| 1 | /* |
| 2 | * Copyright (C) 2001, 2002 Sistina Software (UK) Limited. |
| 3 | * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved. |
| 4 | * |
| 5 | * This file is released under the GPL. |
| 6 | */ |
| 7 | |
| 8 | #include "dm.h" |
| 9 | #include "dm-uevent.h" |
| 10 | |
| 11 | #include <linux/init.h> |
| 12 | #include <linux/module.h> |
| 13 | #include <linux/mutex.h> |
| 14 | #include <linux/moduleparam.h> |
| 15 | #include <linux/blkpg.h> |
| 16 | #include <linux/bio.h> |
| 17 | #include <linux/mempool.h> |
| 18 | #include <linux/slab.h> |
| 19 | #include <linux/idr.h> |
| 20 | #include <linux/hdreg.h> |
| 21 | #include <linux/delay.h> |
| 22 | #include <linux/wait.h> |
| 23 | #include <linux/kthread.h> |
| 24 | #include <linux/ktime.h> |
| 25 | #include <linux/elevator.h> /* for rq_end_sector() */ |
| 26 | #include <linux/blk-mq.h> |
| 27 | |
| 28 | #include <trace/events/block.h> |
| 29 | |
| 30 | #define DM_MSG_PREFIX "core" |
| 31 | |
| 32 | #ifdef CONFIG_PRINTK |
| 33 | /* |
| 34 | * ratelimit state to be used in DMXXX_LIMIT(). |
| 35 | */ |
| 36 | DEFINE_RATELIMIT_STATE(dm_ratelimit_state, |
| 37 | DEFAULT_RATELIMIT_INTERVAL, |
| 38 | DEFAULT_RATELIMIT_BURST); |
| 39 | EXPORT_SYMBOL(dm_ratelimit_state); |
| 40 | #endif |
| 41 | |
| 42 | /* |
| 43 | * Cookies are numeric values sent with CHANGE and REMOVE |
| 44 | * uevents while resuming, removing or renaming the device. |
| 45 | */ |
| 46 | #define DM_COOKIE_ENV_VAR_NAME "DM_COOKIE" |
| 47 | #define DM_COOKIE_LENGTH 24 |
| 48 | |
| 49 | static const char *_name = DM_NAME; |
| 50 | |
| 51 | static unsigned int major = 0; |
| 52 | static unsigned int _major = 0; |
| 53 | |
| 54 | static DEFINE_IDR(_minor_idr); |
| 55 | |
| 56 | static DEFINE_SPINLOCK(_minor_lock); |
| 57 | |
| 58 | static void do_deferred_remove(struct work_struct *w); |
| 59 | |
| 60 | static DECLARE_WORK(deferred_remove_work, do_deferred_remove); |
| 61 | |
| 62 | static struct workqueue_struct *deferred_remove_workqueue; |
| 63 | |
| 64 | /* |
| 65 | * For bio-based dm. |
| 66 | * One of these is allocated per bio. |
| 67 | */ |
| 68 | struct dm_io { |
| 69 | struct mapped_device *md; |
| 70 | int error; |
| 71 | atomic_t io_count; |
| 72 | struct bio *bio; |
| 73 | unsigned long start_time; |
| 74 | spinlock_t endio_lock; |
| 75 | struct dm_stats_aux stats_aux; |
| 76 | }; |
| 77 | |
| 78 | /* |
| 79 | * For request-based dm. |
| 80 | * One of these is allocated per request. |
| 81 | */ |
| 82 | struct dm_rq_target_io { |
| 83 | struct mapped_device *md; |
| 84 | struct dm_target *ti; |
| 85 | struct request *orig, *clone; |
| 86 | struct kthread_work work; |
| 87 | int error; |
| 88 | union map_info info; |
| 89 | struct dm_stats_aux stats_aux; |
| 90 | unsigned long duration_jiffies; |
| 91 | unsigned n_sectors; |
| 92 | }; |
| 93 | |
| 94 | /* |
| 95 | * For request-based dm - the bio clones we allocate are embedded in these |
| 96 | * structs. |
| 97 | * |
| 98 | * We allocate these with bio_alloc_bioset, using the front_pad parameter when |
| 99 | * the bioset is created - this means the bio has to come at the end of the |
| 100 | * struct. |
| 101 | */ |
| 102 | struct dm_rq_clone_bio_info { |
| 103 | struct bio *orig; |
| 104 | struct dm_rq_target_io *tio; |
| 105 | struct bio clone; |
| 106 | }; |
| 107 | |
| 108 | union map_info *dm_get_rq_mapinfo(struct request *rq) |
| 109 | { |
| 110 | if (rq && rq->end_io_data) |
| 111 | return &((struct dm_rq_target_io *)rq->end_io_data)->info; |
| 112 | return NULL; |
| 113 | } |
| 114 | EXPORT_SYMBOL_GPL(dm_get_rq_mapinfo); |
| 115 | |
| 116 | #define MINOR_ALLOCED ((void *)-1) |
| 117 | |
| 118 | /* |
| 119 | * Bits for the md->flags field. |
| 120 | */ |
| 121 | #define DMF_BLOCK_IO_FOR_SUSPEND 0 |
| 122 | #define DMF_SUSPENDED 1 |
| 123 | #define DMF_FROZEN 2 |
| 124 | #define DMF_FREEING 3 |
| 125 | #define DMF_DELETING 4 |
| 126 | #define DMF_NOFLUSH_SUSPENDING 5 |
| 127 | #define DMF_MERGE_IS_OPTIONAL 6 |
| 128 | #define DMF_DEFERRED_REMOVE 7 |
| 129 | #define DMF_SUSPENDED_INTERNALLY 8 |
| 130 | |
| 131 | /* |
| 132 | * A dummy definition to make RCU happy. |
| 133 | * struct dm_table should never be dereferenced in this file. |
| 134 | */ |
| 135 | struct dm_table { |
| 136 | int undefined__; |
| 137 | }; |
| 138 | |
| 139 | /* |
| 140 | * Work processed by per-device workqueue. |
| 141 | */ |
| 142 | struct mapped_device { |
| 143 | struct srcu_struct io_barrier; |
| 144 | struct mutex suspend_lock; |
| 145 | atomic_t holders; |
| 146 | atomic_t open_count; |
| 147 | |
| 148 | /* |
| 149 | * The current mapping. |
| 150 | * Use dm_get_live_table{_fast} or take suspend_lock for |
| 151 | * dereference. |
| 152 | */ |
| 153 | struct dm_table __rcu *map; |
| 154 | |
| 155 | struct list_head table_devices; |
| 156 | struct mutex table_devices_lock; |
| 157 | |
| 158 | unsigned long flags; |
| 159 | |
| 160 | struct request_queue *queue; |
| 161 | unsigned type; |
| 162 | /* Protect queue and type against concurrent access. */ |
| 163 | struct mutex type_lock; |
| 164 | |
| 165 | struct target_type *immutable_target_type; |
| 166 | |
| 167 | struct gendisk *disk; |
| 168 | char name[16]; |
| 169 | |
| 170 | void *interface_ptr; |
| 171 | |
| 172 | /* |
| 173 | * A list of ios that arrived while we were suspended. |
| 174 | */ |
| 175 | atomic_t pending[2]; |
| 176 | wait_queue_head_t wait; |
| 177 | struct work_struct work; |
| 178 | struct bio_list deferred; |
| 179 | spinlock_t deferred_lock; |
| 180 | |
| 181 | /* |
| 182 | * Processing queue (flush) |
| 183 | */ |
| 184 | struct workqueue_struct *wq; |
| 185 | |
| 186 | /* |
| 187 | * io objects are allocated from here. |
| 188 | */ |
| 189 | mempool_t *io_pool; |
| 190 | mempool_t *rq_pool; |
| 191 | |
| 192 | struct bio_set *bs; |
| 193 | |
| 194 | /* |
| 195 | * Event handling. |
| 196 | */ |
| 197 | atomic_t event_nr; |
| 198 | wait_queue_head_t eventq; |
| 199 | atomic_t uevent_seq; |
| 200 | struct list_head uevent_list; |
| 201 | spinlock_t uevent_lock; /* Protect access to uevent_list */ |
| 202 | |
| 203 | /* |
| 204 | * freeze/thaw support require holding onto a super block |
| 205 | */ |
| 206 | struct super_block *frozen_sb; |
| 207 | struct block_device *bdev; |
| 208 | |
| 209 | /* forced geometry settings */ |
| 210 | struct hd_geometry geometry; |
| 211 | |
| 212 | /* kobject and completion */ |
| 213 | struct dm_kobject_holder kobj_holder; |
| 214 | |
| 215 | /* zero-length flush that will be cloned and submitted to targets */ |
| 216 | struct bio flush_bio; |
| 217 | |
| 218 | /* the number of internal suspends */ |
| 219 | unsigned internal_suspend_count; |
| 220 | |
| 221 | struct dm_stats stats; |
| 222 | |
| 223 | struct kthread_worker kworker; |
| 224 | struct task_struct *kworker_task; |
| 225 | |
| 226 | /* for request-based merge heuristic in dm_request_fn() */ |
| 227 | unsigned seq_rq_merge_deadline_usecs; |
| 228 | int last_rq_rw; |
| 229 | sector_t last_rq_pos; |
| 230 | ktime_t last_rq_start_time; |
| 231 | |
| 232 | /* for blk-mq request-based DM support */ |
| 233 | struct blk_mq_tag_set tag_set; |
| 234 | bool use_blk_mq; |
| 235 | }; |
| 236 | |
| 237 | #ifdef CONFIG_DM_MQ_DEFAULT |
| 238 | static bool use_blk_mq = true; |
| 239 | #else |
| 240 | static bool use_blk_mq = false; |
| 241 | #endif |
| 242 | |
| 243 | bool dm_use_blk_mq(struct mapped_device *md) |
| 244 | { |
| 245 | return md->use_blk_mq; |
| 246 | } |
| 247 | |
| 248 | /* |
| 249 | * For mempools pre-allocation at the table loading time. |
| 250 | */ |
| 251 | struct dm_md_mempools { |
| 252 | mempool_t *io_pool; |
| 253 | mempool_t *rq_pool; |
| 254 | struct bio_set *bs; |
| 255 | }; |
| 256 | |
| 257 | struct table_device { |
| 258 | struct list_head list; |
| 259 | atomic_t count; |
| 260 | struct dm_dev dm_dev; |
| 261 | }; |
| 262 | |
| 263 | #define RESERVED_BIO_BASED_IOS 16 |
| 264 | #define RESERVED_REQUEST_BASED_IOS 256 |
| 265 | #define RESERVED_MAX_IOS 1024 |
| 266 | static struct kmem_cache *_io_cache; |
| 267 | static struct kmem_cache *_rq_tio_cache; |
| 268 | static struct kmem_cache *_rq_cache; |
| 269 | |
| 270 | /* |
| 271 | * Bio-based DM's mempools' reserved IOs set by the user. |
| 272 | */ |
| 273 | static unsigned reserved_bio_based_ios = RESERVED_BIO_BASED_IOS; |
| 274 | |
| 275 | /* |
| 276 | * Request-based DM's mempools' reserved IOs set by the user. |
| 277 | */ |
| 278 | static unsigned reserved_rq_based_ios = RESERVED_REQUEST_BASED_IOS; |
| 279 | |
| 280 | static unsigned __dm_get_module_param(unsigned *module_param, |
| 281 | unsigned def, unsigned max) |
| 282 | { |
| 283 | unsigned param = ACCESS_ONCE(*module_param); |
| 284 | unsigned modified_param = 0; |
| 285 | |
| 286 | if (!param) |
| 287 | modified_param = def; |
| 288 | else if (param > max) |
| 289 | modified_param = max; |
| 290 | |
| 291 | if (modified_param) { |
| 292 | (void)cmpxchg(module_param, param, modified_param); |
| 293 | param = modified_param; |
| 294 | } |
| 295 | |
| 296 | return param; |
| 297 | } |
| 298 | |
| 299 | unsigned dm_get_reserved_bio_based_ios(void) |
| 300 | { |
| 301 | return __dm_get_module_param(&reserved_bio_based_ios, |
| 302 | RESERVED_BIO_BASED_IOS, RESERVED_MAX_IOS); |
| 303 | } |
| 304 | EXPORT_SYMBOL_GPL(dm_get_reserved_bio_based_ios); |
| 305 | |
| 306 | unsigned dm_get_reserved_rq_based_ios(void) |
| 307 | { |
| 308 | return __dm_get_module_param(&reserved_rq_based_ios, |
| 309 | RESERVED_REQUEST_BASED_IOS, RESERVED_MAX_IOS); |
| 310 | } |
| 311 | EXPORT_SYMBOL_GPL(dm_get_reserved_rq_based_ios); |
| 312 | |
| 313 | static int __init local_init(void) |
| 314 | { |
| 315 | int r = -ENOMEM; |
| 316 | |
| 317 | /* allocate a slab for the dm_ios */ |
| 318 | _io_cache = KMEM_CACHE(dm_io, 0); |
| 319 | if (!_io_cache) |
| 320 | return r; |
| 321 | |
| 322 | _rq_tio_cache = KMEM_CACHE(dm_rq_target_io, 0); |
| 323 | if (!_rq_tio_cache) |
| 324 | goto out_free_io_cache; |
| 325 | |
| 326 | _rq_cache = kmem_cache_create("dm_clone_request", sizeof(struct request), |
| 327 | __alignof__(struct request), 0, NULL); |
| 328 | if (!_rq_cache) |
| 329 | goto out_free_rq_tio_cache; |
| 330 | |
| 331 | r = dm_uevent_init(); |
| 332 | if (r) |
| 333 | goto out_free_rq_cache; |
| 334 | |
| 335 | deferred_remove_workqueue = alloc_workqueue("kdmremove", WQ_UNBOUND, 1); |
| 336 | if (!deferred_remove_workqueue) { |
| 337 | r = -ENOMEM; |
| 338 | goto out_uevent_exit; |
| 339 | } |
| 340 | |
| 341 | _major = major; |
| 342 | r = register_blkdev(_major, _name); |
| 343 | if (r < 0) |
| 344 | goto out_free_workqueue; |
| 345 | |
| 346 | if (!_major) |
| 347 | _major = r; |
| 348 | |
| 349 | return 0; |
| 350 | |
| 351 | out_free_workqueue: |
| 352 | destroy_workqueue(deferred_remove_workqueue); |
| 353 | out_uevent_exit: |
| 354 | dm_uevent_exit(); |
| 355 | out_free_rq_cache: |
| 356 | kmem_cache_destroy(_rq_cache); |
| 357 | out_free_rq_tio_cache: |
| 358 | kmem_cache_destroy(_rq_tio_cache); |
| 359 | out_free_io_cache: |
| 360 | kmem_cache_destroy(_io_cache); |
| 361 | |
| 362 | return r; |
| 363 | } |
| 364 | |
| 365 | static void local_exit(void) |
| 366 | { |
| 367 | flush_scheduled_work(); |
| 368 | destroy_workqueue(deferred_remove_workqueue); |
| 369 | |
| 370 | kmem_cache_destroy(_rq_cache); |
| 371 | kmem_cache_destroy(_rq_tio_cache); |
| 372 | kmem_cache_destroy(_io_cache); |
