| 1 | // SPDX-License-Identifier: GPL-2.0-only |
| 2 | /* |
| 3 | * Copyright (C) 2001, 2002 Sistina Software (UK) Limited. |
| 4 | * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved. |
| 5 | * |
| 6 | * This file is released under the GPL. |
| 7 | */ |
| 8 | |
| 9 | #include "dm-core.h" |
| 10 | #include "dm-rq.h" |
| 11 | #include "dm-uevent.h" |
| 12 | #include "dm-ima.h" |
| 13 | |
| 14 | #include <linux/bio-integrity.h> |
| 15 | #include <linux/init.h> |
| 16 | #include <linux/module.h> |
| 17 | #include <linux/mutex.h> |
| 18 | #include <linux/sched/mm.h> |
| 19 | #include <linux/sched/signal.h> |
| 20 | #include <linux/blkpg.h> |
| 21 | #include <linux/bio.h> |
| 22 | #include <linux/mempool.h> |
| 23 | #include <linux/dax.h> |
| 24 | #include <linux/slab.h> |
| 25 | #include <linux/idr.h> |
| 26 | #include <linux/uio.h> |
| 27 | #include <linux/hdreg.h> |
| 28 | #include <linux/delay.h> |
| 29 | #include <linux/wait.h> |
| 30 | #include <linux/pr.h> |
| 31 | #include <linux/refcount.h> |
| 32 | #include <linux/part_stat.h> |
| 33 | #include <linux/blk-crypto.h> |
| 34 | #include <linux/blk-crypto-profile.h> |
| 35 | |
| 36 | #define DM_MSG_PREFIX "core" |
| 37 | |
| 38 | /* |
| 39 | * Cookies are numeric values sent with CHANGE and REMOVE |
| 40 | * uevents while resuming, removing or renaming the device. |
| 41 | */ |
| 42 | #define DM_COOKIE_ENV_VAR_NAME "DM_COOKIE" |
| 43 | #define DM_COOKIE_LENGTH 24 |
| 44 | |
| 45 | /* |
| 46 | * For REQ_POLLED fs bio, this flag is set if we link mapped underlying |
| 47 | * dm_io into one list, and reuse bio->bi_private as the list head. Before |
| 48 | * ending this fs bio, we will recover its ->bi_private. |
| 49 | */ |
| 50 | #define REQ_DM_POLL_LIST REQ_DRV |
| 51 | |
| 52 | static const char *_name = DM_NAME; |
| 53 | |
| 54 | static unsigned int major; |
| 55 | static unsigned int _major; |
| 56 | |
| 57 | static DEFINE_IDR(_minor_idr); |
| 58 | |
| 59 | static DEFINE_SPINLOCK(_minor_lock); |
| 60 | |
| 61 | static void do_deferred_remove(struct work_struct *w); |
| 62 | |
| 63 | static DECLARE_WORK(deferred_remove_work, do_deferred_remove); |
| 64 | |
| 65 | static struct workqueue_struct *deferred_remove_workqueue; |
| 66 | |
| 67 | atomic_t dm_global_event_nr = ATOMIC_INIT(0); |
| 68 | DECLARE_WAIT_QUEUE_HEAD(dm_global_eventq); |
| 69 | |
| 70 | void dm_issue_global_event(void) |
| 71 | { |
| 72 | atomic_inc(&dm_global_event_nr); |
| 73 | wake_up(&dm_global_eventq); |
| 74 | } |
| 75 | |
| 76 | DEFINE_STATIC_KEY_FALSE(stats_enabled); |
| 77 | DEFINE_STATIC_KEY_FALSE(swap_bios_enabled); |
| 78 | DEFINE_STATIC_KEY_FALSE(zoned_enabled); |
| 79 | |
| 80 | /* |
| 81 | * One of these is allocated (on-stack) per original bio. |
| 82 | */ |
| 83 | struct clone_info { |
| 84 | struct dm_table *map; |
| 85 | struct bio *bio; |
| 86 | struct dm_io *io; |
| 87 | sector_t sector; |
| 88 | unsigned int sector_count; |
| 89 | bool is_abnormal_io:1; |
| 90 | bool submit_as_polled:1; |
| 91 | }; |
| 92 | |
| 93 | static inline struct dm_target_io *clone_to_tio(struct bio *clone) |
| 94 | { |
| 95 | return container_of(clone, struct dm_target_io, clone); |
| 96 | } |
| 97 | |
| 98 | void *dm_per_bio_data(struct bio *bio, size_t data_size) |
| 99 | { |
| 100 | if (!dm_tio_flagged(clone_to_tio(bio), DM_TIO_INSIDE_DM_IO)) |
| 101 | return (char *)bio - DM_TARGET_IO_BIO_OFFSET - data_size; |
| 102 | return (char *)bio - DM_IO_BIO_OFFSET - data_size; |
| 103 | } |
| 104 | EXPORT_SYMBOL_GPL(dm_per_bio_data); |
| 105 | |
| 106 | struct bio *dm_bio_from_per_bio_data(void *data, size_t data_size) |
| 107 | { |
| 108 | struct dm_io *io = (struct dm_io *)((char *)data + data_size); |
| 109 | |
| 110 | if (io->magic == DM_IO_MAGIC) |
| 111 | return (struct bio *)((char *)io + DM_IO_BIO_OFFSET); |
| 112 | BUG_ON(io->magic != DM_TIO_MAGIC); |
| 113 | return (struct bio *)((char *)io + DM_TARGET_IO_BIO_OFFSET); |
| 114 | } |
| 115 | EXPORT_SYMBOL_GPL(dm_bio_from_per_bio_data); |
| 116 | |
| 117 | unsigned int dm_bio_get_target_bio_nr(const struct bio *bio) |
| 118 | { |
| 119 | return container_of(bio, struct dm_target_io, clone)->target_bio_nr; |
| 120 | } |
| 121 | EXPORT_SYMBOL_GPL(dm_bio_get_target_bio_nr); |
| 122 | |
| 123 | #define MINOR_ALLOCED ((void *)-1) |
| 124 | |
| 125 | #define DM_NUMA_NODE NUMA_NO_NODE |
| 126 | static int dm_numa_node = DM_NUMA_NODE; |
| 127 | |
| 128 | #define DEFAULT_SWAP_BIOS (8 * 1048576 / PAGE_SIZE) |
| 129 | static int swap_bios = DEFAULT_SWAP_BIOS; |
| 130 | static int get_swap_bios(void) |
| 131 | { |
| 132 | int latch = READ_ONCE(swap_bios); |
| 133 | |
| 134 | if (unlikely(latch <= 0)) |
| 135 | latch = DEFAULT_SWAP_BIOS; |
| 136 | return latch; |
| 137 | } |
| 138 | |
| 139 | struct table_device { |
| 140 | struct list_head list; |
| 141 | refcount_t count; |
| 142 | struct dm_dev dm_dev; |
| 143 | }; |
| 144 | |
| 145 | /* |
| 146 | * Bio-based DM's mempools' reserved IOs set by the user. |
| 147 | */ |
| 148 | #define RESERVED_BIO_BASED_IOS 16 |
| 149 | static unsigned int reserved_bio_based_ios = RESERVED_BIO_BASED_IOS; |
| 150 | |
| 151 | static int __dm_get_module_param_int(int *module_param, int min, int max) |
| 152 | { |
| 153 | int param = READ_ONCE(*module_param); |
| 154 | int modified_param = 0; |
| 155 | bool modified = true; |
| 156 | |
| 157 | if (param < min) |
| 158 | modified_param = min; |
| 159 | else if (param > max) |
| 160 | modified_param = max; |
| 161 | else |
| 162 | modified = false; |
| 163 | |
| 164 | if (modified) { |
| 165 | (void)cmpxchg(module_param, param, modified_param); |
| 166 | param = modified_param; |
| 167 | } |
| 168 | |
| 169 | return param; |
| 170 | } |
| 171 | |
| 172 | unsigned int __dm_get_module_param(unsigned int *module_param, unsigned int def, unsigned int max) |
| 173 | { |
| 174 | unsigned int param = READ_ONCE(*module_param); |
| 175 | unsigned int modified_param = 0; |
| 176 | |
| 177 | if (!param) |
| 178 | modified_param = def; |
| 179 | else if (param > max) |
| 180 | modified_param = max; |
| 181 | |
| 182 | if (modified_param) { |
| 183 | (void)cmpxchg(module_param, param, modified_param); |
| 184 | param = modified_param; |
| 185 | } |
| 186 | |
| 187 | return param; |
| 188 | } |
| 189 | |
| 190 | unsigned int dm_get_reserved_bio_based_ios(void) |
| 191 | { |
| 192 | return __dm_get_module_param(&reserved_bio_based_ios, |
| 193 | RESERVED_BIO_BASED_IOS, DM_RESERVED_MAX_IOS); |
| 194 | } |
| 195 | EXPORT_SYMBOL_GPL(dm_get_reserved_bio_based_ios); |
| 196 | |
| 197 | static unsigned int dm_get_numa_node(void) |
| 198 | { |
| 199 | return __dm_get_module_param_int(&dm_numa_node, |
| 200 | DM_NUMA_NODE, num_online_nodes() - 1); |
| 201 | } |
| 202 | |
| 203 | static int __init local_init(void) |
| 204 | { |
| 205 | int r; |
| 206 | |
| 207 | r = dm_uevent_init(); |
| 208 | if (r) |
| 209 | return r; |
| 210 | |
| 211 | deferred_remove_workqueue = alloc_ordered_workqueue("kdmremove", 0); |
| 212 | if (!deferred_remove_workqueue) { |
| 213 | r = -ENOMEM; |
| 214 | goto out_uevent_exit; |
| 215 | } |
| 216 | |
| 217 | _major = major; |
| 218 | r = register_blkdev(_major, _name); |
| 219 | if (r < 0) |
| 220 | goto out_free_workqueue; |
| 221 | |
| 222 | if (!_major) |
| 223 | _major = r; |
| 224 | |
| 225 | return 0; |
| 226 | |
| 227 | out_free_workqueue: |
| 228 | destroy_workqueue(deferred_remove_workqueue); |
| 229 | out_uevent_exit: |
| 230 | dm_uevent_exit(); |
| 231 | |
| 232 | return r; |
| 233 | } |
| 234 | |
| 235 | static void local_exit(void) |
| 236 | { |
| 237 | destroy_workqueue(deferred_remove_workqueue); |
| 238 | |
| 239 | unregister_blkdev(_major, _name); |
| 240 | dm_uevent_exit(); |
| 241 | |
| 242 | _major = 0; |
| 243 | |
| 244 | DMINFO("cleaned up"); |
| 245 | } |
| 246 | |
| 247 | static int (*_inits[])(void) __initdata = { |
| 248 | local_init, |
| 249 | dm_target_init, |
| 250 | dm_linear_init, |
| 251 | dm_stripe_init, |
| 252 | dm_io_init, |
| 253 | dm_kcopyd_init, |
| 254 | dm_interface_init, |
| 255 | dm_statistics_init, |
| 256 | }; |
| 257 | |
| 258 | static void (*_exits[])(void) = { |
| 259 | local_exit, |
| 260 | dm_target_exit, |
| 261 | dm_linear_exit, |
| 262 | dm_stripe_exit, |
| 263 | dm_io_exit, |
| 264 | dm_kcopyd_exit, |
| 265 | dm_interface_exit, |
| 266 | dm_statistics_exit, |
| 267 | }; |
| 268 | |
| 269 | static int __init dm_init(void) |
| 270 | { |
| 271 | const int count = ARRAY_SIZE(_inits); |
| 272 | int r, i; |
| 273 | |
| 274 | #if (IS_ENABLED(CONFIG_IMA) && !IS_ENABLED(CONFIG_IMA_DISABLE_HTABLE)) |
| 275 | DMWARN("CONFIG_IMA_DISABLE_HTABLE is disabled." |
| 276 | " Duplicate IMA measurements will not be recorded in the IMA log."); |
| 277 | #endif |
| 278 | |
| 279 | for (i = 0; i < count; i++) { |
| 280 | r = _inits[i](); |
| 281 | if (r) |
| 282 | goto bad; |
| 283 | } |
| 284 | |
| 285 | return 0; |
| 286 | bad: |
| 287 | while (i--) |
| 288 | _exits[i](); |
| 289 | |
| 290 | return r; |
| 291 | } |
| 292 | |
| 293 | static void __exit dm_exit(void) |
| 294 | { |
| 295 | int i = ARRAY_SIZE(_exits); |
| 296 | |
| 297 | while (i--) |
| 298 | _exits[i](); |
| 299 | |
| 300 | /* |
| 301 | * Should be empty by this point. |
| 302 | */ |
| 303 | idr_destroy(&_minor_idr); |
| 304 | } |
| 305 | |
| 306 | /* |
| 307 | * Block device functions |
| 308 | */ |
| 309 | int dm_deleting_md(struct mapped_device *md) |
| 310 | { |
| 311 | return test_bit(DMF_DELETING, &md->flags); |
| 312 | } |
| 313 | |
| 314 | static int dm_blk_open(struct gendisk *disk, blk_mode_t mode) |
| 315 | { |
| 316 | struct mapped_device *md; |
| 317 | |
| 318 | spin_lock(&_minor_lock); |
| 319 | |
| 320 | md = disk->private_data; |
| 321 | if (!md) |
| 322 | goto out; |
| 323 | |
| 324 | if (test_bit(DMF_FREEING, &md->flags) || |
| 325 | dm_deleting_md(md)) { |
| 326 | md = NULL; |
| 327 | goto out; |
| 328 | } |
| 329 | |
| 330 | dm_get(md); |
| 331 | atomic_inc(&md->open_count); |
| 332 | out: |
| 333 | spin_unlock(&_minor_lock); |
| 334 | |
| 335 | return md ? 0 : -ENXIO; |
| 336 | } |
| 337 | |
| 338 | static void dm_blk_close(struct gendisk *disk) |
| 339 | { |
| 340 | struct mapped_device *md; |
| 341 | |
| 342 | spin_lock(&_minor_lock); |
| 343 | |
| 344 | md = disk->private_data; |
| 345 | if (WARN_ON(!md)) |
| 346 | goto out; |
| 347 | |
| 348 | if (atomic_dec_and_test(&md->open_count) && |
| 349 | (test_bit(DMF_DEFERRED_REMOVE, &md->flags))) |
| 350 | queue_work(deferred_remove_workqueue, &deferred_remove_work); |
| 351 | |
| 352 | dm_put(md); |
| 353 | out: |
| 354 | spin_unlock(&_minor_lock); |
| 355 | } |
| 356 | |
| 357 | int dm_open_count(struct mapped_device *md) |
| 358 | { |
| 359 | return atomic_read(&md->open_count); |
| 360 | } |
| 361 | |
| 362 | /* |
| 363 | * Guarantees nothing is using the device before it's deleted. |
| 364 | */ |
| 365 | int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred) |
| 366 | { |
| 367 | int r = 0; |
| 368 | |
| 369 | spin_lock(&_minor_lock); |
| 370 | |
| 371 | if (dm_open_count(md)) { |
| 372 | r = -EBUSY; |
| 373 | if (mark_deferred) |
| 374 | set_bit(DMF_DEFERRED_REMOVE, &md->flags); |
| 375 | } else if (only_deferred && !test_bit(DMF_DEFERRED_REMOVE, &md->flags)) |
| 376 | r = -EEXIST; |
| 377 | else |
| 378 | set_bit(DMF_DELETING, &md->flags); |
| 379 | |
| 380 | spin_unlock(&_minor_lock); |
| 381 | |
| 382 | return r; |
| 383 | } |
| 384 | |
| 385 | int dm_cancel_deferred_remove(struct mapped_device *md) |
| 386 | { |
| 387 | int r = 0; |
| 388 | |
| 389 | spin_lock(&_minor_lock); |
| 390 | |
| 391 | if (test_bit(DMF_DELETING, &md->flags)) |
| 392 | r = -EBUSY; |
| 393 | else |
| 394 | clear_bit(DMF_DEFERRED_REMOVE, &md->flags); |
| 395 | |
| 396 | spin_unlock(&_minor_lock); |
| 397 | |
| 398 | return r; |
| 399 | } |
| 400 | |
| 401 | static void do_deferred_remove(struct work_struct *w) |
| 402 | { |
| 403 | dm_deferred_remove(); |
| 404 | } |
| 405 | |
| 406 | static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
| 407 | { |
| 408 | struct mapped_device *md = bdev->bd_disk->private_data; |
| 409 | |
| 410 | return dm_get_geometry(md, geo); |
| 411 | } |
| 412 | |
| 413 | static int dm_prepare_ioctl(struct mapped_device *md, int *srcu_idx, |
| 414 | struct block_device **bdev) |
| 415 | { |
| 416 | struct dm_target *ti; |
| 417 | struct dm_table *map; |
| 418 | int r; |
| 419 | |
| 420 | retry: |
| 421 | r = -ENOTTY; |
| 422 | map = dm_get_live_table(md, srcu_idx); |
| 423 | if (!map || !dm_table_get_size(map)) |
| 424 | return r; |
| 425 | |
| 426 | /* We only support devices that have a single target */ |
| 427 | if (map->num_targets != 1) |
| 428 | return r; |
| 429 | |
| 430 | ti = dm_table_get_target(map, 0); |
| 431 | if (!ti->type->prepare_ioctl) |
| 432 | return r; |
| 433 | |
| 434 | if (dm_suspended_md(md)) |
| 435 | return -EAGAIN; |
| 436 | |
| 437 | r = ti->type->prepare_ioctl(ti, bdev); |
| 438 | if (r == -ENOTCONN && !fatal_signal_pending(current)) { |
| 439 | dm_put_live_table(md, *srcu_idx); |
| 440 | fsleep(10000); |
| 441 | goto retry; |
| 442 | } |
| 443 | |
| 444 | return r; |
| 445 | } |
| 446 | |
| 447 | static void dm_unprepare_ioctl(struct mapped_device *md, int srcu_idx) |
| 448 | { |
| 449 | dm_put_live_table(md, srcu_idx); |
| 450 | } |
| 451 | |
| 452 | static int dm_blk_ioctl(struct block_device *bdev, blk_mode_t mode, |
| 453 | unsigned int cmd, unsigned long arg) |
| 454 | { |
| 455 | struct mapped_device *md = bdev->bd_disk->private_data; |
| 456 | int r, srcu_idx; |
| 457 | |
| 458 | r = dm_prepare_ioctl(md, &srcu_idx, &bdev); |
| 459 | if (r < 0) |
| 460 | goto out; |
| 461 | |
| 462 | if (r > 0) { |
| 463 | /* |
| 464 | * Target determined this ioctl is being issued against a |
| 465 | * subset of the parent bdev; require extra privileges. |
| 466 | */ |
| 467 | if (!capable(CAP_SYS_RAWIO)) { |
| 468 | DMDEBUG_LIMIT( |
| 469 | "%s: sending ioctl %x to DM device without required privilege.", |
| 470 | current->comm, cmd); |
| 471 | r = -ENOIOCTLCMD; |
| 472 | goto out; |
| 473 | } |
| 474 | } |
| 475 | |
| 476 | if (!bdev->bd_disk->fops->ioctl) |
| 477 | r = -ENOTTY; |
| 478 | else |
| 479 | r = bdev->bd_disk->fops->ioctl(bdev, mode, cmd, arg); |
| 480 | out: |
| 481 | dm_unprepare_ioctl(md, srcu_idx); |
| 482 | return r; |
| 483 | } |
| 484 | |
| 485 | u64 dm_start_time_ns_from_clone(struct bio *bio) |
| 486 | { |
| 487 | return jiffies_to_nsecs(clone_to_tio(bio)->io->start_time); |
| 488 | } |
| 489 | EXPORT_SYMBOL_GPL(dm_start_time_ns_from_clone); |
| 490 | |
| 491 | static inline bool bio_is_flush_with_data(struct bio *bio) |
| 492 | { |
| 493 | return ((bio->bi_opf & REQ_PREFLUSH) && bio->bi_iter.bi_size); |
| 494 | } |
| 495 | |
| 496 | static inline unsigned int dm_io_sectors(struct dm_io *io, struct bio *bio) |
| 497 | { |
| 498 | /* |
| 499 | * If REQ_PREFLUSH set, don't account payload, it will be |
| 500 | * submitted (and accounted) after this flush completes. |
| 501 | */ |
| 502 | if (bio_is_flush_with_data(bio)) |
| 503 | return 0; |
| 504 | if (unlikely(dm_io_flagged(io, DM_IO_WAS_SPLIT))) |
| 505 | return io->sectors; |
| 506 | return bio_sectors(bio); |
| 507 | } |
| 508 | |
| 509 | static void dm_io_acct(struct dm_io *io, bool end) |
| 510 | { |
| 511 | struct bio *bio = io->orig_bio; |
| 512 | |
| 513 | if (dm_io_flagged(io, DM_IO_BLK_STAT)) { |
| 514 | if (!end) |
| 515 | bdev_start_io_acct(bio->bi_bdev, bio_op(bio), |
