device *md = dax_get_private(dax_dev); 1111 sector_t sector = pgoff * PAGE_SECTORS; 1112 struct dm_target *ti; 1113 long len, ret = -EIO; 1114 int srcu_idx; 1115 1116 ti = dm_dax_get_live_target(md, sector, &srcu_idx); 1117 1118 if (!ti) 1119 goto out; 1120 if (!ti->type->direct_access) 1121 goto out; 1122 len = max_io_len(sector, ti) / PAGE_SECTORS; 1123 if (len < 1) 1124 goto out; 1125 nr_pages = min(len, nr_pages); 1126 ret = ti->type->direct_access(ti, pgoff, nr_pages, kaddr, pfn); 1127 1128 out: 1129 dm_put_live_table(md, srcu_idx); 1130 1131 return ret; 1132 } 1133 1134 static bool dm_dax_supported(struct dax_device *dax_dev, struct block_device *bdev, 1135 int blocksize, sector_t start, sector_t len) 1136 { 1137 struct mapped_device *md = dax_get_private(dax_dev); 1138 struct dm_table *map; 1139 int srcu_idx; 1140 bool ret; 1141 1142 map = dm_get_live_table(md, &srcu_idx); 1143 if (!map) 1144 return false; 1145 1146 ret = dm_table_supports_dax(map, device_supports_dax, &blocksize); 1147 1148 dm_put_live_table(md, srcu_idx); 1149 1150 return ret; 1151 } 1152 1153 static size_t dm_dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, 1154 void *addr, size_t bytes, struct iov_iter *i) 1155 { 1156 struct mapped_device *md = dax_get_private(dax_dev); 1157 sector_t sector = pgoff * PAGE_SECTORS; 1158 struct dm_target *ti; 1159 long ret = 0; 1160 int srcu_idx; 1161 1162 ti = dm_dax_get_live_target(md, sector, &srcu_idx); 1163 1164 if (!ti) 1165 goto out; 1166 if (!ti->type->dax_copy_from_iter) { 1167 ret = copy_from_iter(addr, bytes, i); 1168 goto out; 1169 } 1170 ret = ti->type->dax_copy_from_iter(ti, pgoff, addr, bytes, i); 1171 out: 1172 dm_put_live_table(md, srcu_idx); 1173 1174 return ret; 1175 } 1176 1177 static size_t dm_dax_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff, 1178 void *addr, size_t bytes, struct iov_iter *i) 1179 { 1180 struct mapped_device *md = dax_get_private(dax_dev); 1181 sector_t sector = pgoff * PAGE_SECTORS; 1182 struct dm_target *ti; 1183 long ret = 0; 1184 int srcu_idx; 1185 1186 ti = dm_dax_get_live_target(md, sector, &srcu_idx); 1187 1188 if (!ti) 1189 goto out; 1190 if (!ti->type->dax_copy_to_iter) { 1191 ret = copy_to_iter(addr, bytes, i); 1192 goto out; 1193 } 1194 ret = ti->type->dax_copy_to_iter(ti, pgoff, addr, bytes, i); 1195 out: 1196 dm_put_live_table(md, srcu_idx); 1197 1198 return ret; 1199 } 1200 1201 static int dm_dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff, 1202 size_t nr_pages) 1203 { 1204 struct mapped_device *md = dax_get_private(dax_dev); 1205 sector_t sector = pgoff * PAGE_SECTORS; 1206 struct dm_target *ti; 1207 int ret = -EIO; 1208 int srcu_idx; 1209 1210 ti = dm_dax_get_live_target(md, sector, &srcu_idx); 1211 1212 if (!ti) 1213 goto out; 1214 if (WARN_ON(!ti->type->dax_zero_page_range)) { 1215 /* 1216 * ->zero_page_range() is mandatory dax operation. If we are 1217 * here, something is wrong. 1218 */ 1219 dm_put_live_table(md, srcu_idx); 1220 goto out; 1221 } 1222 ret = ti->type->dax_zero_page_range(ti, pgoff, nr_pages); 1223 1224 out: 1225 dm_put_live_table(md, srcu_idx); 1226 1227 return ret; 1228 } 1229 1230 /* 1231 * A target may call dm_accept_partial_bio only from the map routine. It is 1232 * allowed for all bio types except REQ_PREFLUSH, REQ_OP_ZONE_RESET, 1233 * REQ_OP_ZONE_OPEN, REQ_OP_ZONE_CLOSE and REQ_OP_ZONE_FINISH. 1234 * 1235 * dm_accept_partial_bio informs the dm that the target only wants to process 1236 * additional n_sectors sectors of the bio and the rest of the data should be 1237 * sent in a next bio. 1238 * 1239 * A diagram that explains the arithmetics: 1240 * +--------------------+---------------+-------+ 1241 * | 1 | 2 | 3 | 1242 * +--------------------+---------------+-------+ 1243 * 1244 * <-------------- *tio->len_ptr ---------------> 1245 * <------- bi_size -------> 1246 * <-- n_sectors --> 1247 * 1248 * Region 1 was already iterated over with bio_advance or similar function. 1249 * (it may be empty if the target doesn't use bio_advance) 1250 * Region 2 is the remaining bio size that the target wants to process. 1251 * (it may be empty if region 1 is non-empty, although there is no reason 1252 * to make it empty) 1253 * The target requires that region 3 is to be sent in the next bio. 1254 * 1255 * If the target wants to receive multiple copies of the bio (via num_*bios, etc), 1256 * the partially processed part (the sum of regions 1+2) must be the same for all 1257 * copies of the bio. 1258 */ 1259 void dm_accept_partial_bio(struct bio *bio, unsigned n_sectors) 1260 { 1261 struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone); 1262 unsigned bi_size = bio->bi_iter.bi_size >> SECTOR_SHIFT; 1263 BUG_ON(bio->bi_opf & REQ_PREFLUSH); 1264 BUG_ON(bi_size > *tio->len_ptr); 1265 BUG_ON(n_sectors > bi_size); 1266 *tio->len_ptr -= bi_size - n_sectors; 1267 bio->bi_iter.bi_size = n_sectors << SECTOR_SHIFT; 1268 } 1269 EXPORT_SYMBOL_GPL(dm_accept_partial_bio); 1270 1271 static blk_qc_t __map_bio(struct dm_target_io *tio) 1272 { 1273 int r; 1274 sector_t sector; 1275 struct bio *clone = &tio->clone; 1276 struct dm_io *io = tio->io; 1277 struct dm_target *ti = tio->ti; 1278 blk_qc_t ret = BLK_QC_T_NONE; 1279 1280 clone->bi_end_io = clone_endio; 1281 1282 /* 1283 * Map the clone. If r == 0 we don't need to do 1284 * anything, the target has assumed ownership of 1285 * this io. 1286 */ 1287 atomic_inc(&io->io_count); 1288 sector = clone->bi_iter.bi_sector; 1289 1290 r = ti->type->map(ti, clone); 1291 switch (r) { 1292 case DM_MAPIO_SUBMITTED: 1293 break; 1294 case DM_MAPIO_REMAPPED: 1295 /* the bio has been remapped so dispatch it */ 1296 trace_block_bio_remap(clone->bi_disk->queue, clone, 1297 bio_dev(io->orig_bio), sector); 1298 ret = submit_bio_noacct(clone); 1299 break; 1300 case DM_MAPIO_KILL: 1301 free_tio(tio); 1302 dec_pending(io, BLK_STS_IOERR); 1303 break; 1304 case DM_MAPIO_REQUEUE: 1305 free_tio(tio); 1306 dec_pending(io, BLK_STS_DM_REQUEUE); 1307 break; 1308 default: 1309 DMWARN("unimplemented target map return value: %d", r); 1310 BUG(); 1311 } 1312 1313 return ret; 1314 } 1315 1316 static void bio_setup_sector(struct bio *bio, sector_t sector, unsigned len) 1317 { 1318 bio->bi_iter.bi_sector = sector; 1319 bio->bi_iter.bi_size = to_bytes(len); 1320 } 1321 1322 /* 1323 * Creates a bio that consists of range of complete bvecs. 1324 */ 1325 static int clone_bio(struct dm_target_io *tio, struct bio *bio, 1326 sector_t sector, unsigned len) 1327 { 1328 struct bio *clone = &tio->clone; 1329 int r; 1330 1331 __bio_clone_fast(clone, bio); 1332 1333 r = bio_crypt_clone(clone, bio, GFP_NOIO); 1334 if (r < 0) 1335 return r; 1336 1337 if (bio_integrity(bio)) { 1338 if (unlikely(!dm_target_has_integrity(tio->ti->type) && 1339 !dm_target_passes_integrity(tio->ti->type))) { 1340 DMWARN("%s: the target %s doesn't support integrity data.", 1341 dm_device_name(tio->io->md), 1342 tio->ti->type->name); 1343 return -EIO; 1344 } 1345 1346 r = bio_integrity_clone(clone, bio, GFP_NOIO); 1347 if (r < 0) 1348 return r; 1349 } 1350 1351 bio_advance(clone, to_bytes(sector - clone->bi_iter.bi_sector)); 1352 clone->bi_iter.bi_size = to_bytes(len); 1353 1354 if (bio_integrity(bio)) 1355 bio_integrity_trim(clone); 1356 1357 return 0; 1358 } 1359 1360 static void alloc_multiple_bios(struct bio_list *blist, struct clone_info *ci, 1361 struct dm_target *ti, unsigned num_bios) 1362 { 1363 struct dm_target_io *tio; 1364 int try; 1365 1366 if (!num_bios) 1367 return; 1368 1369 if (num_bios == 