| 373 | unregister_blkdev(_major, _name); |
| 374 | dm_uevent_exit(); |
| 375 | |
| 376 | _major = 0; |
| 377 | |
| 378 | DMINFO("cleaned up"); |
| 379 | } |
| 380 | |
| 381 | static int (*_inits[])(void) __initdata = { |
| 382 | local_init, |
| 383 | dm_target_init, |
| 384 | dm_linear_init, |
| 385 | dm_stripe_init, |
| 386 | dm_io_init, |
| 387 | dm_kcopyd_init, |
| 388 | dm_interface_init, |
| 389 | dm_statistics_init, |
| 390 | }; |
| 391 | |
| 392 | static void (*_exits[])(void) = { |
| 393 | local_exit, |
| 394 | dm_target_exit, |
| 395 | dm_linear_exit, |
| 396 | dm_stripe_exit, |
| 397 | dm_io_exit, |
| 398 | dm_kcopyd_exit, |
| 399 | dm_interface_exit, |
| 400 | dm_statistics_exit, |
| 401 | }; |
| 402 | |
| 403 | static int __init dm_init(void) |
| 404 | { |
| 405 | const int count = ARRAY_SIZE(_inits); |
| 406 | |
| 407 | int r, i; |
| 408 | |
| 409 | for (i = 0; i < count; i++) { |
| 410 | r = _inits[i](); |
| 411 | if (r) |
| 412 | goto bad; |
| 413 | } |
| 414 | |
| 415 | return 0; |
| 416 | |
| 417 | bad: |
| 418 | while (i--) |
| 419 | _exits[i](); |
| 420 | |
| 421 | return r; |
| 422 | } |
| 423 | |
| 424 | static void __exit dm_exit(void) |
| 425 | { |
| 426 | int i = ARRAY_SIZE(_exits); |
| 427 | |
| 428 | while (i--) |
| 429 | _exits[i](); |
| 430 | |
| 431 | /* |
| 432 | * Should be empty by this point. |
| 433 | */ |
| 434 | idr_destroy(&_minor_idr); |
| 435 | } |
| 436 | |
| 437 | /* |
| 438 | * Block device functions |
| 439 | */ |
| 440 | int dm_deleting_md(struct mapped_device *md) |
| 441 | { |
| 442 | return test_bit(DMF_DELETING, &md->flags); |
| 443 | } |
| 444 | |
| 445 | static int dm_blk_open(struct block_device *bdev, fmode_t mode) |
| 446 | { |
| 447 | struct mapped_device *md; |
| 448 | |
| 449 | spin_lock(&_minor_lock); |
| 450 | |
| 451 | md = bdev->bd_disk->private_data; |
| 452 | if (!md) |
| 453 | goto out; |
| 454 | |
| 455 | if (test_bit(DMF_FREEING, &md->flags) || |
| 456 | dm_deleting_md(md)) { |
| 457 | md = NULL; |
| 458 | goto out; |
| 459 | } |
| 460 | |
| 461 | dm_get(md); |
| 462 | atomic_inc(&md->open_count); |
| 463 | out: |
| 464 | spin_unlock(&_minor_lock); |
| 465 | |
| 466 | return md ? 0 : -ENXIO; |
| 467 | } |
| 468 | |
| 469 | static void dm_blk_close(struct gendisk *disk, fmode_t mode) |
| 470 | { |
| 471 | struct mapped_device *md; |
| 472 | |
| 473 | spin_lock(&_minor_lock); |
| 474 | |
| 475 | md = disk->private_data; |
| 476 | if (WARN_ON(!md)) |
| 477 | goto out; |
| 478 | |
| 479 | if (atomic_dec_and_test(&md->open_count) && |
| 480 | (test_bit(DMF_DEFERRED_REMOVE, &md->flags))) |
| 481 | queue_work(deferred_remove_workqueue, &deferred_remove_work); |
| 482 | |
| 483 | dm_put(md); |
| 484 | out: |
| 485 | spin_unlock(&_minor_lock); |
| 486 | } |
| 487 | |
| 488 | int dm_open_count(struct mapped_device *md) |
| 489 | { |
| 490 | return atomic_read(&md->open_count); |
| 491 | } |
| 492 | |
| 493 | /* |
| 494 | * Guarantees nothing is using the device before it's deleted. |
| 495 | */ |
| 496 | int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred) |
| 497 | { |
| 498 | int r = 0; |
| 499 | |
| 500 | spin_lock(&_minor_lock); |
| 501 | |
| 502 | if (dm_open_count(md)) { |
| 503 | r = -EBUSY; |
| 504 | if (mark_deferred) |
| 505 | set_bit(DMF_DEFERRED_REMOVE, &md->flags); |
| 506 | } else if (only_deferred && !test_bit(DMF_DEFERRED_REMOVE, &md->flags)) |
| 507 | r = -EEXIST; |
| 508 | else |
| 509 | set_bit(DMF_DELETING, &md->flags); |
| 510 | |
| 511 | spin_unlock(&_minor_lock); |
| 512 | |
| 513 | return r; |
| 514 | } |
| 515 | |
| 516 | int dm_cancel_deferred_remove(struct mapped_device *md) |
| 517 | { |
| 518 | int r = 0; |
| 519 | |
| 520 | spin_lock(&_minor_lock); |
| 521 | |
| 522 | if (test_bit(DMF_DELETING, &md->flags)) |
| 523 | r = -EBUSY; |
| 524 | else |
| 525 | clear_bit(DMF_DEFERRED_REMOVE, &md->flags); |
| 526 | |
| 527 | spin_unlock(&_minor_lock); |
| 528 | |
| 529 | return r; |
| 530 | } |
| 531 | |
| 532 | static void do_deferred_remove(struct work_struct *w) |
| 533 | { |
| 534 | dm_deferred_remove(); |
| 535 | } |
| 536 | |
| 537 | sector_t dm_get_size(struct mapped_device *md) |
| 538 | { |
| 539 | return get_capacity(md->disk); |
| 540 | } |
| 541 | |
| 542 | struct request_queue *dm_get_md_queue(struct mapped_device *md) |
| 543 | { |
| 544 | return md->queue; |
| 545 | } |
| 546 | |
| 547 | struct dm_stats *dm_get_stats(struct mapped_device *md) |
| 548 | { |
| 549 | return &md->stats; |
| 550 | } |
| 551 | |
| 552 | static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
| 553 | { |
| 554 | struct mapped_device *md = bdev->bd_disk->private_data; |
| 555 | |
| 556 | return dm_get_geometry(md, geo); |
| 557 | } |
| 558 | |
| 559 | static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode, |
| 560 | unsigned int cmd, unsigned long arg) |
| 561 | { |
| 562 | struct mapped_device *md = bdev->bd_disk->private_data; |
| 563 | int srcu_idx; |
| 564 | struct dm_table *map; |
| 565 | struct dm_target *tgt; |
| 566 | int r = -ENOTTY; |
| 567 | |
| 568 | retry: |
| 569 | map = dm_get_live_table(md, &srcu_idx); |
| 570 | |
| 571 | if (!map || !dm_table_get_size(map)) |
| 572 | goto out; |
| 573 | |
| 574 | /* We only support devices that have a single target */ |
| 575 | if (dm_table_get_num_targets(map) != 1) |
| 576 | goto out; |
| 577 | |
| 578 | tgt = dm_table_get_target(map, 0); |
| 579 | if (!tgt->type->ioctl) |
| 580 | goto out; |
| 581 | |
| 582 | if (dm_suspended_md(md)) { |
| 583 | r = -EAGAIN; |
| 584 | goto out; |
| 585 | } |
| 586 | |
| 587 | r = tgt->type->ioctl(tgt, cmd, arg); |
| 588 | |
| 589 | out: |
| 590 | dm_put_live_table(md, srcu_idx); |
| 591 | |
| 592 | if (r == -ENOTCONN) { |
| 593 | msleep(10); |
| 594 | goto retry; |
| 595 | } |
| 596 | |
| 597 | return r; |
| 598 | } |
| 599 | |
| 600 | static struct dm_io *alloc_io(struct mapped_device *md) |
| 601 | { |
| 602 | return mempool_alloc(md->io_pool, GFP_NOIO); |
| 603 | } |
| 604 | |
| 605 | static void free_io(struct mapped_device *md, struct dm_io *io) |
| 606 | { |
| 607 | mempool_free(io, md->io_pool); |
| 608 | } |
| 609 | |
| 610 | static void free_tio(struct mapped_device *md, struct dm_target_io *tio) |
| 611 | { |
| 612 | bio_put(&tio->clone); |
| 613 | } |
| 614 | |
| 615 | static struct dm_rq_target_io *alloc_rq_tio(struct mapped_device *md, |
| 616 | gfp_t gfp_mask) |
| 617 | { |
| 618 | return mempool_alloc(md->io_pool, gfp_mask); |
| 619 | } |
| 620 | |
| 621 | static void free_rq_tio(struct dm_rq_target_io *tio) |
| 622 | { |
| 623 | mempool_free(tio, tio->md->io_pool); |
| 624 | } |
| 625 | |
| 626 | static struct request *alloc_clone_request(struct mapped_device *md, |
| 627 | gfp_t gfp_mask) |
| 628 | { |
| 629 | return mempool_alloc(md->rq_pool, gfp_mask); |
| 630 | } |
| 631 | |
| 632 | static void free_clone_request(struct mapped_device *md, struct request *rq) |
| 633 | { |
| 634 | mempool_free(rq, md->rq_pool); |
| 635 | } |
| 636 | |
| 637 | static int md_in_flight(struct mapped_device *md) |
| 638 | { |
| 639 | return atomic_read(&md->pending[READ]) + |
| 640 | atomic_read(&md->pending[WRITE]); |
| 641 | } |
| 642 | |
| 643 | static void start_io_acct(struct dm_io *io) |
| 644 | { |
| 645 | struct mapped_device *md = io->md; |
| 646 | struct bio *bio = io->bio; |
| 647 | int cpu; |
| 648 | int rw = bio_data_dir(bio); |
| 649 | |
| 650 | io->start_time = jiffies; |
| 651 | |
| 652 | cpu = part_stat_lock(); |
| 653 | part_round_stats(cpu, &dm_disk(md)->part0); |
| 654 | part_stat_unlock(); |
| 655 | atomic_set(&dm_disk(md)->part0.in_flight[rw], |
| 656 | atomic_inc_return(&md->pending[rw])); |
| 657 | |
| 658 | if (unlikely(dm_stats_used(&md->stats))) |
| 659 | dm_stats_account_io(&md->stats, bio->bi_rw, bio->bi_iter.bi_sector, |
| 660 | bio_sectors(bio), false, 0, &io->stats_aux); |
| 661 | } |
| 662 | |
| 663 | static void end_io_acct(struct dm_io *io) |
| 664 | { |
| 665 | struct mapped_device *md = io->md; |
| 666 | struct bio *bio = io->bio; |
| 667 | unsigned long duration = jiffies - io->start_time; |
| 668 | int pending; |
| 669 | int rw = bio_data_dir(bio); |
| 670 | |
| 671 | generic_end_io_acct(rw, &dm_disk(md)->part0, io->start_time); |
| 672 | |
| 673 | if (unlikely(dm_stats_used(&md->stats))) |
| 674 | dm_stats_account_io(&md->stats, bio->bi_rw, bio->bi_iter.bi_sector, |
| 675 | bio_sectors(bio), true, duration, &io->stats_aux); |
| 676 | |
| 677 | /* |
| 678 | * After this is decremented the bio must not be touched if it is |
| 679 | * a flush. |
| 680 | */ |
| 681 | pending = atomic_dec_return(&md->pending[rw]); |
| 682 | atomic_set(&dm_disk(md)->part0.in_flight[rw], pending); |
| 683 | pending += atomic_read(&md->pending[rw^0x1]); |
| 684 | |
| 685 | /* nudge anyone waiting on suspend queue */ |
| 686 | if (!pending) |
| 687 | wake_up(&md->wait); |
| 688 | } |
| 689 | |
| 690 | /* |
| 691 | * Add the bio to the list of deferred io. |
| 692 | */ |
| 693 | static void queue_io(struct mapped_device *md, struct bio *bio) |
| 694 | { |
| 695 | unsigned long flags; |
| 696 | |
| 697 | spin_lock_irqsave(&md->deferred_lock, flags); |
| 698 | bio_list_add(&md->deferred, bio); |
| 699 | spin_unlock_irqrestore(&md->deferred_lock, flags); |
| 700 | queue_work(md->wq, &md->work); |
| 701 | } |
| 702 | |
| 703 | /* |
| 704 | * Everyone (including functions in this file), should use this |
| 705 | * function to access the md->map field, and make sure they call |
| 706 | * dm_put_live_table() when finished. |
| 707 | */ |
| 708 | struct dm_table *dm_get_live_table(struct mapped_device *md, int *srcu_idx) __acquires(md->io_barrier) |
| 709 | { |
| 710 | *srcu_idx = srcu_read_lock(&md->io_barrier); |
| 711 | |
| 712 | return srcu_dereference(md->map, &md->io_barrier); |
| 713 | } |
| 714 | |
| 715 | void dm_put_live_table(struct mapped_device *md, int srcu_idx) __releases(md->io_barrier) |
| 716 | { |
| 717 | srcu_read_unlock(&md->io_barrier, srcu_idx); |
| 718 | } |
| 719 | |
| 720 | void dm_sync_table(struct mapped_device *md) |
| 721 | { |
| 722 | synchronize_srcu(&md->io_barrier); |
| 723 | synchronize_rcu_expedited(); |
| 724 | } |
| 725 | |
| 726 | /* |
| 727 | * A fast alternative to dm_get_live_table/dm_put_live_table. |
| 728 | * The caller must not block between these two functions. |
| 729 | */ |
| 730 | static struct dm_table *dm_get_live_table_fast(struct mapped_device *md) __acquires(RCU) |
| 731 | { |
| 732 | rcu_read_lock(); |
| 733 | return rcu_dereference(md->map); |
| 734 | } |
| 735 | |
| 736 | static void dm_put_live_table_fast(struct mapped_device *md) __releases(RCU) |
| 737 | { |
| 738 | rcu_read_unlock(); |
| 739 | } |
| 740 | |
| 741 | /* |
| 742 | * Open a table device so we can use it as a map destination. |
| 743 | */ |
| 744 | static int open_table_device(struct table_device *td, dev_t dev, |
| 745 | struct mapped_device *md) |
| 746 | { |
| 747 | static char *_claim_ptr = "I belong to device-mapper"; |
| 748 | struct block_device *bdev; |
| 749 | |
| 750 | int r; |
| 751 | |
| 752 | BUG_ON(td->dm_dev.bdev); |
| 753 | |
| 754 | bdev = blkdev_get_by_dev(dev, td->dm_dev.mode | FMODE_EXCL, _claim_ptr); |
| 755 | if (IS_ERR(bdev)) |
| 756 | return PTR_ERR(bdev); |
| 757 | |
| 758 | r = bd_link_disk_holder(bdev, dm_disk(md)); |
| 759 | if (r) { |
| 760 | blkdev_put(bdev, td->dm_dev.mode | FMODE_EXCL); |
| 761 | return r; |