| 516 | io->start_time); |
| 517 | else |
| 518 | bdev_end_io_acct(bio->bi_bdev, bio_op(bio), |
| 519 | dm_io_sectors(io, bio), |
| 520 | io->start_time); |
| 521 | } |
| 522 | |
| 523 | if (static_branch_unlikely(&stats_enabled) && |
| 524 | unlikely(dm_stats_used(&io->md->stats))) { |
| 525 | sector_t sector; |
| 526 | |
| 527 | if (unlikely(dm_io_flagged(io, DM_IO_WAS_SPLIT))) |
| 528 | sector = bio_end_sector(bio) - io->sector_offset; |
| 529 | else |
| 530 | sector = bio->bi_iter.bi_sector; |
| 531 | |
| 532 | dm_stats_account_io(&io->md->stats, bio_data_dir(bio), |
| 533 | sector, dm_io_sectors(io, bio), |
| 534 | end, io->start_time, &io->stats_aux); |
| 535 | } |
| 536 | } |
| 537 | |
| 538 | static void __dm_start_io_acct(struct dm_io *io) |
| 539 | { |
| 540 | dm_io_acct(io, false); |
| 541 | } |
| 542 | |
| 543 | static void dm_start_io_acct(struct dm_io *io, struct bio *clone) |
| 544 | { |
| 545 | /* |
| 546 | * Ensure IO accounting is only ever started once. |
| 547 | */ |
| 548 | if (dm_io_flagged(io, DM_IO_ACCOUNTED)) |
| 549 | return; |
| 550 | |
| 551 | /* Expect no possibility for race unless DM_TIO_IS_DUPLICATE_BIO. */ |
| 552 | if (!clone || likely(dm_tio_is_normal(clone_to_tio(clone)))) { |
| 553 | dm_io_set_flag(io, DM_IO_ACCOUNTED); |
| 554 | } else { |
| 555 | unsigned long flags; |
| 556 | /* Can afford locking given DM_TIO_IS_DUPLICATE_BIO */ |
| 557 | spin_lock_irqsave(&io->lock, flags); |
| 558 | if (dm_io_flagged(io, DM_IO_ACCOUNTED)) { |
| 559 | spin_unlock_irqrestore(&io->lock, flags); |
| 560 | return; |
| 561 | } |
| 562 | dm_io_set_flag(io, DM_IO_ACCOUNTED); |
| 563 | spin_unlock_irqrestore(&io->lock, flags); |
| 564 | } |
| 565 | |
| 566 | __dm_start_io_acct(io); |
| 567 | } |
| 568 | |
| 569 | static void dm_end_io_acct(struct dm_io *io) |
| 570 | { |
| 571 | dm_io_acct(io, true); |
| 572 | } |
| 573 | |
| 574 | static struct dm_io *alloc_io(struct mapped_device *md, struct bio *bio, gfp_t gfp_mask) |
| 575 | { |
| 576 | struct dm_io *io; |
| 577 | struct dm_target_io *tio; |
| 578 | struct bio *clone; |
| 579 | |
| 580 | clone = bio_alloc_clone(NULL, bio, gfp_mask, &md->mempools->io_bs); |
| 581 | if (unlikely(!clone)) |
| 582 | return NULL; |
| 583 | tio = clone_to_tio(clone); |
| 584 | tio->flags = 0; |
| 585 | dm_tio_set_flag(tio, DM_TIO_INSIDE_DM_IO); |
| 586 | tio->io = NULL; |
| 587 | |
| 588 | io = container_of(tio, struct dm_io, tio); |
| 589 | io->magic = DM_IO_MAGIC; |
| 590 | io->status = BLK_STS_OK; |
| 591 | |
| 592 | /* one ref is for submission, the other is for completion */ |
| 593 | atomic_set(&io->io_count, 2); |
| 594 | this_cpu_inc(*md->pending_io); |
| 595 | io->orig_bio = bio; |
| 596 | io->md = md; |
| 597 | spin_lock_init(&io->lock); |
| 598 | io->start_time = jiffies; |
| 599 | io->flags = 0; |
| 600 | if (blk_queue_io_stat(md->queue)) |
| 601 | dm_io_set_flag(io, DM_IO_BLK_STAT); |
| 602 | |
| 603 | if (static_branch_unlikely(&stats_enabled) && |
| 604 | unlikely(dm_stats_used(&md->stats))) |
| 605 | dm_stats_record_start(&md->stats, &io->stats_aux); |
| 606 | |
| 607 | return io; |
| 608 | } |
| 609 | |
| 610 | static void free_io(struct dm_io *io) |
| 611 | { |
| 612 | bio_put(&io->tio.clone); |
| 613 | } |
| 614 | |
| 615 | static struct bio *alloc_tio(struct clone_info *ci, struct dm_target *ti, |
| 616 | unsigned int target_bio_nr, unsigned int *len, gfp_t gfp_mask) |
| 617 | { |
| 618 | struct mapped_device *md = ci->io->md; |
| 619 | struct dm_target_io *tio; |
| 620 | struct bio *clone; |
| 621 | |
| 622 | if (!ci->io->tio.io) { |
| 623 | /* the dm_target_io embedded in ci->io is available */ |
| 624 | tio = &ci->io->tio; |
| 625 | /* alloc_io() already initialized embedded clone */ |
| 626 | clone = &tio->clone; |
| 627 | } else { |
| 628 | clone = bio_alloc_clone(NULL, ci->bio, gfp_mask, |
| 629 | &md->mempools->bs); |
| 630 | if (!clone) |
| 631 | return NULL; |
| 632 | |
| 633 | /* REQ_DM_POLL_LIST shouldn't be inherited */ |
| 634 | clone->bi_opf &= ~REQ_DM_POLL_LIST; |
| 635 | |
| 636 | tio = clone_to_tio(clone); |
| 637 | tio->flags = 0; /* also clears DM_TIO_INSIDE_DM_IO */ |
| 638 | } |
| 639 | |
| 640 | tio->magic = DM_TIO_MAGIC; |
| 641 | tio->io = ci->io; |
| 642 | tio->ti = ti; |
| 643 | tio->target_bio_nr = target_bio_nr; |
| 644 | tio->len_ptr = len; |
| 645 | tio->old_sector = 0; |
| 646 | |
| 647 | /* Set default bdev, but target must bio_set_dev() before issuing IO */ |
| 648 | clone->bi_bdev = md->disk->part0; |
| 649 | if (likely(ti != NULL) && unlikely(ti->needs_bio_set_dev)) |
| 650 | bio_set_dev(clone, md->disk->part0); |
| 651 | |
| 652 | if (len) { |
| 653 | clone->bi_iter.bi_size = to_bytes(*len); |
| 654 | if (bio_integrity(clone)) |
| 655 | bio_integrity_trim(clone); |
| 656 | } |
| 657 | |
| 658 | return clone; |
| 659 | } |
| 660 | |
| 661 | static void free_tio(struct bio *clone) |
| 662 | { |
| 663 | if (dm_tio_flagged(clone_to_tio(clone), DM_TIO_INSIDE_DM_IO)) |
| 664 | return; |
| 665 | bio_put(clone); |
| 666 | } |
| 667 | |
| 668 | /* |
| 669 | * Add the bio to the list of deferred io. |
| 670 | */ |
| 671 | static void queue_io(struct mapped_device *md, struct bio *bio) |
| 672 | { |
| 673 | unsigned long flags; |
| 674 | |
| 675 | spin_lock_irqsave(&md->deferred_lock, flags); |
| 676 | bio_list_add(&md->deferred, bio); |
| 677 | spin_unlock_irqrestore(&md->deferred_lock, flags); |
| 678 | queue_work(md->wq, &md->work); |
| 679 | } |
| 680 | |
| 681 | /* |
| 682 | * Everyone (including functions in this file), should use this |
| 683 | * function to access the md->map field, and make sure they call |
| 684 | * dm_put_live_table() when finished. |
| 685 | */ |
| 686 | struct dm_table *dm_get_live_table(struct mapped_device *md, |
| 687 | int *srcu_idx) __acquires(md->io_barrier) |
| 688 | { |
| 689 | *srcu_idx = srcu_read_lock(&md->io_barrier); |
| 690 | |
| 691 | return srcu_dereference(md->map, &md->io_barrier); |
| 692 | } |
| 693 | |
| 694 | void dm_put_live_table(struct mapped_device *md, |
| 695 | int srcu_idx) __releases(md->io_barrier) |
| 696 | { |
| 697 | srcu_read_unlock(&md->io_barrier, srcu_idx); |
| 698 | } |
| 699 | |
| 700 | void dm_sync_table(struct mapped_device *md) |
| 701 | { |
| 702 | synchronize_srcu(&md->io_barrier); |
| 703 | synchronize_rcu_expedited(); |
| 704 | } |
| 705 | |
| 706 | /* |
| 707 | * A fast alternative to dm_get_live_table/dm_put_live_table. |
| 708 | * The caller must not block between these two functions. |
| 709 | */ |
| 710 | static struct dm_table *dm_get_live_table_fast(struct mapped_device *md) __acquires(RCU) |
| 711 | { |
| 712 | rcu_read_lock(); |
| 713 | return rcu_dereference(md->map); |
| 714 | } |
| 715 | |
| 716 | static void dm_put_live_table_fast(struct mapped_device *md) __releases(RCU) |
| 717 | { |
| 718 | rcu_read_unlock(); |
| 719 | } |
| 720 | |
| 721 | static char *_dm_claim_ptr = "I belong to device-mapper"; |
| 722 | |
| 723 | /* |
| 724 | * Open a table device so we can use it as a map destination. |
| 725 | */ |
| 726 | static struct table_device *open_table_device(struct mapped_device *md, |
| 727 | dev_t dev, blk_mode_t mode) |
| 728 | { |
| 729 | struct table_device *td; |
| 730 | struct file *bdev_file; |
| 731 | struct block_device *bdev; |
| 732 | u64 part_off; |
| 733 | int r; |
| 734 | |
| 735 | td = kmalloc_node(sizeof(*td), GFP_KERNEL, md->numa_node_id); |
| 736 | if (!td) |
| 737 | return ERR_PTR(-ENOMEM); |
| 738 | refcount_set(&td->count, 1); |
| 739 | |
| 740 | bdev_file = bdev_file_open_by_dev(dev, mode, _dm_claim_ptr, NULL); |
| 741 | if (IS_ERR(bdev_file)) { |
| 742 | r = PTR_ERR(bdev_file); |
| 743 | goto out_free_td; |
| 744 | } |
| 745 | |
| 746 | bdev = file_bdev(bdev_file); |
| 747 | |
| 748 | /* |
| 749 | * We can be called before the dm disk is added. In that case we can't |
| 750 | * register the holder relation here. It will be done once add_disk was |
| 751 | * called. |
| 752 | */ |
| 753 | if (md->disk->slave_dir) { |
| 754 | r = bd_link_disk_holder(bdev, md->disk); |
| 755 | if (r) |
| 756 | goto out_blkdev_put; |
| 757 | } |
| 758 | |
| 759 | td->dm_dev.mode = mode; |
| 760 | td->dm_dev.bdev = bdev; |
| 761 | td->dm_dev.bdev_file = bdev_file; |
| 762 | td->dm_dev.dax_dev = fs_dax_get_by_bdev(bdev, &part_off, |
| 763 | NULL, NULL); |
| 764 | format_dev_t(td->dm_dev.name, dev); |
| 765 | list_add(&td->list, &md->table_devices); |
| 766 | return td; |
| 767 | |
| 768 | out_blkdev_put: |
| 769 | __fput_sync(bdev_file); |
| 770 | out_free_td: |
| 771 | kfree(td); |
| 772 | return ERR_PTR(r); |
| 773 | } |
| 774 | |
| 775 | /* |
| 776 | * Close a table device that we've been using. |
| 777 | */ |
| 778 | static void close_table_device(struct table_device *td, struct mapped_device *md) |
| 779 | { |
| 780 | if (md->disk->slave_dir) |
| 781 | bd_unlink_disk_holder(td->dm_dev.bdev, md->disk); |
| 782 | |
| 783 | /* Leverage async fput() if DMF_DEFERRED_REMOVE set */ |
| 784 | if (unlikely(test_bit(DMF_DEFERRED_REMOVE, &md->flags))) |
| 785 | fput(td->dm_dev.bdev_file); |
| 786 | else |
| 787 | __fput_sync(td->dm_dev.bdev_file); |
| 788 | |
| 789 | put_dax(td->dm_dev.dax_dev); |
| 790 | list_del(&td->list); |
| 791 | kfree(td); |
| 792 | } |
| 793 | |
| 794 | static struct table_device *find_table_device(struct list_head *l, dev_t dev, |
| 795 | blk_mode_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, blk_mode_t mode, |
| 807 | struct dm_dev **result) |
| 808 | { |
| 809 | struct table_device *td; |
| 810 | |
| 811 | mutex_lock(&md->table_devices_lock); |
| 812 | td = find_table_device(&md->table_devices, dev, mode); |
| 813 | if (!td) { |
| 814 | td = open_table_device(md, dev, mode); |
| 815 | if (IS_ERR(td)) { |
| 816 | mutex_unlock(&md->table_devices_lock); |
| 817 | return PTR_ERR(td); |
| 818 | } |
| 819 | } else { |
| 820 | refcount_inc(&td->count); |
| 821 | } |
| 822 | mutex_unlock(&md->table_devices_lock); |
| 823 | |
| 824 | *result = &td->dm_dev; |
| 825 | return 0; |
| 826 | } |
| 827 | |
| 828 | void dm_put_table_device(struct mapped_device *md, struct dm_dev *d) |
| 829 | { |
| 830 | struct table_device *td = container_of(d, struct table_device, dm_dev); |
| 831 | |
| 832 | mutex_lock(&md->table_devices_lock); |
| 833 | if (refcount_dec_and_test(&td->count)) |
| 834 | close_table_device(td, md); |
| 835 | mutex_unlock(&md->table_devices_lock); |
| 836 | } |
| 837 | |
| 838 | /* |
| 839 | * Get the geometry associated with a dm device |
| 840 | */ |
| 841 | int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo) |
| 842 | { |
| 843 | *geo = md->geometry; |
| 844 | |
| 845 | return 0; |
| 846 | } |
| 847 | |
| 848 | /* |
| 849 | * Set the geometry of a device. |
| 850 | */ |
| 851 | int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo) |
| 852 | { |
| 853 | sector_t sz = (sector_t)geo->cylinders * geo->heads * geo->sectors; |
| 854 | |
| 855 | if (geo->start > sz) { |
| 856 | DMERR("Start sector is beyond the geometry limits."); |
| 857 | return -EINVAL; |
| 858 | } |
| 859 | |
| 860 | md->geometry = *geo; |
| 861 | |
| 862 | return 0; |
| 863 | } |
| 864 | |
| 865 | static int __noflush_suspending(struct mapped_device *md) |
| 866 | { |
| 867 | return test_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); |
| 868 | } |
| 869 | |
| 870 | static void dm_requeue_add_io(struct dm_io *io, bool first_stage) |
| 871 | { |
| 872 | struct mapped_device *md = io->md; |
| 873 | |
| 874 | if (first_stage) { |
| 875 | struct dm_io *next = md->requeue_list; |
| 876 | |
| 877 | md->requeue_list = io; |
| 878 | io->next = next; |
| 879 | } else { |
| 880 | bio_list_add_head(&md->deferred, io->orig_bio); |
| 881 | } |
| 882 | } |
| 883 | |
| 884 | static void dm_kick_requeue(struct mapped_device *md, bool first_stage) |
| 885 | { |
| 886 | if (first_stage) |
| 887 | queue_work(md->wq, &md->requeue_work); |
| 888 | else |
| 889 | queue_work(md->wq, &md->work); |
| 890 | } |
| 891 | |
| 892 | /* |
| 893 | * Return true if the dm_io's original bio is requeued. |
| 894 | * io->status is updated with error if requeue disallowed. |
| 895 | */ |
| 896 | static bool dm_handle_requeue(struct dm_io *io, bool first_stage) |
| 897 | { |
| 898 | struct bio *bio = io->orig_bio; |
| 899 | bool handle_requeue = (io->status == BLK_STS_DM_REQUEUE); |
| 900 | bool handle_polled_eagain = ((io->status == BLK_STS_AGAIN) && |
| 901 | (bio->bi_opf & REQ_POLLED)); |
| 902 | struct mapped_device *md = io->md; |
| 903 | bool requeued = false; |
| 904 | |
| 905 | if (handle_requeue || handle_polled_eagain) { |
| 906 | unsigned long flags; |
| 907 | |
| 908 | if (bio->bi_opf & REQ_POLLED) { |
| 909 | /* |
| 910 | * Upper layer won't help us poll split bio |
| 911 | * (io->orig_bio may only reflect a subset of the |
| 912 | * pre-split original) so clear REQ_POLLED. |
| 913 | */ |
| 914 | bio_clear_polled(bio); |
| 915 | } |
| 916 | |
| 917 | /* |
| 918 | * Target requested pushing back the I/O or |
| 919 | * polled IO hit BLK_STS_AGAIN. |
| 920 | */ |
| 921 | spin_lock_irqsave(&md->deferred_lock, flags); |
| 922 | if ((__noflush_suspending(md) && |
| 923 | !WARN_ON_ONCE(dm_is_zone_write(md, bio))) || |
| 924 | handle_polled_eagain || first_stage) { |
| 925 | dm_requeue_add_io(io, first_stage); |
| 926 | requeued = true; |
| 927 | } else { |
| 928 | /* |
| 929 | * noflush suspend was interrupted or this is |
| 930 | * a write to a zoned target. |
| 931 | */ |
| 932 | io->status = BLK_STS_IOERR; |
| 933 | } |
| 934 | spin_unlock_irqrestore(&md->deferred_lock, flags); |
| 935 | } |
| 936 | |
| 937 | if (requeued) |
| 938 | dm_kick_requeue(md, first_stage); |
| 939 | |
| 940 | return requeued; |
| 941 | } |
| 942 | |
| 943 | static void __dm_io_complete(struct dm_io *io, bool first_stage) |
| 944 | { |
| 945 | struct bio *bio = io->orig_bio; |
| 946 | struct mapped_device *md = io->md; |
| 947 | blk_status_t io_error; |
| 948 | bool requeued; |
| 949 | |
| 950 | requeued = dm_handle_requeue(io, first_stage); |
| 951 | if (requeued && first_stage) |
| 952 | return; |
| 953 | |
| 954 | io_error = io->status; |
| 955 | if (dm_io_flagged(io, DM_IO_ACCOUNTED)) |
| 956 | dm_end_io_acct(io); |
| 957 | else if (!io_error) { |
| 958 | /* |
| 959 | * Must handle target that DM_MAPIO_SUBMITTED only to |
| 960 | * then bio_endio() rather than dm_submit_bio_remap() |
| 961 | */ |
| 962 | __dm_start_io_acct(io); |
| 963 | dm_end_io_acct(io); |
| 964 | } |
| 965 | free_io(io); |
| 966 | smp_wmb(); |
| 967 | this_cpu_dec(*md->pending_io); |
| 968 | |
| 969 | /* nudge anyone waiting on suspend queue */ |
| 970 | if (unlikely(wq_has_sleeper(&md->wait))) |
| 971 | wake_up(&md->wait); |
| 972 | |
| 973 | /* Return early if the original bio was requeued */ |
| 974 | if (requeued) |
| 975 | return; |
| 976 | |
| 977 | if (bio_is_flush_with_data(bio)) { |
| 978 | /* |
| 979 | * Preflush done for flush with data, reissue |
| 980 | * without REQ_PREFLUSH. |
| 981 | */ |
| 982 | bio->bi_opf &= ~REQ_PREFLUSH; |
| 983 | queue_io(md, bio); |
| 984 | } else { |
| 985 | /* done with normal IO or empty flush */ |
| 986 | if (io_error) |
| 987 | bio->bi_status = io_error; |
| 988 | bio_endio(bio); |
| 989 | } |
| 990 | } |
| 991 | |
| 992 | static void dm_wq_requeue_work(struct work_struct *work) |
| 993 | { |
| 994 | struct mapped_device *md = container_of(work, struct mapped_device, |
| 995 | requeue_work); |
| 996 | unsigned long flags; |