1) { 1370 tio = alloc_tio(ci, ti, 0, GFP_NOIO); 1371 bio_list_add(blist, &tio->clone); 1372 return; 1373 } 1374 1375 for (try = 0; try < 2; try++) { 1376 int bio_nr; 1377 struct bio *bio; 1378 1379 if (try) 1380 mutex_lock(&ci->io->md->table_devices_lock); 1381 for (bio_nr = 0; bio_nr < num_bios; bio_nr++) { 1382 tio = alloc_tio(ci, ti, bio_nr, try ? GFP_NOIO : GFP_NOWAIT); 1383 if (!tio) 1384 break; 1385 1386 bio_list_add(blist, &tio->clone); 1387 } 1388 if (try) 1389 mutex_unlock(&ci->io->md->table_devices_lock); 1390 if (bio_nr == num_bios) 1391 return; 1392 1393 while ((bio = bio_list_pop(blist))) { 1394 tio = container_of(bio, struct dm_target_io, clone); 1395 free_tio(tio); 1396 } 1397 } 1398 } 1399 1400 static blk_qc_t __clone_and_map_simple_bio(struct clone_info *ci, 1401 struct dm_target_io *tio, unsigned *len) 1402 { 1403 struct bio *clone = &tio->clone; 1404 1405 tio->len_ptr = len; 1406 1407 __bio_clone_fast(clone, ci->bio); 1408 if (len) 1409 bio_setup_sector(clone, ci->sector, *len); 1410 1411 return __map_bio(tio); 1412 } 1413 1414 static void __send_duplicate_bios(struct clone_info *ci, struct dm_target *ti, 1415 unsigned num_bios, unsigned *len) 1416 { 1417 struct bio_list blist = BIO_EMPTY_LIST; 1418 struct bio *bio; 1419 struct dm_target_io *tio; 1420 1421 alloc_multiple_bios(&blist, ci, ti, num_bios); 1422 1423 while ((bio = bio_list_pop(&blist))) { 1424 tio = container_of(bio, struct dm_target_io, clone); 1425 (void) __clone_and_map_simple_bio(ci, tio, len); 1426 } 1427 } 1428 1429 static int __send_empty_flush(struct clone_info *ci) 1430 { 1431 unsigned target_nr = 0; 1432 struct dm_target *ti; 1433 1434 /* 1435 * Empty flush uses a statically initialized bio, as the base for 1436 * cloning. However, blkg association requires that a bdev is 1437 * associated with a gendisk, which doesn't happen until the bdev is 1438 * opened. So, blkg association is done at issue time of the flush 1439 * rather than when the device is created in alloc_dev(). 1440 */ 1441 bio_set_dev(ci->bio, ci->io->md->bdev); 1442 1443 BUG_ON(bio_has_data(ci->bio)); 1444 while ((ti = dm_table_get_target(ci->map, target_nr++))) 1445 __send_duplicate_bios(ci, ti, ti->num_flush_bios, NULL); 1446 return 0; 1447 } 1448 1449 static int __clone_and_map_data_bio(struct clone_info *ci, struct dm_target *ti, 1450 sector_t sector, unsigned *len) 1451 { 1452 struct bio *bio = ci->bio; 1453 struct dm_target_io *tio; 1454 int r; 1455 1456 tio = alloc_tio(ci, ti, 0, GFP_NOIO); 1457 tio->len_ptr = len; 1458 r = clone_bio(tio, bio, sector, *len); 1459 if (r < 0) { 1460 free_tio(tio); 1461 return r; 1462 } 1463 (void) __map_bio(tio); 1464 1465 return 0; 1466 } 1467 1468 typedef unsigned (*get_num_bios_fn)(struct dm_target *ti); 1469 1470 static unsigned get_num_discard_bios(struct dm_target *ti) 1471 { 1472 return ti->num_discard_bios; 1473 } 1474 1475 static unsigned get_num_secure_erase_bios(struct dm_target *ti) 1476 { 1477 return ti->num_secure_erase_bios; 1478 } 1479 1480 static unsigned get_num_write_same_bios(struct dm_target *ti) 1481 { 1482 return ti->num_write_same_bios; 1483 } 1484 1485 static unsigned get_num_write_zeroes_bios(struct dm_target *ti) 1486 { 1487 return ti->num_write_zeroes_bios; 1488 } 1489 1490 static int __send_changing_extent_only(struct clone_info *ci, struct dm_target *ti, 1491 unsigned num_bios) 1492 { 1493 unsigned len; 1494 1495 /* 1496 * Even though the device advertised support for this type of 1497 * request, that does not mean every target supports it, and 1498 * reconfiguration might also have changed that since the 1499 * check was performed. 1500 */ 1501 if (!num_bios) 1502 return -EOPNOTSUPP; 1503 1504 len = min((sector_t)ci->sector_count, max_io_len_target_boundary(ci->sector, ti)); 1505 1506 __send_duplicate_bios(ci, ti, num_bios, &len); 1507 1508 ci->sector += len; 1509 ci->sector_count -= len; 1510 1511 return 0; 1512 } 1513 1514 static int __send_discard(struct clone_info *ci, struct dm_target *ti) 1515 { 1516 return __send_changing_extent_only(ci, ti, get_num_discard_bios(ti)); 1517 } 1518 1519 static int __send_secure_erase(struct clone_info *ci, struct dm_target *ti) 1520 { 1521 return __send_changing_extent_only(ci, ti, get_num_secure_erase_bios(ti)); 1522 } 1523 1524 static int __send_write_same(struct clone_info *ci, struct dm_target *ti) 1525 { 1526 return __send_changing_extent_only(ci, ti, get_num_write_same_bios(ti)); 1527 } 1528 1529 static int __send_write_zeroes(struct clone_info *ci, struct dm_target *ti) 1530 { 1531 return __send_changing_extent_only(ci, ti, get_num_write_zeroes_bios(ti)); 1532 } 1533 1534 static bool is_abnormal_io(struct bio *bio) 1535 { 1536 bool r = false; 1537 1538 switch (bio_op(bio)) { 1539 case REQ_OP_DISCARD: 1540 case REQ_OP_SECURE_ERASE: 1541 case REQ_OP_WRITE_SAME: 1542 case REQ_OP_WRITE_ZEROES: 1543 r = true; 1544 break; 1545 } 1546 1547 return r; 1548 } 1549 1550 static bool __process_abnormal_io(struct clone_info *ci, struct dm_target *ti, 1551 int *result) 1552 { 1553 struct bio *bio = ci->bio; 1554 1555 if (bio_op(bio) == REQ_OP_DISCARD) 1556 *result = __send_discard(ci, ti); 1557 else if (bio_op(bio) == REQ_OP_SECURE_ERASE) 1558 *result = __send_secure_erase(ci, ti); 1559 else if (bio_op(bio) == REQ_OP_WRITE_SAME) 1560 *result = __send_write_same(ci, ti); 1561 else if (bio_op(bio) == REQ_OP_WRITE_ZEROES) 1562 *result = __send_write_zeroes(ci, ti); 1563 else 1564 return false; 1565 1566 return true; 1567 } 1568 1569 /* 1570 * Select the correct strategy for processing a non-flush bio. 1571 */ 1572 static int __split_and_process_non_flush(struct clone_info *ci) 1573 { 1574 struct dm_target *ti; 1575 unsigned len; 1576 int r; 1577 1578 ti = dm_table_find_target(ci->map, ci->sector); 1579 if (!ti) 1580 return -EIO; 1581 1582 if (__process_abnormal_io(ci, ti, &r)) 1583 return r; 1584 1585 len = min_t(sector_t, max_io_len(ci->sector, ti), ci->sector_count); 1586 1587 r = __clone_and_map_data_bio(ci, ti, ci->sector, &len); 1588 if (r < 0) 1589 return r; 1590 1591 ci->sector += len; 1592 ci->sector_count -= len; 1593 1594 return 0; 1595 } 1596 1597 static void init_clone_info(struct clone_info *ci, struct mapped_device *md, 1598 struct dm_table *map, struct bio *bio) 1599 { 1600 ci->map = map; 1601 ci->io = alloc_io(md, bio); 1602 ci->sector = bio->bi_iter.bi_sector; 1603 } 1604 1605 #define __dm_part_stat_sub(part, field, subnd) \ 1606 (part_stat_get(part, field) -= (subnd)) 1607 1608 /* 1609 * Entry point to split a bio into clones and submit them to the targets. 1610 */ 1611 static blk_qc_t __split_and_process_bio(struct mapped_device *md, 1612 struct dm_table *map, struct bio *bio) 1613 { 1614 struct clone_info ci; 1615 blk_qc_t ret = BLK_QC_T_NONE; 1616 int error = 0; 1617 1618 init_clone_info(&ci, md, map, bio); 1619 1620 if (bio->bi_opf & REQ_PREFLUSH) { 1621 struct bio flush_bio; 1622 1623 /* 1624 * Use an on-stack bio for this, it's safe since we don't 1625 * need to reference it after submit. It's just used as 1626 * the basis for the clone(s). 1627 */ 1628 bio_init(&flush_bio, NULL, 0); 1629 flush_bio.bi_opf = REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC; 1630 ci.bio = &flush_bio; 1631 ci.sector_count = 0; 1632 error = __send_empty_flush(&ci); 1633 bio_uninit(ci.bio); 1634 /* dec_pending submits any data associated with flush */ 1635 } else if (op_is_zone_mgmt(bio_op(bio))) { 1636 ci.bio = bio; 1637 ci.sector_count = 0; 1638 error = __split_and_process_non_flush(&ci); 1639 } else { 1640 ci.bio = bio; 1641 ci.sector_count = bio_sectors(bio); 1642 while (ci.sector_count && !error) { 1643 error = __split_and_process_non_flush(&ci); 1644 if (current->bio_list && ci.sector_count && !error) { 1645 /* 1646 * Remainder must be passed to submit_bio_noacct() 1647 * so that it gets handled *after* bios already submitted 1648 * have been completely processed. 