| 762 | } |
| 763 | |
| 764 | td->dm_dev.bdev = bdev; |
| 765 | return 0; |
| 766 | } |
| 767 | |
| 768 | /* |
| 769 | * Close a table device that we've been using. |
| 770 | */ |
| 771 | static void close_table_device(struct table_device *td, struct mapped_device *md) |
| 772 | { |
| 773 | if (!td->dm_dev.bdev) |
| 774 | return; |
| 775 | |
| 776 | bd_unlink_disk_holder(td->dm_dev.bdev, dm_disk(md)); |
| 777 | blkdev_put(td->dm_dev.bdev, td->dm_dev.mode | FMODE_EXCL); |
| 778 | td->dm_dev.bdev = NULL; |
| 779 | } |
| 780 | |
| 781 | static struct table_device *find_table_device(struct list_head *l, dev_t dev, |
| 782 | fmode_t mode) { |
| 783 | struct table_device *td; |
| 784 | |
| 785 | list_for_each_entry(td, l, list) |
| 786 | if (td->dm_dev.bdev->bd_dev == dev && td->dm_dev.mode == mode) |
| 787 | return td; |
| 788 | |
| 789 | return NULL; |
| 790 | } |
| 791 | |
| 792 | int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode, |
| 793 | struct dm_dev **result) { |
| 794 | int r; |
| 795 | struct table_device *td; |
| 796 | |
| 797 | mutex_lock(&md->table_devices_lock); |
| 798 | td = find_table_device(&md->table_devices, dev, mode); |
| 799 | if (!td) { |
| 800 | td = kmalloc(sizeof(*td), GFP_KERNEL); |
| 801 | if (!td) { |
| 802 | mutex_unlock(&md->table_devices_lock); |
| 803 | return -ENOMEM; |
| 804 | } |
| 805 | |
| 806 | td->dm_dev.mode = mode; |
| 807 | td->dm_dev.bdev = NULL; |
| 808 | |
| 809 | if ((r = open_table_device(td, dev, md))) { |
| 810 | mutex_unlock(&md->table_devices_lock); |
| 811 | kfree(td); |
| 812 | return r; |
| 813 | } |
| 814 | |
| 815 | format_dev_t(td->dm_dev.name, dev); |
| 816 | |
| 817 | atomic_set(&td->count, 0); |
| 818 | list_add(&td->list, &md->table_devices); |
| 819 | } |
| 820 | atomic_inc(&td->count); |
| 821 | mutex_unlock(&md->table_devices_lock); |
| 822 | |
| 823 | *result = &td->dm_dev; |
| 824 | return 0; |
| 825 | } |
| 826 | EXPORT_SYMBOL_GPL(dm_get_table_device); |
| 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 (atomic_dec_and_test(&td->count)) { |
| 834 | close_table_device(td, md); |
| 835 | list_del(&td->list); |
| 836 | kfree(td); |
| 837 | } |
| 838 | mutex_unlock(&md->table_devices_lock); |
| 839 | } |
| 840 | EXPORT_SYMBOL(dm_put_table_device); |
| 841 | |
| 842 | static void free_table_devices(struct list_head *devices) |
| 843 | { |
| 844 | struct list_head *tmp, *next; |
| 845 | |
| 846 | list_for_each_safe(tmp, next, devices) { |
| 847 | struct table_device *td = list_entry(tmp, struct table_device, list); |
| 848 | |
| 849 | DMWARN("dm_destroy: %s still exists with %d references", |
| 850 | td->dm_dev.name, atomic_read(&td->count)); |
| 851 | kfree(td); |
| 852 | } |
| 853 | } |
| 854 | |
| 855 | /* |
| 856 | * Get the geometry associated with a dm device |
| 857 | */ |
| 858 | int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo) |
| 859 | { |
| 860 | *geo = md->geometry; |
| 861 | |
| 862 | return 0; |
| 863 | } |
| 864 | |
| 865 | /* |
| 866 | * Set the geometry of a device. |
| 867 | */ |
| 868 | int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo) |
| 869 | { |
| 870 | sector_t sz = (sector_t)geo->cylinders * geo->heads * geo->sectors; |
| 871 | |
| 872 | if (geo->start > sz) { |
| 873 | DMWARN("Start sector is beyond the geometry limits."); |
| 874 | return -EINVAL; |
| 875 | } |
| 876 | |
| 877 | md->geometry = *geo; |
| 878 | |
| 879 | return 0; |
| 880 | } |
| 881 | |
| 882 | /*----------------------------------------------------------------- |
| 883 | * CRUD START: |
| 884 | * A more elegant soln is in the works that uses the queue |
| 885 | * merge fn, unfortunately there are a couple of changes to |
| 886 | * the block layer that I want to make for this. So in the |
| 887 | * interests of getting something for people to use I give |
| 888 | * you this clearly demarcated crap. |
| 889 | *---------------------------------------------------------------*/ |
| 890 | |
| 891 | static int __noflush_suspending(struct mapped_device *md) |
| 892 | { |
| 893 | return test_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); |
| 894 | } |
| 895 | |
| 896 | /* |
| 897 | * Decrements the number of outstanding ios that a bio has been |
| 898 | * cloned into, completing the original io if necc. |
| 899 | */ |
| 900 | static void dec_pending(struct dm_io *io, int error) |
| 901 | { |
| 902 | unsigned long flags; |
| 903 | int io_error; |
| 904 | struct bio *bio; |
| 905 | struct mapped_device *md = io->md; |
| 906 | |
| 907 | /* Push-back supersedes any I/O errors */ |
| 908 | if (unlikely(error)) { |
| 909 | spin_lock_irqsave(&io->endio_lock, flags); |
| 910 | if (!(io->error > 0 && __noflush_suspending(md))) |
| 911 | io->error = error; |
| 912 | spin_unlock_irqrestore(&io->endio_lock, flags); |
| 913 | } |
| 914 | |
| 915 | if (atomic_dec_and_test(&io->io_count)) { |
| 916 | if (io->error == DM_ENDIO_REQUEUE) { |
| 917 | /* |
| 918 | * Target requested pushing back the I/O. |
| 919 | */ |
| 920 | spin_lock_irqsave(&md->deferred_lock, flags); |
| 921 | if (__noflush_suspending(md)) |
| 922 | bio_list_add_head(&md->deferred, io->bio); |
| 923 | else |
| 924 | /* noflush suspend was interrupted. */ |
| 925 | io->error = -EIO; |
| 926 | spin_unlock_irqrestore(&md->deferred_lock, flags); |
| 927 | } |
| 928 | |
| 929 | io_error = io->error; |
| 930 | bio = io->bio; |
| 931 | end_io_acct(io); |
| 932 | free_io(md, io); |
| 933 | |
| 934 | if (io_error == DM_ENDIO_REQUEUE) |
| 935 | return; |
| 936 | |
| 937 | if ((bio->bi_rw & REQ_FLUSH) && bio->bi_iter.bi_size) { |
| 938 | /* |
| 939 | * Preflush done for flush with data, reissue |
| 940 | * without REQ_FLUSH. |
| 941 | */ |
| 942 | bio->bi_rw &= ~REQ_FLUSH; |
| 943 | queue_io(md, bio); |
| 944 | } else { |
| 945 | /* done with normal IO or empty flush */ |
| 946 | trace_block_bio_complete(md->queue, bio, io_error); |
| 947 | bio_endio(bio, io_error); |
| 948 | } |
| 949 | } |
| 950 | } |
| 951 | |
| 952 | static void disable_write_same(struct mapped_device *md) |
| 953 | { |
| 954 | struct queue_limits *limits = dm_get_queue_limits(md); |
| 955 | |
| 956 | /* device doesn't really support WRITE SAME, disable it */ |
| 957 | limits->max_write_same_sectors = 0; |
| 958 | } |
| 959 | |
| 960 | static void clone_endio(struct bio *bio, int error) |
| 961 | { |
| 962 | int r = error; |
| 963 | struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone); |
| 964 | struct dm_io *io = tio->io; |
| 965 | struct mapped_device *md = tio->io->md; |
| 966 | dm_endio_fn endio = tio->ti->type->end_io; |
| 967 | |
| 968 | if (!bio_flagged(bio, BIO_UPTODATE) && !error) |
| 969 | error = -EIO; |
| 970 | |
| 971 | if (endio) { |
| 972 | r = endio(tio->ti, bio, error); |
| 973 | if (r < 0 || r == DM_ENDIO_REQUEUE) |
| 974 | /* |
| 975 | * error and requeue request are handled |
| 976 | * in dec_pending(). |
| 977 | */ |
| 978 | error = r; |
| 979 | else if (r == DM_ENDIO_INCOMPLETE) |
| 980 | /* The target will handle the io */ |
| 981 | return; |
| 982 | else if (r) { |
| 983 | DMWARN("unimplemented target endio return value: %d", r); |
| 984 | BUG(); |
| 985 | } |
| 986 | } |
| 987 | |
| 988 | if (unlikely(r == -EREMOTEIO && (bio->bi_rw & REQ_WRITE_SAME) && |
| 989 | !bdev_get_queue(bio->bi_bdev)->limits.max_write_same_sectors)) |
| 990 | disable_write_same(md); |
| 991 | |
| 992 | free_tio(md, tio); |
| 993 | dec_pending(io, error); |
| 994 | } |
| 995 | |
| 996 | /* |
| 997 | * Partial completion handling for request-based dm |
| 998 | */ |
| 999 | static void end_clone_bio(struct bio *clone, int error) |
| 1000 | { |
| 1001 | struct dm_rq_clone_bio_info *info = |
| 1002 | container_of(clone, struct dm_rq_clone_bio_info, clone); |
| 1003 | struct dm_rq_target_io *tio = info->tio; |
| 1004 | struct bio *bio = info->orig; |
| 1005 | unsigned int nr_bytes = info->orig->bi_iter.bi_size; |
| 1006 | |
| 1007 | bio_put(clone); |
| 1008 | |
| 1009 | if (tio->error) |
| 1010 | /* |
| 1011 | * An error has already been detected on the request. |
| 1012 | * Once error occurred, just let clone->end_io() handle |
| 1013 | * the remainder. |
| 1014 | */ |
| 1015 | return; |
| 1016 | else if (error) { |
| 1017 | /* |
| 1018 | * Don't notice the error to the upper layer yet. |
| 1019 | * The error handling decision is made by the target driver, |
| 1020 | * when the request is completed. |
| 1021 | */ |
| 1022 | tio->error = error; |
| 1023 | return; |
| 1024 | } |
| 1025 | |
| 1026 | /* |
| 1027 | * I/O for the bio successfully completed. |
| 1028 | * Notice the data completion to the upper layer. |
| 1029 | */ |
| 1030 | |
| 1031 | /* |
| 1032 | * bios are processed from the head of the list. |
| 1033 | * So the completing bio should always be rq->bio. |
| 1034 | * If it's not, something wrong is happening. |
| 1035 | */ |
| 1036 | if (tio->orig->bio != bio) |
| 1037 | DMERR("bio completion is going in the middle of the request"); |
| 1038 | |
| 1039 | /* |
| 1040 | * Update the original request. |
| 1041 | * Do not use blk_end_request() here, because it may complete |
| 1042 | * the original request before the clone, and break the ordering. |
| 1043 | */ |
| 1044 | blk_update_request(tio->orig, 0, nr_bytes); |
| 1045 | } |
| 1046 | |
| 1047 | static struct dm_rq_target_io *tio_from_request(struct request *rq) |
| 1048 | { |
| 1049 | return (rq->q->mq_ops ? blk_mq_rq_to_pdu(rq) : rq->special); |
| 1050 | } |
| 1051 | |
| 1052 | static void rq_end_stats(struct mapped_device *md, struct request *orig) |
| 1053 | { |
| 1054 | if (unlikely(dm_stats_used(&md->stats))) { |
| 1055 | struct dm_rq_target_io *tio = tio_from_request(orig); |
| 1056 | tio->duration_jiffies = jiffies - tio->duration_jiffies; |
| 1057 | dm_stats_account_io(&md->stats, orig->cmd_flags, blk_rq_pos(orig), |
| 1058 | tio->n_sectors, true, tio->duration_jiffies, |
| 1059 | &tio->stats_aux); |
| 1060 | } |
| 1061 | } |
| 1062 | |
| 1063 | /* |
| 1064 | * Don't touch any member of the md after calling this function because |
| 1065 | * the md may be freed in dm_put() at the end of this function. |
| 1066 | * Or do dm_get() before calling this function and dm_put() later. |
| 1067 | */ |
| 1068 | static void rq_completed(struct mapped_device *md, int rw, bool run_queue) |
| 1069 | { |
| 1070 | int nr_requests_pending; |
| 1071 | |
| 1072 | atomic_dec(&md->pending[rw]); |
| 1073 | |
| 1074 | /* nudge anyone waiting on suspend queue */ |
| 1075 | nr_requests_pending = md_in_flight(md); |
| 1076 | if (!nr_requests_pending) |
| 1077 | wake_up(&md->wait); |
| 1078 | |
| 1079 | /* |
| 1080 | * Run this off this callpath, as drivers could invoke end_io while |
| 1081 | * inside their request_fn (and holding the queue lock). Calling |
| 1082 | * back into ->request_fn() could deadlock attempting to grab the |
| 1083 | * queue lock again. |
| 1084 | */ |
| 1085 | if (run_queue) { |
| 1086 | if (md->queue->mq_ops) |
| 1087 | blk_mq_run_hw_queues(md->queue, true); |
| 1088 | else if (!nr_requests_pending || |
| 1089 | (nr_requests_pending >= md->queue->nr_congestion_on)) |
| 1090 | blk_run_queue_async(md->queue); |
| 1091 | } |
| 1092 | |
| 1093 | /* |
| 1094 | * dm_put() must be at the end of this function. See the comment above |
| 1095 | */ |
| 1096 | dm_put(md); |
| 1097 | } |
| 1098 | |
| 1099 | static void free_rq_clone(struct request *clone) |
| 1100 | { |