| 997 | struct dm_io *io; |
| 998 | |
| 999 | /* reuse deferred lock to simplify dm_handle_requeue */ |
| 1000 | spin_lock_irqsave(&md->deferred_lock, flags); |
| 1001 | io = md->requeue_list; |
| 1002 | md->requeue_list = NULL; |
| 1003 | spin_unlock_irqrestore(&md->deferred_lock, flags); |
| 1004 | |
| 1005 | while (io) { |
| 1006 | struct dm_io *next = io->next; |
| 1007 | |
| 1008 | dm_io_rewind(io, &md->disk->bio_split); |
| 1009 | |
| 1010 | io->next = NULL; |
| 1011 | __dm_io_complete(io, false); |
| 1012 | io = next; |
| 1013 | cond_resched(); |
| 1014 | } |
| 1015 | } |
| 1016 | |
| 1017 | /* |
| 1018 | * Two staged requeue: |
| 1019 | * |
| 1020 | * 1) io->orig_bio points to the real original bio, and the part mapped to |
| 1021 | * this io must be requeued, instead of other parts of the original bio. |
| 1022 | * |
| 1023 | * 2) io->orig_bio points to new cloned bio which matches the requeued dm_io. |
| 1024 | */ |
| 1025 | static void dm_io_complete(struct dm_io *io) |
| 1026 | { |
| 1027 | bool first_requeue; |
| 1028 | |
| 1029 | /* |
| 1030 | * Only dm_io that has been split needs two stage requeue, otherwise |
| 1031 | * we may run into long bio clone chain during suspend and OOM could |
| 1032 | * be triggered. |
| 1033 | * |
| 1034 | * Also flush data dm_io won't be marked as DM_IO_WAS_SPLIT, so they |
| 1035 | * also aren't handled via the first stage requeue. |
| 1036 | */ |
| 1037 | if (dm_io_flagged(io, DM_IO_WAS_SPLIT)) |
| 1038 | first_requeue = true; |
| 1039 | else |
| 1040 | first_requeue = false; |
| 1041 | |
| 1042 | __dm_io_complete(io, first_requeue); |
| 1043 | } |
| 1044 | |
| 1045 | /* |
| 1046 | * Decrements the number of outstanding ios that a bio has been |
| 1047 | * cloned into, completing the original io if necc. |
| 1048 | */ |
| 1049 | static inline void __dm_io_dec_pending(struct dm_io *io) |
| 1050 | { |
| 1051 | if (atomic_dec_and_test(&io->io_count)) |
| 1052 | dm_io_complete(io); |
| 1053 | } |
| 1054 | |
| 1055 | static void dm_io_set_error(struct dm_io *io, blk_status_t error) |
| 1056 | { |
| 1057 | unsigned long flags; |
| 1058 | |
| 1059 | /* Push-back supersedes any I/O errors */ |
| 1060 | spin_lock_irqsave(&io->lock, flags); |
| 1061 | if (!(io->status == BLK_STS_DM_REQUEUE && |
| 1062 | __noflush_suspending(io->md))) { |
| 1063 | io->status = error; |
| 1064 | } |
| 1065 | spin_unlock_irqrestore(&io->lock, flags); |
| 1066 | } |
| 1067 | |
| 1068 | static void dm_io_dec_pending(struct dm_io *io, blk_status_t error) |
| 1069 | { |
| 1070 | if (unlikely(error)) |
| 1071 | dm_io_set_error(io, error); |
| 1072 | |
| 1073 | __dm_io_dec_pending(io); |
| 1074 | } |
| 1075 | |
| 1076 | /* |
| 1077 | * The queue_limits are only valid as long as you have a reference |
| 1078 | * count on 'md'. But _not_ imposing verification to avoid atomic_read(), |
| 1079 | */ |
| 1080 | static inline struct queue_limits *dm_get_queue_limits(struct mapped_device *md) |
| 1081 | { |
| 1082 | return &md->queue->limits; |
| 1083 | } |
| 1084 | |
| 1085 | void disable_discard(struct mapped_device *md) |
| 1086 | { |
| 1087 | struct queue_limits *limits = dm_get_queue_limits(md); |
| 1088 | |
| 1089 | /* device doesn't really support DISCARD, disable it */ |
| 1090 | limits->max_hw_discard_sectors = 0; |
| 1091 | } |
| 1092 | |
| 1093 | void disable_write_zeroes(struct mapped_device *md) |
| 1094 | { |
| 1095 | struct queue_limits *limits = dm_get_queue_limits(md); |
| 1096 | |
| 1097 | /* device doesn't really support WRITE ZEROES, disable it */ |
| 1098 | limits->max_write_zeroes_sectors = 0; |
| 1099 | } |
| 1100 | |
| 1101 | static bool swap_bios_limit(struct dm_target *ti, struct bio *bio) |
| 1102 | { |
| 1103 | return unlikely((bio->bi_opf & REQ_SWAP) != 0) && unlikely(ti->limit_swap_bios); |
| 1104 | } |
| 1105 | |
| 1106 | static void clone_endio(struct bio *bio) |
| 1107 | { |
| 1108 | blk_status_t error = bio->bi_status; |
| 1109 | struct dm_target_io *tio = clone_to_tio(bio); |
| 1110 | struct dm_target *ti = tio->ti; |
| 1111 | dm_endio_fn endio = likely(ti != NULL) ? ti->type->end_io : NULL; |
| 1112 | struct dm_io *io = tio->io; |
| 1113 | struct mapped_device *md = io->md; |
| 1114 | |
| 1115 | if (unlikely(error == BLK_STS_TARGET)) { |
| 1116 | if (bio_op(bio) == REQ_OP_DISCARD && |
| 1117 | !bdev_max_discard_sectors(bio->bi_bdev)) |
| 1118 | disable_discard(md); |
| 1119 | else if (bio_op(bio) == REQ_OP_WRITE_ZEROES && |
| 1120 | !bdev_write_zeroes_sectors(bio->bi_bdev)) |
| 1121 | disable_write_zeroes(md); |
| 1122 | } |
| 1123 | |
| 1124 | if (static_branch_unlikely(&zoned_enabled) && |
| 1125 | unlikely(bdev_is_zoned(bio->bi_bdev))) |
| 1126 | dm_zone_endio(io, bio); |
| 1127 | |
| 1128 | if (endio) { |
| 1129 | int r = endio(ti, bio, &error); |
| 1130 | |
| 1131 | switch (r) { |
| 1132 | case DM_ENDIO_REQUEUE: |
| 1133 | if (static_branch_unlikely(&zoned_enabled)) { |
| 1134 | /* |
| 1135 | * Requeuing writes to a sequential zone of a zoned |
| 1136 | * target will break the sequential write pattern: |
| 1137 | * fail such IO. |
| 1138 | */ |
| 1139 | if (WARN_ON_ONCE(dm_is_zone_write(md, bio))) |
| 1140 | error = BLK_STS_IOERR; |
| 1141 | else |
| 1142 | error = BLK_STS_DM_REQUEUE; |
| 1143 | } else |
| 1144 | error = BLK_STS_DM_REQUEUE; |
| 1145 | fallthrough; |
| 1146 | case DM_ENDIO_DONE: |
| 1147 | break; |
| 1148 | case DM_ENDIO_INCOMPLETE: |
| 1149 | /* The target will handle the io */ |
| 1150 | return; |
| 1151 | default: |
| 1152 | DMCRIT("unimplemented target endio return value: %d", r); |
| 1153 | BUG(); |
| 1154 | } |
| 1155 | } |
| 1156 | |
| 1157 | if (static_branch_unlikely(&swap_bios_enabled) && |
| 1158 | likely(ti != NULL) && unlikely(swap_bios_limit(ti, bio))) |
| 1159 | up(&md->swap_bios_semaphore); |
| 1160 | |
| 1161 | free_tio(bio); |
| 1162 | dm_io_dec_pending(io, error); |
| 1163 | } |
| 1164 | |
| 1165 | /* |
| 1166 | * Return maximum size of I/O possible at the supplied sector up to the current |
| 1167 | * target boundary. |
| 1168 | */ |
| 1169 | static inline sector_t max_io_len_target_boundary(struct dm_target *ti, |
| 1170 | sector_t target_offset) |
| 1171 | { |
| 1172 | return ti->len - target_offset; |
| 1173 | } |
| 1174 | |
| 1175 | static sector_t __max_io_len(struct dm_target *ti, sector_t sector, |
| 1176 | unsigned int max_granularity, |
| 1177 | unsigned int max_sectors) |
| 1178 | { |
| 1179 | sector_t target_offset = dm_target_offset(ti, sector); |
| 1180 | sector_t len = max_io_len_target_boundary(ti, target_offset); |
| 1181 | |
| 1182 | /* |
| 1183 | * Does the target need to split IO even further? |
| 1184 | * - varied (per target) IO splitting is a tenet of DM; this |
| 1185 | * explains why stacked chunk_sectors based splitting via |
| 1186 | * bio_split_to_limits() isn't possible here. |
| 1187 | */ |
| 1188 | if (!max_granularity) |
| 1189 | return len; |
| 1190 | return min_t(sector_t, len, |
| 1191 | min(max_sectors ? : queue_max_sectors(ti->table->md->queue), |
| 1192 | blk_boundary_sectors_left(target_offset, max_granularity))); |
| 1193 | } |
| 1194 | |
| 1195 | static inline sector_t max_io_len(struct dm_target *ti, sector_t sector) |
| 1196 | { |
| 1197 | return __max_io_len(ti, sector, ti->max_io_len, 0); |
| 1198 | } |
| 1199 | |
| 1200 | int dm_set_target_max_io_len(struct dm_target *ti, sector_t len) |
| 1201 | { |
| 1202 | if (len > UINT_MAX) { |
| 1203 | DMERR("Specified maximum size of target IO (%llu) exceeds limit (%u)", |
| 1204 | (unsigned long long)len, UINT_MAX); |
| 1205 | ti->error = "Maximum size of target IO is too large"; |
| 1206 | return -EINVAL; |
| 1207 | } |
| 1208 | |
| 1209 | ti->max_io_len = (uint32_t) len; |
| 1210 | |
| 1211 | return 0; |
| 1212 | } |
| 1213 | EXPORT_SYMBOL_GPL(dm_set_target_max_io_len); |
| 1214 | |
| 1215 | static struct dm_target *dm_dax_get_live_target(struct mapped_device *md, |
| 1216 | sector_t sector, int *srcu_idx) |
| 1217 | __acquires(md->io_barrier) |
| 1218 | { |
| 1219 | struct dm_table *map; |
| 1220 | struct dm_target *ti; |
| 1221 | |
| 1222 | map = dm_get_live_table(md, srcu_idx); |
| 1223 | if (!map) |
| 1224 | return NULL; |
| 1225 | |
| 1226 | ti = dm_table_find_target(map, sector); |
| 1227 | if (!ti) |
| 1228 | return NULL; |
| 1229 | |
| 1230 | return ti; |
| 1231 | } |
| 1232 | |
| 1233 | static long dm_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, |
| 1234 | long nr_pages, enum dax_access_mode mode, void **kaddr, |
| 1235 | pfn_t *pfn) |
| 1236 | { |
| 1237 | struct mapped_device *md = dax_get_private(dax_dev); |
| 1238 | sector_t sector = pgoff * PAGE_SECTORS; |
| 1239 | struct dm_target *ti; |
| 1240 | long len, ret = -EIO; |
| 1241 | int srcu_idx; |
| 1242 | |
| 1243 | ti = dm_dax_get_live_target(md, sector, &srcu_idx); |
| 1244 | |
| 1245 | if (!ti) |
| 1246 | goto out; |
| 1247 | if (!ti->type->direct_access) |
| 1248 | goto out; |
| 1249 | len = max_io_len(ti, sector) / PAGE_SECTORS; |
| 1250 | if (len < 1) |
| 1251 | goto out; |
| 1252 | nr_pages = min(len, nr_pages); |
| 1253 | ret = ti->type->direct_access(ti, pgoff, nr_pages, mode, kaddr, pfn); |
| 1254 | |
| 1255 | out: |
| 1256 | dm_put_live_table(md, srcu_idx); |
| 1257 | |
| 1258 | return ret; |
| 1259 | } |
| 1260 | |
| 1261 | static int dm_dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff, |
| 1262 | size_t nr_pages) |
| 1263 | { |
| 1264 | struct mapped_device *md = dax_get_private(dax_dev); |
| 1265 | sector_t sector = pgoff * PAGE_SECTORS; |
| 1266 | struct dm_target *ti; |
| 1267 | int ret = -EIO; |
| 1268 | int srcu_idx; |
| 1269 | |
| 1270 | ti = dm_dax_get_live_target(md, sector, &srcu_idx); |
| 1271 | |
| 1272 | if (!ti) |
| 1273 | goto out; |
| 1274 | if (WARN_ON(!ti->type->dax_zero_page_range)) { |
| 1275 | /* |
| 1276 | * ->zero_page_range() is mandatory dax operation. If we are |
| 1277 | * here, something is wrong. |
| 1278 | */ |
| 1279 | goto out; |
| 1280 | } |
| 1281 | ret = ti->type->dax_zero_page_range(ti, pgoff, nr_pages); |
| 1282 | out: |
| 1283 | dm_put_live_table(md, srcu_idx); |
| 1284 | |
| 1285 | return ret; |
| 1286 | } |
| 1287 | |
| 1288 | static size_t dm_dax_recovery_write(struct dax_device *dax_dev, pgoff_t pgoff, |
| 1289 | void *addr, size_t bytes, struct iov_iter *i) |
| 1290 | { |
| 1291 | struct mapped_device *md = dax_get_private(dax_dev); |
| 1292 | sector_t sector = pgoff * PAGE_SECTORS; |
| 1293 | struct dm_target *ti; |
| 1294 | int srcu_idx; |
| 1295 | long ret = 0; |
| 1296 | |
| 1297 | ti = dm_dax_get_live_target(md, sector, &srcu_idx); |
| 1298 | if (!ti || !ti->type->dax_recovery_write) |
| 1299 | goto out; |
| 1300 | |
| 1301 | ret = ti->type->dax_recovery_write(ti, pgoff, addr, bytes, i); |
| 1302 | out: |
| 1303 | dm_put_live_table(md, srcu_idx); |
| 1304 | return ret; |
| 1305 | } |
| 1306 | |
| 1307 | /* |
| 1308 | * A target may call dm_accept_partial_bio only from the map routine. It is |
| 1309 | * allowed for all bio types except REQ_PREFLUSH, REQ_OP_ZONE_* zone management |
| 1310 | * operations, REQ_OP_ZONE_APPEND (zone append writes) and any bio serviced by |
| 1311 | * __send_duplicate_bios(). |
| 1312 | * |
| 1313 | * dm_accept_partial_bio informs the dm that the target only wants to process |
| 1314 | * additional n_sectors sectors of the bio and the rest of the data should be |
| 1315 | * sent in a next bio. |
| 1316 | * |
| 1317 | * A diagram that explains the arithmetics: |
| 1318 | * +--------------------+---------------+-------+ |
| 1319 | * | 1 | 2 | 3 | |
| 1320 | * +--------------------+---------------+-------+ |
| 1321 | * |
| 1322 | * <-------------- *tio->len_ptr ---------------> |
| 1323 | * <----- bio_sectors -----> |
| 1324 | * <-- n_sectors --> |
| 1325 | * |
| 1326 | * Region 1 was already iterated over with bio_advance or similar function. |
| 1327 | * (it may be empty if the target doesn't use bio_advance) |
| 1328 | * Region 2 is the remaining bio size that the target wants to process. |
| 1329 | * (it may be empty if region 1 is non-empty, although there is no reason |
| 1330 | * to make it empty) |
| 1331 | * The target requires that region 3 is to be sent in the next bio. |
| 1332 | * |
| 1333 | * If the target wants to receive multiple copies of the bio (via num_*bios, etc), |
| 1334 | * the partially processed part (the sum of regions 1+2) must be the same for all |
| 1335 | * copies of the bio. |
| 1336 | */ |
| 1337 | void dm_accept_partial_bio(struct bio *bio, unsigned int n_sectors) |
| 1338 | { |
| 1339 | struct dm_target_io *tio = clone_to_tio(bio); |
| 1340 | struct dm_io *io = tio->io; |
| 1341 | unsigned int bio_sectors = bio_sectors(bio); |
| 1342 | |
| 1343 | BUG_ON(dm_tio_flagged(tio, DM_TIO_IS_DUPLICATE_BIO)); |
| 1344 | BUG_ON(op_is_zone_mgmt(bio_op(bio))); |
| 1345 | BUG_ON(bio_op(bio) == REQ_OP_ZONE_APPEND); |
| 1346 | BUG_ON(bio_sectors > *tio->len_ptr); |
| 1347 | BUG_ON(n_sectors > bio_sectors); |
| 1348 | |
| 1349 | *tio->len_ptr -= bio_sectors - n_sectors; |
| 1350 | bio->bi_iter.bi_size = n_sectors << SECTOR_SHIFT; |
| 1351 | |
| 1352 | /* |
| 1353 | * __split_and_process_bio() may have already saved mapped part |
| 1354 | * for accounting but it is being reduced so update accordingly. |
| 1355 | */ |
| 1356 | dm_io_set_flag(io, DM_IO_WAS_SPLIT); |
| 1357 | io->sectors = n_sectors; |
| 1358 | io->sector_offset = bio_sectors(io->orig_bio); |
| 1359 | } |
| 1360 | EXPORT_SYMBOL_GPL(dm_accept_partial_bio); |
| 1361 | |
| 1362 | /* |
| 1363 | * @clone: clone bio that DM core passed to target's .map function |
| 1364 | * @tgt_clone: clone of @clone bio that target needs submitted |
| 1365 | * |
| 1366 | * Targets should use this interface to submit bios they take |
| 1367 | * ownership of when returning DM_MAPIO_SUBMITTED. |
| 1368 | * |
| 1369 | * Target should also enable ti->accounts_remapped_io |
| 1370 | */ |
| 1371 | void dm_submit_bio_remap(struct bio *clone, struct bio *tgt_clone) |
| 1372 | { |
| 1373 | struct dm_target_io *tio = clone_to_tio(clone); |
| 1374 | struct dm_io *io = tio->io; |
| 1375 | |
| 1376 | /* establish bio that will get submitted */ |
| 1377 | if (!tgt_clone) |
| 1378 | tgt_clone = clone; |
| 1379 | |
| 1380 | /* |
| 1381 | * Account io->origin_bio to DM dev on behalf of target |
| 1382 | * that took ownership of IO with DM_MAPIO_SUBMITTED. |
| 1383 | */ |
| 1384 | dm_start_io_acct(io, clone); |
| 1385 | |
| 1386 | trace_block_bio_remap(tgt_clone, disk_devt(io->md->disk), |
| 1387 | tio->old_sector); |
| 1388 | submit_bio_noacct(tgt_clone); |
| 1389 | } |
| 1390 | EXPORT_SYMBOL_GPL(dm_submit_bio_remap); |
| 1391 | |
| 1392 | static noinline void __set_swap_bios_limit(struct mapped_device *md, int latch) |
| 1393 | { |
| 1394 | mutex_lock(&md->swap_bios_lock); |
| 1395 | while (latch < md->swap_bios) { |
| 1396 | cond_resched(); |
| 1397 | down(&md->swap_bios_semaphore); |
| 1398 | md->swap_bios--; |
| 1399 | } |
| 1400 | while (latch > md->swap_bios) { |
| 1401 | cond_resched(); |
| 1402 | up(&md->swap_bios_semaphore); |
| 1403 | md->swap_bios++; |
| 1404 | } |
| 1405 | mutex_unlock(&md->swap_bios_lock); |
| 1406 | } |
| 1407 | |
| 1408 | static void __map_bio(struct bio *clone) |
| 1409 | { |
| 1410 | struct dm_target_io *tio = clone_to_tio(clone); |
| 1411 | struct dm_target *ti = tio->ti; |
| 1412 | struct dm_io *io = tio->io; |
| 1413 | struct mapped_device *md = io->md; |
| 1414 | int r; |
| 1415 | |