1649 * We take a clone of the original to store in 1650 * ci.io->orig_bio to be used by end_io_acct() and 1651 * for dec_pending to use for completion handling. 1652 */ 1653 struct bio *b = bio_split(bio, bio_sectors(bio) - ci.sector_count, 1654 GFP_NOIO, &md->queue->bio_split); 1655 ci.io->orig_bio = b; 1656 1657 /* 1658 * Adjust IO stats for each split, otherwise upon queue 1659 * reentry there will be redundant IO accounting. 1660 * NOTE: this is a stop-gap fix, a proper fix involves 1661 * significant refactoring of DM core's bio splitting 1662 * (by eliminating DM's splitting and just using bio_split) 1663 */ 1664 part_stat_lock(); 1665 __dm_part_stat_sub(&dm_disk(md)->part0, 1666 sectors[op_stat_group(bio_op(bio))], ci.sector_count); 1667 part_stat_unlock(); 1668 1669 bio_chain(b, bio); 1670 trace_block_split(md->queue, b, bio->bi_iter.bi_sector); 1671 ret = submit_bio_noacct(bio); 1672 break; 1673 } 1674 } 1675 } 1676 1677 /* drop the extra reference count */ 1678 dec_pending(ci.io, errno_to_blk_status(error)); 1679 return ret; 1680 } 1681 1682 /* 1683 * Optimized variant of __split_and_process_bio that leverages the 1684 * fact that targets that use it do _not_ have a need to split bios. 1685 */ 1686 static blk_qc_t __process_bio(struct mapped_device *md, struct dm_table *map, 1687 struct bio *bio, struct dm_target *ti) 1688 { 1689 struct clone_info ci; 1690 blk_qc_t ret = BLK_QC_T_NONE; 1691 int error = 0; 1692 1693 init_clone_info(&ci, md, map, bio); 1694 1695 if (bio->bi_opf & REQ_PREFLUSH) { 1696 struct bio flush_bio; 1697 1698 /* 1699 * Use an on-stack bio for this, it's safe since we don't 1700 * need to reference it after submit. It's just used as 1701 * the basis for the clone(s). 1702 */ 1703 bio_init(&flush_bio, NULL, 0); 1704 flush_bio.bi_opf = REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC; 1705 ci.bio = &flush_bio; 1706 ci.sector_count = 0; 1707 error = __send_empty_flush(&ci); 1708 bio_uninit(ci.bio); 1709 /* dec_pending submits any data associated with flush */ 1710 } else { 1711 struct dm_target_io *tio; 1712 1713 ci.bio = bio; 1714 ci.sector_count = bio_sectors(bio); 1715 if (__process_abnormal_io(&ci, ti, &error)) 1716 goto out; 1717 1718 tio = alloc_tio(&ci, ti, 0, GFP_NOIO); 1719 ret = __clone_and_map_simple_bio(&ci, tio, NULL); 1720 } 1721 out: 1722 /* drop the extra reference count */ 1723 dec_pending(ci.io, errno_to_blk_status(error)); 1724 return ret; 1725 } 1726 1727 static void dm_queue_split(struct mapped_device *md, struct dm_target *ti, struct bio **bio) 1728 { 1729 unsigned len, sector_count; 1730 1731 sector_count = bio_sectors(*bio); 1732 len = min_t(sector_t, max_io_len((*bio)->bi_iter.bi_sector, ti), sector_count); 1733 1734 if (sector_count > len) { 1735 struct bio *split = bio_split(*bio, len, GFP_NOIO, &md->queue->bio_split); 1736 1737 bio_chain(split, *bio); 1738 trace_block_split(md->queue, split, (*bio)->bi_iter.bi_sector); 1739 submit_bio_noacct(*bio); 1740 *bio = split; 1741 } 1742 } 1743 1744 static blk_qc_t dm_process_bio(struct mapped_device *md, 1745 struct dm_table *map, struct bio *bio) 1746 { 1747 blk_qc_t ret = BLK_QC_T_NONE; 1748 struct dm_target *ti = md->immutable_target; 1749 1750 if (unlikely(!map)) { 1751 bio_io_error(bio); 1752 return ret; 1753 } 1754 1755 if (!ti) { 1756 ti = dm_table_find_target(map, bio->bi_iter.bi_sector); 1757 if (unlikely(!ti)) { 1758 bio_io_error(bio); 1759 return ret; 1760 } 1761 } 1762 1763 /* 1764 * If in ->queue_bio we need to use blk_queue_split(), otherwise 1765 * queue_limits for abnormal requests (e.g. discard, writesame, etc) 1766 * won't be imposed. 1767 */ 1768 if (current->bio_list) { 1769 if (is_abnormal_io(bio)) 1770 blk_queue_split(&bio); 1771 else 1772 dm_queue_split(md, ti, &bio); 1773 } 1774 1775 if (dm_get_md_type(md) == DM_TYPE_NVME_BIO_BASED) 1776 return __process_bio(md, map, bio, ti); 1777 else 1778 return __split_and_process_bio(md, map, bio); 1779 } 1780 1781 static blk_qc_t dm_submit_bio(struct bio *bio) 1782 { 1783 struct mapped_device *md = bio->bi_disk->private_data; 1784 blk_qc_t ret = BLK_QC_T_NONE; 1785 int srcu_idx; 1786 struct dm_table *map; 1787 1788 if (dm_get_md_type(md) == DM_TYPE_REQUEST_BASED) { 1789 /* 1790 * We are called with a live reference on q_usage_counter, but 1791 * that one will be released as soon as we return. Grab an 1792 * extra one as blk_mq_submit_bio expects to be able to consume 1793 * a reference (which lives until the request is freed in case a 1794 * request is allocated). 1795 */ 1796 percpu_ref_get(&bio->bi_disk->queue->q_usage_counter); 1797 return blk_mq_submit_bio(bio); 1798 } 1799 1800 map = dm_get_live_table(md, &srcu_idx); 1801 1802 /* if we're suspended, we have to queue this io for later */ 1803 if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags))) { 1804 dm_put_live_table(md, srcu_idx); 1805 1806 if (bio->bi_opf & REQ_NOWAIT) 1807 bio_wouldblock_error(bio); 1808 else if (!(bio->bi_opf & REQ_RAHEAD)) 1809 queue_io(md, bio); 1810 else 1811 bio_io_error(bio); 1812 return ret; 1813 } 1814 1815 ret = dm_process_bio(md, map, bio); 1816 1817 dm_put_live_table(md, srcu_idx); 1818 return ret; 1819 } 1820 1821 /*----------------------------------------------------------------- 1822 * An IDR is used to keep track of allocated minor numbers. 1823 *---------------------------------------------------------------*/ 1824 static void free_minor(int minor) 1825 { 1826 spin_lock(&_minor_lock); 1827 idr_remove(&_minor_idr, minor); 1828 spin_unlock(&_minor_lock); 1829 } 1830 1831 /* 1832 * See if the device with a specific minor # is free. 1833 */ 1834 static int specific_minor(int minor) 1835 { 1836 int r; 1837 1838 if (minor >= (1 << MINORBITS)) 1839 return -EINVAL; 1840 1841 idr_preload(GFP_KERNEL); 1842 spin_lock(&_minor_lock); 1843 1844 r = idr_alloc(&_minor_idr, MINOR_ALLOCED, minor, minor + 1, GFP_NOWAIT); 1845 1846 spin_unlock(&_minor_lock); 1847 idr_preload_end(); 1848 if (r < 0) 1849 return r == -ENOSPC ? -EBUSY : r; 1850 return 0; 1851 } 1852 1853 static int next_free_minor(int *minor) 1854 { 1855 int r; 1856 1857 idr_preload(GFP_KERNEL); 1858 spin_lock(&_minor_lock); 1859 1860 r = idr_alloc(&_minor_idr, MINOR_ALLOCED, 0, 1 << MINORBITS, GFP_NOWAIT); 1861 1862 spin_unlock(&_minor_lock); 1863 idr_preload_end(); 1864 if (r < 0) 1865 return r; 1866 *minor = r; 1867 return 0; 1868 } 1869 1870 static const struct block_device_operations dm_blk_dops; 1871 static const struct dax_operations dm_dax_ops; 1872 1873 static void dm_wq_work(struct work_struct *work); 1874 1875 static void cleanup_mapped_device(struct mapped_device *md) 1876 { 1877 if (md->wq) 1878 destroy_workqueue(md->wq); 1879 bioset_exit(&md->bs); 1880 bioset_exit(&md->io_bs); 1881 1882 if (md->dax_dev) { 1883 kill_dax(md->dax_dev); 1884 put_dax(md->dax_dev); 1885 md->dax_dev = NULL; 1886 } 1887 1888 if (md->disk) { 1889 spin_lock(&_minor_lock); 1890 md->disk->private_data = NULL; 1891 spin_unlock(&_minor_lock); 1892 del_gendisk(md->disk); 1893 put_disk(md->disk); 1894 } 1895 1896 if (md->queue) 1897 blk_cleanup_queue(md->queue); 1898 1899 cleanup_srcu_struct(&md->io_barrier); 1900 1901 if (md->bdev) { 1902 bdput(md->bdev); 1903 md->bdev = NULL; 1904 } 1905 1906 mutex_destroy(&md->suspend_lock); 1907 mutex_destroy(&md->type_lock); 1908 mutex_destroy(&md->table_devices_lock); 1909 1910 dm_mq_cleanup_mapped_device(md); 1911 } 1912 1913 /* 1914 * Allocate and initialise a blank device with a given minor. 