| 1101 | struct dm_rq_target_io *tio = clone->end_io_data; |
| 1102 | struct mapped_device *md = tio->md; |
| 1103 | |
| 1104 | blk_rq_unprep_clone(clone); |
| 1105 | |
| 1106 | if (md->type == DM_TYPE_MQ_REQUEST_BASED) |
| 1107 | /* stacked on blk-mq queue(s) */ |
| 1108 | tio->ti->type->release_clone_rq(clone); |
| 1109 | else if (!md->queue->mq_ops) |
| 1110 | /* request_fn queue stacked on request_fn queue(s) */ |
| 1111 | free_clone_request(md, clone); |
| 1112 | /* |
| 1113 | * NOTE: for the blk-mq queue stacked on request_fn queue(s) case: |
| 1114 | * no need to call free_clone_request() because we leverage blk-mq by |
| 1115 | * allocating the clone at the end of the blk-mq pdu (see: clone_rq) |
| 1116 | */ |
| 1117 | |
| 1118 | if (!md->queue->mq_ops) |
| 1119 | free_rq_tio(tio); |
| 1120 | } |
| 1121 | |
| 1122 | /* |
| 1123 | * Complete the clone and the original request. |
| 1124 | * Must be called without clone's queue lock held, |
| 1125 | * see end_clone_request() for more details. |
| 1126 | */ |
| 1127 | static void dm_end_request(struct request *clone, int error) |
| 1128 | { |
| 1129 | int rw = rq_data_dir(clone); |
| 1130 | struct dm_rq_target_io *tio = clone->end_io_data; |
| 1131 | struct mapped_device *md = tio->md; |
| 1132 | struct request *rq = tio->orig; |
| 1133 | |
| 1134 | if (rq->cmd_type == REQ_TYPE_BLOCK_PC) { |
| 1135 | rq->errors = clone->errors; |
| 1136 | rq->resid_len = clone->resid_len; |
| 1137 | |
| 1138 | if (rq->sense) |
| 1139 | /* |
| 1140 | * We are using the sense buffer of the original |
| 1141 | * request. |
| 1142 | * So setting the length of the sense data is enough. |
| 1143 | */ |
| 1144 | rq->sense_len = clone->sense_len; |
| 1145 | } |
| 1146 | |
| 1147 | free_rq_clone(clone); |
| 1148 | rq_end_stats(md, rq); |
| 1149 | if (!rq->q->mq_ops) |
| 1150 | blk_end_request_all(rq, error); |
| 1151 | else |
| 1152 | blk_mq_end_request(rq, error); |
| 1153 | rq_completed(md, rw, true); |
| 1154 | } |
| 1155 | |
| 1156 | static void dm_unprep_request(struct request *rq) |
| 1157 | { |
| 1158 | struct dm_rq_target_io *tio = tio_from_request(rq); |
| 1159 | struct request *clone = tio->clone; |
| 1160 | |
| 1161 | if (!rq->q->mq_ops) { |
| 1162 | rq->special = NULL; |
| 1163 | rq->cmd_flags &= ~REQ_DONTPREP; |
| 1164 | } |
| 1165 | |
| 1166 | if (clone) |
| 1167 | free_rq_clone(clone); |
| 1168 | } |
| 1169 | |
| 1170 | /* |
| 1171 | * Requeue the original request of a clone. |
| 1172 | */ |
| 1173 | static void old_requeue_request(struct request *rq) |
| 1174 | { |
| 1175 | struct request_queue *q = rq->q; |
| 1176 | unsigned long flags; |
| 1177 | |
| 1178 | spin_lock_irqsave(q->queue_lock, flags); |
| 1179 | blk_requeue_request(q, rq); |
| 1180 | blk_run_queue_async(q); |
| 1181 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 1182 | } |
| 1183 | |
| 1184 | static void dm_requeue_original_request(struct mapped_device *md, |
| 1185 | struct request *rq) |
| 1186 | { |
| 1187 | int rw = rq_data_dir(rq); |
| 1188 | |
| 1189 | dm_unprep_request(rq); |
| 1190 | |
| 1191 | rq_end_stats(md, rq); |
| 1192 | if (!rq->q->mq_ops) |
| 1193 | old_requeue_request(rq); |
| 1194 | else { |
| 1195 | blk_mq_requeue_request(rq); |
| 1196 | blk_mq_kick_requeue_list(rq->q); |
| 1197 | } |
| 1198 | |
| 1199 | rq_completed(md, rw, false); |
| 1200 | } |
| 1201 | |
| 1202 | static void old_stop_queue(struct request_queue *q) |
| 1203 | { |
| 1204 | unsigned long flags; |
| 1205 | |
| 1206 | if (blk_queue_stopped(q)) |
| 1207 | return; |
| 1208 | |
| 1209 | spin_lock_irqsave(q->queue_lock, flags); |
| 1210 | blk_stop_queue(q); |
| 1211 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 1212 | } |
| 1213 | |
| 1214 | static void stop_queue(struct request_queue *q) |
| 1215 | { |
| 1216 | if (!q->mq_ops) |
| 1217 | old_stop_queue(q); |
| 1218 | else |
| 1219 | blk_mq_stop_hw_queues(q); |
| 1220 | } |
| 1221 | |
| 1222 | static void old_start_queue(struct request_queue *q) |
| 1223 | { |
| 1224 | unsigned long flags; |
| 1225 | |
| 1226 | spin_lock_irqsave(q->queue_lock, flags); |
| 1227 | if (blk_queue_stopped(q)) |
| 1228 | blk_start_queue(q); |
| 1229 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 1230 | } |
| 1231 | |
| 1232 | static void start_queue(struct request_queue *q) |
| 1233 | { |
| 1234 | if (!q->mq_ops) |
| 1235 | old_start_queue(q); |
| 1236 | else |
| 1237 | blk_mq_start_stopped_hw_queues(q, true); |
| 1238 | } |
| 1239 | |
| 1240 | static void dm_done(struct request *clone, int error, bool mapped) |
| 1241 | { |
| 1242 | int r = error; |
| 1243 | struct dm_rq_target_io *tio = clone->end_io_data; |
| 1244 | dm_request_endio_fn rq_end_io = NULL; |
| 1245 | |
| 1246 | if (tio->ti) { |
| 1247 | rq_end_io = tio->ti->type->rq_end_io; |
| 1248 | |
| 1249 | if (mapped && rq_end_io) |
| 1250 | r = rq_end_io(tio->ti, clone, error, &tio->info); |
| 1251 | } |
| 1252 | |
| 1253 | if (unlikely(r == -EREMOTEIO && (clone->cmd_flags & REQ_WRITE_SAME) && |
| 1254 | !clone->q->limits.max_write_same_sectors)) |
| 1255 | disable_write_same(tio->md); |
| 1256 | |
| 1257 | if (r <= 0) |
| 1258 | /* The target wants to complete the I/O */ |
| 1259 | dm_end_request(clone, r); |
| 1260 | else if (r == DM_ENDIO_INCOMPLETE) |
| 1261 | /* The target will handle the I/O */ |
| 1262 | return; |
| 1263 | else if (r == DM_ENDIO_REQUEUE) |
| 1264 | /* The target wants to requeue the I/O */ |
| 1265 | dm_requeue_original_request(tio->md, tio->orig); |
| 1266 | else { |
| 1267 | DMWARN("unimplemented target endio return value: %d", r); |
| 1268 | BUG(); |
| 1269 | } |
| 1270 | } |
| 1271 | |
| 1272 | /* |
| 1273 | * Request completion handler for request-based dm |
| 1274 | */ |
| 1275 | static void dm_softirq_done(struct request *rq) |
| 1276 | { |
| 1277 | bool mapped = true; |
| 1278 | struct dm_rq_target_io *tio = tio_from_request(rq); |
| 1279 | struct request *clone = tio->clone; |
| 1280 | int rw; |
| 1281 | |
| 1282 | if (!clone) { |
| 1283 | rq_end_stats(tio->md, rq); |
| 1284 | rw = rq_data_dir(rq); |
| 1285 | if (!rq->q->mq_ops) { |
| 1286 | blk_end_request_all(rq, tio->error); |
| 1287 | rq_completed(tio->md, rw, false); |
| 1288 | free_rq_tio(tio); |
| 1289 | } else { |
| 1290 | blk_mq_end_request(rq, tio->error); |
| 1291 | rq_completed(tio->md, rw, false); |
| 1292 | } |
| 1293 | return; |
| 1294 | } |
| 1295 | |
| 1296 | if (rq->cmd_flags & REQ_FAILED) |
| 1297 | mapped = false; |
| 1298 | |
| 1299 | dm_done(clone, tio->error, mapped); |
| 1300 | } |
| 1301 | |
| 1302 | /* |
| 1303 | * Complete the clone and the original request with the error status |
| 1304 | * through softirq context. |
| 1305 | */ |
| 1306 | static void dm_complete_request(struct request *rq, int error) |
| 1307 | { |
| 1308 | struct dm_rq_target_io *tio = tio_from_request(rq); |
| 1309 | |
| 1310 | tio->error = error; |
| 1311 | blk_complete_request(rq); |
| 1312 | } |
| 1313 | |
| 1314 | /* |
| 1315 | * Complete the not-mapped clone and the original request with the error status |
| 1316 | * through softirq context. |
| 1317 | * Target's rq_end_io() function isn't called. |
| 1318 | * This may be used when the target's map_rq() or clone_and_map_rq() functions fail. |
| 1319 | */ |
| 1320 | static void dm_kill_unmapped_request(struct request *rq, int error) |
| 1321 | { |
| 1322 | rq->cmd_flags |= REQ_FAILED; |
| 1323 | dm_complete_request(rq, error); |
| 1324 | } |
| 1325 | |
| 1326 | /* |
| 1327 | * Called with the clone's queue lock held (for non-blk-mq) |
| 1328 | */ |
| 1329 | static void end_clone_request(struct request *clone, int error) |
| 1330 | { |
| 1331 | struct dm_rq_target_io *tio = clone->end_io_data; |
| 1332 | |
| 1333 | if (!clone->q->mq_ops) { |
| 1334 | /* |
| 1335 | * For just cleaning up the information of the queue in which |
| 1336 | * the clone was dispatched. |
| 1337 | * The clone is *NOT* freed actually here because it is alloced |
| 1338 | * from dm own mempool (REQ_ALLOCED isn't set). |
| 1339 | */ |
| 1340 | __blk_put_request(clone->q, clone); |
| 1341 | } |
| 1342 | |
| 1343 | /* |
| 1344 | * Actual request completion is done in a softirq context which doesn't |
| 1345 | * hold the clone's queue lock. Otherwise, deadlock could occur because: |
| 1346 | * - another request may be submitted by the upper level driver |
| 1347 | * of the stacking during the completion |
| 1348 | * - the submission which requires queue lock may be done |
| 1349 | * against this clone's queue |
| 1350 | */ |
| 1351 | dm_complete_request(tio->orig, error); |
| 1352 | } |
| 1353 | |
| 1354 | /* |
| 1355 | * Return maximum size of I/O possible at the supplied sector up to the current |
| 1356 | * target boundary. |
| 1357 | */ |
| 1358 | static sector_t max_io_len_target_boundary(sector_t sector, struct dm_target *ti) |
| 1359 | { |
| 1360 | sector_t target_offset = dm_target_offset(ti, sector); |
| 1361 | |
| 1362 | return ti->len - target_offset; |
| 1363 | } |
| 1364 | |
| 1365 | static sector_t max_io_len(sector_t sector, struct dm_target *ti) |
| 1366 | { |
| 1367 | sector_t len = max_io_len_target_boundary(sector, ti); |
| 1368 | sector_t offset, max_len; |
| 1369 | |
| 1370 | /* |
| 1371 | * Does the target need to split even further? |
| 1372 | */ |
| 1373 | if (ti->max_io_len) { |
| 1374 | offset = dm_target_offset(ti, sector); |
| 1375 | if (unlikely(ti->max_io_len & (ti->max_io_len - 1))) |
| 1376 | max_len = sector_div(offset, ti->max_io_len); |
| 1377 | else |
| 1378 | max_len = offset & (ti->max_io_len - 1); |
| 1379 | max_len = ti->max_io_len - max_len; |
| 1380 | |
| 1381 | if (len > max_len) |
| 1382 | len = max_len; |
| 1383 | } |
| 1384 | |
| 1385 | return len; |
| 1386 | } |
| 1387 | |
| 1388 | int dm_set_target_max_io_len(struct dm_target *ti, sector_t len) |
| 1389 | { |
| 1390 | if (len > UINT_MAX) { |
| 1391 | DMERR("Specified maximum size of target IO (%llu) exceeds limit (%u)", |
| 1392 | (unsigned long long)len, UINT_MAX); |
| 1393 | ti->error = "Maximum size of target IO is too large"; |
| 1394 | return -EINVAL; |
| 1395 | } |
| 1396 | |
| 1397 | ti->max_io_len = (uint32_t) len; |
| 1398 | |
| 1399 | return 0; |
| 1400 | } |
| 1401 | EXPORT_SYMBOL_GPL(dm_set_target_max_io_len); |
| 1402 | |
| 1403 | /* |
| 1404 | * A target may call dm_accept_partial_bio only from the map routine. It is |
| 1405 | * allowed for all bio types except REQ_FLUSH. |
| 1406 | * |
| 1407 | * dm_accept_partial_bio informs the dm that the target only wants to process |
| 1408 | * additional n_sectors sectors of the bio and the rest of the data should be |
| 1409 | * sent in a next bio. |
| 1410 | * |
| 1411 | * A diagram that explains the arithmetics: |
| 1412 | * +--------------------+---------------+-------+ |
| 1413 | * | 1 | 2 | 3 | |
| 1414 | * +--------------------+---------------+-------+ |
| 1415 | * |
| 1416 | * <-------------- *tio->len_ptr ---------------> |
| 1417 | * <------- bi_size -------> |
| 1418 | * <-- n_sectors --> |
| 1419 | * |
| 1420 | * Region 1 was already iterated over with bio_advance or similar function. |
| 1421 | * (it may be empty if the target doesn't use bio_advance) |
| 1422 | * Region 2 is the remaining bio size that the target wants to process. |
| 1423 | * (it may be empty if region 1 is non-empty, although there is no reason |
| 1424 | * to make it empty) |
| 1425 | * The target requires that region 3 is to be sent in the next bio. |