| 1416 | clone->bi_end_io = clone_endio; |
| 1417 | |
| 1418 | /* |
| 1419 | * Map the clone. |
| 1420 | */ |
| 1421 | tio->old_sector = clone->bi_iter.bi_sector; |
| 1422 | |
| 1423 | if (static_branch_unlikely(&swap_bios_enabled) && |
| 1424 | unlikely(swap_bios_limit(ti, clone))) { |
| 1425 | int latch = get_swap_bios(); |
| 1426 | |
| 1427 | if (unlikely(latch != md->swap_bios)) |
| 1428 | __set_swap_bios_limit(md, latch); |
| 1429 | down(&md->swap_bios_semaphore); |
| 1430 | } |
| 1431 | |
| 1432 | if (likely(ti->type->map == linear_map)) |
| 1433 | r = linear_map(ti, clone); |
| 1434 | else if (ti->type->map == stripe_map) |
| 1435 | r = stripe_map(ti, clone); |
| 1436 | else |
| 1437 | r = ti->type->map(ti, clone); |
| 1438 | |
| 1439 | switch (r) { |
| 1440 | case DM_MAPIO_SUBMITTED: |
| 1441 | /* target has assumed ownership of this io */ |
| 1442 | if (!ti->accounts_remapped_io) |
| 1443 | dm_start_io_acct(io, clone); |
| 1444 | break; |
| 1445 | case DM_MAPIO_REMAPPED: |
| 1446 | dm_submit_bio_remap(clone, NULL); |
| 1447 | break; |
| 1448 | case DM_MAPIO_KILL: |
| 1449 | case DM_MAPIO_REQUEUE: |
| 1450 | if (static_branch_unlikely(&swap_bios_enabled) && |
| 1451 | unlikely(swap_bios_limit(ti, clone))) |
| 1452 | up(&md->swap_bios_semaphore); |
| 1453 | free_tio(clone); |
| 1454 | if (r == DM_MAPIO_KILL) |
| 1455 | dm_io_dec_pending(io, BLK_STS_IOERR); |
| 1456 | else |
| 1457 | dm_io_dec_pending(io, BLK_STS_DM_REQUEUE); |
| 1458 | break; |
| 1459 | default: |
| 1460 | DMCRIT("unimplemented target map return value: %d", r); |
| 1461 | BUG(); |
| 1462 | } |
| 1463 | } |
| 1464 | |
| 1465 | static void setup_split_accounting(struct clone_info *ci, unsigned int len) |
| 1466 | { |
| 1467 | struct dm_io *io = ci->io; |
| 1468 | |
| 1469 | if (ci->sector_count > len) { |
| 1470 | /* |
| 1471 | * Split needed, save the mapped part for accounting. |
| 1472 | * NOTE: dm_accept_partial_bio() will update accordingly. |
| 1473 | */ |
| 1474 | dm_io_set_flag(io, DM_IO_WAS_SPLIT); |
| 1475 | io->sectors = len; |
| 1476 | io->sector_offset = bio_sectors(ci->bio); |
| 1477 | } |
| 1478 | } |
| 1479 | |
| 1480 | static void alloc_multiple_bios(struct bio_list *blist, struct clone_info *ci, |
| 1481 | struct dm_target *ti, unsigned int num_bios, |
| 1482 | unsigned *len, gfp_t gfp_flag) |
| 1483 | { |
| 1484 | struct bio *bio; |
| 1485 | int try = (gfp_flag & GFP_NOWAIT) ? 0 : 1; |
| 1486 | |
| 1487 | for (; try < 2; try++) { |
| 1488 | int bio_nr; |
| 1489 | |
| 1490 | if (try && num_bios > 1) |
| 1491 | mutex_lock(&ci->io->md->table_devices_lock); |
| 1492 | for (bio_nr = 0; bio_nr < num_bios; bio_nr++) { |
| 1493 | bio = alloc_tio(ci, ti, bio_nr, len, |
| 1494 | try ? GFP_NOIO : GFP_NOWAIT); |
| 1495 | if (!bio) |
| 1496 | break; |
| 1497 | |
| 1498 | bio_list_add(blist, bio); |
| 1499 | } |
| 1500 | if (try && num_bios > 1) |
| 1501 | mutex_unlock(&ci->io->md->table_devices_lock); |
| 1502 | if (bio_nr == num_bios) |
| 1503 | return; |
| 1504 | |
| 1505 | while ((bio = bio_list_pop(blist))) |
| 1506 | free_tio(bio); |
| 1507 | } |
| 1508 | } |
| 1509 | |
| 1510 | static unsigned int __send_duplicate_bios(struct clone_info *ci, struct dm_target *ti, |
| 1511 | unsigned int num_bios, unsigned int *len, |
| 1512 | gfp_t gfp_flag) |
| 1513 | { |
| 1514 | struct bio_list blist = BIO_EMPTY_LIST; |
| 1515 | struct bio *clone; |
| 1516 | unsigned int ret = 0; |
| 1517 | |
| 1518 | if (WARN_ON_ONCE(num_bios == 0)) /* num_bios = 0 is a bug in caller */ |
| 1519 | return 0; |
| 1520 | |
| 1521 | /* dm_accept_partial_bio() is not supported with shared tio->len_ptr */ |
| 1522 | if (len) |
| 1523 | setup_split_accounting(ci, *len); |
| 1524 | |
| 1525 | /* |
| 1526 | * Using alloc_multiple_bios(), even if num_bios is 1, to consistently |
| 1527 | * support allocating using GFP_NOWAIT with GFP_NOIO fallback. |
| 1528 | */ |
| 1529 | alloc_multiple_bios(&blist, ci, ti, num_bios, len, gfp_flag); |
| 1530 | while ((clone = bio_list_pop(&blist))) { |
| 1531 | if (num_bios > 1) |
| 1532 | dm_tio_set_flag(clone_to_tio(clone), DM_TIO_IS_DUPLICATE_BIO); |
| 1533 | __map_bio(clone); |
| 1534 | ret += 1; |
| 1535 | } |
| 1536 | |
| 1537 | return ret; |
| 1538 | } |
| 1539 | |
| 1540 | static void __send_empty_flush(struct clone_info *ci) |
| 1541 | { |
| 1542 | struct dm_table *t = ci->map; |
| 1543 | struct bio flush_bio; |
| 1544 | |
| 1545 | /* |
| 1546 | * Use an on-stack bio for this, it's safe since we don't |
| 1547 | * need to reference it after submit. It's just used as |
| 1548 | * the basis for the clone(s). |
| 1549 | */ |
| 1550 | bio_init(&flush_bio, ci->io->md->disk->part0, NULL, 0, |
| 1551 | REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC); |
| 1552 | |
| 1553 | ci->bio = &flush_bio; |
| 1554 | ci->sector_count = 0; |
| 1555 | ci->io->tio.clone.bi_iter.bi_size = 0; |
| 1556 | |
| 1557 | if (!t->flush_bypasses_map) { |
| 1558 | for (unsigned int i = 0; i < t->num_targets; i++) { |
| 1559 | unsigned int bios; |
| 1560 | struct dm_target *ti = dm_table_get_target(t, i); |
| 1561 | |
| 1562 | if (unlikely(ti->num_flush_bios == 0)) |
| 1563 | continue; |
| 1564 | |
| 1565 | atomic_add(ti->num_flush_bios, &ci->io->io_count); |
| 1566 | bios = __send_duplicate_bios(ci, ti, ti->num_flush_bios, |
| 1567 | NULL, GFP_NOWAIT); |
| 1568 | atomic_sub(ti->num_flush_bios - bios, &ci->io->io_count); |
| 1569 | } |
| 1570 | } else { |
| 1571 | /* |
| 1572 | * Note that there's no need to grab t->devices_lock here |
| 1573 | * because the targets that support flush optimization don't |
| 1574 | * modify the list of devices. |
| 1575 | */ |
| 1576 | struct list_head *devices = dm_table_get_devices(t); |
| 1577 | unsigned int len = 0; |
| 1578 | struct dm_dev_internal *dd; |
| 1579 | list_for_each_entry(dd, devices, list) { |
| 1580 | struct bio *clone; |
| 1581 | /* |
| 1582 | * Note that the structure dm_target_io is not |
| 1583 | * associated with any target (because the device may be |
| 1584 | * used by multiple targets), so we set tio->ti = NULL. |
| 1585 | * We must check for NULL in the I/O processing path, to |
| 1586 | * avoid NULL pointer dereference. |
| 1587 | */ |
| 1588 | clone = alloc_tio(ci, NULL, 0, &len, GFP_NOIO); |
| 1589 | atomic_add(1, &ci->io->io_count); |
| 1590 | bio_set_dev(clone, dd->dm_dev->bdev); |
| 1591 | clone->bi_end_io = clone_endio; |
| 1592 | dm_submit_bio_remap(clone, NULL); |
| 1593 | } |
| 1594 | } |
| 1595 | |
| 1596 | /* |
| 1597 | * alloc_io() takes one extra reference for submission, so the |
| 1598 | * reference won't reach 0 without the following subtraction |
| 1599 | */ |
| 1600 | atomic_sub(1, &ci->io->io_count); |
| 1601 | |
| 1602 | bio_uninit(ci->bio); |
| 1603 | } |
| 1604 | |
| 1605 | static void __send_abnormal_io(struct clone_info *ci, struct dm_target *ti, |
| 1606 | unsigned int num_bios, unsigned int max_granularity, |
| 1607 | unsigned int max_sectors) |
| 1608 | { |
| 1609 | unsigned int len, bios; |
| 1610 | |
| 1611 | len = min_t(sector_t, ci->sector_count, |
| 1612 | __max_io_len(ti, ci->sector, max_granularity, max_sectors)); |
| 1613 | |
| 1614 | atomic_add(num_bios, &ci->io->io_count); |
| 1615 | bios = __send_duplicate_bios(ci, ti, num_bios, &len, GFP_NOIO); |
| 1616 | /* |
| 1617 | * alloc_io() takes one extra reference for submission, so the |
| 1618 | * reference won't reach 0 without the following (+1) subtraction |
| 1619 | */ |
| 1620 | atomic_sub(num_bios - bios + 1, &ci->io->io_count); |
| 1621 | |
| 1622 | ci->sector += len; |
| 1623 | ci->sector_count -= len; |
| 1624 | } |
| 1625 | |
| 1626 | static bool is_abnormal_io(struct bio *bio) |
| 1627 | { |
| 1628 | switch (bio_op(bio)) { |
| 1629 | case REQ_OP_READ: |
| 1630 | case REQ_OP_WRITE: |
| 1631 | case REQ_OP_FLUSH: |
| 1632 | return false; |
| 1633 | case REQ_OP_DISCARD: |
| 1634 | case REQ_OP_SECURE_ERASE: |
| 1635 | case REQ_OP_WRITE_ZEROES: |
| 1636 | case REQ_OP_ZONE_RESET_ALL: |
| 1637 | return true; |
| 1638 | default: |
| 1639 | return false; |
| 1640 | } |
| 1641 | } |
| 1642 | |
| 1643 | static blk_status_t __process_abnormal_io(struct clone_info *ci, |
| 1644 | struct dm_target *ti) |
| 1645 | { |
| 1646 | unsigned int num_bios = 0; |
| 1647 | unsigned int max_granularity = 0; |
| 1648 | unsigned int max_sectors = 0; |
| 1649 | struct queue_limits *limits = dm_get_queue_limits(ti->table->md); |
| 1650 | |
| 1651 | switch (bio_op(ci->bio)) { |
| 1652 | case REQ_OP_DISCARD: |
| 1653 | num_bios = ti->num_discard_bios; |
| 1654 | max_sectors = limits->max_discard_sectors; |
| 1655 | if (ti->max_discard_granularity) |
| 1656 | max_granularity = max_sectors; |
| 1657 | break; |
| 1658 | case REQ_OP_SECURE_ERASE: |
| 1659 | num_bios = ti->num_secure_erase_bios; |
| 1660 | max_sectors = limits->max_secure_erase_sectors; |
| 1661 | break; |
| 1662 | case REQ_OP_WRITE_ZEROES: |
| 1663 | num_bios = ti->num_write_zeroes_bios; |
| 1664 | max_sectors = limits->max_write_zeroes_sectors; |
| 1665 | break; |
| 1666 | default: |
| 1667 | break; |
| 1668 | } |
| 1669 | |
| 1670 | /* |
| 1671 | * Even though the device advertised support for this type of |
| 1672 | * request, that does not mean every target supports it, and |
| 1673 | * reconfiguration might also have changed that since the |
| 1674 | * check was performed. |
| 1675 | */ |
| 1676 | if (unlikely(!num_bios)) |
| 1677 | return BLK_STS_NOTSUPP; |
| 1678 | |
| 1679 | __send_abnormal_io(ci, ti, num_bios, max_granularity, max_sectors); |
| 1680 | |
| 1681 | return BLK_STS_OK; |
| 1682 | } |
| 1683 | |
| 1684 | /* |
| 1685 | * Reuse ->bi_private as dm_io list head for storing all dm_io instances |
| 1686 | * associated with this bio, and this bio's bi_private needs to be |
| 1687 | * stored in dm_io->data before the reuse. |
| 1688 | * |
| 1689 | * bio->bi_private is owned by fs or upper layer, so block layer won't |
| 1690 | * touch it after splitting. Meantime it won't be changed by anyone after |
| 1691 | * bio is submitted. So this reuse is safe. |
| 1692 | */ |
| 1693 | static inline struct dm_io **dm_poll_list_head(struct bio *bio) |
| 1694 | { |
| 1695 | return (struct dm_io **)&bio->bi_private; |
| 1696 | } |
| 1697 | |
| 1698 | static void dm_queue_poll_io(struct bio *bio, struct dm_io *io) |
| 1699 | { |
| 1700 | struct dm_io **head = dm_poll_list_head(bio); |
| 1701 | |
| 1702 | if (!(bio->bi_opf & REQ_DM_POLL_LIST)) { |
| 1703 | bio->bi_opf |= REQ_DM_POLL_LIST; |
| 1704 | /* |
| 1705 | * Save .bi_private into dm_io, so that we can reuse |
| 1706 | * .bi_private as dm_io list head for storing dm_io list |
| 1707 | */ |
| 1708 | io->data = bio->bi_private; |
| 1709 | |
| 1710 | /* tell block layer to poll for completion */ |
| 1711 | bio->bi_cookie = ~BLK_QC_T_NONE; |
| 1712 | |
| 1713 | io->next = NULL; |
| 1714 | } else { |
| 1715 | /* |
| 1716 | * bio recursed due to split, reuse original poll list, |
| 1717 | * and save bio->bi_private too. |
| 1718 | */ |
| 1719 | io->data = (*head)->data; |
| 1720 | io->next = *head; |
| 1721 | } |
| 1722 | |
| 1723 | *head = io; |
| 1724 | } |
| 1725 | |
| 1726 | /* |
| 1727 | * Select the correct strategy for processing a non-flush bio. |
| 1728 | */ |
| 1729 | static blk_status_t __split_and_process_bio(struct clone_info *ci) |
| 1730 | { |
| 1731 | struct bio *clone; |
| 1732 | struct dm_target *ti; |
| 1733 | unsigned int len; |
| 1734 | |
| 1735 | ti = dm_table_find_target(ci->map, ci->sector); |
| 1736 | if (unlikely(!ti)) |
| 1737 | return BLK_STS_IOERR; |
| 1738 | |
| 1739 | if (unlikely(ci->is_abnormal_io)) |
| 1740 | return __process_abnormal_io(ci, ti); |
| 1741 | |
| 1742 | /* |
| 1743 | * Only support bio polling for normal IO, and the target io is |
| 1744 | * exactly inside the dm_io instance (verified in dm_poll_dm_io) |
| 1745 | */ |
| 1746 | ci->submit_as_polled = !!(ci->bio->bi_opf & REQ_POLLED); |
| 1747 | |
| 1748 | len = min_t(sector_t, max_io_len(ti, ci->sector), ci->sector_count); |
| 1749 | setup_split_accounting(ci, len); |
| 1750 | |
| 1751 | if (unlikely(ci->bio->bi_opf & REQ_NOWAIT)) { |
| 1752 | if (unlikely(!dm_target_supports_nowait(ti->type))) |
| 1753 | return BLK_STS_NOTSUPP; |
| 1754 | |
| 1755 | clone = alloc_tio(ci, ti, 0, &len, GFP_NOWAIT); |
| 1756 | if (unlikely(!clone)) |
| 1757 | return BLK_STS_AGAIN; |
| 1758 | } else { |
| 1759 | clone = alloc_tio(ci, ti, 0, &len, GFP_NOIO); |
| 1760 | } |
| 1761 | __map_bio(clone); |
| 1762 | |
| 1763 | ci->sector += len; |
| 1764 | ci->sector_count -= len; |
| 1765 | |
| 1766 | return BLK_STS_OK; |
| 1767 | } |
| 1768 | |
| 1769 | static void init_clone_info(struct clone_info *ci, struct dm_io *io, |
| 1770 | struct dm_table *map, struct bio *bio, bool is_abnormal) |
| 1771 | { |
| 1772 | ci->map = map; |
| 1773 | ci->io = io; |
| 1774 | ci->bio = bio; |
| 1775 | ci->is_abnormal_io = is_abnormal; |
| 1776 | ci->submit_as_polled = false; |
| 1777 | ci->sector = bio->bi_iter.bi_sector; |
| 1778 | ci->sector_count = bio_sectors(bio); |
| 1779 | |
| 1780 | /* Shouldn't happen but sector_count was being set to 0 so... */ |
| 1781 | if (static_branch_unlikely(&zoned_enabled) && |
| 1782 | WARN_ON_ONCE(op_is_zone_mgmt(bio_op(bio)) && ci->sector_count)) |
| 1783 | ci->sector_count = 0; |
| 1784 | } |
| 1785 | |
| 1786 | #ifdef CONFIG_BLK_DEV_ZONED |
| 1787 | static inline bool dm_zone_bio_needs_split(struct mapped_device *md, |
| 1788 | struct bio *bio) |
| 1789 | { |
| 1790 | /* |
| 1791 | * For mapped device that need zone append emulation, we must |
| 1792 | * split any large BIO that straddles zone boundaries. |
| 1793 | */ |
| 1794 | return dm_emulate_zone_append(md) && bio_straddles_zones(bio) && |
| 1795 | !bio_flagged(bio, BIO_ZONE_WRITE_PLUGGING); |
| 1796 | } |
| 1797 | static inline bool dm_zone_plug_bio(struct mapped_device *md, struct bio *bio) |
| 1798 | { |
| 1799 | return dm_emulate_zone_append(md) && blk_zone_plug_bio(bio, 0); |
| 1800 | } |
| 1801 | |
| 1802 | static blk_status_t __send_zone_reset_all_emulated(struct clone_info *ci, |
| 1803 | struct dm_target *ti) |
| 1804 | { |
| 1805 | struct bio_list blist = BIO_EMPTY_LIST; |
| 1806 | struct mapped_device *md = ci->io->md; |
| 1807 | unsigned int zone_sectors = md->disk->queue->limits.chunk_sectors; |
| 1808 | unsigned long *need_reset; |
| 1809 | unsigned int i, nr_zones, nr_reset; |
| 1810 | unsigned int num_bios = 0; |
| 1811 | blk_status_t sts = BLK_STS_OK; |
| 1812 | sector_t sector = ti->begin; |
| 1813 | struct bio *clone; |
| 1814 | int ret; |
| 1815 | |
| 1816 | nr_zones = ti->len >> ilog2(zone_sectors); |
| 1817 | need_reset = bitmap_zalloc(nr_zones, GFP_NOIO); |
| 1818 | if (!need_reset) |
| 1819 | return BLK_STS_RESOURCE; |
| 1820 | |
| 1821 | ret = dm_zone_get_reset_bitmap(md, ci->map, ti->begin, |
| 1822 | nr_zones, need_reset); |
| 1823 | if (ret) { |
| 1824 | sts = BLK_STS_IOERR; |
| 1825 | goto free_bitmap; |
| 1826 | } |
| 1827 | |
| 1828 | /* If we have no zone to reset, we are done. */ |
| 1829 | nr_reset = bitmap_weight(need_reset, nr_zones); |
| 1830 | if (!nr_reset) |
| 1831 | goto free_bitmap; |
| 1832 | |
| 1833 | atomic_add(nr_zones, &ci->io->io_count); |
| 1834 | |
| 1835 | for (i = 0; i < nr_zones; i++) { |
| 1836 | |
| 1837 | if (!test_bit(i, need_reset)) { |
| 1838 | sector += zone_sectors; |
| 1839 | continue; |
| 1840 | } |
| 1841 | |
| 1842 | if (bio_list_empty(&blist)) { |
| 1843 | /* This may take a while, so be nice to others */ |