1915 */ 1916 static struct mapped_device *alloc_dev(int minor) 1917 { 1918 int r, numa_node_id = dm_get_numa_node(); 1919 struct mapped_device *md; 1920 void *old_md; 1921 1922 md = kvzalloc_node(sizeof(*md), GFP_KERNEL, numa_node_id); 1923 if (!md) { 1924 DMWARN("unable to allocate device, out of memory."); 1925 return NULL; 1926 } 1927 1928 if (!try_module_get(THIS_MODULE)) 1929 goto bad_module_get; 1930 1931 /* get a minor number for the dev */ 1932 if (minor == DM_ANY_MINOR) 1933 r = next_free_minor(&minor); 1934 else 1935 r = specific_minor(minor); 1936 if (r < 0) 1937 goto bad_minor; 1938 1939 r = init_srcu_struct(&md->io_barrier); 1940 if (r < 0) 1941 goto bad_io_barrier; 1942 1943 md->numa_node_id = numa_node_id; 1944 md->init_tio_pdu = false; 1945 md->type = DM_TYPE_NONE; 1946 mutex_init(&md->suspend_lock); 1947 mutex_init(&md->type_lock); 1948 mutex_init(&md->table_devices_lock); 1949 spin_lock_init(&md->deferred_lock); 1950 atomic_set(&md->holders, 1); 1951 atomic_set(&md->open_count, 0); 1952 atomic_set(&md->event_nr, 0); 1953 atomic_set(&md->uevent_seq, 0); 1954 INIT_LIST_HEAD(&md->uevent_list); 1955 INIT_LIST_HEAD(&md->table_devices); 1956 spin_lock_init(&md->uevent_lock); 1957 1958 /* 1959 * default to bio-based until DM table is loaded and md->type 1960 * established. If request-based table is loaded: blk-mq will 1961 * override accordingly. 1962 */ 1963 md->queue = blk_alloc_queue(numa_node_id); 1964 if (!md->queue) 1965 goto bad; 1966 1967 md->disk = alloc_disk_node(1, md->numa_node_id); 1968 if (!md->disk) 1969 goto bad; 1970 1971 init_waitqueue_head(&md->wait); 1972 INIT_WORK(&md->work, dm_wq_work); 1973 init_waitqueue_head(&md->eventq); 1974 init_completion(&md->kobj_holder.completion); 1975 1976 md->disk->major = _major; 1977 md->disk->first_minor = minor; 1978 md->disk->fops = &dm_blk_dops; 1979 md->disk->queue = md->queue; 1980 md->disk->private_data = md; 1981 sprintf(md->disk->disk_name, "dm-%d", minor); 1982 1983 if (IS_ENABLED(CONFIG_DAX_DRIVER)) { 1984 md->dax_dev = alloc_dax(md, md->disk->disk_name, 1985 &dm_dax_ops, 0); 1986 if (IS_ERR(md->dax_dev)) 1987 goto bad; 1988 } 1989 1990 add_disk_no_queue_reg(md->disk); 1991 format_dev_t(md->name, MKDEV(_major, minor)); 1992 1993 md->wq = alloc_workqueue("kdmflush", WQ_MEM_RECLAIM, 0); 1994 if (!md->wq) 1995 goto bad; 1996 1997 md->bdev = bdget_disk(md->disk, 0); 1998 if (!md->bdev) 1999 goto bad; 2000 2001 dm_stats_init(&md->stats); 2002 2003 /* Populate the mapping, nobody knows we exist yet */ 2004 spin_lock(&_minor_lock); 2005 old_md = idr_replace(&_minor_idr, md, minor); 2006 spin_unlock(&_minor_lock); 2007 2008 BUG_ON(old_md != MINOR_ALLOCED); 2009 2010 return md; 2011 2012 bad: 2013 cleanup_mapped_device(md); 2014 bad_io_barrier: 2015 free_minor(minor); 2016 bad_minor: 2017 module_put(THIS_MODULE); 2018 bad_module_get: 2019 kvfree(md); 2020 return NULL; 2021 } 2022 2023 static void unlock_fs(struct mapped_device *md); 2024 2025 static void free_dev(struct mapped_device *md) 2026 { 2027 int minor = MINOR(disk_devt(md->disk)); 2028 2029 unlock_fs(md); 2030 2031 cleanup_mapped_device(md); 2032 2033 free_table_devices(&md->table_devices); 2034 dm_stats_cleanup(&md->stats); 2035 free_minor(minor); 2036 2037 module_put(THIS_MODULE); 2038 kvfree(md); 2039 } 2040 2041 static int __bind_mempools(struct mapped_device *md, struct dm_table *t) 2042 { 2043 struct dm_md_mempools *p = dm_table_get_md_mempools(t); 2044 int ret = 0; 2045 2046 if (dm_table_bio_based(t)) { 2047 /* 2048 * The md may already have mempools that need changing. 2049 * If so, reload bioset because front_pad may have changed 2050 * because a different table was loaded. 2051 */ 2052 bioset_exit(&md->bs); 2053 bioset_exit(&md->io_bs); 2054 2055 } else if (bioset_initialized(&md->bs)) { 2056 /* 2057 * There's no need to reload with request-based dm 2058 * because the size of front_pad doesn't change. 2059 * Note for future: If you are to reload bioset, 2060 * prep-ed requests in the queue may refer 2061 * to bio from the old bioset, so you must walk 2062 * through the queue to unprep. 2063 */ 2064 goto out; 2065 } 2066 2067 BUG_ON(!p || 2068 bioset_initialized(&md->bs) || 2069 bioset_initialized(&md->io_bs)); 2070 2071 ret = bioset_init_from_src(&md->bs, &p->bs); 2072 if (ret) 2073 goto out; 2074 ret = bioset_init_from_src(&md->io_bs, &p->io_bs); 2075 if (ret) 2076 bioset_exit(&md->bs); 2077 out: 2078 /* mempool bind completed, no longer need any mempools in the table */ 2079 dm_table_free_md_mempools(t); 2080 return ret; 2081 } 2082 2083 /* 2084 * Bind a table to the device. 2085 */ 2086 static void event_callback(void *context) 2087 { 2088 unsigned long flags; 2089 LIST_HEAD(uevents); 2090 struct mapped_device *md = (struct mapped_device *) context; 2091 2092 spin_lock_irqsave(&md->uevent_lock, flags); 2093 list_splice_init(&md->uevent_list, &uevents); 2094 spin_unlock_irqrestore(&md->uevent_lock, flags); 2095 2096 dm_send_uevents(&uevents, &disk_to_dev(md->disk)->kobj); 2097 2098 atomic_inc(&md->event_nr); 2099 wake_up(&md->eventq); 2100 dm_issue_global_event(); 2101 } 2102 2103 /* 2104 * Returns old map, which caller must destroy. 2105 */ 2106 static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t, 2107 struct queue_limits *limits) 2108 { 2109 struct dm_table *old_map; 2110 struct request_queue *q = md->queue; 2111 bool request_based = dm_table_request_based(t); 2112 sector_t size; 2113 int ret; 2114 2115 lockdep_assert_held(&md->suspend_lock); 2116 2117 size = dm_table_get_size(t); 2118 2119 /* 2120 * Wipe any geometry if the size of the table changed. 2121 */ 2122 if (size != dm_get_size(md)) 2123 memset(&md->geometry, 0, sizeof(md->geometry)); 2124 2125 set_capacity(md->disk, size); 2126 bd_set_nr_sectors(md->bdev, size); 2127 2128 dm_table_event_callback(t, event_callback, md); 2129 2130 /* 2131 * The queue hasn't been stopped yet, if the old table type wasn't 2132 * for request-based during suspension. So stop it to prevent 2133 * I/O mapping before resume. 2134 * This must be done before setting the queue restrictions, 2135 * because request-based dm may be run just after the setting. 2136 */ 2137 if (request_based) 2138 dm_stop_queue(q); 2139 2140 if (request_based || md->type == DM_TYPE_NVME_BIO_BASED) { 2141 /* 2142 * Leverage the fact that request-based DM targets and 2143 * NVMe bio based targets are immutable singletons 2144 * - used to optimize both dm_request_fn and dm_mq_queue_rq; 2145 * and __process_bio. 2146 */ 2147 md->immutable_target = dm_table_get_immutable_target(t); 2148 } 2149 2150 ret = __bind_mempools(md, t); 2151 if (ret) { 2152 old_map = ERR_PTR(ret); 2153 goto out; 2154 } 2155 2156 old_map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock)); 2157 rcu_assign_pointer(md->map, (void *)t); 2158 md->immutable_target_type = dm_table_get_immutable_target_type(t); 2159 2160 dm_table_set_restrictions(t, q, limits); 2161 if (old_map) 2162 dm_sync_table(md); 2163 2164 out: 2165 return old_map; 2166 } 2167 2168 /* 2169 * Returns unbound table for the caller to free. 2170 */ 2171 static struct dm_table *__unbind(struct mapped_device *md) 2172 { 2173 struct dm_table *map = rcu_dereference_protected(md->map, 1); 2174 2175 if (!map) 2176 return NULL; 2177 2178 dm_table_event_callback(map, NULL, NULL); 2179 RCU_INIT_POINTER(md->map, NULL); 2180 dm_sync_table(md); 2181 2182 return map; 2183 } 2184 2185 /* 2186 * Constructor for a new device. 