| 1426 | * |
| 1427 | * If the target wants to receive multiple copies of the bio (via num_*bios, etc), |
| 1428 | * the partially processed part (the sum of regions 1+2) must be the same for all |
| 1429 | * copies of the bio. |
| 1430 | */ |
| 1431 | void dm_accept_partial_bio(struct bio *bio, unsigned n_sectors) |
| 1432 | { |
| 1433 | struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone); |
| 1434 | unsigned bi_size = bio->bi_iter.bi_size >> SECTOR_SHIFT; |
| 1435 | BUG_ON(bio->bi_rw & REQ_FLUSH); |
| 1436 | BUG_ON(bi_size > *tio->len_ptr); |
| 1437 | BUG_ON(n_sectors > bi_size); |
| 1438 | *tio->len_ptr -= bi_size - n_sectors; |
| 1439 | bio->bi_iter.bi_size = n_sectors << SECTOR_SHIFT; |
| 1440 | } |
| 1441 | EXPORT_SYMBOL_GPL(dm_accept_partial_bio); |
| 1442 | |
| 1443 | static void __map_bio(struct dm_target_io *tio) |
| 1444 | { |
| 1445 | int r; |
| 1446 | sector_t sector; |
| 1447 | struct mapped_device *md; |
| 1448 | struct bio *clone = &tio->clone; |
| 1449 | struct dm_target *ti = tio->ti; |
| 1450 | |
| 1451 | clone->bi_end_io = clone_endio; |
| 1452 | |
| 1453 | /* |
| 1454 | * Map the clone. If r == 0 we don't need to do |
| 1455 | * anything, the target has assumed ownership of |
| 1456 | * this io. |
| 1457 | */ |
| 1458 | atomic_inc(&tio->io->io_count); |
| 1459 | sector = clone->bi_iter.bi_sector; |
| 1460 | r = ti->type->map(ti, clone); |
| 1461 | if (r == DM_MAPIO_REMAPPED) { |
| 1462 | /* the bio has been remapped so dispatch it */ |
| 1463 | |
| 1464 | trace_block_bio_remap(bdev_get_queue(clone->bi_bdev), clone, |
| 1465 | tio->io->bio->bi_bdev->bd_dev, sector); |
| 1466 | |
| 1467 | generic_make_request(clone); |
| 1468 | } else if (r < 0 || r == DM_MAPIO_REQUEUE) { |
| 1469 | /* error the io and bail out, or requeue it if needed */ |
| 1470 | md = tio->io->md; |
| 1471 | dec_pending(tio->io, r); |
| 1472 | free_tio(md, tio); |
| 1473 | } else if (r) { |
| 1474 | DMWARN("unimplemented target map return value: %d", r); |
| 1475 | BUG(); |
| 1476 | } |
| 1477 | } |
| 1478 | |
| 1479 | struct clone_info { |
| 1480 | struct mapped_device *md; |
| 1481 | struct dm_table *map; |
| 1482 | struct bio *bio; |
| 1483 | struct dm_io *io; |
| 1484 | sector_t sector; |
| 1485 | unsigned sector_count; |
| 1486 | }; |
| 1487 | |
| 1488 | static void bio_setup_sector(struct bio *bio, sector_t sector, unsigned len) |
| 1489 | { |
| 1490 | bio->bi_iter.bi_sector = sector; |
| 1491 | bio->bi_iter.bi_size = to_bytes(len); |
| 1492 | } |
| 1493 | |
| 1494 | /* |
| 1495 | * Creates a bio that consists of range of complete bvecs. |
| 1496 | */ |
| 1497 | static void clone_bio(struct dm_target_io *tio, struct bio *bio, |
| 1498 | sector_t sector, unsigned len) |
| 1499 | { |
| 1500 | struct bio *clone = &tio->clone; |
| 1501 | |
| 1502 | __bio_clone_fast(clone, bio); |
| 1503 | |
| 1504 | if (bio_integrity(bio)) |
| 1505 | bio_integrity_clone(clone, bio, GFP_NOIO); |
| 1506 | |
| 1507 | bio_advance(clone, to_bytes(sector - clone->bi_iter.bi_sector)); |
| 1508 | clone->bi_iter.bi_size = to_bytes(len); |
| 1509 | |
| 1510 | if (bio_integrity(bio)) |
| 1511 | bio_integrity_trim(clone, 0, len); |
| 1512 | } |
| 1513 | |
| 1514 | static struct dm_target_io *alloc_tio(struct clone_info *ci, |
| 1515 | struct dm_target *ti, |
| 1516 | unsigned target_bio_nr) |
| 1517 | { |
| 1518 | struct dm_target_io *tio; |
| 1519 | struct bio *clone; |
| 1520 | |
| 1521 | clone = bio_alloc_bioset(GFP_NOIO, 0, ci->md->bs); |
| 1522 | tio = container_of(clone, struct dm_target_io, clone); |
| 1523 | |
| 1524 | tio->io = ci->io; |
| 1525 | tio->ti = ti; |
| 1526 | tio->target_bio_nr = target_bio_nr; |
| 1527 | |
| 1528 | return tio; |
| 1529 | } |
| 1530 | |
| 1531 | static void __clone_and_map_simple_bio(struct clone_info *ci, |
| 1532 | struct dm_target *ti, |
| 1533 | unsigned target_bio_nr, unsigned *len) |
| 1534 | { |
| 1535 | struct dm_target_io *tio = alloc_tio(ci, ti, target_bio_nr); |
| 1536 | struct bio *clone = &tio->clone; |
| 1537 | |
| 1538 | tio->len_ptr = len; |
| 1539 | |
| 1540 | __bio_clone_fast(clone, ci->bio); |
| 1541 | if (len) |
| 1542 | bio_setup_sector(clone, ci->sector, *len); |
| 1543 | |
| 1544 | __map_bio(tio); |
| 1545 | } |
| 1546 | |
| 1547 | static void __send_duplicate_bios(struct clone_info *ci, struct dm_target *ti, |
| 1548 | unsigned num_bios, unsigned *len) |
| 1549 | { |
| 1550 | unsigned target_bio_nr; |
| 1551 | |
| 1552 | for (target_bio_nr = 0; target_bio_nr < num_bios; target_bio_nr++) |
| 1553 | __clone_and_map_simple_bio(ci, ti, target_bio_nr, len); |
| 1554 | } |
| 1555 | |
| 1556 | static int __send_empty_flush(struct clone_info *ci) |
| 1557 | { |
| 1558 | unsigned target_nr = 0; |
| 1559 | struct dm_target *ti; |
| 1560 | |
| 1561 | BUG_ON(bio_has_data(ci->bio)); |
| 1562 | while ((ti = dm_table_get_target(ci->map, target_nr++))) |
| 1563 | __send_duplicate_bios(ci, ti, ti->num_flush_bios, NULL); |
| 1564 | |
| 1565 | return 0; |
| 1566 | } |
| 1567 | |
| 1568 | static void __clone_and_map_data_bio(struct clone_info *ci, struct dm_target *ti, |
| 1569 | sector_t sector, unsigned *len) |
| 1570 | { |
| 1571 | struct bio *bio = ci->bio; |
| 1572 | struct dm_target_io *tio; |
| 1573 | unsigned target_bio_nr; |
| 1574 | unsigned num_target_bios = 1; |
| 1575 | |
| 1576 | /* |
| 1577 | * Does the target want to receive duplicate copies of the bio? |
| 1578 | */ |
| 1579 | if (bio_data_dir(bio) == WRITE && ti->num_write_bios) |
| 1580 | num_target_bios = ti->num_write_bios(ti, bio); |
| 1581 | |
| 1582 | for (target_bio_nr = 0; target_bio_nr < num_target_bios; target_bio_nr++) { |
| 1583 | tio = alloc_tio(ci, ti, target_bio_nr); |
| 1584 | tio->len_ptr = len; |
| 1585 | clone_bio(tio, bio, sector, *len); |
| 1586 | __map_bio(tio); |
| 1587 | } |
| 1588 | } |
| 1589 | |
| 1590 | typedef unsigned (*get_num_bios_fn)(struct dm_target *ti); |
| 1591 | |
| 1592 | static unsigned get_num_discard_bios(struct dm_target *ti) |
| 1593 | { |
| 1594 | return ti->num_discard_bios; |
| 1595 | } |
| 1596 | |
| 1597 | static unsigned get_num_write_same_bios(struct dm_target *ti) |
| 1598 | { |
| 1599 | return ti->num_write_same_bios; |
| 1600 | } |
| 1601 | |
| 1602 | typedef bool (*is_split_required_fn)(struct dm_target *ti); |
| 1603 | |
| 1604 | static bool is_split_required_for_discard(struct dm_target *ti) |
| 1605 | { |
| 1606 | return ti->split_discard_bios; |
| 1607 | } |
| 1608 | |
| 1609 | static int __send_changing_extent_only(struct clone_info *ci, |
| 1610 | get_num_bios_fn get_num_bios, |
| 1611 | is_split_required_fn is_split_required) |
| 1612 | { |
| 1613 | struct dm_target *ti; |
| 1614 | unsigned len; |
| 1615 | unsigned num_bios; |
| 1616 | |
| 1617 | do { |
| 1618 | ti = dm_table_find_target(ci->map, ci->sector); |
| 1619 | if (!dm_target_is_valid(ti)) |
| 1620 | return -EIO; |
| 1621 | |
| 1622 | /* |
| 1623 | * Even though the device advertised support for this type of |
| 1624 | * request, that does not mean every target supports it, and |
| 1625 | * reconfiguration might also have changed that since the |
| 1626 | * check was performed. |
| 1627 | */ |
| 1628 | num_bios = get_num_bios ? get_num_bios(ti) : 0; |
| 1629 | if (!num_bios) |
| 1630 | return -EOPNOTSUPP; |
| 1631 | |
| 1632 | if (is_split_required && !is_split_required(ti)) |
| 1633 | len = min((sector_t)ci->sector_count, max_io_len_target_boundary(ci->sector, ti)); |
| 1634 | else |
| 1635 | len = min((sector_t)ci->sector_count, max_io_len(ci->sector, ti)); |
| 1636 | |
| 1637 | __send_duplicate_bios(ci, ti, num_bios, &len); |
| 1638 | |
| 1639 | ci->sector += len; |
| 1640 | } while (ci->sector_count -= len); |
| 1641 | |
| 1642 | return 0; |
| 1643 | } |
| 1644 | |
| 1645 | static int __send_discard(struct clone_info *ci) |
| 1646 | { |
| 1647 | return __send_changing_extent_only(ci, get_num_discard_bios, |
| 1648 | is_split_required_for_discard); |
| 1649 | } |
| 1650 | |
| 1651 | static int __send_write_same(struct clone_info *ci) |
| 1652 | { |
| 1653 | return __send_changing_extent_only(ci, get_num_write_same_bios, NULL); |
| 1654 | } |
| 1655 | |
| 1656 | /* |
| 1657 | * Select the correct strategy for processing a non-flush bio. |
| 1658 | */ |
| 1659 | static int __split_and_process_non_flush(struct clone_info *ci) |
| 1660 | { |
| 1661 | struct bio *bio = ci->bio; |
| 1662 | struct dm_target *ti; |
| 1663 | unsigned len; |
| 1664 | |
| 1665 | if (unlikely(bio->bi_rw & REQ_DISCARD)) |
| 1666 | return __send_discard(ci); |
| 1667 | else if (unlikely(bio->bi_rw & REQ_WRITE_SAME)) |
| 1668 | return __send_write_same(ci); |
| 1669 | |
| 1670 | ti = dm_table_find_target(ci->map, ci->sector); |
| 1671 | if (!dm_target_is_valid(ti)) |
| 1672 | return -EIO; |
| 1673 | |
| 1674 | len = min_t(sector_t, max_io_len(ci->sector, ti), ci->sector_count); |
| 1675 | |
| 1676 | __clone_and_map_data_bio(ci, ti, ci->sector, &len); |
| 1677 | |
| 1678 | ci->sector += len; |
| 1679 | ci->sector_count -= len; |
| 1680 | |
| 1681 | return 0; |
| 1682 | } |
| 1683 | |
| 1684 | /* |
| 1685 | * Entry point to split a bio into clones and submit them to the targets. |
| 1686 | */ |
| 1687 | static void __split_and_process_bio(struct mapped_device *md, |
| 1688 | struct dm_table *map, struct bio *bio) |
| 1689 | { |
| 1690 | struct clone_info ci; |
| 1691 | int error = 0; |
| 1692 | |
| 1693 | if (unlikely(!map)) { |
| 1694 | bio_io_error(bio); |
| 1695 | return; |
| 1696 | } |
| 1697 | |
| 1698 | ci.map = map; |
| 1699 | ci.md = md; |
| 1700 | ci.io = alloc_io(md); |
| 1701 | ci.io->error = 0; |
| 1702 | atomic_set(&ci.io->io_count, 1); |
| 1703 | ci.io->bio = bio; |
| 1704 | ci.io->md = md; |
| 1705 | spin_lock_init(&ci.io->endio_lock); |
| 1706 | ci.sector = bio->bi_iter.bi_sector; |
| 1707 | |
| 1708 | start_io_acct(ci.io); |
| 1709 | |
| 1710 | if (bio->bi_rw & REQ_FLUSH) { |
| 1711 | ci.bio = &ci.md->flush_bio; |
| 1712 | ci.sector_count = 0; |
| 1713 | error = __send_empty_flush(&ci); |
| 1714 | /* dec_pending submits any data associated with flush */ |
| 1715 | } else { |
| 1716 | ci.bio = bio; |
| 1717 | ci.sector_count = bio_sectors(bio); |
| 1718 | while (ci.sector_count && !error) |
| 1719 | error = __split_and_process_non_flush(&ci); |
| 1720 | } |
| 1721 | |
| 1722 | /* drop the extra reference count */ |
| 1723 | dec_pending(ci.io, error); |
| 1724 | } |
| 1725 | /*----------------------------------------------------------------- |
| 1726 | * CRUD END |
| 1727 | *---------------------------------------------------------------*/ |
| 1728 | |
| 1729 | static int dm_merge_bvec(struct request_queue *q, |
| 1730 | struct bvec_merge_data *bvm, |
| 1731 | struct bio_vec *biovec) |
| 1732 | { |
| 1733 | struct mapped_device *md = q->queuedata; |
| 1734 | struct dm_table *map = dm_get_live_table_fast(md); |
| 1735 | struct dm_target *ti; |
| 1736 | sector_t max_sectors, max_size = 0; |
| 1737 | |
| 1738 | if (unlikely(!map)) |
| 1739 | goto out; |
| 1740 | |
| 1741 | ti = dm_table_find_target(map, bvm->bi_sector); |
| 1742 | if (!dm_target_is_valid(ti)) |
| 1743 | goto out; |
| 1744 | |
| 1745 | /* |
| 1746 | * Find maximum amount of I/O that won't need splitting |
| 1747 | */ |
| 1748 | max_sectors = min(max_io_len(bvm->bi_sector, ti), |
| 1749 | (sector_t) queue_max_sectors(q)); |
| 1750 | max_size = (max_sectors << SECTOR_SHIFT) - bvm->bi_size; |