| 1844 | if (num_bios) |
| 1845 | cond_resched(); |
| 1846 | |
| 1847 | /* |
| 1848 | * We may need to reset thousands of zones, so let's |
| 1849 | * not go crazy with the clone allocation. |
| 1850 | */ |
| 1851 | alloc_multiple_bios(&blist, ci, ti, min(nr_reset, 32), |
| 1852 | NULL, GFP_NOIO); |
| 1853 | } |
| 1854 | |
| 1855 | /* Get a clone and change it to a regular reset operation. */ |
| 1856 | clone = bio_list_pop(&blist); |
| 1857 | clone->bi_opf &= ~REQ_OP_MASK; |
| 1858 | clone->bi_opf |= REQ_OP_ZONE_RESET | REQ_SYNC; |
| 1859 | clone->bi_iter.bi_sector = sector; |
| 1860 | clone->bi_iter.bi_size = 0; |
| 1861 | __map_bio(clone); |
| 1862 | |
| 1863 | sector += zone_sectors; |
| 1864 | num_bios++; |
| 1865 | nr_reset--; |
| 1866 | } |
| 1867 | |
| 1868 | WARN_ON_ONCE(!bio_list_empty(&blist)); |
| 1869 | atomic_sub(nr_zones - num_bios, &ci->io->io_count); |
| 1870 | ci->sector_count = 0; |
| 1871 | |
| 1872 | free_bitmap: |
| 1873 | bitmap_free(need_reset); |
| 1874 | |
| 1875 | return sts; |
| 1876 | } |
| 1877 | |
| 1878 | static void __send_zone_reset_all_native(struct clone_info *ci, |
| 1879 | struct dm_target *ti) |
| 1880 | { |
| 1881 | unsigned int bios; |
| 1882 | |
| 1883 | atomic_add(1, &ci->io->io_count); |
| 1884 | bios = __send_duplicate_bios(ci, ti, 1, NULL, GFP_NOIO); |
| 1885 | atomic_sub(1 - bios, &ci->io->io_count); |
| 1886 | |
| 1887 | ci->sector_count = 0; |
| 1888 | } |
| 1889 | |
| 1890 | static blk_status_t __send_zone_reset_all(struct clone_info *ci) |
| 1891 | { |
| 1892 | struct dm_table *t = ci->map; |
| 1893 | blk_status_t sts = BLK_STS_OK; |
| 1894 | |
| 1895 | for (unsigned int i = 0; i < t->num_targets; i++) { |
| 1896 | struct dm_target *ti = dm_table_get_target(t, i); |
| 1897 | |
| 1898 | if (ti->zone_reset_all_supported) { |
| 1899 | __send_zone_reset_all_native(ci, ti); |
| 1900 | continue; |
| 1901 | } |
| 1902 | |
| 1903 | sts = __send_zone_reset_all_emulated(ci, ti); |
| 1904 | if (sts != BLK_STS_OK) |
| 1905 | break; |
| 1906 | } |
| 1907 | |
| 1908 | /* Release the reference that alloc_io() took for submission. */ |
| 1909 | atomic_sub(1, &ci->io->io_count); |
| 1910 | |
| 1911 | return sts; |
| 1912 | } |
| 1913 | |
| 1914 | #else |
| 1915 | static inline bool dm_zone_bio_needs_split(struct mapped_device *md, |
| 1916 | struct bio *bio) |
| 1917 | { |
| 1918 | return false; |
| 1919 | } |
| 1920 | static inline bool dm_zone_plug_bio(struct mapped_device *md, struct bio *bio) |
| 1921 | { |
| 1922 | return false; |
| 1923 | } |
| 1924 | static blk_status_t __send_zone_reset_all(struct clone_info *ci) |
| 1925 | { |
| 1926 | return BLK_STS_NOTSUPP; |
| 1927 | } |
| 1928 | #endif |
| 1929 | |
| 1930 | /* |
| 1931 | * Entry point to split a bio into clones and submit them to the targets. |
| 1932 | */ |
| 1933 | static void dm_split_and_process_bio(struct mapped_device *md, |
| 1934 | struct dm_table *map, struct bio *bio) |
| 1935 | { |
| 1936 | struct clone_info ci; |
| 1937 | struct dm_io *io; |
| 1938 | blk_status_t error = BLK_STS_OK; |
| 1939 | bool is_abnormal, need_split; |
| 1940 | |
| 1941 | is_abnormal = is_abnormal_io(bio); |
| 1942 | if (static_branch_unlikely(&zoned_enabled)) { |
| 1943 | /* Special case REQ_OP_ZONE_RESET_ALL as it cannot be split. */ |
| 1944 | need_split = (bio_op(bio) != REQ_OP_ZONE_RESET_ALL) && |
| 1945 | (is_abnormal || dm_zone_bio_needs_split(md, bio)); |
| 1946 | } else { |
| 1947 | need_split = is_abnormal; |
| 1948 | } |
| 1949 | |
| 1950 | if (unlikely(need_split)) { |
| 1951 | /* |
| 1952 | * Use bio_split_to_limits() for abnormal IO (e.g. discard, etc) |
| 1953 | * otherwise associated queue_limits won't be imposed. |
| 1954 | * Also split the BIO for mapped devices needing zone append |
| 1955 | * emulation to ensure that the BIO does not cross zone |
| 1956 | * boundaries. |
| 1957 | */ |
| 1958 | bio = bio_split_to_limits(bio); |
| 1959 | if (!bio) |
| 1960 | return; |
| 1961 | } |
| 1962 | |
| 1963 | /* |
| 1964 | * Use the block layer zone write plugging for mapped devices that |
| 1965 | * need zone append emulation (e.g. dm-crypt). |
| 1966 | */ |
| 1967 | if (static_branch_unlikely(&zoned_enabled) && dm_zone_plug_bio(md, bio)) |
| 1968 | return; |
| 1969 | |
| 1970 | /* Only support nowait for normal IO */ |
| 1971 | if (unlikely(bio->bi_opf & REQ_NOWAIT) && !is_abnormal) { |
| 1972 | io = alloc_io(md, bio, GFP_NOWAIT); |
| 1973 | if (unlikely(!io)) { |
| 1974 | /* Unable to do anything without dm_io. */ |
| 1975 | bio_wouldblock_error(bio); |
| 1976 | return; |
| 1977 | } |
| 1978 | } else { |
| 1979 | io = alloc_io(md, bio, GFP_NOIO); |
| 1980 | } |
| 1981 | init_clone_info(&ci, io, map, bio, is_abnormal); |
| 1982 | |
| 1983 | if (bio->bi_opf & REQ_PREFLUSH) { |
| 1984 | __send_empty_flush(&ci); |
| 1985 | /* dm_io_complete submits any data associated with flush */ |
| 1986 | goto out; |
| 1987 | } |
| 1988 | |
| 1989 | if (static_branch_unlikely(&zoned_enabled) && |
| 1990 | (bio_op(bio) == REQ_OP_ZONE_RESET_ALL)) { |
| 1991 | error = __send_zone_reset_all(&ci); |
| 1992 | goto out; |
| 1993 | } |
| 1994 | |
| 1995 | error = __split_and_process_bio(&ci); |
| 1996 | if (error || !ci.sector_count) |
| 1997 | goto out; |
| 1998 | /* |
| 1999 | * Remainder must be passed to submit_bio_noacct() so it gets handled |
| 2000 | * *after* bios already submitted have been completely processed. |
| 2001 | */ |
| 2002 | bio_trim(bio, io->sectors, ci.sector_count); |
| 2003 | trace_block_split(bio, bio->bi_iter.bi_sector); |
| 2004 | bio_inc_remaining(bio); |
| 2005 | submit_bio_noacct(bio); |
| 2006 | out: |
| 2007 | /* |
| 2008 | * Drop the extra reference count for non-POLLED bio, and hold one |
| 2009 | * reference for POLLED bio, which will be released in dm_poll_bio |
| 2010 | * |
| 2011 | * Add every dm_io instance into the dm_io list head which is stored |
| 2012 | * in bio->bi_private, so that dm_poll_bio can poll them all. |
| 2013 | */ |
| 2014 | if (error || !ci.submit_as_polled) { |
| 2015 | /* |
| 2016 | * In case of submission failure, the extra reference for |
| 2017 | * submitting io isn't consumed yet |
| 2018 | */ |
| 2019 | if (error) |
| 2020 | atomic_dec(&io->io_count); |
| 2021 | dm_io_dec_pending(io, error); |
| 2022 | } else |
| 2023 | dm_queue_poll_io(bio, io); |
| 2024 | } |
| 2025 | |
| 2026 | static void dm_submit_bio(struct bio *bio) |
| 2027 | { |
| 2028 | struct mapped_device *md = bio->bi_bdev->bd_disk->private_data; |
| 2029 | int srcu_idx; |
| 2030 | struct dm_table *map; |
| 2031 | |
| 2032 | map = dm_get_live_table(md, &srcu_idx); |
| 2033 | if (unlikely(!map)) { |
| 2034 | DMERR_LIMIT("%s: mapping table unavailable, erroring io", |
| 2035 | dm_device_name(md)); |
| 2036 | bio_io_error(bio); |
| 2037 | goto out; |
| 2038 | } |
| 2039 | |
| 2040 | /* If suspended, queue this IO for later */ |
| 2041 | if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags))) { |
| 2042 | if (bio->bi_opf & REQ_NOWAIT) |
| 2043 | bio_wouldblock_error(bio); |
| 2044 | else if (bio->bi_opf & REQ_RAHEAD) |
| 2045 | bio_io_error(bio); |
| 2046 | else |
| 2047 | queue_io(md, bio); |
| 2048 | goto out; |
| 2049 | } |
| 2050 | |
| 2051 | dm_split_and_process_bio(md, map, bio); |
| 2052 | out: |
| 2053 | dm_put_live_table(md, srcu_idx); |
| 2054 | } |
| 2055 | |
| 2056 | static bool dm_poll_dm_io(struct dm_io *io, struct io_comp_batch *iob, |
| 2057 | unsigned int flags) |
| 2058 | { |
| 2059 | WARN_ON_ONCE(!dm_tio_is_normal(&io->tio)); |
| 2060 | |
| 2061 | /* don't poll if the mapped io is done */ |
| 2062 | if (atomic_read(&io->io_count) > 1) |
| 2063 | bio_poll(&io->tio.clone, iob, flags); |
| 2064 | |
| 2065 | /* bio_poll holds the last reference */ |
| 2066 | return atomic_read(&io->io_count) == 1; |
| 2067 | } |
| 2068 | |
| 2069 | static int dm_poll_bio(struct bio *bio, struct io_comp_batch *iob, |
| 2070 | unsigned int flags) |
| 2071 | { |
| 2072 | struct dm_io **head = dm_poll_list_head(bio); |
| 2073 | struct dm_io *list = *head; |
| 2074 | struct dm_io *tmp = NULL; |
| 2075 | struct dm_io *curr, *next; |
| 2076 | |
| 2077 | /* Only poll normal bio which was marked as REQ_DM_POLL_LIST */ |
| 2078 | if (!(bio->bi_opf & REQ_DM_POLL_LIST)) |
| 2079 | return 0; |
| 2080 | |
| 2081 | WARN_ON_ONCE(!list); |
| 2082 | |
| 2083 | /* |
| 2084 | * Restore .bi_private before possibly completing dm_io. |
| 2085 | * |
| 2086 | * bio_poll() is only possible once @bio has been completely |
| 2087 | * submitted via submit_bio_noacct()'s depth-first submission. |
| 2088 | * So there is no dm_queue_poll_io() race associated with |
| 2089 | * clearing REQ_DM_POLL_LIST here. |
| 2090 | */ |
| 2091 | bio->bi_opf &= ~REQ_DM_POLL_LIST; |
| 2092 | bio->bi_private = list->data; |
| 2093 | |
| 2094 | for (curr = list, next = curr->next; curr; curr = next, next = |
| 2095 | curr ? curr->next : NULL) { |
| 2096 | if (dm_poll_dm_io(curr, iob, flags)) { |
| 2097 | /* |
| 2098 | * clone_endio() has already occurred, so no |
| 2099 | * error handling is needed here. |
| 2100 | */ |
| 2101 | __dm_io_dec_pending(curr); |
| 2102 | } else { |
| 2103 | curr->next = tmp; |
| 2104 | tmp = curr; |
| 2105 | } |
| 2106 | } |
| 2107 | |
| 2108 | /* Not done? */ |
| 2109 | if (tmp) { |
| 2110 | bio->bi_opf |= REQ_DM_POLL_LIST; |
| 2111 | /* Reset bio->bi_private to dm_io list head */ |
| 2112 | *head = tmp; |
| 2113 | return 0; |
| 2114 | } |
| 2115 | return 1; |
| 2116 | } |
| 2117 | |
| 2118 | /* |
| 2119 | *--------------------------------------------------------------- |
| 2120 | * An IDR is used to keep track of allocated minor numbers. |
| 2121 | *--------------------------------------------------------------- |
| 2122 | */ |
| 2123 | static void free_minor(int minor) |
| 2124 | { |
| 2125 | spin_lock(&_minor_lock); |
| 2126 | idr_remove(&_minor_idr, minor); |
| 2127 | spin_unlock(&_minor_lock); |
| 2128 | } |
| 2129 | |
| 2130 | /* |
| 2131 | * See if the device with a specific minor # is free. |
| 2132 | */ |
| 2133 | static int specific_minor(int minor) |
| 2134 | { |
| 2135 | int r; |
| 2136 | |
| 2137 | if (minor >= (1 << MINORBITS)) |
| 2138 | return -EINVAL; |
| 2139 | |
| 2140 | idr_preload(GFP_KERNEL); |
| 2141 | spin_lock(&_minor_lock); |
| 2142 | |
| 2143 | r = idr_alloc(&_minor_idr, MINOR_ALLOCED, minor, minor + 1, GFP_NOWAIT); |
| 2144 | |
| 2145 | spin_unlock(&_minor_lock); |
| 2146 | idr_preload_end(); |
| 2147 | if (r < 0) |
| 2148 | return r == -ENOSPC ? -EBUSY : r; |
| 2149 | return 0; |
| 2150 | } |
| 2151 | |
| 2152 | static int next_free_minor(int *minor) |
| 2153 | { |
| 2154 | int r; |
| 2155 | |
| 2156 | idr_preload(GFP_KERNEL); |
| 2157 | spin_lock(&_minor_lock); |
| 2158 | |
| 2159 | r = idr_alloc(&_minor_idr, MINOR_ALLOCED, 0, 1 << MINORBITS, GFP_NOWAIT); |
| 2160 | |
| 2161 | spin_unlock(&_minor_lock); |
| 2162 | idr_preload_end(); |
| 2163 | if (r < 0) |
| 2164 | return r; |
| 2165 | *minor = r; |
| 2166 | return 0; |
| 2167 | } |
| 2168 | |
| 2169 | static const struct block_device_operations dm_blk_dops; |
| 2170 | static const struct block_device_operations dm_rq_blk_dops; |
| 2171 | static const struct dax_operations dm_dax_ops; |
| 2172 | |
| 2173 | static void dm_wq_work(struct work_struct *work); |
| 2174 | |
| 2175 | #ifdef CONFIG_BLK_INLINE_ENCRYPTION |
| 2176 | static void dm_queue_destroy_crypto_profile(struct request_queue *q) |
| 2177 | { |
| 2178 | dm_destroy_crypto_profile(q->crypto_profile); |
| 2179 | } |
| 2180 | |
| 2181 | #else /* CONFIG_BLK_INLINE_ENCRYPTION */ |
| 2182 | |
| 2183 | static inline void dm_queue_destroy_crypto_profile(struct request_queue *q) |
| 2184 | { |
| 2185 | } |
| 2186 | #endif /* !CONFIG_BLK_INLINE_ENCRYPTION */ |
| 2187 | |
| 2188 | static void cleanup_mapped_device(struct mapped_device *md) |
| 2189 | { |
| 2190 | if (md->wq) |
| 2191 | destroy_workqueue(md->wq); |
| 2192 | dm_free_md_mempools(md->mempools); |
| 2193 | |
| 2194 | if (md->dax_dev) { |
| 2195 | dax_remove_host(md->disk); |
| 2196 | kill_dax(md->dax_dev); |
| 2197 | put_dax(md->dax_dev); |
| 2198 | md->dax_dev = NULL; |
| 2199 | } |
| 2200 | |
| 2201 | if (md->disk) { |
| 2202 | spin_lock(&_minor_lock); |
| 2203 | md->disk->private_data = NULL; |
| 2204 | spin_unlock(&_minor_lock); |
| 2205 | if (dm_get_md_type(md) != DM_TYPE_NONE) { |
| 2206 | struct table_device *td; |
| 2207 | |
| 2208 | dm_sysfs_exit(md); |
| 2209 | list_for_each_entry(td, &md->table_devices, list) { |
| 2210 | bd_unlink_disk_holder(td->dm_dev.bdev, |
| 2211 | md->disk); |
| 2212 | } |
| 2213 | |
| 2214 | /* |
| 2215 | * Hold lock to make sure del_gendisk() won't concurrent |
| 2216 | * with open/close_table_device(). |
| 2217 | */ |
| 2218 | mutex_lock(&md->table_devices_lock); |
| 2219 | del_gendisk(md->disk); |
| 2220 | mutex_unlock(&md->table_devices_lock); |
| 2221 | } |
| 2222 | dm_queue_destroy_crypto_profile(md->queue); |
| 2223 | put_disk(md->disk); |
| 2224 | } |
| 2225 | |
| 2226 | if (md->pending_io) { |
| 2227 | free_percpu(md->pending_io); |
| 2228 | md->pending_io = NULL; |
| 2229 | } |
| 2230 | |
| 2231 | cleanup_srcu_struct(&md->io_barrier); |
| 2232 | |
| 2233 | mutex_destroy(&md->suspend_lock); |
| 2234 | mutex_destroy(&md->type_lock); |
| 2235 | mutex_destroy(&md->table_devices_lock); |
| 2236 | mutex_destroy(&md->swap_bios_lock); |
| 2237 | |
| 2238 | dm_mq_cleanup_mapped_device(md); |
| 2239 | } |
| 2240 | |
| 2241 | /* |
| 2242 | * Allocate and initialise a blank device with a given minor. |
| 2243 | */ |
| 2244 | static struct mapped_device *alloc_dev(int minor) |
| 2245 | { |
| 2246 | int r, numa_node_id = dm_get_numa_node(); |
| 2247 | struct dax_device *dax_dev; |
| 2248 | struct mapped_device *md; |
| 2249 | void *old_md; |
| 2250 | |
| 2251 | md = kvzalloc_node(sizeof(*md), GFP_KERNEL, numa_node_id); |
| 2252 | if (!md) { |
| 2253 | DMERR("unable to allocate device, out of memory."); |
| 2254 | return NULL; |
| 2255 | } |
| 2256 | |
| 2257 | if (!try_module_get(THIS_MODULE)) |
| 2258 | goto bad_module_get; |
| 2259 | |
| 2260 | /* get a minor number for the dev */ |
| 2261 | if (minor == DM_ANY_MINOR) |
| 2262 | r = next_free_minor(&minor); |
| 2263 | else |
| 2264 | r = specific_minor(minor); |
| 2265 | if (r < 0) |
| 2266 | goto bad_minor; |
| 2267 | |
| 2268 | r = init_srcu_struct(&md->io_barrier); |
| 2269 | if (r < 0) |
| 2270 | goto bad_io_barrier; |
| 2271 | |
| 2272 | md->numa_node_id = numa_node_id; |
| 2273 | md->init_tio_pdu = false; |
| 2274 | md->type = DM_TYPE_NONE; |
| 2275 | mutex_init(&md->suspend_lock); |
| 2276 | mutex_init(&md->type_lock); |
| 2277 | mutex_init(&md->table_devices_lock); |
| 2278 | spin_lock_init(&md->deferred_lock); |
| 2279 | atomic_set(&md->holders, 1); |
| 2280 | atomic_set(&md->open_count, 0); |
| 2281 | atomic_set(&md->event_nr, 0); |
| 2282 | atomic_set(&md->uevent_seq, 0); |
| 2283 | INIT_LIST_HEAD(&md->uevent_list); |
| 2284 | INIT_LIST_HEAD(&md->table_devices); |
| 2285 | spin_lock_init(&md->uevent_lock); |
| 2286 | |
| 2287 | /* |
| 2288 | * default to bio-based until DM table is loaded and md->type |
| 2289 | * established. If request-based table is loaded: blk-mq will |
| 2290 | * override accordingly. |
| 2291 | */ |
| 2292 | md->disk = blk_alloc_disk(NULL, md->numa_node_id); |
| 2293 | if (IS_ERR(md->disk)) |
| 2294 | goto bad; |
| 2295 | md->queue = md->disk->queue; |
| 2296 | |
| 2297 | init_waitqueue_head(&md->wait); |