2187 */ 2188 int dm_create(int minor, struct mapped_device **result) 2189 { 2190 int r; 2191 struct mapped_device *md; 2192 2193 md = alloc_dev(minor); 2194 if (!md) 2195 return -ENXIO; 2196 2197 r = dm_sysfs_init(md); 2198 if (r) { 2199 free_dev(md); 2200 return r; 2201 } 2202 2203 *result = md; 2204 return 0; 2205 } 2206 2207 /* 2208 * Functions to manage md->type. 2209 * All are required to hold md->type_lock. 2210 */ 2211 void dm_lock_md_type(struct mapped_device *md) 2212 { 2213 mutex_lock(&md->type_lock); 2214 } 2215 2216 void dm_unlock_md_type(struct mapped_device *md) 2217 { 2218 mutex_unlock(&md->type_lock); 2219 } 2220 2221 void dm_set_md_type(struct mapped_device *md, enum dm_queue_mode type) 2222 { 2223 BUG_ON(!mutex_is_locked(&md->type_lock)); 2224 md->type = type; 2225 } 2226 2227 enum dm_queue_mode dm_get_md_type(struct mapped_device *md) 2228 { 2229 return md->type; 2230 } 2231 2232 struct target_type *dm_get_immutable_target_type(struct mapped_device *md) 2233 { 2234 return md->immutable_target_type; 2235 } 2236 2237 /* 2238 * The queue_limits are only valid as long as you have a reference 2239 * count on 'md'. 2240 */ 2241 struct queue_limits *dm_get_queue_limits(struct mapped_device *md) 2242 { 2243 BUG_ON(!atomic_read(&md->holders)); 2244 return &md->queue->limits; 2245 } 2246 EXPORT_SYMBOL_GPL(dm_get_queue_limits); 2247 2248 /* 2249 * Setup the DM device's queue based on md's type 2250 */ 2251 int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t) 2252 { 2253 int r; 2254 struct queue_limits limits; 2255 enum dm_queue_mode type = dm_get_md_type(md); 2256 2257 switch (type) { 2258 case DM_TYPE_REQUEST_BASED: 2259 r = dm_mq_init_request_queue(md, t); 2260 if (r) { 2261 DMERR("Cannot initialize queue for request-based dm-mq mapped device"); 2262 return r; 2263 } 2264 break; 2265 case DM_TYPE_BIO_BASED: 2266 case DM_TYPE_DAX_BIO_BASED: 2267 case DM_TYPE_NVME_BIO_BASED: 2268 break; 2269 case DM_TYPE_NONE: 2270 WARN_ON_ONCE(true); 2271 break; 2272 } 2273 2274 r = dm_calculate_queue_limits(t, &limits); 2275 if (r) { 2276 DMERR("Cannot calculate initial queue limits"); 2277 return r; 2278 } 2279 dm_table_set_restrictions(t, md->queue, &limits); 2280 blk_register_queue(md->disk); 2281 2282 return 0; 2283 } 2284 2285 struct mapped_device *dm_get_md(dev_t dev) 2286 { 2287 struct mapped_device *md; 2288 unsigned minor = MINOR(dev); 2289 2290 if (MAJOR(dev) != _major || minor >= (1 << MINORBITS)) 2291 return NULL; 2292 2293 spin_lock(&_minor_lock); 2294 2295 md = idr_find(&_minor_idr, minor); 2296 if (!md || md == MINOR_ALLOCED || (MINOR(disk_devt(dm_disk(md))) != minor) || 2297 test_bit(DMF_FREEING, &md->flags) || dm_deleting_md(md)) { 2298 md = NULL; 2299 goto out; 2300 } 2301 dm_get(md); 2302 out: 2303 spin_unlock(&_minor_lock); 2304 2305 return md; 2306 } 2307 EXPORT_SYMBOL_GPL(dm_get_md); 2308 2309 void *dm_get_mdptr(struct mapped_device *md) 2310 { 2311 return md->interface_ptr; 2312 } 2313 2314 void dm_set_mdptr(struct mapped_device *md, void *ptr) 2315 { 2316 md->interface_ptr = ptr; 2317 } 2318 2319 void dm_get(struct mapped_device *md) 2320 { 2321 atomic_inc(&md->holders); 2322 BUG_ON(test_bit(DMF_FREEING, &md->flags)); 2323 } 2324 2325 int dm_hold(struct mapped_device *md) 2326 { 2327 spin_lock(&_minor_lock); 2328 if (test_bit(DMF_FREEING, &md->flags)) { 2329 spin_unlock(&_minor_lock); 2330 return -EBUSY; 2331 } 2332 dm_get(md); 2333 spin_unlock(&_minor_lock); 2334 return 0; 2335 } 2336 EXPORT_SYMBOL_GPL(dm_hold); 2337 2338 const char *dm_device_name(struct mapped_device *md) 2339 { 2340 return md->name; 2341 } 2342 EXPORT_SYMBOL_GPL(dm_device_name); 2343 2344 static void __dm_destroy(struct mapped_device *md, bool wait) 2345 { 2346 struct dm_table *map; 2347 int srcu_idx; 2348 2349 might_sleep(); 2350 2351 spin_lock(&_minor_lock); 2352 idr_replace(&_minor_idr, MINOR_ALLOCED, MINOR(disk_devt(dm_disk(md)))); 2353 set_bit(DMF_FREEING, &md->flags); 2354 spin_unlock(&_minor_lock); 2355 2356 blk_set_queue_dying(md->queue); 2357 2358 /* 2359 * Take suspend_lock so that presuspend and postsuspend methods 2360 * do not race with internal suspend. 2361 */ 2362 mutex_lock(&md->suspend_lock); 2363 map = dm_get_live_table(md, &srcu_idx); 2364 if (!dm_suspended_md(md)) { 2365 dm_table_presuspend_targets(map); 2366 set_bit(DMF_SUSPENDED, &md->flags); 2367 set_bit(DMF_POST_SUSPENDING, &md->flags); 2368 dm_table_postsuspend_targets(map); 2369 } 2370 /* dm_put_live_table must be before msleep, otherwise deadlock is possible */ 2371 dm_put_live_table(md, srcu_idx); 2372 mutex_unlock(&md->suspend_lock); 2373 2374 /* 2375 * Rare, but there may be I/O requests still going to complete, 2376 * for example. Wait for all references to disappear. 2377 * No one should increment the reference count of the mapped_device, 2378 * after the mapped_device state becomes DMF_FREEING. 2379 */ 2380 if (wait) 2381 while (atomic_read(&md->holders)) 2382 msleep(1); 2383 else if (atomic_read(&md->holders)) 2384 DMWARN("%s: Forcibly removing mapped_device still in use! (%d users)", 2385 dm_device_name(md), atomic_read(&md->holders)); 2386 2387 dm_sysfs_exit(md); 2388 dm_table_destroy(__unbind(md)); 2389 free_dev(md); 2390 } 2391 2392 void dm_destroy(struct mapped_device *md) 2393 { 2394 __dm_destroy(md, true); 2395 } 2396 2397 void dm_destroy_immediate(struct mapped_device *md) 2398 { 2399 __dm_destroy(md, false); 2400 } 2401 2402 void dm_put(struct mapped_device *md) 2403 { 2404 atomic_dec(&md->holders); 2405 } 2406 EXPORT_SYMBOL_GPL(dm_put); 2407 2408 static bool md_in_flight_bios(struct mapped_device *md) 2409 { 2410 int cpu; 2411 struct hd_struct *part = &dm_disk(md)->part0; 2412 long sum = 0; 2413 2414 for_each_possible_cpu(cpu) { 2415 sum += part_stat_local_read_cpu(part, in_flight[0], cpu); 2416 sum += part_stat_local_read_cpu(part, in_flight[1], cpu); 2417 } 2418 2419 return sum != 0; 2420 } 2421 2422 static int dm_wait_for_bios_completion(struct mapped_device *md, long task_state) 2423 { 2424 int r = 0; 2425 DEFINE_WAIT(wait); 2426 2427 while (true) { 2428 prepare_to_wait(&md->wait, &wait, task_state); 2429 2430 if (!md_in_flight_bios(md)) 2431 break; 2432 2433 if (signal_pending_state(task_state, current)) { 2434 r = -EINTR; 2435 break; 2436 } 2437 2438 io_schedule(); 2439 } 2440 finish_wait(&md->wait, &wait); 2441 2442 return r; 2443 } 2444 2445 static int dm_wait_for_completion(struct mapped_device *md, long task_state) 2446 { 2447 int r = 0; 2448 2449 if (!queue_is_mq(md->queue)) 2450 return dm_wait_for_bios_completion(md, task_state); 2451 2452 while (true) { 2453 if (!blk_mq_queue_inflight(md->queue)) 2454 break; 2455 2456 if (signal_pending_state(task_state, current)) { 2457 r = -EINTR; 2458 break; 2459 } 2460 2461 msleep(5); 2462 } 2463 2464 return r; 2465 } 2466 2467 /* 2468 * Process the deferred bios 2469 */ 2470 static void dm_wq_work(struct work_struct *work) 2471 { 2472 struct mapped_device *md = container_of(work, struct mapped_device, 2473 work); 2474 struct bio *c; 2475 int srcu_idx; 2476 struct dm_table *map; 2477 2478 map = dm_get_live_table(md, &srcu_idx); 2479 2480 while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) { 2481 spin_lock_irq(&md->deferred_lock); 2482 c = bio_list_pop(&md->deferred); 2483 spin_unlock_irq(&md->deferred_lock); 2484 2485 if (!c) 2486 break; 2487 2488 if (dm_request_based(md)) 2489 (void) submit_bio_noacct(c); 2490 else 2491 (void) dm_process_bio(md, map, c); 2492 } 2493 2494 dm_put_live_table(md, srcu_idx); 2495 } 2496 2497 static void dm_queue_flush(struct mapped_device *md) 2498 { 2499 clear_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags); 2500 smp_mb__after_atomic(); 2501 queue_work(md->wq, &md->work); 2502 } 2503 2504 /* 2505 * Swap in a new table, returning the old one for the caller to destroy. 