| 1751 | |
| 1752 | /* |
| 1753 | * FIXME: this stop-gap fix _must_ be cleaned up (by passing a sector_t |
| 1754 | * to the targets' merge function since it holds sectors not bytes). |
| 1755 | * Just doing this as an interim fix for stable@ because the more |
| 1756 | * comprehensive cleanup of switching to sector_t will impact every |
| 1757 | * DM target that implements a ->merge hook. |
| 1758 | */ |
| 1759 | if (max_size > INT_MAX) |
| 1760 | max_size = INT_MAX; |
| 1761 | |
| 1762 | /* |
| 1763 | * merge_bvec_fn() returns number of bytes |
| 1764 | * it can accept at this offset |
| 1765 | * max is precomputed maximal io size |
| 1766 | */ |
| 1767 | if (max_size && ti->type->merge) |
| 1768 | max_size = ti->type->merge(ti, bvm, biovec, (int) max_size); |
| 1769 | /* |
| 1770 | * If the target doesn't support merge method and some of the devices |
| 1771 | * provided their merge_bvec method (we know this by looking for the |
| 1772 | * max_hw_sectors that dm_set_device_limits may set), then we can't |
| 1773 | * allow bios with multiple vector entries. So always set max_size |
| 1774 | * to 0, and the code below allows just one page. |
| 1775 | */ |
| 1776 | else if (queue_max_hw_sectors(q) <= PAGE_SIZE >> 9) |
| 1777 | max_size = 0; |
| 1778 | |
| 1779 | out: |
| 1780 | dm_put_live_table_fast(md); |
| 1781 | /* |
| 1782 | * Always allow an entire first page |
| 1783 | */ |
| 1784 | if (max_size <= biovec->bv_len && !(bvm->bi_size >> SECTOR_SHIFT)) |
| 1785 | max_size = biovec->bv_len; |
| 1786 | |
| 1787 | return max_size; |
| 1788 | } |
| 1789 | |
| 1790 | /* |
| 1791 | * The request function that just remaps the bio built up by |
| 1792 | * dm_merge_bvec. |
| 1793 | */ |
| 1794 | static void dm_make_request(struct request_queue *q, struct bio *bio) |
| 1795 | { |
| 1796 | int rw = bio_data_dir(bio); |
| 1797 | struct mapped_device *md = q->queuedata; |
| 1798 | int srcu_idx; |
| 1799 | struct dm_table *map; |
| 1800 | |
| 1801 | map = dm_get_live_table(md, &srcu_idx); |
| 1802 | |
| 1803 | generic_start_io_acct(rw, bio_sectors(bio), &dm_disk(md)->part0); |
| 1804 | |
| 1805 | /* if we're suspended, we have to queue this io for later */ |
| 1806 | if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags))) { |
| 1807 | dm_put_live_table(md, srcu_idx); |
| 1808 | |
| 1809 | if (bio_rw(bio) != READA) |
| 1810 | queue_io(md, bio); |
| 1811 | else |
| 1812 | bio_io_error(bio); |
| 1813 | return; |
| 1814 | } |
| 1815 | |
| 1816 | __split_and_process_bio(md, map, bio); |
| 1817 | dm_put_live_table(md, srcu_idx); |
| 1818 | return; |
| 1819 | } |
| 1820 | |
| 1821 | int dm_request_based(struct mapped_device *md) |
| 1822 | { |
| 1823 | return blk_queue_stackable(md->queue); |
| 1824 | } |
| 1825 | |
| 1826 | static void dm_dispatch_clone_request(struct request *clone, struct request *rq) |
| 1827 | { |
| 1828 | int r; |
| 1829 | |
| 1830 | if (blk_queue_io_stat(clone->q)) |
| 1831 | clone->cmd_flags |= REQ_IO_STAT; |
| 1832 | |
| 1833 | clone->start_time = jiffies; |
| 1834 | r = blk_insert_cloned_request(clone->q, clone); |
| 1835 | if (r) |
| 1836 | /* must complete clone in terms of original request */ |
| 1837 | dm_complete_request(rq, r); |
| 1838 | } |
| 1839 | |
| 1840 | static int dm_rq_bio_constructor(struct bio *bio, struct bio *bio_orig, |
| 1841 | void *data) |
| 1842 | { |
| 1843 | struct dm_rq_target_io *tio = data; |
| 1844 | struct dm_rq_clone_bio_info *info = |
| 1845 | container_of(bio, struct dm_rq_clone_bio_info, clone); |
| 1846 | |
| 1847 | info->orig = bio_orig; |
| 1848 | info->tio = tio; |
| 1849 | bio->bi_end_io = end_clone_bio; |
| 1850 | |
| 1851 | return 0; |
| 1852 | } |
| 1853 | |
| 1854 | static int setup_clone(struct request *clone, struct request *rq, |
| 1855 | struct dm_rq_target_io *tio, gfp_t gfp_mask) |
| 1856 | { |
| 1857 | int r; |
| 1858 | |
| 1859 | r = blk_rq_prep_clone(clone, rq, tio->md->bs, gfp_mask, |
| 1860 | dm_rq_bio_constructor, tio); |
| 1861 | if (r) |
| 1862 | return r; |
| 1863 | |
| 1864 | clone->cmd = rq->cmd; |
| 1865 | clone->cmd_len = rq->cmd_len; |
| 1866 | clone->sense = rq->sense; |
| 1867 | clone->end_io = end_clone_request; |
| 1868 | clone->end_io_data = tio; |
| 1869 | |
| 1870 | tio->clone = clone; |
| 1871 | |
| 1872 | return 0; |
| 1873 | } |
| 1874 | |
| 1875 | static struct request *clone_rq(struct request *rq, struct mapped_device *md, |
| 1876 | struct dm_rq_target_io *tio, gfp_t gfp_mask) |
| 1877 | { |
| 1878 | /* |
| 1879 | * Do not allocate a clone if tio->clone was already set |
| 1880 | * (see: dm_mq_queue_rq). |
| 1881 | */ |
| 1882 | bool alloc_clone = !tio->clone; |
| 1883 | struct request *clone; |
| 1884 | |
| 1885 | if (alloc_clone) { |
| 1886 | clone = alloc_clone_request(md, gfp_mask); |
| 1887 | if (!clone) |
| 1888 | return NULL; |
| 1889 | } else |
| 1890 | clone = tio->clone; |
| 1891 | |
| 1892 | blk_rq_init(NULL, clone); |
| 1893 | if (setup_clone(clone, rq, tio, gfp_mask)) { |
| 1894 | /* -ENOMEM */ |
| 1895 | if (alloc_clone) |
| 1896 | free_clone_request(md, clone); |
| 1897 | return NULL; |
| 1898 | } |
| 1899 | |
| 1900 | return clone; |
| 1901 | } |
| 1902 | |
| 1903 | static void map_tio_request(struct kthread_work *work); |
| 1904 | |
| 1905 | static void init_tio(struct dm_rq_target_io *tio, struct request *rq, |
| 1906 | struct mapped_device *md) |
| 1907 | { |
| 1908 | tio->md = md; |
| 1909 | tio->ti = NULL; |
| 1910 | tio->clone = NULL; |
| 1911 | tio->orig = rq; |
| 1912 | tio->error = 0; |
| 1913 | memset(&tio->info, 0, sizeof(tio->info)); |
| 1914 | if (md->kworker_task) |
| 1915 | init_kthread_work(&tio->work, map_tio_request); |
| 1916 | } |
| 1917 | |
| 1918 | static struct dm_rq_target_io *prep_tio(struct request *rq, |
| 1919 | struct mapped_device *md, gfp_t gfp_mask) |
| 1920 | { |
| 1921 | struct dm_rq_target_io *tio; |
| 1922 | int srcu_idx; |
| 1923 | struct dm_table *table; |
| 1924 | |
| 1925 | tio = alloc_rq_tio(md, gfp_mask); |
| 1926 | if (!tio) |
| 1927 | return NULL; |
| 1928 | |
| 1929 | init_tio(tio, rq, md); |
| 1930 | |
| 1931 | table = dm_get_live_table(md, &srcu_idx); |
| 1932 | if (!dm_table_mq_request_based(table)) { |
| 1933 | if (!clone_rq(rq, md, tio, gfp_mask)) { |
| 1934 | dm_put_live_table(md, srcu_idx); |
| 1935 | free_rq_tio(tio); |
| 1936 | return NULL; |
| 1937 | } |
| 1938 | } |
| 1939 | dm_put_live_table(md, srcu_idx); |
| 1940 | |
| 1941 | return tio; |
| 1942 | } |
| 1943 | |
| 1944 | /* |
| 1945 | * Called with the queue lock held. |
| 1946 | */ |
| 1947 | static int dm_prep_fn(struct request_queue *q, struct request *rq) |
| 1948 | { |
| 1949 | struct mapped_device *md = q->queuedata; |
| 1950 | struct dm_rq_target_io *tio; |
| 1951 | |
| 1952 | if (unlikely(rq->special)) { |
| 1953 | DMWARN("Already has something in rq->special."); |
| 1954 | return BLKPREP_KILL; |
| 1955 | } |
| 1956 | |
| 1957 | tio = prep_tio(rq, md, GFP_ATOMIC); |
| 1958 | if (!tio) |
| 1959 | return BLKPREP_DEFER; |
| 1960 | |
| 1961 | rq->special = tio; |
| 1962 | rq->cmd_flags |= REQ_DONTPREP; |
| 1963 | |
| 1964 | return BLKPREP_OK; |
| 1965 | } |
| 1966 | |
| 1967 | /* |
| 1968 | * Returns: |
| 1969 | * 0 : the request has been processed |
| 1970 | * DM_MAPIO_REQUEUE : the original request needs to be requeued |
| 1971 | * < 0 : the request was completed due to failure |
| 1972 | */ |
| 1973 | static int map_request(struct dm_rq_target_io *tio, struct request *rq, |
| 1974 | struct mapped_device *md) |
| 1975 | { |
| 1976 | int r; |
| 1977 | struct dm_target *ti = tio->ti; |
| 1978 | struct request *clone = NULL; |
| 1979 | |
| 1980 | if (tio->clone) { |
| 1981 | clone = tio->clone; |
| 1982 | r = ti->type->map_rq(ti, clone, &tio->info); |
| 1983 | } else { |
| 1984 | r = ti->type->clone_and_map_rq(ti, rq, &tio->info, &clone); |
| 1985 | if (r < 0) { |
| 1986 | /* The target wants to complete the I/O */ |
| 1987 | dm_kill_unmapped_request(rq, r); |
| 1988 | return r; |
| 1989 | } |
| 1990 | if (r != DM_MAPIO_REMAPPED) |
| 1991 | return r; |
| 1992 | if (setup_clone(clone, rq, tio, GFP_ATOMIC)) { |
| 1993 | /* -ENOMEM */ |
| 1994 | ti->type->release_clone_rq(clone); |
| 1995 | return DM_MAPIO_REQUEUE; |
| 1996 | } |
| 1997 | } |
| 1998 | |
| 1999 | switch (r) { |
| 2000 | case DM_MAPIO_SUBMITTED: |
| 2001 | /* The target has taken the I/O to submit by itself later */ |
| 2002 | break; |
| 2003 | case DM_MAPIO_REMAPPED: |
| 2004 | /* The target has remapped the I/O so dispatch it */ |
| 2005 | trace_block_rq_remap(clone->q, clone, disk_devt(dm_disk(md)), |
| 2006 | blk_rq_pos(rq)); |
| 2007 | dm_dispatch_clone_request(clone, rq); |
| 2008 | break; |
| 2009 | case DM_MAPIO_REQUEUE: |
| 2010 | /* The target wants to requeue the I/O */ |
| 2011 | dm_requeue_original_request(md, tio->orig); |
| 2012 | break; |
| 2013 | default: |
| 2014 | if (r > 0) { |
| 2015 | DMWARN("unimplemented target map return value: %d", r); |
| 2016 | BUG(); |
| 2017 | } |
| 2018 | |
| 2019 | /* The target wants to complete the I/O */ |
| 2020 | dm_kill_unmapped_request(rq, r); |
| 2021 | return r; |
| 2022 | } |
| 2023 | |
| 2024 | return 0; |
| 2025 | } |
| 2026 | |
| 2027 | static void map_tio_request(struct kthread_work *work) |
| 2028 | { |
| 2029 | struct dm_rq_target_io *tio = container_of(work, struct dm_rq_target_io, work); |
| 2030 | struct request *rq = tio->orig; |
| 2031 | struct mapped_device *md = tio->md; |
| 2032 | |
| 2033 | if (map_request(tio, rq, md) == DM_MAPIO_REQUEUE) |
| 2034 | dm_requeue_original_request(md, rq); |
| 2035 | } |
| 2036 | |
| 2037 | static void dm_start_request(struct mapped_device *md, struct request *orig) |
| 2038 | { |
| 2039 | if (!orig->q->mq_ops) |
| 2040 | blk_start_request(orig); |
| 2041 | else |
| 2042 | blk_mq_start_request(orig); |
| 2043 | atomic_inc(&md->pending[rq_data_dir(orig)]); |
| 2044 | |
| 2045 | if (md->seq_rq_merge_deadline_usecs) { |
| 2046 | md->last_rq_pos = rq_end_sector(orig); |
| 2047 | md->last_rq_rw = rq_data_dir(orig); |
| 2048 | md->last_rq_start_time = ktime_get(); |
| 2049 | } |
| 2050 | |
| 2051 | if (unlikely(dm_stats_used(&md->stats))) { |
| 2052 | struct dm_rq_target_io *tio = tio_from_request(orig); |
| 2053 | tio->duration_jiffies = jiffies; |
| 2054 | tio->n_sectors = blk_rq_sectors(orig); |
| 2055 | dm_stats_account_io(&md->stats, orig->cmd_flags, blk_rq_pos(orig), |
| 2056 | tio->n_sectors, false, 0, &tio->stats_aux); |
| 2057 | } |
| 2058 | |
| 2059 | /* |
| 2060 | * Hold the md reference here for the in-flight I/O. |
| 2061 | * We can't rely on the reference count by device opener, |
| 2062 | * because the device may be closed during the request completion |
| 2063 | * when all bios are completed. |
| 2064 | * See the comment in rq_completed() too. |
| 2065 | */ |
| 2066 | dm_get(md); |
| 2067 | } |
| 2068 | |
| 2069 | #define MAX_SEQ_RQ_MERGE_DEADLINE_USECS 100000 |
| 2070 | |
| 2071 | ssize_t dm_attr_rq_based_seq_io_merge_deadline_show(struct mapped_device *md, char *buf) |
| 2072 | { |
| 2073 | return sprintf(buf, "%u\n", md->seq_rq_merge_deadline_usecs); |
| 2074 | } |
| 2075 | |
| 2076 | ssize_t dm_attr_rq_based_seq_io_merge_deadline_store(struct mapped_device *md, |
| 2077 | const char *buf, size_t count) |
| 2078 | { |
| 2079 | unsigned deadline; |
| 2080 | |
| 2081 | if (!dm_request_based(md) || md->use_blk_mq) |