| 2298 | INIT_WORK(&md->work, dm_wq_work); |
| 2299 | INIT_WORK(&md->requeue_work, dm_wq_requeue_work); |
| 2300 | init_waitqueue_head(&md->eventq); |
| 2301 | init_completion(&md->kobj_holder.completion); |
| 2302 | |
| 2303 | md->requeue_list = NULL; |
| 2304 | md->swap_bios = get_swap_bios(); |
| 2305 | sema_init(&md->swap_bios_semaphore, md->swap_bios); |
| 2306 | mutex_init(&md->swap_bios_lock); |
| 2307 | |
| 2308 | md->disk->major = _major; |
| 2309 | md->disk->first_minor = minor; |
| 2310 | md->disk->minors = 1; |
| 2311 | md->disk->flags |= GENHD_FL_NO_PART; |
| 2312 | md->disk->fops = &dm_blk_dops; |
| 2313 | md->disk->private_data = md; |
| 2314 | sprintf(md->disk->disk_name, "dm-%d", minor); |
| 2315 | |
| 2316 | dax_dev = alloc_dax(md, &dm_dax_ops); |
| 2317 | if (IS_ERR(dax_dev)) { |
| 2318 | if (PTR_ERR(dax_dev) != -EOPNOTSUPP) |
| 2319 | goto bad; |
| 2320 | } else { |
| 2321 | set_dax_nocache(dax_dev); |
| 2322 | set_dax_nomc(dax_dev); |
| 2323 | md->dax_dev = dax_dev; |
| 2324 | if (dax_add_host(dax_dev, md->disk)) |
| 2325 | goto bad; |
| 2326 | } |
| 2327 | |
| 2328 | format_dev_t(md->name, MKDEV(_major, minor)); |
| 2329 | |
| 2330 | md->wq = alloc_workqueue("kdmflush/%s", WQ_MEM_RECLAIM, 0, md->name); |
| 2331 | if (!md->wq) |
| 2332 | goto bad; |
| 2333 | |
| 2334 | md->pending_io = alloc_percpu(unsigned long); |
| 2335 | if (!md->pending_io) |
| 2336 | goto bad; |
| 2337 | |
| 2338 | r = dm_stats_init(&md->stats); |
| 2339 | if (r < 0) |
| 2340 | goto bad; |
| 2341 | |
| 2342 | /* Populate the mapping, nobody knows we exist yet */ |
| 2343 | spin_lock(&_minor_lock); |
| 2344 | old_md = idr_replace(&_minor_idr, md, minor); |
| 2345 | spin_unlock(&_minor_lock); |
| 2346 | |
| 2347 | BUG_ON(old_md != MINOR_ALLOCED); |
| 2348 | |
| 2349 | return md; |
| 2350 | |
| 2351 | bad: |
| 2352 | cleanup_mapped_device(md); |
| 2353 | bad_io_barrier: |
| 2354 | free_minor(minor); |
| 2355 | bad_minor: |
| 2356 | module_put(THIS_MODULE); |
| 2357 | bad_module_get: |
| 2358 | kvfree(md); |
| 2359 | return NULL; |
| 2360 | } |
| 2361 | |
| 2362 | static void unlock_fs(struct mapped_device *md); |
| 2363 | |
| 2364 | static void free_dev(struct mapped_device *md) |
| 2365 | { |
| 2366 | int minor = MINOR(disk_devt(md->disk)); |
| 2367 | |
| 2368 | unlock_fs(md); |
| 2369 | |
| 2370 | cleanup_mapped_device(md); |
| 2371 | |
| 2372 | WARN_ON_ONCE(!list_empty(&md->table_devices)); |
| 2373 | dm_stats_cleanup(&md->stats); |
| 2374 | free_minor(minor); |
| 2375 | |
| 2376 | module_put(THIS_MODULE); |
| 2377 | kvfree(md); |
| 2378 | } |
| 2379 | |
| 2380 | /* |
| 2381 | * Bind a table to the device. |
| 2382 | */ |
| 2383 | static void event_callback(void *context) |
| 2384 | { |
| 2385 | unsigned long flags; |
| 2386 | LIST_HEAD(uevents); |
| 2387 | struct mapped_device *md = context; |
| 2388 | |
| 2389 | spin_lock_irqsave(&md->uevent_lock, flags); |
| 2390 | list_splice_init(&md->uevent_list, &uevents); |
| 2391 | spin_unlock_irqrestore(&md->uevent_lock, flags); |
| 2392 | |
| 2393 | dm_send_uevents(&uevents, &disk_to_dev(md->disk)->kobj); |
| 2394 | |
| 2395 | atomic_inc(&md->event_nr); |
| 2396 | wake_up(&md->eventq); |
| 2397 | dm_issue_global_event(); |
| 2398 | } |
| 2399 | |
| 2400 | /* |
| 2401 | * Returns old map, which caller must destroy. |
| 2402 | */ |
| 2403 | static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t, |
| 2404 | struct queue_limits *limits) |
| 2405 | { |
| 2406 | struct dm_table *old_map; |
| 2407 | sector_t size; |
| 2408 | int ret; |
| 2409 | |
| 2410 | lockdep_assert_held(&md->suspend_lock); |
| 2411 | |
| 2412 | size = dm_table_get_size(t); |
| 2413 | |
| 2414 | /* |
| 2415 | * Wipe any geometry if the size of the table changed. |
| 2416 | */ |
| 2417 | if (size != dm_get_size(md)) |
| 2418 | memset(&md->geometry, 0, sizeof(md->geometry)); |
| 2419 | |
| 2420 | set_capacity(md->disk, size); |
| 2421 | |
| 2422 | dm_table_event_callback(t, event_callback, md); |
| 2423 | |
| 2424 | if (dm_table_request_based(t)) { |
| 2425 | /* |
| 2426 | * Leverage the fact that request-based DM targets are |
| 2427 | * immutable singletons - used to optimize dm_mq_queue_rq. |
| 2428 | */ |
| 2429 | md->immutable_target = dm_table_get_immutable_target(t); |
| 2430 | |
| 2431 | /* |
| 2432 | * There is no need to reload with request-based dm because the |
| 2433 | * size of front_pad doesn't change. |
| 2434 | * |
| 2435 | * Note for future: If you are to reload bioset, prep-ed |
| 2436 | * requests in the queue may refer to bio from the old bioset, |
| 2437 | * so you must walk through the queue to unprep. |
| 2438 | */ |
| 2439 | if (!md->mempools) { |
| 2440 | md->mempools = t->mempools; |
| 2441 | t->mempools = NULL; |
| 2442 | } |
| 2443 | } else { |
| 2444 | /* |
| 2445 | * The md may already have mempools that need changing. |
| 2446 | * If so, reload bioset because front_pad may have changed |
| 2447 | * because a different table was loaded. |
| 2448 | */ |
| 2449 | dm_free_md_mempools(md->mempools); |
| 2450 | md->mempools = t->mempools; |
| 2451 | t->mempools = NULL; |
| 2452 | } |
| 2453 | |
| 2454 | ret = dm_table_set_restrictions(t, md->queue, limits); |
| 2455 | if (ret) { |
| 2456 | old_map = ERR_PTR(ret); |
| 2457 | goto out; |
| 2458 | } |
| 2459 | |
| 2460 | old_map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock)); |
| 2461 | rcu_assign_pointer(md->map, (void *)t); |
| 2462 | md->immutable_target_type = dm_table_get_immutable_target_type(t); |
| 2463 | |
| 2464 | if (old_map) |
| 2465 | dm_sync_table(md); |
| 2466 | out: |
| 2467 | return old_map; |
| 2468 | } |
| 2469 | |
| 2470 | /* |
| 2471 | * Returns unbound table for the caller to free. |
| 2472 | */ |
| 2473 | static struct dm_table *__unbind(struct mapped_device *md) |
| 2474 | { |
| 2475 | struct dm_table *map = rcu_dereference_protected(md->map, 1); |
| 2476 | |
| 2477 | if (!map) |
| 2478 | return NULL; |
| 2479 | |
| 2480 | dm_table_event_callback(map, NULL, NULL); |
| 2481 | RCU_INIT_POINTER(md->map, NULL); |
| 2482 | dm_sync_table(md); |
| 2483 | |
| 2484 | return map; |
| 2485 | } |
| 2486 | |
| 2487 | /* |
| 2488 | * Constructor for a new device. |
| 2489 | */ |
| 2490 | int dm_create(int minor, struct mapped_device **result) |
| 2491 | { |
| 2492 | struct mapped_device *md; |
| 2493 | |
| 2494 | md = alloc_dev(minor); |
| 2495 | if (!md) |
| 2496 | return -ENXIO; |
| 2497 | |
| 2498 | dm_ima_reset_data(md); |
| 2499 | |
| 2500 | *result = md; |
| 2501 | return 0; |
| 2502 | } |
| 2503 | |
| 2504 | /* |
| 2505 | * Functions to manage md->type. |
| 2506 | * All are required to hold md->type_lock. |
| 2507 | */ |
| 2508 | void dm_lock_md_type(struct mapped_device *md) |
| 2509 | { |
| 2510 | mutex_lock(&md->type_lock); |
| 2511 | } |
| 2512 | |
| 2513 | void dm_unlock_md_type(struct mapped_device *md) |
| 2514 | { |
| 2515 | mutex_unlock(&md->type_lock); |
| 2516 | } |
| 2517 | |
| 2518 | void dm_set_md_type(struct mapped_device *md, enum dm_queue_mode type) |
| 2519 | { |
| 2520 | BUG_ON(!mutex_is_locked(&md->type_lock)); |
| 2521 | md->type = type; |
| 2522 | } |
| 2523 | |
| 2524 | enum dm_queue_mode dm_get_md_type(struct mapped_device *md) |
| 2525 | { |
| 2526 | return md->type; |
| 2527 | } |
| 2528 | |
| 2529 | struct target_type *dm_get_immutable_target_type(struct mapped_device *md) |
| 2530 | { |
| 2531 | return md->immutable_target_type; |
| 2532 | } |
| 2533 | |
| 2534 | /* |
| 2535 | * Setup the DM device's queue based on md's type |
| 2536 | */ |
| 2537 | int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t) |
| 2538 | { |
| 2539 | enum dm_queue_mode type = dm_table_get_type(t); |
| 2540 | struct queue_limits limits; |
| 2541 | struct table_device *td; |
| 2542 | int r; |
| 2543 | |
| 2544 | WARN_ON_ONCE(type == DM_TYPE_NONE); |
| 2545 | |
| 2546 | if (type == DM_TYPE_REQUEST_BASED) { |
| 2547 | md->disk->fops = &dm_rq_blk_dops; |
| 2548 | r = dm_mq_init_request_queue(md, t); |
| 2549 | if (r) { |
| 2550 | DMERR("Cannot initialize queue for request-based dm mapped device"); |
| 2551 | return r; |
| 2552 | } |
| 2553 | } |
| 2554 | |
| 2555 | r = dm_calculate_queue_limits(t, &limits); |
| 2556 | if (r) { |
| 2557 | DMERR("Cannot calculate initial queue limits"); |
| 2558 | return r; |
| 2559 | } |
| 2560 | r = dm_table_set_restrictions(t, md->queue, &limits); |
| 2561 | if (r) |
| 2562 | return r; |
| 2563 | |
| 2564 | /* |
| 2565 | * Hold lock to make sure add_disk() and del_gendisk() won't concurrent |
| 2566 | * with open_table_device() and close_table_device(). |
| 2567 | */ |
| 2568 | mutex_lock(&md->table_devices_lock); |
| 2569 | r = add_disk(md->disk); |
| 2570 | mutex_unlock(&md->table_devices_lock); |
| 2571 | if (r) |
| 2572 | return r; |
| 2573 | |
| 2574 | /* |
| 2575 | * Register the holder relationship for devices added before the disk |
| 2576 | * was live. |
| 2577 | */ |
| 2578 | list_for_each_entry(td, &md->table_devices, list) { |
| 2579 | r = bd_link_disk_holder(td->dm_dev.bdev, md->disk); |
| 2580 | if (r) |
| 2581 | goto out_undo_holders; |
| 2582 | } |
| 2583 | |
| 2584 | r = dm_sysfs_init(md); |
| 2585 | if (r) |
| 2586 | goto out_undo_holders; |
| 2587 | |
| 2588 | md->type = type; |
| 2589 | return 0; |
| 2590 | |
| 2591 | out_undo_holders: |
| 2592 | list_for_each_entry_continue_reverse(td, &md->table_devices, list) |
| 2593 | bd_unlink_disk_holder(td->dm_dev.bdev, md->disk); |
| 2594 | mutex_lock(&md->table_devices_lock); |
| 2595 | del_gendisk(md->disk); |
| 2596 | mutex_unlock(&md->table_devices_lock); |
| 2597 | return r; |
| 2598 | } |
| 2599 | |
| 2600 | struct mapped_device *dm_get_md(dev_t dev) |
| 2601 | { |
| 2602 | struct mapped_device *md; |
| 2603 | unsigned int minor = MINOR(dev); |
| 2604 | |
| 2605 | if (MAJOR(dev) != _major || minor >= (1 << MINORBITS)) |
| 2606 | return NULL; |
| 2607 | |
| 2608 | spin_lock(&_minor_lock); |
| 2609 | |
| 2610 | md = idr_find(&_minor_idr, minor); |
| 2611 | if (!md || md == MINOR_ALLOCED || (MINOR(disk_devt(dm_disk(md))) != minor) || |
| 2612 | test_bit(DMF_FREEING, &md->flags) || dm_deleting_md(md)) { |
| 2613 | md = NULL; |
| 2614 | goto out; |
| 2615 | } |
| 2616 | dm_get(md); |
| 2617 | out: |
| 2618 | spin_unlock(&_minor_lock); |
| 2619 | |
| 2620 | return md; |
| 2621 | } |
| 2622 | EXPORT_SYMBOL_GPL(dm_get_md); |
| 2623 | |
| 2624 | void *dm_get_mdptr(struct mapped_device *md) |
| 2625 | { |
| 2626 | return md->interface_ptr; |
| 2627 | } |
| 2628 | |
| 2629 | void dm_set_mdptr(struct mapped_device *md, void *ptr) |
| 2630 | { |
| 2631 | md->interface_ptr = ptr; |
| 2632 | } |
| 2633 | |
| 2634 | void dm_get(struct mapped_device *md) |
| 2635 | { |
| 2636 | atomic_inc(&md->holders); |
| 2637 | BUG_ON(test_bit(DMF_FREEING, &md->flags)); |
| 2638 | } |
| 2639 | |
| 2640 | int dm_hold(struct mapped_device *md) |
| 2641 | { |
| 2642 | spin_lock(&_minor_lock); |
| 2643 | if (test_bit(DMF_FREEING, &md->flags)) { |
| 2644 | spin_unlock(&_minor_lock); |
| 2645 | return -EBUSY; |
| 2646 | } |
| 2647 | dm_get(md); |
| 2648 | spin_unlock(&_minor_lock); |
| 2649 | return 0; |
| 2650 | } |
| 2651 | EXPORT_SYMBOL_GPL(dm_hold); |
| 2652 | |
| 2653 | const char *dm_device_name(struct mapped_device *md) |
| 2654 | { |
| 2655 | return md->name; |
| 2656 | } |
| 2657 | EXPORT_SYMBOL_GPL(dm_device_name); |
| 2658 | |
| 2659 | static void __dm_destroy(struct mapped_device *md, bool wait) |
| 2660 | { |
| 2661 | struct dm_table *map; |
| 2662 | int srcu_idx; |
| 2663 | |
| 2664 | might_sleep(); |
| 2665 | |
| 2666 | spin_lock(&_minor_lock); |
| 2667 | idr_replace(&_minor_idr, MINOR_ALLOCED, MINOR(disk_devt(dm_disk(md)))); |
| 2668 | set_bit(DMF_FREEING, &md->flags); |
| 2669 | spin_unlock(&_minor_lock); |
| 2670 | |
| 2671 | blk_mark_disk_dead(md->disk); |
| 2672 | |
| 2673 | /* |
| 2674 | * Take suspend_lock so that presuspend and postsuspend methods |
| 2675 | * do not race with internal suspend. |
| 2676 | */ |
| 2677 | mutex_lock(&md->suspend_lock); |
| 2678 | map = dm_get_live_table(md, &srcu_idx); |
| 2679 | if (!dm_suspended_md(md)) { |
| 2680 | dm_table_presuspend_targets(map); |
| 2681 | set_bit(DMF_SUSPENDED, &md->flags); |
| 2682 | set_bit(DMF_POST_SUSPENDING, &md->flags); |
| 2683 | dm_table_postsuspend_targets(map); |
| 2684 | } |
| 2685 | /* dm_put_live_table must be before fsleep, otherwise deadlock is possible */ |
| 2686 | dm_put_live_table(md, srcu_idx); |
| 2687 | mutex_unlock(&md->suspend_lock); |
| 2688 | |
| 2689 | /* |
| 2690 | * Rare, but there may be I/O requests still going to complete, |
| 2691 | * for example. Wait for all references to disappear. |
| 2692 | * No one should increment the reference count of the mapped_device, |
| 2693 | * after the mapped_device state becomes DMF_FREEING. |
| 2694 | */ |
| 2695 | if (wait) |
| 2696 | while (atomic_read(&md->holders)) |
| 2697 | fsleep(1000); |
| 2698 | else if (atomic_read(&md->holders)) |
| 2699 | DMWARN("%s: Forcibly removing mapped_device still in use! (%d users)", |
| 2700 | dm_device_name(md), atomic_read(&md->holders)); |
| 2701 | |
| 2702 | dm_table_destroy(__unbind(md)); |
| 2703 | free_dev(md); |
| 2704 | } |
| 2705 | |
| 2706 | void dm_destroy(struct mapped_device *md) |
| 2707 | { |
| 2708 | __dm_destroy(md, true); |
| 2709 | } |
| 2710 | |
| 2711 | void dm_destroy_immediate(struct mapped_device *md) |
| 2712 | { |
| 2713 | __dm_destroy(md, false); |
| 2714 | } |
| 2715 | |
| 2716 | void dm_put(struct mapped_device *md) |
| 2717 | { |
| 2718 | atomic_dec(&md->holders); |
| 2719 | } |
| 2720 | EXPORT_SYMBOL_GPL(dm_put); |
| 2721 | |
| 2722 | static bool dm_in_flight_bios(struct mapped_device *md) |
| 2723 | { |
| 2724 | int cpu; |
| 2725 | unsigned long sum = 0; |
| 2726 | |
| 2727 | for_each_possible_cpu(cpu) |
| 2728 | sum += *per_cpu_ptr(md->pending_io, cpu); |
| 2729 | |
| 2730 | return sum != 0; |
| 2731 | } |
| 2732 | |
| 2733 | static int dm_wait_for_bios_completion(struct mapped_device *md, unsigned int task_state) |
| 2734 | { |
| 2735 | int r = 0; |
| 2736 | DEFINE_WAIT(wait); |
| 2737 | |
| 2738 | while (true) { |
| 2739 | prepare_to_wait(&md->wait, &wait, task_state); |
| 2740 | |
| 2741 | if (!dm_in_flight_bios(md)) |
| 2742 | break; |
| 2743 | |
| 2744 | if (signal_pending_state(task_state, current)) { |
| 2745 | r = -ERESTARTSYS; |
| 2746 | break; |
| 2747 | } |
| 2748 | |
| 2749 | io_schedule(); |
| 2750 | } |
| 2751 | finish_wait(&md->wait, &wait); |
| 2752 | |
| 2753 | smp_rmb(); |
| 2754 | |
| 2755 | return r; |
| 2756 | } |
| 2757 | |
| 2758 | static int dm_wait_for_completion(struct mapped_device *md, unsigned int task_state) |
| 2759 | { |
| 2760 | int r = 0; |
| 2761 | |
| 2762 | if (!queue_is_mq(md->queue)) |
| 2763 | return dm_wait_for_bios_completion(md, task_state); |
| 2764 | |
| 2765 | while (true) { |
| 2766 | if (!blk_mq_queue_inflight(md->queue)) |
| 2767 | break; |
| 2768 | |
| 2769 | if (signal_pending_state(task_state, current)) { |
| 2770 | r = -ERESTARTSYS; |
| 2771 | break; |
| 2772 | } |
| 2773 | |
| 2774 | fsleep(5000); |
| 2775 | } |
| 2776 | |
| 2777 | return r; |
| 2778 | } |
| 2779 | |
| 2780 | /* |
| 2781 | * Process the deferred bios |
| 2782 | */ |
| 2783 | static void dm_wq_work(struct work_struct *work) |
| 2784 | { |
| 2785 | struct mapped_device *md = container_of(work, struct mapped_device, work); |
| 2786 | struct bio *bio; |
| 2787 | |