2506 */ 2507 struct dm_table *dm_swap_table(struct mapped_device *md, struct dm_table *table) 2508 { 2509 struct dm_table *live_map = NULL, *map = ERR_PTR(-EINVAL); 2510 struct queue_limits limits; 2511 int r; 2512 2513 mutex_lock(&md->suspend_lock); 2514 2515 /* device must be suspended */ 2516 if (!dm_suspended_md(md)) 2517 goto out; 2518 2519 /* 2520 * If the new table has no data devices, retain the existing limits. 2521 * This helps multipath with queue_if_no_path if all paths disappear, 2522 * then new I/O is queued based on these limits, and then some paths 2523 * reappear. 2524 */ 2525 if (dm_table_has_no_data_devices(table)) { 2526 live_map = dm_get_live_table_fast(md); 2527 if (live_map) 2528 limits = md->queue->limits; 2529 dm_put_live_table_fast(md); 2530 } 2531 2532 if (!live_map) { 2533 r = dm_calculate_queue_limits(table, &limits); 2534 if (r) { 2535 map = ERR_PTR(r); 2536 goto out; 2537 } 2538 } 2539 2540 map = __bind(md, table, &limits); 2541 dm_issue_global_event(); 2542 2543 out: 2544 mutex_unlock(&md->suspend_lock); 2545 return map; 2546 } 2547 2548 /* 2549 * Functions to lock and unlock any filesystem running on the 2550 * device. 2551 */ 2552 static int lock_fs(struct mapped_device *md) 2553 { 2554 int r; 2555 2556 WARN_ON(md->frozen_sb); 2557 2558 md->frozen_sb = freeze_bdev(md->bdev); 2559 if (IS_ERR(md->frozen_sb)) { 2560 r = PTR_ERR(md->frozen_sb); 2561 md->frozen_sb = NULL; 2562 return r; 2563 } 2564 2565 set_bit(DMF_FROZEN, &md->flags); 2566 2567 return 0; 2568 } 2569 2570 static void unlock_fs(struct mapped_device *md) 2571 { 2572 if (!test_bit(DMF_FROZEN, &md->flags)) 2573 return; 2574 2575 thaw_bdev(md->bdev, md->frozen_sb); 2576 md->frozen_sb = NULL; 2577 clear_bit(DMF_FROZEN, &md->flags); 2578 } 2579 2580 /* 2581 * @suspend_flags: DM_SUSPEND_LOCKFS_FLAG and/or DM_SUSPEND_NOFLUSH_FLAG 2582 * @task_state: e.g. TASK_INTERRUPTIBLE or TASK_UNINTERRUPTIBLE 2583 * @dmf_suspended_flag: DMF_SUSPENDED or DMF_SUSPENDED_INTERNALLY 2584 * 2585 * If __dm_suspend returns 0, the device is completely quiescent 2586 * now. There is no request-processing activity. All new requests 2587 * are being added to md->deferred list. 2588 */ 2589 static int __dm_suspend(struct mapped_device *md, struct dm_table *map, 2590 unsigned suspend_flags, long task_state, 2591 int dmf_suspended_flag) 2592 { 2593 bool do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG; 2594 bool noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG; 2595 int r; 2596 2597 lockdep_assert_held(&md->suspend_lock); 2598 2599 /* 2600 * DMF_NOFLUSH_SUSPENDING must be set before presuspend. 2601 * This flag is cleared before dm_suspend returns. 2602 */ 2603 if (noflush) 2604 set_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); 2605 else 2606 DMDEBUG("%s: suspending with flush", dm_device_name(md)); 2607 2608 /* 2609 * This gets reverted if there's an error later and the targets 2610 * provide the .presuspend_undo hook. 2611 */ 2612 dm_table_presuspend_targets(map); 2613 2614 /* 2615 * Flush I/O to the device. 2616 * Any I/O submitted after lock_fs() may not be flushed. 2617 * noflush takes precedence over do_lockfs. 2618 * (lock_fs() flushes I/Os and waits for them to complete.) 2619 */ 2620 if (!noflush && do_lockfs) { 2621 r = lock_fs(md); 2622 if (r) { 2623 dm_table_presuspend_undo_targets(map); 2624 return r; 2625 } 2626 } 2627 2628 /* 2629 * Here we must make sure that no processes are submitting requests 2630 * to target drivers i.e. no one may be executing 2631 * __split_and_process_bio. This is called from dm_request and 2632 * dm_wq_work. 2633 * 2634 * To get all processes out of __split_and_process_bio in dm_request, 2635 * we take the write lock. To prevent any process from reentering 2636 * __split_and_process_bio from dm_request and quiesce the thread 2637 * (dm_wq_work), we set BMF_BLOCK_IO_FOR_SUSPEND and call 2638 * flush_workqueue(md->wq). 2639 */ 2640 set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags); 2641 if (map) 2642 synchronize_srcu(&md->io_barrier); 2643 2644 /* 2645 * Stop md->queue before flushing md->wq in case request-based 2646 * dm defers requests to md->wq from md->queue. 2647 */ 2648 if (dm_request_based(md)) 2649 dm_stop_queue(md->queue); 2650 2651 flush_workqueue(md->wq); 2652 2653 /* 2654 * At this point no more requests are entering target request routines. 2655 * We call dm_wait_for_completion to wait for all existing requests 2656 * to finish. 2657 */ 2658 r = dm_wait_for_completion(md, task_state); 2659 if (!r) 2660 set_bit(dmf_suspended_flag, &md->flags); 2661 2662 if (noflush) 2663 clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); 2664 if (map) 2665 synchronize_srcu(&md->io_barrier); 2666 2667 /* were we interrupted ? */ 2668 if (r < 0) { 2669 dm_queue_flush(md); 2670 2671 if (dm_request_based(md)) 2672 dm_start_queue(md->queue); 2673 2674 unlock_fs(md); 2675 dm_table_presuspend_undo_targets(map); 2676 /* pushback list is already flushed, so skip flush */ 2677 } 2678 2679 return r; 2680 } 2681 2682 /* 2683 * We need to be able to change a mapping table under a mounted 2684 * filesystem. For example we might want to move some data in 2685 * the background. Before the table can be swapped with 2686 * dm_bind_table, dm_suspend must be called to flush any in 2687 * flight bios and ensure that any further io gets deferred. 2688 */ 2689 /* 2690 * Suspend mechanism in request-based dm. 2691 * 2692 * 1. Flush all I/Os by lock_fs() if needed. 2693 * 2. Stop dispatching any I/O by stopping the request_queue. 2694 * 3. Wait for all in-flight I/Os to be completed or requeued. 2695 * 2696 * To abort suspend, start the request_queue. 2697 */ 2698 int dm_suspend(struct mapped_device *md, unsigned suspend_flags) 2699 { 2700 struct dm_table *map = NULL; 2701 int r = 0; 2702 2703 retry: 2704 mutex_lock_nested(&md->suspend_lock, SINGLE_DEPTH_NESTING); 2705 2706 if (dm_suspended_md(md)) { 2707 r = -EINVAL; 2708 goto out_unlock; 2709 } 2710 2711 if (dm_suspended_internally_md(md)) { 2712 /* already internally suspended, wait for internal resume */ 2713 mutex_unlock(&md->suspend_lock); 2714 r = wait_on_bit(&md->flags, DMF_SUSPENDED_INTERNALLY, TASK_INTERRUPTIBLE); 2715 if (r) 2716 return r; 2717 goto retry; 2718 } 2719 2720 map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock)); 2721 2722 r = __dm_suspend(md, map, suspend_flags, TASK_INTERRUPTIBLE, DMF_SUSPENDED); 2723 if (r) 2724 goto out_unlock; 2725 2726 set_bit(DMF_POST_SUSPENDING, &md->flags); 2727 dm_table_postsuspend_targets(map); 2728 clear_bit(DMF_POST_SUSPENDING, &md->flags); 2729 2730 out_unlock: 2731 mutex_unlock(&md->suspend_lock); 2732 return r; 2733 } 2734 2735 static int __dm_resume(struct mapped_device *md, struct dm_table *map) 2736 { 2737 if (map) { 2738 int r = dm_table_resume_targets(map); 2739 if (r) 2740 return r; 2741 } 2742 2743 dm_queue_flush(md); 2744 2745 /* 2746 * Flushing deferred I/Os must be done after targets are resumed 2747 * so that mapping of targets can work correctly. 