| 2082 | return count; |
| 2083 | |
| 2084 | if (kstrtouint(buf, 10, &deadline)) |
| 2085 | return -EINVAL; |
| 2086 | |
| 2087 | if (deadline > MAX_SEQ_RQ_MERGE_DEADLINE_USECS) |
| 2088 | deadline = MAX_SEQ_RQ_MERGE_DEADLINE_USECS; |
| 2089 | |
| 2090 | md->seq_rq_merge_deadline_usecs = deadline; |
| 2091 | |
| 2092 | return count; |
| 2093 | } |
| 2094 | |
| 2095 | static bool dm_request_peeked_before_merge_deadline(struct mapped_device *md) |
| 2096 | { |
| 2097 | ktime_t kt_deadline; |
| 2098 | |
| 2099 | if (!md->seq_rq_merge_deadline_usecs) |
| 2100 | return false; |
| 2101 | |
| 2102 | kt_deadline = ns_to_ktime((u64)md->seq_rq_merge_deadline_usecs * NSEC_PER_USEC); |
| 2103 | kt_deadline = ktime_add_safe(md->last_rq_start_time, kt_deadline); |
| 2104 | |
| 2105 | return !ktime_after(ktime_get(), kt_deadline); |
| 2106 | } |
| 2107 | |
| 2108 | /* |
| 2109 | * q->request_fn for request-based dm. |
| 2110 | * Called with the queue lock held. |
| 2111 | */ |
| 2112 | static void dm_request_fn(struct request_queue *q) |
| 2113 | { |
| 2114 | struct mapped_device *md = q->queuedata; |
| 2115 | int srcu_idx; |
| 2116 | struct dm_table *map = dm_get_live_table(md, &srcu_idx); |
| 2117 | struct dm_target *ti; |
| 2118 | struct request *rq; |
| 2119 | struct dm_rq_target_io *tio; |
| 2120 | sector_t pos; |
| 2121 | |
| 2122 | /* |
| 2123 | * For suspend, check blk_queue_stopped() and increment |
| 2124 | * ->pending within a single queue_lock not to increment the |
| 2125 | * number of in-flight I/Os after the queue is stopped in |
| 2126 | * dm_suspend(). |
| 2127 | */ |
| 2128 | while (!blk_queue_stopped(q)) { |
| 2129 | rq = blk_peek_request(q); |
| 2130 | if (!rq) |
| 2131 | goto out; |
| 2132 | |
| 2133 | /* always use block 0 to find the target for flushes for now */ |
| 2134 | pos = 0; |
| 2135 | if (!(rq->cmd_flags & REQ_FLUSH)) |
| 2136 | pos = blk_rq_pos(rq); |
| 2137 | |
| 2138 | ti = dm_table_find_target(map, pos); |
| 2139 | if (!dm_target_is_valid(ti)) { |
| 2140 | /* |
| 2141 | * Must perform setup, that rq_completed() requires, |
| 2142 | * before calling dm_kill_unmapped_request |
| 2143 | */ |
| 2144 | DMERR_LIMIT("request attempted access beyond the end of device"); |
| 2145 | dm_start_request(md, rq); |
| 2146 | dm_kill_unmapped_request(rq, -EIO); |
| 2147 | continue; |
| 2148 | } |
| 2149 | |
| 2150 | if (dm_request_peeked_before_merge_deadline(md) && |
| 2151 | md_in_flight(md) && rq->bio && rq->bio->bi_vcnt == 1 && |
| 2152 | md->last_rq_pos == pos && md->last_rq_rw == rq_data_dir(rq)) |
| 2153 | goto delay_and_out; |
| 2154 | |
| 2155 | if (ti->type->busy && ti->type->busy(ti)) |
| 2156 | goto delay_and_out; |
| 2157 | |
| 2158 | dm_start_request(md, rq); |
| 2159 | |
| 2160 | tio = tio_from_request(rq); |
| 2161 | /* Establish tio->ti before queuing work (map_tio_request) */ |
| 2162 | tio->ti = ti; |
| 2163 | queue_kthread_work(&md->kworker, &tio->work); |
| 2164 | BUG_ON(!irqs_disabled()); |
| 2165 | } |
| 2166 | |
| 2167 | goto out; |
| 2168 | |
| 2169 | delay_and_out: |
| 2170 | blk_delay_queue(q, HZ / 100); |
| 2171 | out: |
| 2172 | dm_put_live_table(md, srcu_idx); |
| 2173 | } |
| 2174 | |
| 2175 | static int dm_any_congested(void *congested_data, int bdi_bits) |
| 2176 | { |
| 2177 | int r = bdi_bits; |
| 2178 | struct mapped_device *md = congested_data; |
| 2179 | struct dm_table *map; |
| 2180 | |
| 2181 | if (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) { |
| 2182 | map = dm_get_live_table_fast(md); |
| 2183 | if (map) { |
| 2184 | /* |
| 2185 | * Request-based dm cares about only own queue for |
| 2186 | * the query about congestion status of request_queue |
| 2187 | */ |
| 2188 | if (dm_request_based(md)) |
| 2189 | r = md->queue->backing_dev_info.wb.state & |
| 2190 | bdi_bits; |
| 2191 | else |
| 2192 | r = dm_table_any_congested(map, bdi_bits); |
| 2193 | } |
| 2194 | dm_put_live_table_fast(md); |
| 2195 | } |
| 2196 | |
| 2197 | return r; |
| 2198 | } |
| 2199 | |
| 2200 | /*----------------------------------------------------------------- |
| 2201 | * An IDR is used to keep track of allocated minor numbers. |
| 2202 | *---------------------------------------------------------------*/ |
| 2203 | static void free_minor(int minor) |
| 2204 | { |
| 2205 | spin_lock(&_minor_lock); |
| 2206 | idr_remove(&_minor_idr, minor); |
| 2207 | spin_unlock(&_minor_lock); |
| 2208 | } |
| 2209 | |
| 2210 | /* |
| 2211 | * See if the device with a specific minor # is free. |
| 2212 | */ |
| 2213 | static int specific_minor(int minor) |
| 2214 | { |
| 2215 | int r; |
| 2216 | |
| 2217 | if (minor >= (1 << MINORBITS)) |
| 2218 | return -EINVAL; |
| 2219 | |
| 2220 | idr_preload(GFP_KERNEL); |
| 2221 | spin_lock(&_minor_lock); |
| 2222 | |
| 2223 | r = idr_alloc(&_minor_idr, MINOR_ALLOCED, minor, minor + 1, GFP_NOWAIT); |
| 2224 | |
| 2225 | spin_unlock(&_minor_lock); |
| 2226 | idr_preload_end(); |
| 2227 | if (r < 0) |
| 2228 | return r == -ENOSPC ? -EBUSY : r; |
| 2229 | return 0; |
| 2230 | } |
| 2231 | |
| 2232 | static int next_free_minor(int *minor) |
| 2233 | { |
| 2234 | int r; |
| 2235 | |
| 2236 | idr_preload(GFP_KERNEL); |
| 2237 | spin_lock(&_minor_lock); |
| 2238 | |
| 2239 | r = idr_alloc(&_minor_idr, MINOR_ALLOCED, 0, 1 << MINORBITS, GFP_NOWAIT); |
| 2240 | |
| 2241 | spin_unlock(&_minor_lock); |
| 2242 | idr_preload_end(); |
| 2243 | if (r < 0) |
| 2244 | return r; |
| 2245 | *minor = r; |
| 2246 | return 0; |
| 2247 | } |
| 2248 | |
| 2249 | static const struct block_device_operations dm_blk_dops; |
| 2250 | |
| 2251 | static void dm_wq_work(struct work_struct *work); |
| 2252 | |
| 2253 | static void dm_init_md_queue(struct mapped_device *md) |
| 2254 | { |
| 2255 | /* |
| 2256 | * Request-based dm devices cannot be stacked on top of bio-based dm |
| 2257 | * devices. The type of this dm device may not have been decided yet. |
| 2258 | * The type is decided at the first table loading time. |
| 2259 | * To prevent problematic device stacking, clear the queue flag |
| 2260 | * for request stacking support until then. |
| 2261 | * |
| 2262 | * This queue is new, so no concurrency on the queue_flags. |
| 2263 | */ |
| 2264 | queue_flag_clear_unlocked(QUEUE_FLAG_STACKABLE, md->queue); |
| 2265 | } |
| 2266 | |
| 2267 | static void dm_init_old_md_queue(struct mapped_device *md) |
| 2268 | { |
| 2269 | md->use_blk_mq = false; |
| 2270 | dm_init_md_queue(md); |
| 2271 | |
| 2272 | /* |
| 2273 | * Initialize aspects of queue that aren't relevant for blk-mq |
| 2274 | */ |
| 2275 | md->queue->queuedata = md; |
| 2276 | md->queue->backing_dev_info.congested_fn = dm_any_congested; |
| 2277 | md->queue->backing_dev_info.congested_data = md; |
| 2278 | |
| 2279 | blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY); |
| 2280 | } |
| 2281 | |
| 2282 | static void cleanup_mapped_device(struct mapped_device *md) |
| 2283 | { |
| 2284 | cleanup_srcu_struct(&md->io_barrier); |
| 2285 | |
| 2286 | if (md->wq) |
| 2287 | destroy_workqueue(md->wq); |
| 2288 | if (md->kworker_task) |
| 2289 | kthread_stop(md->kworker_task); |
| 2290 | if (md->io_pool) |
| 2291 | mempool_destroy(md->io_pool); |
| 2292 | if (md->rq_pool) |
| 2293 | mempool_destroy(md->rq_pool); |
| 2294 | if (md->bs) |
| 2295 | bioset_free(md->bs); |
| 2296 | |
| 2297 | if (md->disk) { |
| 2298 | spin_lock(&_minor_lock); |
| 2299 | md->disk->private_data = NULL; |
| 2300 | spin_unlock(&_minor_lock); |
| 2301 | if (blk_get_integrity(md->disk)) |
| 2302 | blk_integrity_unregister(md->disk); |
| 2303 | del_gendisk(md->disk); |
| 2304 | put_disk(md->disk); |
| 2305 | } |
| 2306 | |
| 2307 | if (md->queue) |
| 2308 | blk_cleanup_queue(md->queue); |
| 2309 | |
| 2310 | if (md->bdev) { |
| 2311 | bdput(md->bdev); |
| 2312 | md->bdev = NULL; |
| 2313 | } |
| 2314 | } |
| 2315 | |
| 2316 | /* |
| 2317 | * Allocate and initialise a blank device with a given minor. |
| 2318 | */ |
| 2319 | static struct mapped_device *alloc_dev(int minor) |
| 2320 | { |
| 2321 | int r; |
| 2322 | struct mapped_device *md = kzalloc(sizeof(*md), GFP_KERNEL); |
| 2323 | void *old_md; |
| 2324 | |
| 2325 | if (!md) { |
| 2326 | DMWARN("unable to allocate device, out of memory."); |
| 2327 | return NULL; |
| 2328 | } |
| 2329 | |
| 2330 | if (!try_module_get(THIS_MODULE)) |
| 2331 | goto bad_module_get; |
| 2332 | |
| 2333 | /* get a minor number for the dev */ |
| 2334 | if (minor == DM_ANY_MINOR) |
| 2335 | r = next_free_minor(&minor); |
| 2336 | else |
| 2337 | r = specific_minor(minor); |
| 2338 | if (r < 0) |
| 2339 | goto bad_minor; |
| 2340 | |
| 2341 | r = init_srcu_struct(&md->io_barrier); |
| 2342 | if (r < 0) |
| 2343 | goto bad_io_barrier; |
| 2344 | |
| 2345 | md->use_blk_mq = use_blk_mq; |
| 2346 | md->type = DM_TYPE_NONE; |
| 2347 | mutex_init(&md->suspend_lock); |
| 2348 | mutex_init(&md->type_lock); |
| 2349 | mutex_init(&md->table_devices_lock); |
| 2350 | spin_lock_init(&md->deferred_lock); |
| 2351 | atomic_set(&md->holders, 1); |
| 2352 | atomic_set(&md->open_count, 0); |
| 2353 | atomic_set(&md->event_nr, 0); |
| 2354 | atomic_set(&md->uevent_seq, 0); |
| 2355 | INIT_LIST_HEAD(&md->uevent_list); |
| 2356 | INIT_LIST_HEAD(&md->table_devices); |
| 2357 | spin_lock_init(&md->uevent_lock); |
| 2358 | |
| 2359 | md->queue = blk_alloc_queue(GFP_KERNEL); |
| 2360 | if (!md->queue) |
| 2361 | goto bad; |
| 2362 | |
| 2363 | dm_init_md_queue(md); |
| 2364 | |
| 2365 | md->disk = alloc_disk(1); |
| 2366 | if (!md->disk) |
| 2367 | goto bad; |
| 2368 | |
| 2369 | atomic_set(&md->pending[0], 0); |
| 2370 | atomic_set(&md->pending[1], 0); |
| 2371 | init_waitqueue_head(&md->wait); |
| 2372 | INIT_WORK(&md->work, dm_wq_work); |
| 2373 | init_waitqueue_head(&md->eventq); |
| 2374 | init_completion(&md->kobj_holder.completion); |
| 2375 | md->kworker_task = NULL; |
| 2376 | |
| 2377 | md->disk->major = _major; |
| 2378 | md->disk->first_minor = minor; |
| 2379 | md->disk->fops = &dm_blk_dops; |
| 2380 | md->disk->queue = md->queue; |
| 2381 | md->disk->private_data = md; |
| 2382 | sprintf(md->disk->disk_name, "dm-%d", minor); |
| 2383 | add_disk(md->disk); |
| 2384 | format_dev_t(md->name, MKDEV(_major, minor)); |
| 2385 | |
| 2386 | md->wq = alloc_workqueue("kdmflush", WQ_MEM_RECLAIM, 0); |
| 2387 | if (!md->wq) |
| 2388 | goto bad; |
| 2389 | |
| 2390 | md->bdev = bdget_disk(md->disk, 0); |
| 2391 | if (!md->bdev) |
| 2392 | goto bad; |
| 2393 | |
| 2394 | bio_init(&md->flush_bio); |
| 2395 | md->flush_bio.bi_bdev = md->bdev; |
| 2396 | md->flush_bio.bi_rw = WRITE_FLUSH; |
| 2397 | |
| 2398 | dm_stats_init(&md->stats); |
| 2399 | |
| 2400 | /* Populate the mapping, nobody knows we exist yet */ |
| 2401 | spin_lock(&_minor_lock); |
| 2402 | old_md = idr_replace(&_minor_idr, md, minor); |
| 2403 | spin_unlock(&_minor_lock); |
| 2404 | |
| 2405 | BUG_ON(old_md != MINOR_ALLOCED); |
| 2406 | |
| 2407 | return md; |
| 2408 | |
| 2409 | bad: |
| 2410 | cleanup_mapped_device(md); |
| 2411 | bad_io_barrier: |
| 2412 | free_minor(minor); |
| 2413 | bad_minor: |
| 2414 | module_put(THIS_MODULE); |
| 2415 | bad_module_get: |
| 2416 | kfree(md); |
| 2417 | return NULL; |
| 2418 | } |
| 2419 | |
| 2420 | static void unlock_fs(struct mapped_device *md); |
| 2421 | |
| 2422 | static void free_dev(struct mapped_device *md) |
| 2423 | { |
| 2424 | int minor = MINOR(disk_devt(md->disk)); |