| 2788 | while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) { |
| 2789 | spin_lock_irq(&md->deferred_lock); |
| 2790 | bio = bio_list_pop(&md->deferred); |
| 2791 | spin_unlock_irq(&md->deferred_lock); |
| 2792 | |
| 2793 | if (!bio) |
| 2794 | break; |
| 2795 | |
| 2796 | submit_bio_noacct(bio); |
| 2797 | cond_resched(); |
| 2798 | } |
| 2799 | } |
| 2800 | |
| 2801 | static void dm_queue_flush(struct mapped_device *md) |
| 2802 | { |
| 2803 | clear_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags); |
| 2804 | smp_mb__after_atomic(); |
| 2805 | queue_work(md->wq, &md->work); |
| 2806 | } |
| 2807 | |
| 2808 | /* |
| 2809 | * Swap in a new table, returning the old one for the caller to destroy. |
| 2810 | */ |
| 2811 | struct dm_table *dm_swap_table(struct mapped_device *md, struct dm_table *table) |
| 2812 | { |
| 2813 | struct dm_table *live_map = NULL, *map = ERR_PTR(-EINVAL); |
| 2814 | struct queue_limits limits; |
| 2815 | int r; |
| 2816 | |
| 2817 | mutex_lock(&md->suspend_lock); |
| 2818 | |
| 2819 | /* device must be suspended */ |
| 2820 | if (!dm_suspended_md(md)) |
| 2821 | goto out; |
| 2822 | |
| 2823 | /* |
| 2824 | * If the new table has no data devices, retain the existing limits. |
| 2825 | * This helps multipath with queue_if_no_path if all paths disappear, |
| 2826 | * then new I/O is queued based on these limits, and then some paths |
| 2827 | * reappear. |
| 2828 | */ |
| 2829 | if (dm_table_has_no_data_devices(table)) { |
| 2830 | live_map = dm_get_live_table_fast(md); |
| 2831 | if (live_map) |
| 2832 | limits = md->queue->limits; |
| 2833 | dm_put_live_table_fast(md); |
| 2834 | } |
| 2835 | |
| 2836 | if (!live_map) { |
| 2837 | r = dm_calculate_queue_limits(table, &limits); |
| 2838 | if (r) { |
| 2839 | map = ERR_PTR(r); |
| 2840 | goto out; |
| 2841 | } |
| 2842 | } |
| 2843 | |
| 2844 | map = __bind(md, table, &limits); |
| 2845 | dm_issue_global_event(); |
| 2846 | |
| 2847 | out: |
| 2848 | mutex_unlock(&md->suspend_lock); |
| 2849 | return map; |
| 2850 | } |
| 2851 | |
| 2852 | /* |
| 2853 | * Functions to lock and unlock any filesystem running on the |
| 2854 | * device. |
| 2855 | */ |
| 2856 | static int lock_fs(struct mapped_device *md) |
| 2857 | { |
| 2858 | int r; |
| 2859 | |
| 2860 | WARN_ON(test_bit(DMF_FROZEN, &md->flags)); |
| 2861 | |
| 2862 | r = bdev_freeze(md->disk->part0); |
| 2863 | if (!r) |
| 2864 | set_bit(DMF_FROZEN, &md->flags); |
| 2865 | return r; |
| 2866 | } |
| 2867 | |
| 2868 | static void unlock_fs(struct mapped_device *md) |
| 2869 | { |
| 2870 | if (!test_bit(DMF_FROZEN, &md->flags)) |
| 2871 | return; |
| 2872 | bdev_thaw(md->disk->part0); |
| 2873 | clear_bit(DMF_FROZEN, &md->flags); |
| 2874 | } |
| 2875 | |
| 2876 | /* |
| 2877 | * @suspend_flags: DM_SUSPEND_LOCKFS_FLAG and/or DM_SUSPEND_NOFLUSH_FLAG |
| 2878 | * @task_state: e.g. TASK_INTERRUPTIBLE or TASK_UNINTERRUPTIBLE |
| 2879 | * @dmf_suspended_flag: DMF_SUSPENDED or DMF_SUSPENDED_INTERNALLY |
| 2880 | * |
| 2881 | * If __dm_suspend returns 0, the device is completely quiescent |
| 2882 | * now. There is no request-processing activity. All new requests |
| 2883 | * are being added to md->deferred list. |
| 2884 | */ |
| 2885 | static int __dm_suspend(struct mapped_device *md, struct dm_table *map, |
| 2886 | unsigned int suspend_flags, unsigned int task_state, |
| 2887 | int dmf_suspended_flag) |
| 2888 | { |
| 2889 | bool do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG; |
| 2890 | bool noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG; |
| 2891 | int r; |
| 2892 | |
| 2893 | lockdep_assert_held(&md->suspend_lock); |
| 2894 | |
| 2895 | /* |
| 2896 | * DMF_NOFLUSH_SUSPENDING must be set before presuspend. |
| 2897 | * This flag is cleared before dm_suspend returns. |
| 2898 | */ |
| 2899 | if (noflush) |
| 2900 | set_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); |
| 2901 | else |
| 2902 | DMDEBUG("%s: suspending with flush", dm_device_name(md)); |
| 2903 | |
| 2904 | /* |
| 2905 | * This gets reverted if there's an error later and the targets |
| 2906 | * provide the .presuspend_undo hook. |
| 2907 | */ |
| 2908 | dm_table_presuspend_targets(map); |
| 2909 | |
| 2910 | /* |
| 2911 | * Flush I/O to the device. |
| 2912 | * Any I/O submitted after lock_fs() may not be flushed. |
| 2913 | * noflush takes precedence over do_lockfs. |
| 2914 | * (lock_fs() flushes I/Os and waits for them to complete.) |
| 2915 | */ |
| 2916 | if (!noflush && do_lockfs) { |
| 2917 | r = lock_fs(md); |
| 2918 | if (r) { |
| 2919 | dm_table_presuspend_undo_targets(map); |
| 2920 | return r; |
| 2921 | } |
| 2922 | } |
| 2923 | |
| 2924 | /* |
| 2925 | * Here we must make sure that no processes are submitting requests |
| 2926 | * to target drivers i.e. no one may be executing |
| 2927 | * dm_split_and_process_bio from dm_submit_bio. |
| 2928 | * |
| 2929 | * To get all processes out of dm_split_and_process_bio in dm_submit_bio, |
| 2930 | * we take the write lock. To prevent any process from reentering |
| 2931 | * dm_split_and_process_bio from dm_submit_bio and quiesce the thread |
| 2932 | * (dm_wq_work), we set DMF_BLOCK_IO_FOR_SUSPEND and call |
| 2933 | * flush_workqueue(md->wq). |
| 2934 | */ |
| 2935 | set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags); |
| 2936 | if (map) |
| 2937 | synchronize_srcu(&md->io_barrier); |
| 2938 | |
| 2939 | /* |
| 2940 | * Stop md->queue before flushing md->wq in case request-based |
| 2941 | * dm defers requests to md->wq from md->queue. |
| 2942 | */ |
| 2943 | if (dm_request_based(md)) |
| 2944 | dm_stop_queue(md->queue); |
| 2945 | |
| 2946 | flush_workqueue(md->wq); |
| 2947 | |
| 2948 | /* |
| 2949 | * At this point no more requests are entering target request routines. |
| 2950 | * We call dm_wait_for_completion to wait for all existing requests |
| 2951 | * to finish. |
| 2952 | */ |
| 2953 | r = dm_wait_for_completion(md, task_state); |
| 2954 | if (!r) |
| 2955 | set_bit(dmf_suspended_flag, &md->flags); |
| 2956 | |
| 2957 | if (noflush) |
| 2958 | clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); |
| 2959 | if (map) |
| 2960 | synchronize_srcu(&md->io_barrier); |
| 2961 | |
| 2962 | /* were we interrupted ? */ |
| 2963 | if (r < 0) { |
| 2964 | dm_queue_flush(md); |
| 2965 | |
| 2966 | if (dm_request_based(md)) |
| 2967 | dm_start_queue(md->queue); |
| 2968 | |
| 2969 | unlock_fs(md); |
| 2970 | dm_table_presuspend_undo_targets(map); |
| 2971 | /* pushback list is already flushed, so skip flush */ |
| 2972 | } |
| 2973 | |
| 2974 | return r; |
| 2975 | } |
| 2976 | |
| 2977 | /* |
| 2978 | * We need to be able to change a mapping table under a mounted |
| 2979 | * filesystem. For example we might want to move some data in |
| 2980 | * the background. Before the table can be swapped with |
| 2981 | * dm_bind_table, dm_suspend must be called to flush any in |
| 2982 | * flight bios and ensure that any further io gets deferred. |
| 2983 | */ |
| 2984 | /* |
| 2985 | * Suspend mechanism in request-based dm. |
| 2986 | * |
| 2987 | * 1. Flush all I/Os by lock_fs() if needed. |
| 2988 | * 2. Stop dispatching any I/O by stopping the request_queue. |
| 2989 | * 3. Wait for all in-flight I/Os to be completed or requeued. |
| 2990 | * |
| 2991 | * To abort suspend, start the request_queue. |
| 2992 | */ |
| 2993 | int dm_suspend(struct mapped_device *md, unsigned int suspend_flags) |
| 2994 | { |
| 2995 | struct dm_table *map = NULL; |
| 2996 | int r = 0; |
| 2997 | |
| 2998 | retry: |
| 2999 | mutex_lock_nested(&md->suspend_lock, SINGLE_DEPTH_NESTING); |
| 3000 | |
| 3001 | if (dm_suspended_md(md)) { |
| 3002 | r = -EINVAL; |
| 3003 | goto out_unlock; |
| 3004 | } |
| 3005 | |
| 3006 | if (dm_suspended_internally_md(md)) { |
| 3007 | /* already internally suspended, wait for internal resume */ |
| 3008 | mutex_unlock(&md->suspend_lock); |
| 3009 | r = wait_on_bit(&md->flags, DMF_SUSPENDED_INTERNALLY, TASK_INTERRUPTIBLE); |
| 3010 | if (r) |
| 3011 | return r; |
| 3012 | goto retry; |
| 3013 | } |
| 3014 | |
| 3015 | map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock)); |
| 3016 | if (!map) { |
| 3017 | /* avoid deadlock with fs/namespace.c:do_mount() */ |
| 3018 | suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG; |
| 3019 | } |
| 3020 | |
| 3021 | r = __dm_suspend(md, map, suspend_flags, TASK_INTERRUPTIBLE, DMF_SUSPENDED); |
| 3022 | if (r) |
| 3023 | goto out_unlock; |
| 3024 | |
| 3025 | set_bit(DMF_POST_SUSPENDING, &md->flags); |
| 3026 | dm_table_postsuspend_targets(map); |
| 3027 | clear_bit(DMF_POST_SUSPENDING, &md->flags); |
| 3028 | |
| 3029 | out_unlock: |
| 3030 | mutex_unlock(&md->suspend_lock); |
| 3031 | return r; |
| 3032 | } |
| 3033 | |
| 3034 | static int __dm_resume(struct mapped_device *md, struct dm_table *map) |
| 3035 | { |
| 3036 | if (map) { |
| 3037 | int r = dm_table_resume_targets(map); |
| 3038 | |
| 3039 | if (r) |
| 3040 | return r; |
| 3041 | } |
| 3042 | |
| 3043 | dm_queue_flush(md); |
| 3044 | |
| 3045 | /* |
| 3046 | * Flushing deferred I/Os must be done after targets are resumed |
| 3047 | * so that mapping of targets can work correctly. |
| 3048 | * Request-based dm is queueing the deferred I/Os in its request_queue. |
| 3049 | */ |
| 3050 | if (dm_request_based(md)) |
| 3051 | dm_start_queue(md->queue); |
| 3052 | |
| 3053 | unlock_fs(md); |
| 3054 | |
| 3055 | return 0; |
| 3056 | } |
| 3057 | |
| 3058 | int dm_resume(struct mapped_device *md) |
| 3059 | { |
| 3060 | int r; |
| 3061 | struct dm_table *map = NULL; |
| 3062 | |
| 3063 | retry: |
| 3064 | r = -EINVAL; |
| 3065 | mutex_lock_nested(&md->suspend_lock, SINGLE_DEPTH_NESTING); |
| 3066 | |
| 3067 | if (!dm_suspended_md(md)) |
| 3068 | goto out; |
| 3069 | |
| 3070 | if (dm_suspended_internally_md(md)) { |
| 3071 | /* already internally suspended, wait for internal resume */ |
| 3072 | mutex_unlock(&md->suspend_lock); |
| 3073 | r = wait_on_bit(&md->flags, DMF_SUSPENDED_INTERNALLY, TASK_INTERRUPTIBLE); |
| 3074 | if (r) |
| 3075 | return r; |
| 3076 | goto retry; |
| 3077 | } |
| 3078 | |
| 3079 | map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock)); |
| 3080 | if (!map || !dm_table_get_size(map)) |
| 3081 | goto out; |
| 3082 | |
| 3083 | r = __dm_resume(md, map); |
| 3084 | if (r) |
| 3085 | goto out; |
| 3086 | |
| 3087 | clear_bit(DMF_SUSPENDED, &md->flags); |
| 3088 | out: |
| 3089 | mutex_unlock(&md->suspend_lock); |
| 3090 | |
| 3091 | return r; |
| 3092 | } |
| 3093 | |
| 3094 | /* |
| 3095 | * Internal suspend/resume works like userspace-driven suspend. It waits |
| 3096 | * until all bios finish and prevents issuing new bios to the target drivers. |
| 3097 | * It may be used only from the kernel. |
| 3098 | */ |
| 3099 | |
| 3100 | static void __dm_internal_suspend(struct mapped_device *md, unsigned int suspend_flags) |
| 3101 | { |
| 3102 | struct dm_table *map = NULL; |
| 3103 | |
| 3104 | lockdep_assert_held(&md->suspend_lock); |
| 3105 | |
| 3106 | if (md->internal_suspend_count++) |
| 3107 | return; /* nested internal suspend */ |
| 3108 | |
| 3109 | if (dm_suspended_md(md)) { |
| 3110 | set_bit(DMF_SUSPENDED_INTERNALLY, &md->flags); |
| 3111 | return; /* nest suspend */ |
| 3112 | } |
| 3113 | |
| 3114 | map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock)); |
| 3115 | |
| 3116 | /* |
| 3117 | * Using TASK_UNINTERRUPTIBLE because only NOFLUSH internal suspend is |
| 3118 | * supported. Properly supporting a TASK_INTERRUPTIBLE internal suspend |
| 3119 | * would require changing .presuspend to return an error -- avoid this |
| 3120 | * until there is a need for more elaborate variants of internal suspend. |
| 3121 | */ |
| 3122 | (void) __dm_suspend(md, map, suspend_flags, TASK_UNINTERRUPTIBLE, |
| 3123 | DMF_SUSPENDED_INTERNALLY); |
| 3124 | |
| 3125 | set_bit(DMF_POST_SUSPENDING, &md->flags); |
| 3126 | dm_table_postsuspend_targets(map); |
| 3127 | clear_bit(DMF_POST_SUSPENDING, &md->flags); |
| 3128 | } |
| 3129 | |
| 3130 | static void __dm_internal_resume(struct mapped_device *md) |
| 3131 | { |
| 3132 | int r; |
| 3133 | struct dm_table *map; |
| 3134 | |
| 3135 | BUG_ON(!md->internal_suspend_count); |
| 3136 | |
| 3137 | if (--md->internal_suspend_count) |
| 3138 | return; /* resume from nested internal suspend */ |
| 3139 | |
| 3140 | if (dm_suspended_md(md)) |
| 3141 | goto done; /* resume from nested suspend */ |
| 3142 | |
| 3143 | map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock)); |
| 3144 | r = __dm_resume(md, map); |
| 3145 | if (r) { |
| 3146 | /* |
| 3147 | * If a preresume method of some target failed, we are in a |
| 3148 | * tricky situation. We can't return an error to the caller. We |
| 3149 | * can't fake success because then the "resume" and |
| 3150 | * "postsuspend" methods would not be paired correctly, and it |
| 3151 | * would break various targets, for example it would cause list |
| 3152 | * corruption in the "origin" target. |
| 3153 | * |
| 3154 | * So, we fake normal suspend here, to make sure that the |
| 3155 | * "resume" and "postsuspend" methods will be paired correctly. |
| 3156 | */ |
| 3157 | DMERR("Preresume method failed: %d", r); |
| 3158 | set_bit(DMF_SUSPENDED, &md->flags); |
| 3159 | } |
| 3160 | done: |
| 3161 | clear_bit(DMF_SUSPENDED_INTERNALLY, &md->flags); |
| 3162 | smp_mb__after_atomic(); |
| 3163 | wake_up_bit(&md->flags, DMF_SUSPENDED_INTERNALLY); |
| 3164 | } |
| 3165 | |
| 3166 | void dm_internal_suspend_noflush(struct mapped_device *md) |
| 3167 | { |
| 3168 | mutex_lock(&md->suspend_lock); |
| 3169 | __dm_internal_suspend(md, DM_SUSPEND_NOFLUSH_FLAG); |
| 3170 | mutex_unlock(&md->suspend_lock); |
| 3171 | } |
| 3172 | EXPORT_SYMBOL_GPL(dm_internal_suspend_noflush); |
| 3173 | |
| 3174 | void dm_internal_resume(struct mapped_device *md) |
| 3175 | { |
| 3176 | mutex_lock(&md->suspend_lock); |
| 3177 | __dm_internal_resume(md); |
| 3178 | mutex_unlock(&md->suspend_lock); |
| 3179 | } |
| 3180 | EXPORT_SYMBOL_GPL(dm_internal_resume); |
| 3181 | |
| 3182 | /* |
| 3183 | * Fast variants of internal suspend/resume hold md->suspend_lock, |
| 3184 | * which prevents interaction with userspace-driven suspend. |
| 3185 | */ |
| 3186 | |
| 3187 | void dm_internal_suspend_fast(struct mapped_device *md) |
| 3188 | { |
| 3189 | mutex_lock(&md->suspend_lock); |
| 3190 | if (dm_suspended_md(md) || dm_suspended_internally_md(md)) |
| 3191 | return; |
| 3192 | |
| 3193 | set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags); |
| 3194 | synchronize_srcu(&md->io_barrier); |
| 3195 | flush_workqueue(md->wq); |
| 3196 | dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE); |
| 3197 | } |
| 3198 | EXPORT_SYMBOL_GPL(dm_internal_suspend_fast); |
| 3199 | |
| 3200 | void dm_internal_resume_fast(struct mapped_device *md) |
| 3201 | { |
| 3202 | if (dm_suspended_md(md) || dm_suspended_internally_md(md)) |
| 3203 | goto done; |
| 3204 | |
| 3205 | dm_queue_flush(md); |
| 3206 | |
| 3207 | done: |
| 3208 | mutex_unlock(&md->suspend_lock); |
| 3209 | } |
| 3210 | EXPORT_SYMBOL_GPL(dm_internal_resume_fast); |
| 3211 | |
| 3212 | /* |
| 3213 | *--------------------------------------------------------------- |
| 3214 | * Event notification. |
| 3215 | *--------------------------------------------------------------- |
| 3216 | */ |
| 3217 | int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action, |
| 3218 | unsigned int cookie, bool need_resize_uevent) |