2748 * Request-based dm is queueing the deferred I/Os in its request_queue. 2749 */ 2750 if (dm_request_based(md)) 2751 dm_start_queue(md->queue); 2752 2753 unlock_fs(md); 2754 2755 return 0; 2756 } 2757 2758 int dm_resume(struct mapped_device *md) 2759 { 2760 int r; 2761 struct dm_table *map = NULL; 2762 2763 retry: 2764 r = -EINVAL; 2765 mutex_lock_nested(&md->suspend_lock, SINGLE_DEPTH_NESTING); 2766 2767 if (!dm_suspended_md(md)) 2768 goto out; 2769 2770 if (dm_suspended_internally_md(md)) { 2771 /* already internally suspended, wait for internal resume */ 2772 mutex_unlock(&md->suspend_lock); 2773 r = wait_on_bit(&md->flags, DMF_SUSPENDED_INTERNALLY, TASK_INTERRUPTIBLE); 2774 if (r) 2775 return r; 2776 goto retry; 2777 } 2778 2779 map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock)); 2780 if (!map || !dm_table_get_size(map)) 2781 goto out; 2782 2783 r = __dm_resume(md, map); 2784 if (r) 2785 goto out; 2786 2787 clear_bit(DMF_SUSPENDED, &md->flags); 2788 out: 2789 mutex_unlock(&md->suspend_lock); 2790 2791 return r; 2792 } 2793 2794 /* 2795 * Internal suspend/resume works like userspace-driven suspend. It waits 2796 * until all bios finish and prevents issuing new bios to the target drivers. 2797 * It may be used only from the kernel. 2798 */ 2799 2800 static void __dm_internal_suspend(struct mapped_device *md, unsigned suspend_flags) 2801 { 2802 struct dm_table *map = NULL; 2803 2804 lockdep_assert_held(&md->suspend_lock); 2805 2806 if (md->internal_suspend_count++) 2807 return; /* nested internal suspend */ 2808 2809 if (dm_suspended_md(md)) { 2810 set_bit(DMF_SUSPENDED_INTERNALLY, &md->flags); 2811 return; /* nest suspend */ 2812 } 2813 2814 map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock)); 2815 2816 /* 2817 * Using TASK_UNINTERRUPTIBLE because only NOFLUSH internal suspend is 2818 * supported. Properly supporting a TASK_INTERRUPTIBLE internal suspend 2819 * would require changing .presuspend to return an error -- avoid this 2820 * until there is a need for more elaborate variants of internal suspend. 2821 */ 2822 (void) __dm_suspend(md, map, suspend_flags, TASK_UNINTERRUPTIBLE, 2823 DMF_SUSPENDED_INTERNALLY); 2824 2825 set_bit(DMF_POST_SUSPENDING, &md->flags); 2826 dm_table_postsuspend_targets(map); 2827 clear_bit(DMF_POST_SUSPENDING, &md->flags); 2828 } 2829 2830 static void __dm_internal_resume(struct mapped_device *md) 2831 { 2832 BUG_ON(!md->internal_suspend_count); 2833 2834 if (--md->internal_suspend_count) 2835 return; /* resume from nested internal suspend */ 2836 2837 if (dm_suspended_md(md)) 2838 goto done; /* resume from nested suspend */ 2839 2840 /* 2841 * NOTE: existing callers don't need to call dm_table_resume_targets 2842 * (which may fail -- so best to avoid it for now by passing NULL map) 2843 */ 2844 (void) __dm_resume(md, NULL); 2845 2846 done: 2847 clear_bit(DMF_SUSPENDED_INTERNALLY, &md->flags); 2848 smp_mb__after_atomic(); 2849 wake_up_bit(&md->flags, DMF_SUSPENDED_INTERNALLY); 2850 } 2851 2852 void dm_internal_suspend_noflush(struct mapped_device *md) 2853 { 2854 mutex_lock(&md->suspend_lock); 2855 __dm_internal_suspend(md, DM_SUSPEND_NOFLUSH_FLAG); 2856 mutex_unlock(&md->suspend_lock); 2857 } 2858 EXPORT_SYMBOL_GPL(dm_internal_suspend_noflush); 2859 2860 void dm_internal_resume(struct mapped_device *md) 2861 { 2862 mutex_lock(&md->suspend_lock); 2863 __dm_internal_resume(md); 2864 mutex_unlock(&md->suspend_lock); 2865 } 2866 EXPORT_SYMBOL_GPL(dm_internal_resume); 2867 2868 /* 2869 * Fast variants of internal suspend/resume hold md->suspend_lock, 2870 * which prevents interaction with userspace-driven suspend. 2871 */ 2872 2873 void dm_internal_suspend_fast(struct mapped_device *md) 2874 { 2875 mutex_lock(&md->suspend_lock); 2876 if (dm_suspended_md(md) || dm_suspended_internally_md(md)) 2877 return; 2878 2879 set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags); 2880 synchronize_srcu(&md->io_barrier); 2881 flush_workqueue(md->wq); 2882 dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE); 2883 } 2884 EXPORT_SYMBOL_GPL(dm_internal_suspend_fast); 2885 2886 void dm_internal_resume_fast(struct mapped_device *md) 2887 { 2888 if (dm_suspended_md(md) || dm_suspended_internally_md(md)) 2889 goto done; 2890 2891 dm_queue_flush(md); 2892 2893 done: 2894 mutex_unlock(&md->suspend_lock); 2895 } 2896 EXPORT_SYMBOL_GPL(dm_internal_resume_fast); 2897 2898 /*----------------------------------------------------------------- 2899 * Event notification. 2900 *---------------------------------------------------------------*/ 2901 int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action, 2902 unsigned cookie) 2903 { 2904 int r; 2905 unsigned noio_flag; 2906 char udev_cookie[DM_COOKIE_LENGTH]; 2907 char *envp[] = { udev_cookie, NULL }; 2908 2909 noio_flag = memalloc_noio_save(); 2910 2911 if (!cookie) 2912 r = kobject_uevent(&disk_to_dev(md->disk)->kobj, action); 2913 else { 2914 snprintf(udev_cookie, DM_COOKIE_LENGTH, "%s=%u", 2915 DM_COOKIE_ENV_VAR_NAME, cookie); 2916 r = kobject_uevent_env(&disk_to_dev(md->disk)->kobj, 2917 action, envp); 2918 } 2919 2920 memalloc_noio_restore(noio_flag); 2921 2922 return r; 2923 } 2924 2925 uint32_t dm_next_uevent_seq(struct mapped_device *md) 2926 { 2927 return atomic_add_return(1, &md->uevent_seq); 2928 } 2929 2930 uint32_t dm_get_event_nr(struct mapped_device *md) 2931 { 2932 return atomic_read(&md->event_nr); 2933 } 2934 2935 int dm_wait_event(struct mapped_device *md, int event_nr) 2936 { 2937 return wait_event_interruptible(md->eventq, 2938 (event_nr != atomic_read(&md->event_nr))); 2939 } 2940 2941 void dm_uevent_add(struct mapped_device *md, struct list_head *elist) 2942 { 2943 unsigned long flags; 2944 2945 spin_lock_irqsave(&md->uevent_lock, flags); 2946 list_add(elist, &md->uevent_list); 2947 spin_unlock_irqrestore(&md->uevent_lock, flags); 2948 } 2949 2950 /* 2951 * The gendisk is only valid as long as you have a reference 2952 * count on 'md'. 2953 */ 2954 struct gendisk *dm_disk(struct mapped_device *md) 2955 { 2956 return md->disk; 2957 } 2958 EXPORT_SYMBOL_GPL(dm_disk); 2959 2960 struct kobject *dm_kobject(struct mapped_device *md) 2961 { 2962 return &md->kobj_holder.kobj; 2963 } 2964 2965 struct mapped_device *dm_get_from_kobject(struct kobject *kobj) 2966 { 2967 struct mapped_device *md; 2968 2969 md = container_of(kobj, struct mapped_device, kobj_holder.kobj); 2970 2971 spin_lock(&_minor_lock); 2972 if (test_bit(DMF_FREEING, &md->flags) || dm_deleting_md(md)) { 2973 md = NULL; 2974 goto out; 2975 } 2976 dm_get(md); 2977 out: 2978 spin_unlock(&_minor_lock); 2979 2980 return md; 2981 } 2982 2983 int dm_suspended_md(struct mapped_device *md) 2984 { 2985 return test_bit(DMF_SUSPENDED, &md->flags); 2986 } 2987 2988 static int dm_post_suspending_md(struct mapped_device *md) 2989 { 2990 return test_bit(DMF_POST_SUSPENDING, &md->flags); 2991 } 2992 2993 int dm_suspended_internally_md(struct mapped_device *md) 2994 { 2995 return test_bit(DMF_SUSPENDED_INTERNALLY, &md->flags); 2996 } 2997 2998 int dm_test_deferred_remove_flag(struct mapped_device *md) 2999 { 3000 return test_bit(DMF_DEFERRED_REMOVE, &md->flags); 3001 } 3002 3003 int dm_suspended(struct dm_target *ti) 3004 { 3005 return dm_suspended_md(dm_table_get_md(ti->table)); 3006 } 3007 EXPORT_SYMBOL_GPL(dm_suspended); 3008 3009 int dm_post_suspending(struct dm_target *ti) 3010 { 3011 return dm_post_suspending_md(dm_table_get_md(ti->table)); 3012 } 3013 