| 3219 | { |
| 3220 | int r; |
| 3221 | unsigned int noio_flag; |
| 3222 | char udev_cookie[DM_COOKIE_LENGTH]; |
| 3223 | char *envp[3] = { NULL, NULL, NULL }; |
| 3224 | char **envpp = envp; |
| 3225 | if (cookie) { |
| 3226 | snprintf(udev_cookie, DM_COOKIE_LENGTH, "%s=%u", |
| 3227 | DM_COOKIE_ENV_VAR_NAME, cookie); |
| 3228 | *envpp++ = udev_cookie; |
| 3229 | } |
| 3230 | if (need_resize_uevent) { |
| 3231 | *envpp++ = "RESIZE=1"; |
| 3232 | } |
| 3233 | |
| 3234 | noio_flag = memalloc_noio_save(); |
| 3235 | |
| 3236 | r = kobject_uevent_env(&disk_to_dev(md->disk)->kobj, action, envp); |
| 3237 | |
| 3238 | memalloc_noio_restore(noio_flag); |
| 3239 | |
| 3240 | return r; |
| 3241 | } |
| 3242 | |
| 3243 | uint32_t dm_next_uevent_seq(struct mapped_device *md) |
| 3244 | { |
| 3245 | return atomic_add_return(1, &md->uevent_seq); |
| 3246 | } |
| 3247 | |
| 3248 | uint32_t dm_get_event_nr(struct mapped_device *md) |
| 3249 | { |
| 3250 | return atomic_read(&md->event_nr); |
| 3251 | } |
| 3252 | |
| 3253 | int dm_wait_event(struct mapped_device *md, int event_nr) |
| 3254 | { |
| 3255 | return wait_event_interruptible(md->eventq, |
| 3256 | (event_nr != atomic_read(&md->event_nr))); |
| 3257 | } |
| 3258 | |
| 3259 | void dm_uevent_add(struct mapped_device *md, struct list_head *elist) |
| 3260 | { |
| 3261 | unsigned long flags; |
| 3262 | |
| 3263 | spin_lock_irqsave(&md->uevent_lock, flags); |
| 3264 | list_add(elist, &md->uevent_list); |
| 3265 | spin_unlock_irqrestore(&md->uevent_lock, flags); |
| 3266 | } |
| 3267 | |
| 3268 | /* |
| 3269 | * The gendisk is only valid as long as you have a reference |
| 3270 | * count on 'md'. |
| 3271 | */ |
| 3272 | struct gendisk *dm_disk(struct mapped_device *md) |
| 3273 | { |
| 3274 | return md->disk; |
| 3275 | } |
| 3276 | EXPORT_SYMBOL_GPL(dm_disk); |
| 3277 | |
| 3278 | struct kobject *dm_kobject(struct mapped_device *md) |
| 3279 | { |
| 3280 | return &md->kobj_holder.kobj; |
| 3281 | } |
| 3282 | |
| 3283 | struct mapped_device *dm_get_from_kobject(struct kobject *kobj) |
| 3284 | { |
| 3285 | struct mapped_device *md; |
| 3286 | |
| 3287 | md = container_of(kobj, struct mapped_device, kobj_holder.kobj); |
| 3288 | |
| 3289 | spin_lock(&_minor_lock); |
| 3290 | if (test_bit(DMF_FREEING, &md->flags) || dm_deleting_md(md)) { |
| 3291 | md = NULL; |
| 3292 | goto out; |
| 3293 | } |
| 3294 | dm_get(md); |
| 3295 | out: |
| 3296 | spin_unlock(&_minor_lock); |
| 3297 | |
| 3298 | return md; |
| 3299 | } |
| 3300 | |
| 3301 | int dm_suspended_md(struct mapped_device *md) |
| 3302 | { |
| 3303 | return test_bit(DMF_SUSPENDED, &md->flags); |
| 3304 | } |
| 3305 | |
| 3306 | static int dm_post_suspending_md(struct mapped_device *md) |
| 3307 | { |
| 3308 | return test_bit(DMF_POST_SUSPENDING, &md->flags); |
| 3309 | } |
| 3310 | |
| 3311 | int dm_suspended_internally_md(struct mapped_device *md) |
| 3312 | { |
| 3313 | return test_bit(DMF_SUSPENDED_INTERNALLY, &md->flags); |
| 3314 | } |
| 3315 | |
| 3316 | int dm_test_deferred_remove_flag(struct mapped_device *md) |
| 3317 | { |
| 3318 | return test_bit(DMF_DEFERRED_REMOVE, &md->flags); |
| 3319 | } |
| 3320 | |
| 3321 | int dm_suspended(struct dm_target *ti) |
| 3322 | { |
| 3323 | return dm_suspended_md(ti->table->md); |
| 3324 | } |
| 3325 | EXPORT_SYMBOL_GPL(dm_suspended); |
| 3326 | |
| 3327 | int dm_post_suspending(struct dm_target *ti) |
| 3328 | { |
| 3329 | return dm_post_suspending_md(ti->table->md); |
| 3330 | } |
| 3331 | EXPORT_SYMBOL_GPL(dm_post_suspending); |
| 3332 | |
| 3333 | int dm_noflush_suspending(struct dm_target *ti) |
| 3334 | { |
| 3335 | return __noflush_suspending(ti->table->md); |
| 3336 | } |
| 3337 | EXPORT_SYMBOL_GPL(dm_noflush_suspending); |
| 3338 | |
| 3339 | void dm_free_md_mempools(struct dm_md_mempools *pools) |
| 3340 | { |
| 3341 | if (!pools) |
| 3342 | return; |
| 3343 | |
| 3344 | bioset_exit(&pools->bs); |
| 3345 | bioset_exit(&pools->io_bs); |
| 3346 | |
| 3347 | kfree(pools); |
| 3348 | } |
| 3349 | |
| 3350 | struct dm_pr { |
| 3351 | u64 old_key; |
| 3352 | u64 new_key; |
| 3353 | u32 flags; |
| 3354 | bool abort; |
| 3355 | bool fail_early; |
| 3356 | int ret; |
| 3357 | enum pr_type type; |
| 3358 | struct pr_keys *read_keys; |
| 3359 | struct pr_held_reservation *rsv; |
| 3360 | }; |
| 3361 | |
| 3362 | static int dm_call_pr(struct block_device *bdev, iterate_devices_callout_fn fn, |
| 3363 | struct dm_pr *pr) |
| 3364 | { |
| 3365 | struct mapped_device *md = bdev->bd_disk->private_data; |
| 3366 | struct dm_table *table; |
| 3367 | struct dm_target *ti; |
| 3368 | int ret = -ENOTTY, srcu_idx; |
| 3369 | |
| 3370 | table = dm_get_live_table(md, &srcu_idx); |
| 3371 | if (!table || !dm_table_get_size(table)) |
| 3372 | goto out; |
| 3373 | |
| 3374 | /* We only support devices that have a single target */ |
| 3375 | if (table->num_targets != 1) |
| 3376 | goto out; |
| 3377 | ti = dm_table_get_target(table, 0); |
| 3378 | |
| 3379 | if (dm_suspended_md(md)) { |
| 3380 | ret = -EAGAIN; |
| 3381 | goto out; |
| 3382 | } |
| 3383 | |
| 3384 | ret = -EINVAL; |
| 3385 | if (!ti->type->iterate_devices) |
| 3386 | goto out; |
| 3387 | |
| 3388 | ti->type->iterate_devices(ti, fn, pr); |
| 3389 | ret = 0; |
| 3390 | out: |
| 3391 | dm_put_live_table(md, srcu_idx); |
| 3392 | return ret; |
| 3393 | } |
| 3394 | |
| 3395 | /* |
| 3396 | * For register / unregister we need to manually call out to every path. |
| 3397 | */ |
| 3398 | static int __dm_pr_register(struct dm_target *ti, struct dm_dev *dev, |
| 3399 | sector_t start, sector_t len, void *data) |
| 3400 | { |
| 3401 | struct dm_pr *pr = data; |
| 3402 | const struct pr_ops *ops = dev->bdev->bd_disk->fops->pr_ops; |
| 3403 | int ret; |
| 3404 | |
| 3405 | if (!ops || !ops->pr_register) { |
| 3406 | pr->ret = -EOPNOTSUPP; |
| 3407 | return -1; |
| 3408 | } |
| 3409 | |
| 3410 | ret = ops->pr_register(dev->bdev, pr->old_key, pr->new_key, pr->flags); |
| 3411 | if (!ret) |
| 3412 | return 0; |
| 3413 | |
| 3414 | if (!pr->ret) |
| 3415 | pr->ret = ret; |
| 3416 | |
| 3417 | if (pr->fail_early) |
| 3418 | return -1; |
| 3419 | |
| 3420 | return 0; |
| 3421 | } |
| 3422 | |
| 3423 | static int dm_pr_register(struct block_device *bdev, u64 old_key, u64 new_key, |
| 3424 | u32 flags) |
| 3425 | { |
| 3426 | struct dm_pr pr = { |
| 3427 | .old_key = old_key, |
| 3428 | .new_key = new_key, |
| 3429 | .flags = flags, |
| 3430 | .fail_early = true, |
| 3431 | .ret = 0, |
| 3432 | }; |
| 3433 | int ret; |
| 3434 | |
| 3435 | ret = dm_call_pr(bdev, __dm_pr_register, &pr); |
| 3436 | if (ret) { |
| 3437 | /* Didn't even get to register a path */ |
| 3438 | return ret; |
| 3439 | } |
| 3440 | |
| 3441 | if (!pr.ret) |
| 3442 | return 0; |
| 3443 | ret = pr.ret; |
| 3444 | |
| 3445 | if (!new_key) |
| 3446 | return ret; |
| 3447 | |
| 3448 | /* unregister all paths if we failed to register any path */ |
| 3449 | pr.old_key = new_key; |
| 3450 | pr.new_key = 0; |
| 3451 | pr.flags = 0; |
| 3452 | pr.fail_early = false; |
| 3453 | (void) dm_call_pr(bdev, __dm_pr_register, &pr); |
| 3454 | return ret; |
| 3455 | } |
| 3456 | |
| 3457 | |
| 3458 | static int __dm_pr_reserve(struct dm_target *ti, struct dm_dev *dev, |
| 3459 | sector_t start, sector_t len, void *data) |
| 3460 | { |
| 3461 | struct dm_pr *pr = data; |
| 3462 | const struct pr_ops *ops = dev->bdev->bd_disk->fops->pr_ops; |
| 3463 | |
| 3464 | if (!ops || !ops->pr_reserve) { |
| 3465 | pr->ret = -EOPNOTSUPP; |
| 3466 | return -1; |
| 3467 | } |
| 3468 | |
| 3469 | pr->ret = ops->pr_reserve(dev->bdev, pr->old_key, pr->type, pr->flags); |
| 3470 | if (!pr->ret) |
| 3471 | return -1; |
| 3472 | |
| 3473 | return 0; |
| 3474 | } |
| 3475 | |
| 3476 | static int dm_pr_reserve(struct block_device *bdev, u64 key, enum pr_type type, |
| 3477 | u32 flags) |
| 3478 | { |
| 3479 | struct dm_pr pr = { |
| 3480 | .old_key = key, |
| 3481 | .flags = flags, |
| 3482 | .type = type, |
| 3483 | .fail_early = false, |
| 3484 | .ret = 0, |
| 3485 | }; |
| 3486 | int ret; |
| 3487 | |
| 3488 | ret = dm_call_pr(bdev, __dm_pr_reserve, &pr); |
| 3489 | if (ret) |
| 3490 | return ret; |
| 3491 | |
| 3492 | return pr.ret; |
| 3493 | } |
| 3494 | |
| 3495 | /* |
| 3496 | * If there is a non-All Registrants type of reservation, the release must be |
| 3497 | * sent down the holding path. For the cases where there is no reservation or |
| 3498 | * the path is not the holder the device will also return success, so we must |
| 3499 | * try each path to make sure we got the correct path. |
| 3500 | */ |
| 3501 | static int __dm_pr_release(struct dm_target *ti, struct dm_dev *dev, |
| 3502 | sector_t start, sector_t len, void *data) |
| 3503 | { |
| 3504 | struct dm_pr *pr = data; |
| 3505 | const struct pr_ops *ops = dev->bdev->bd_disk->fops->pr_ops; |
| 3506 | |
| 3507 | if (!ops || !ops->pr_release) { |
| 3508 | pr->ret = -EOPNOTSUPP; |
| 3509 | return -1; |
| 3510 | } |
| 3511 | |
| 3512 | pr->ret = ops->pr_release(dev->bdev, pr->old_key, pr->type); |
| 3513 | if (pr->ret) |
| 3514 | return -1; |
| 3515 | |
| 3516 | return 0; |
| 3517 | } |
| 3518 | |
| 3519 | static int dm_pr_release(struct block_device *bdev, u64 key, enum pr_type type) |
| 3520 | { |
| 3521 | struct dm_pr pr = { |
| 3522 | .old_key = key, |
| 3523 | .type = type, |
| 3524 | .fail_early = false, |
| 3525 | }; |
| 3526 | int ret; |
| 3527 | |
| 3528 | ret = dm_call_pr(bdev, __dm_pr_release, &pr); |
| 3529 | if (ret) |
| 3530 | return ret; |
| 3531 | |
| 3532 | return pr.ret; |
| 3533 | } |
| 3534 | |
| 3535 | static int __dm_pr_preempt(struct dm_target *ti, struct dm_dev *dev, |
| 3536 | sector_t start, sector_t len, void *data) |
| 3537 | { |
| 3538 | struct dm_pr *pr = data; |
| 3539 | const struct pr_ops *ops = dev->bdev->bd_disk->fops->pr_ops; |
| 3540 | |
| 3541 | if (!ops || !ops->pr_preempt) { |
| 3542 | pr->ret = -EOPNOTSUPP; |
| 3543 | return -1; |
| 3544 | } |
| 3545 | |
| 3546 | pr->ret = ops->pr_preempt(dev->bdev, pr->old_key, pr->new_key, pr->type, |
| 3547 | pr->abort); |
| 3548 | if (!pr->ret) |
| 3549 | return -1; |
| 3550 | |
| 3551 | return 0; |
| 3552 | } |
| 3553 | |
| 3554 | static int dm_pr_preempt(struct block_device *bdev, u64 old_key, u64 new_key, |
| 3555 | enum pr_type type, bool abort) |
| 3556 | { |
| 3557 | struct dm_pr pr = { |
| 3558 | .new_key = new_key, |
| 3559 | .old_key = old_key, |
| 3560 | .type = type, |
| 3561 | .fail_early = false, |
| 3562 | }; |
| 3563 | int ret; |
| 3564 | |
| 3565 | ret = dm_call_pr(bdev, __dm_pr_preempt, &pr); |
| 3566 | if (ret) |
| 3567 | return ret; |
| 3568 | |
| 3569 | return pr.ret; |
| 3570 | } |
| 3571 | |
| 3572 | static int dm_pr_clear(struct block_device *bdev, u64 key) |
| 3573 | { |
| 3574 | struct mapped_device *md = bdev->bd_disk->private_data; |
| 3575 | const struct pr_ops *ops; |
| 3576 | int r, srcu_idx; |
| 3577 | |
| 3578 | r = dm_prepare_ioctl(md, &srcu_idx, &bdev); |
| 3579 | if (r < 0) |
| 3580 | goto out; |
| 3581 | |
| 3582 | ops = bdev->bd_disk->fops->pr_ops; |
| 3583 | if (ops && ops->pr_clear) |
| 3584 | r = ops->pr_clear(bdev, key); |
| 3585 | else |
| 3586 | r = -EOPNOTSUPP; |
| 3587 | out: |
| 3588 | dm_unprepare_ioctl(md, srcu_idx); |
| 3589 | return r; |
| 3590 | } |
| 3591 | |
| 3592 | static int __dm_pr_read_keys(struct dm_target *ti, struct dm_dev *dev, |
| 3593 | sector_t start, sector_t len, void *data) |
| 3594 | { |
| 3595 | struct dm_pr *pr = data; |
| 3596 | const struct pr_ops *ops = dev->bdev->bd_disk->fops->pr_ops; |
| 3597 | |
| 3598 | if (!ops || !ops->pr_read_keys) { |
| 3599 | pr->ret = -EOPNOTSUPP; |
| 3600 | return -1; |
| 3601 | } |
| 3602 | |
| 3603 | pr->ret = ops->pr_read_keys(dev->bdev, pr->read_keys); |
| 3604 | if (!pr->ret) |
| 3605 | return -1; |
| 3606 | |
| 3607 | return 0; |
| 3608 | } |
| 3609 | |
| 3610 | static int dm_pr_read_keys(struct block_device *bdev, struct pr_keys *keys) |
| 3611 | { |
| 3612 | struct dm_pr pr = { |
| 3613 | .read_keys = keys, |
| 3614 | }; |
| 3615 | int ret; |
| 3616 | |
| 3617 | ret = dm_call_pr(bdev, __dm_pr_read_keys, &pr); |
| 3618 | if (ret) |
| 3619 | return ret; |
| 3620 | |
| 3621 | return pr.ret; |
| 3622 | } |
| 3623 | |
| 3624 | static int __dm_pr_read_reservation(struct dm_target *ti, struct dm_dev *dev, |
| 3625 | sector_t start, sector_t len, void *data) |
| 3626 | { |
| 3627 | struct dm_pr *pr = data; |
| 3628 | const struct pr_ops *ops = dev->bdev->bd_disk->fops->pr_ops; |
| 3629 | |
| 3630 | if (!ops || !ops->pr_read_reservation) { |
| 3631 | pr->ret = -EOPNOTSUPP; |
| 3632 | return -1; |
| 3633 | } |
| 3634 | |
| 3635 | pr->ret = ops->pr_read_reservation(dev->bdev, pr->rsv); |
| 3636 | if (!pr->ret) |
| 3637 | return -1; |
| 3638 | |
| 3639 | return 0; |
| 3640 | } |
| 3641 | |
| 3642 | static int dm_pr_read_reservation(struct block_device *bdev, |
| 3643 | struct pr_held_reservation *rsv) |
| 3644 | { |
| 3645 | struct dm_pr pr = { |
| 3646 | .rsv = rsv, |
| 3647 | }; |
| 3648 | int ret; |
| 3649 | |
| 3650 | ret = dm_call_pr(bdev, __dm_pr_read_reservation, &pr); |
| 3651 | if (ret) |
| 3652 | return ret; |
| 3653 | |
| 3654 | return pr.ret; |
| 3655 | } |
| 3656 | |
| 3657 | static const struct pr_ops dm_pr_ops = { |
| 3658 | .pr_register = dm_pr_register, |
| 3659 | .pr_reserve = dm_pr_reserve, |
| 3660 | .pr_release = dm_pr_release, |
| 3661 | .pr_preempt = dm_pr_preempt, |
| 3662 | .pr_clear = dm_pr_clear, |
| 3663 | .pr_read_keys = dm_pr_read_keys, |
| 3664 | .pr_read_reservation = dm_pr_read_reservation, |
| 3665 | }; |
| 3666 | |
| 3667 | static const struct block_device_operations dm_blk_dops = { |
| 3668 | .submit_bio = dm_submit_bio, |
| 3669 | .poll_bio = dm_poll_bio, |
| 3670 | .open = dm_blk_open, |
| 3671 | .release = dm_blk_close, |
| 3672 | .ioctl = dm_blk_ioctl, |
| 3673 | .getgeo = dm_blk_getgeo, |
| 3674 | .report_zones = dm_blk_report_zones, |
| 3675 | .pr_ops = &dm_pr_ops, |
| 3676 | .owner = THIS_MODULE |
| 3677 | }; |
| 3678 | |
| 3679 | static const struct block_device_operations dm_rq_blk_dops = { |
| 3680 | .open = dm_blk_open, |
| 3681 | .release = dm_blk_close, |
| 3682 | .ioctl = dm_blk_ioctl, |
| 3683 | .getgeo = dm_blk_getgeo, |
| 3684 | .pr_ops = &dm_pr_ops, |
| 3685 | .owner = THIS_MODULE |
| 3686 | }; |
| 3687 | |
| 3688 | static const struct dax_operations dm_dax_ops = { |
| 3689 | .direct_access = dm_dax_direct_access, |
| 3690 | .zero_page_range = dm_dax_zero_page_range, |
| 3691 | .recovery_write = dm_dax_recovery_write, |
| 3692 | }; |
| 3693 | |
| 3694 | /* |
| 3695 | * module hooks |
| 3696 | */ |
| 3697 | module_init(dm_init); |
| 3698 | module_exit(dm_exit); |
| 3699 | |
| 3700 | module_param(major, uint, 0); |
| 3701 | MODULE_PARM_DESC(major, "The major number of the device mapper"); |
| 3702 | |
| 3703 | module_param(reserved_bio_based_ios, uint, 0644); |
| 3704 | MODULE_PARM_DESC(reserved_bio_based_ios, "Reserved IOs in bio-based mempools"); |
| 3705 | |
| 3706 | module_param(dm_numa_node, int, 0644); |
| 3707 | MODULE_PARM_DESC(dm_numa_node, "NUMA node for DM device memory allocations"); |
| 3708 | |
| 3709 | module_param(swap_bios, int, 0644); |
| 3710 | MODULE_PARM_DESC(swap_bios, "Maximum allowed inflight swap IOs"); |
| 3711 | |
| 3712 | MODULE_DESCRIPTION(DM_NAME " driver"); |
| 3713 | MODULE_AUTHOR("Joe Thornber <dm-devel@lists.linux.dev>"); |
| 3714 | MODULE_LICENSE("GPL"); |