EXPORT_SYMBOL_GPL(dm_post_suspending); 3014 3015 int dm_noflush_suspending(struct dm_target *ti) 3016 { 3017 return __noflush_suspending(dm_table_get_md(ti->table)); 3018 } 3019 EXPORT_SYMBOL_GPL(dm_noflush_suspending); 3020 3021 struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, enum dm_queue_mode type, 3022 unsigned integrity, unsigned per_io_data_size, 3023 unsigned min_pool_size) 3024 { 3025 struct dm_md_mempools *pools = kzalloc_node(sizeof(*pools), GFP_KERNEL, md->numa_node_id); 3026 unsigned int pool_size = 0; 3027 unsigned int front_pad, io_front_pad; 3028 int ret; 3029 3030 if (!pools) 3031 return NULL; 3032 3033 switch (type) { 3034 case DM_TYPE_BIO_BASED: 3035 case DM_TYPE_DAX_BIO_BASED: 3036 case DM_TYPE_NVME_BIO_BASED: 3037 pool_size = max(dm_get_reserved_bio_based_ios(), min_pool_size); 3038 front_pad = roundup(per_io_data_size, __alignof__(struct dm_target_io)) + offsetof(struct dm_target_io, clone); 3039 io_front_pad = roundup(front_pad, __alignof__(struct dm_io)) + offsetof(struct dm_io, tio); 3040 ret = bioset_init(&pools->io_bs, pool_size, io_front_pad, 0); 3041 if (ret) 3042 goto out; 3043 if (integrity && bioset_integrity_create(&pools->io_bs, pool_size)) 3044 goto out; 3045 break; 3046 case DM_TYPE_REQUEST_BASED: 3047 pool_size = max(dm_get_reserved_rq_based_ios(), min_pool_size); 3048 front_pad = offsetof(struct dm_rq_clone_bio_info, clone); 3049 /* per_io_data_size is used for blk-mq pdu at queue allocation */ 3050 break; 3051 default: 3052 BUG(); 3053 } 3054 3055 ret = bioset_init(&pools->bs, pool_size, front_pad, 0); 3056 if (ret) 3057 goto out; 3058 3059 if (integrity && bioset_integrity_create(&pools->bs, pool_size)) 3060 goto out; 3061 3062 return pools; 3063 3064 out: 3065 dm_free_md_mempools(pools); 3066 3067 return NULL; 3068 } 3069 3070 void dm_free_md_mempools(struct dm_md_mempools *pools) 3071 { 3072 if (!pools) 3073 return; 3074 3075 bioset_exit(&pools->bs); 3076 bioset_exit(&pools->io_bs); 3077 3078 kfree(pools); 3079 } 3080 3081 struct dm_pr { 3082 u64 old_key; 3083 u64 new_key; 3084 u32 flags; 3085 bool fail_early; 3086 }; 3087 3088 static int dm_call_pr(struct block_device *bdev, iterate_devices_callout_fn fn, 3089 void *data) 3090 { 3091 struct mapped_device *md = bdev->bd_disk->private_data; 3092 struct dm_table *table; 3093 struct dm_target *ti; 3094 int ret = -ENOTTY, srcu_idx; 3095 3096 table = dm_get_live_table(md, &srcu_idx); 3097 if (!table || !dm_table_get_size(table)) 3098 goto out; 3099 3100 /* We only support devices that have a single target */ 3101 if (dm_table_get_num_targets(table) != 1) 3102 goto out; 3103 ti = dm_table_get_target(table, 0); 3104 3105 ret = -EINVAL; 3106 if (!ti->type->iterate_devices) 3107 goto out; 3108 3109 ret = ti->type->iterate_devices(ti, fn, data); 3110 out: 3111 dm_put_live_table(md, srcu_idx); 3112 return ret; 3113 } 3114 3115 /* 3116 * For register / unregister we need to manually call out to every path. 3117 */ 3118 static int __dm_pr_register(struct dm_target *ti, struct dm_dev *dev, 3119 sector_t start, sector_t len, void *data) 3120 { 3121 struct dm_pr *pr = data; 3122 const struct pr_ops *ops = dev->bdev->bd_disk->fops->pr_ops; 3123 3124 if (!ops || !ops->pr_register) 3125 return -EOPNOTSUPP; 3126 return ops->pr_register(dev->bdev, pr->old_key, pr->new_key, pr->flags); 3127 } 3128 3129 static int dm_pr_register(struct block_device *bdev, u64 old_key, u64 new_key, 3130 u32 flags) 3131 { 3132 struct dm_pr pr = { 3133 .old_key = old_key, 3134 .new_key = new_key, 3135 .flags = flags, 3136 .fail_early = true, 3137 }; 3138 int ret; 3139 3140 ret = dm_call_pr(bdev, __dm_pr_register, &pr); 3141 if (ret && new_key) { 3142 /* unregister all paths if we failed to register any path */ 3143 pr.old_key = new_key; 3144 pr.new_key = 0; 3145 pr.flags = 0; 3146 pr.fail_early = false; 3147 dm_call_pr(bdev, __dm_pr_register, &pr); 3148 } 3149 3150 return ret; 3151 } 3152 3153 static int dm_pr_reserve(struct block_device *bdev, u64 key, enum pr_type type, 3154 u32 flags) 3155 { 3156 struct mapped_device *md = bdev->bd_disk->private_data; 3157 const struct pr_ops *ops; 3158 int r, srcu_idx; 3159 3160 r = dm_prepare_ioctl(md, &srcu_idx, &bdev); 3161 if (r < 0) 3162 goto out; 3163 3164 ops = bdev->bd_disk->fops->pr_ops; 3165 if (ops && ops->pr_reserve) 3166 r = ops->pr_reserve(bdev, key, type, flags); 3167 else 3168 r = -EOPNOTSUPP; 3169 out: 3170 dm_unprepare_ioctl(md, srcu_idx); 3171 return r; 3172 } 3173 3174 static int dm_pr_release(struct block_device *bdev, u64 key, enum pr_type type) 3175 { 3176 struct mapped_device *md = bdev->bd_disk->private_data; 3177 const struct pr_ops *ops; 3178 int r, srcu_idx; 3179 3180 r = dm_prepare_ioctl(md, &srcu_idx, &bdev); 3181 if (r < 0) 3182 goto out; 3183 3184 ops = bdev->bd_disk->fops->pr_ops; 3185 if (ops && ops->pr_release) 3186 r = ops->pr_release(bdev, key, type); 3187 else 3188 r = -EOPNOTSUPP; 3189 out: 3190 dm_unprepare_ioctl(md, srcu_idx); 3191 return r; 3192 } 3193 3194 static int dm_pr_preempt(struct block_device *bdev, u64 old_key, u64 new_key, 3195 enum pr_type type, bool abort) 3196 { 3197 struct mapped_device *md = bdev->bd_disk->private_data; 3198 const struct pr_ops *ops; 3199 int r, srcu_idx; 3200 3201 r = dm_prepare_ioctl(md, &srcu_idx, &bdev); 3202 if (r < 0) 3203 goto out; 3204 3205 ops = bdev->bd_disk->fops->pr_ops; 3206 if (ops && ops->pr_preempt) 3207 r = ops->pr_preempt(bdev, old_key, new_key, type, abort); 3208 else 3209 r = -EOPNOTSUPP; 3210 out: 3211 dm_unprepare_ioctl(md, srcu_idx); 3212 return r; 3213 } 3214 3215 static int dm_pr_clear(struct block_device *bdev, u64 key) 3216 { 3217 struct mapped_device *md = bdev->bd_disk->private_data; 3218 const struct pr_ops *ops; 3219 int r, srcu_idx; 3220 3221 r = dm_prepare_ioctl(md, &srcu_idx, &bdev); 3222 if (r < 0) 3223 goto out; 3224 3225 ops = bdev->bd_disk->fops->pr_ops; 3226 if (ops && ops->pr_clear) 3227 r = ops->pr_clear(bdev, key); 3228 else 3229 r = -EOPNOTSUPP; 3230 out: 3231 dm_unprepare_ioctl(md, srcu_idx); 3232 return r; 3233 } 3234 3235 static const struct pr_ops dm_pr_ops = { 3236 .pr_register = dm_pr_register, 3237 .pr_reserve = dm_pr_reserve, 3238 .pr_release = dm_pr_release, 3239 .pr_preempt = dm_pr_preempt, 3240 .pr_clear = dm_pr_clear, 3241 }; 3242 3243 static const struct block_device_operations dm_blk_dops = { 3244 .submit_bio = dm_submit_bio, 3245 .open = dm_blk_open, 3246 .release = dm_blk_close, 3247 .ioctl = dm_blk_ioctl, 3248 .getgeo = dm_blk_getgeo, 3249 .report_zones = dm_blk_report_zones, 3250 .pr_ops = &dm_pr_ops, 3251 .owner = THIS_MODULE 3252 }; 3253 3254 static const struct dax_operations dm_dax_ops = { 3255 .direct_access = dm_dax_direct_access, 3256 .dax_supported = dm_dax_supported, 3257 .copy_from_iter = dm_dax_copy_from_iter, 3258 .copy_to_iter = dm_dax_copy_to_iter, 3259 .zero_page_range = dm_dax_zero_page_range, 3260 }; 3261 3262 /* 3263 * module hooks 3264 */ 3265 module_init(dm_init); 3266 module_exit(dm_exit); 3267 3268 module_param(major, uint, 0); 3269 MODULE_PARM_DESC(major, "The major number of the device mapper"); 3270 3271 module_param(reserved_bio_based_ios, uint, S_IRUGO | S_IWUSR); 3272 MODULE_PARM_DESC(reserved_bio_based_ios, "Reserved IOs in bio-based mempools"); 3273 3274 module_param(dm_numa_node, int, S_IRUGO | S_IWUSR); 3275 MODULE_PARM_DESC(dm_numa_node, "NUMA node for DM device memory allocations"); 3276 3277 MODULE_DESCRIPTION(DM_NAME " driver"); 3278 MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>"); 3279 MODULE_LICENSE("GPL"); 3280