| 2425 | |
| 2426 | unlock_fs(md); |
| 2427 | |
| 2428 | cleanup_mapped_device(md); |
| 2429 | if (md->use_blk_mq) |
| 2430 | blk_mq_free_tag_set(&md->tag_set); |
| 2431 | |
| 2432 | free_table_devices(&md->table_devices); |
| 2433 | dm_stats_cleanup(&md->stats); |
| 2434 | free_minor(minor); |
| 2435 | |
| 2436 | module_put(THIS_MODULE); |
| 2437 | kfree(md); |
| 2438 | } |
| 2439 | |
| 2440 | static void __bind_mempools(struct mapped_device *md, struct dm_table *t) |
| 2441 | { |
| 2442 | struct dm_md_mempools *p = dm_table_get_md_mempools(t); |
| 2443 | |
| 2444 | if (md->bs) { |
| 2445 | /* The md already has necessary mempools. */ |
| 2446 | if (dm_table_get_type(t) == DM_TYPE_BIO_BASED) { |
| 2447 | /* |
| 2448 | * Reload bioset because front_pad may have changed |
| 2449 | * because a different table was loaded. |
| 2450 | */ |
| 2451 | bioset_free(md->bs); |
| 2452 | md->bs = p->bs; |
| 2453 | p->bs = NULL; |
| 2454 | } |
| 2455 | /* |
| 2456 | * There's no need to reload with request-based dm |
| 2457 | * because the size of front_pad doesn't change. |
| 2458 | * Note for future: If you are to reload bioset, |
| 2459 | * prep-ed requests in the queue may refer |
| 2460 | * to bio from the old bioset, so you must walk |
| 2461 | * through the queue to unprep. |
| 2462 | */ |
| 2463 | goto out; |
| 2464 | } |
| 2465 | |
| 2466 | BUG_ON(!p || md->io_pool || md->rq_pool || md->bs); |
| 2467 | |
| 2468 | md->io_pool = p->io_pool; |
| 2469 | p->io_pool = NULL; |
| 2470 | md->rq_pool = p->rq_pool; |
| 2471 | p->rq_pool = NULL; |
| 2472 | md->bs = p->bs; |
| 2473 | p->bs = NULL; |
| 2474 | |
| 2475 | out: |
| 2476 | /* mempool bind completed, no longer need any mempools in the table */ |
| 2477 | dm_table_free_md_mempools(t); |
| 2478 | } |
| 2479 | |
| 2480 | /* |
| 2481 | * Bind a table to the device. |
| 2482 | */ |
| 2483 | static void event_callback(void *context) |
| 2484 | { |
| 2485 | unsigned long flags; |
| 2486 | LIST_HEAD(uevents); |
| 2487 | struct mapped_device *md = (struct mapped_device *) context; |
| 2488 | |
| 2489 | spin_lock_irqsave(&md->uevent_lock, flags); |
| 2490 | list_splice_init(&md->uevent_list, &uevents); |
| 2491 | spin_unlock_irqrestore(&md->uevent_lock, flags); |
| 2492 | |
| 2493 | dm_send_uevents(&uevents, &disk_to_dev(md->disk)->kobj); |
| 2494 | |
| 2495 | atomic_inc(&md->event_nr); |
| 2496 | wake_up(&md->eventq); |
| 2497 | } |
| 2498 | |
| 2499 | /* |
| 2500 | * Protected by md->suspend_lock obtained by dm_swap_table(). |
| 2501 | */ |
| 2502 | static void __set_size(struct mapped_device *md, sector_t size) |
| 2503 | { |
| 2504 | set_capacity(md->disk, size); |
| 2505 | |
| 2506 | i_size_write(md->bdev->bd_inode, (loff_t)size << SECTOR_SHIFT); |
| 2507 | } |
| 2508 | |
| 2509 | /* |
| 2510 | * Return 1 if the queue has a compulsory merge_bvec_fn function. |
| 2511 | * |
| 2512 | * If this function returns 0, then the device is either a non-dm |
| 2513 | * device without a merge_bvec_fn, or it is a dm device that is |
| 2514 | * able to split any bios it receives that are too big. |
| 2515 | */ |
| 2516 | int dm_queue_merge_is_compulsory(struct request_queue *q) |
| 2517 | { |
| 2518 | struct mapped_device *dev_md; |
| 2519 | |
| 2520 | if (!q->merge_bvec_fn) |
| 2521 | return 0; |
| 2522 | |
| 2523 | if (q->make_request_fn == dm_make_request) { |
| 2524 | dev_md = q->queuedata; |
| 2525 | if (test_bit(DMF_MERGE_IS_OPTIONAL, &dev_md->flags)) |
| 2526 | return 0; |
| 2527 | } |
| 2528 | |
| 2529 | return 1; |
| 2530 | } |
| 2531 | |
| 2532 | static int dm_device_merge_is_compulsory(struct dm_target *ti, |
| 2533 | struct dm_dev *dev, sector_t start, |
| 2534 | sector_t len, void *data) |
| 2535 | { |
| 2536 | struct block_device *bdev = dev->bdev; |
| 2537 | struct request_queue *q = bdev_get_queue(bdev); |
| 2538 | |
| 2539 | return dm_queue_merge_is_compulsory(q); |
| 2540 | } |
| 2541 | |
| 2542 | /* |
| 2543 | * Return 1 if it is acceptable to ignore merge_bvec_fn based |
| 2544 | * on the properties of the underlying devices. |
| 2545 | */ |
| 2546 | static int dm_table_merge_is_optional(struct dm_table *table) |
| 2547 | { |
| 2548 | unsigned i = 0; |
| 2549 | struct dm_target *ti; |
| 2550 | |
| 2551 | while (i < dm_table_get_num_targets(table)) { |
| 2552 | ti = dm_table_get_target(table, i++); |
| 2553 | |
| 2554 | if (ti->type->iterate_devices && |
| 2555 | ti->type->iterate_devices(ti, dm_device_merge_is_compulsory, NULL)) |
| 2556 | return 0; |
| 2557 | } |
| 2558 | |
| 2559 | return 1; |
| 2560 | } |
| 2561 | |
| 2562 | /* |
| 2563 | * Returns old map, which caller must destroy. |
| 2564 | */ |
| 2565 | static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t, |
| 2566 | struct queue_limits *limits) |
| 2567 | { |
| 2568 | struct dm_table *old_map; |
| 2569 | struct request_queue *q = md->queue; |
| 2570 | sector_t size; |
| 2571 | int merge_is_optional; |
| 2572 | |
| 2573 | size = dm_table_get_size(t); |
| 2574 | |
| 2575 | /* |
| 2576 | * Wipe any geometry if the size of the table changed. |
| 2577 | */ |
| 2578 | if (size != dm_get_size(md)) |
| 2579 | memset(&md->geometry, 0, sizeof(md->geometry)); |
| 2580 | |
| 2581 | __set_size(md, size); |
| 2582 | |
| 2583 | dm_table_event_callback(t, event_callback, md); |
| 2584 | |
| 2585 | /* |
| 2586 | * The queue hasn't been stopped yet, if the old table type wasn't |
| 2587 | * for request-based during suspension. So stop it to prevent |
| 2588 | * I/O mapping before resume. |
| 2589 | * This must be done before setting the queue restrictions, |
| 2590 | * because request-based dm may be run just after the setting. |
| 2591 | */ |
| 2592 | if (dm_table_request_based(t)) |
| 2593 | stop_queue(q); |
| 2594 | |
| 2595 | __bind_mempools(md, t); |
| 2596 | |
| 2597 | merge_is_optional = dm_table_merge_is_optional(t); |
| 2598 | |
| 2599 | old_map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock)); |
| 2600 | rcu_assign_pointer(md->map, t); |
| 2601 | md->immutable_target_type = dm_table_get_immutable_target_type(t); |
| 2602 | |
| 2603 | dm_table_set_restrictions(t, q, limits); |
| 2604 | if (merge_is_optional) |
| 2605 | set_bit(DMF_MERGE_IS_OPTIONAL, &md->flags); |
| 2606 | else |
| 2607 | clear_bit(DMF_MERGE_IS_OPTIONAL, &md->flags); |
| 2608 | if (old_map) |
| 2609 | dm_sync_table(md); |
| 2610 | |
| 2611 | return old_map; |
| 2612 | } |
| 2613 | |
| 2614 | /* |
| 2615 | * Returns unbound table for the caller to free. |
| 2616 | */ |
| 2617 | static struct dm_table *__unbind(struct mapped_device *md) |
| 2618 | { |
| 2619 | struct dm_table *map = rcu_dereference_protected(md->map, 1); |
| 2620 | |
| 2621 | if (!map) |
| 2622 | return NULL; |
| 2623 | |
| 2624 | dm_table_event_callback(map, NULL, NULL); |
| 2625 | RCU_INIT_POINTER(md->map, NULL); |
| 2626 | dm_sync_table(md); |
| 2627 | |
| 2628 | return map; |
| 2629 | } |
| 2630 | |
| 2631 | /* |
| 2632 | * Constructor for a new device. |
| 2633 | */ |
| 2634 | int dm_create(int minor, struct mapped_device **result) |
| 2635 | { |
| 2636 | struct mapped_device *md; |
| 2637 | |
| 2638 | md = alloc_dev(minor); |
| 2639 | if (!md) |
| 2640 | return -ENXIO; |
| 2641 | |
| 2642 | dm_sysfs_init(md); |
| 2643 | |
| 2644 | *result = md; |
| 2645 | return 0; |
| 2646 | } |
| 2647 | |
| 2648 | /* |
| 2649 | * Functions to manage md->type. |
| 2650 | * All are required to hold md->type_lock. |
| 2651 | */ |
| 2652 | void dm_lock_md_type(struct mapped_device *md) |
| 2653 | { |
| 2654 | mutex_lock(&md->type_lock); |
| 2655 | } |
| 2656 | |
| 2657 | void dm_unlock_md_type(struct mapped_device *md) |
| 2658 | { |
| 2659 | mutex_unlock(&md->type_lock); |
| 2660 | } |
| 2661 | |
| 2662 | void dm_set_md_type(struct mapped_device *md, unsigned type) |
| 2663 | { |
| 2664 | BUG_ON(!mutex_is_locked(&md->type_lock)); |
| 2665 | md->type = type; |
| 2666 | } |
| 2667 | |
| 2668 | unsigned dm_get_md_type(struct mapped_device *md) |
| 2669 | { |
| 2670 | BUG_ON(!mutex_is_locked(&md->type_lock)); |
| 2671 | return md->type; |
| 2672 | } |
| 2673 | |
| 2674 | struct target_type *dm_get_immutable_target_type(struct mapped_device *md) |
| 2675 | { |
| 2676 | return md->immutable_target_type; |
| 2677 | } |
| 2678 | |
| 2679 | /* |
| 2680 | * The queue_limits are only valid as long as you have a reference |
| 2681 | * count on 'md'. |
| 2682 | */ |
| 2683 | struct queue_limits *dm_get_queue_limits(struct mapped_device *md) |
| 2684 | { |
| 2685 | BUG_ON(!atomic_read(&md->holders)); |
| 2686 | return &md->queue->limits; |
| 2687 | } |
| 2688 | EXPORT_SYMBOL_GPL(dm_get_queue_limits); |
| 2689 | |
| 2690 | static void init_rq_based_worker_thread(struct mapped_device *md) |
| 2691 | { |
| 2692 | /* Initialize the request-based DM worker thread */ |
| 2693 | init_kthread_worker(&md->kworker); |
| 2694 | md->kworker_task = kthread_run(kthread_worker_fn, &md->kworker, |
| 2695 | "kdmwork-%s", dm_device_name(md)); |
| 2696 | } |
| 2697 | |
| 2698 | /* |
| 2699 | * Fully initialize a request-based queue (->elevator, ->request_fn, etc). |
| 2700 | */ |
| 2701 | static int dm_init_request_based_queue(struct mapped_device *md) |
| 2702 | { |
| 2703 | struct request_queue *q = NULL; |
| 2704 | |
| 2705 | /* Fully initialize the queue */ |
| 2706 | q = blk_init_allocated_queue(md->queue, dm_request_fn, NULL); |
| 2707 | if (!q) |
| 2708 | return -EINVAL; |
| 2709 | |
| 2710 | /* disable dm_request_fn's merge heuristic by default */ |
| 2711 | md->seq_rq_merge_deadline_usecs = 0; |
| 2712 | |
| 2713 | md->queue = q; |
| 2714 | dm_init_old_md_queue(md); |
| 2715 | blk_queue_softirq_done(md->queue, dm_softirq_done); |
| 2716 | blk_queue_prep_rq(md->queue, dm_prep_fn); |
| 2717 | |
| 2718 | init_rq_based_worker_thread(md); |
| 2719 | |
| 2720 | elv_register_queue(md->queue); |
| 2721 | |
| 2722 | return 0; |
| 2723 | } |
| 2724 | |
| 2725 | static int dm_mq_init_request(void *data, struct request *rq, |
| 2726 | unsigned int hctx_idx, unsigned int request_idx, |
| 2727 | unsigned int numa_node) |
| 2728 | { |
| 2729 | struct mapped_device *md = data; |
| 2730 | struct dm_rq_target_io *tio = blk_mq_rq_to_pdu(rq); |
| 2731 | |
| 2732 | /* |
| 2733 | * Must initialize md member of tio, otherwise it won't |
| 2734 | * be available in dm_mq_queue_rq. |
| 2735 | */ |
| 2736 | tio->md = md; |
| 2737 | |
| 2738 | return 0; |
| 2739 | } |
| 2740 | |
| 2741 | static int dm_mq_queue_rq(struct blk_mq_hw_ctx *hctx, |
| 2742 | const struct blk_mq_queue_data *bd) |
| 2743 | { |
| 2744 | struct request *rq = bd->rq; |
| 2745 | struct dm_rq_target_io *tio = blk_mq_rq_to_pdu(rq); |
| 2746 | struct mapped_device *md = tio->md; |
| 2747 | int srcu_idx; |
| 2748 | struct dm_table *map = dm_get_live_table(md, &srcu_idx); |
| 2749 | struct dm_target *ti; |
| 2750 | sector_t pos; |
| 2751 | |
| 2752 | /* always use block 0 to find the target for flushes for now */ |
| 2753 | pos = 0; |
| 2754 | if (!(rq->cmd_flags & REQ_FLUSH)) |
| 2755 | pos = blk_rq_pos(rq); |
| 2756 | |
| 2757 | ti = dm_table_find_target(map, pos); |
| 2758 | if (!dm_target_is_valid(ti)) { |
| 2759 | dm_put_live_table(md, srcu_idx); |
| 2760 | DMERR_LIMIT("request attempted access beyond the end of device"); |
| 2761 | /* |
| 2762 | * Must perform setup, that rq_completed() requires, |
| 2763 | * before returning BLK_MQ_RQ_QUEUE_ERROR |
| 2764 | */ |
| 2765 | dm_start_request(md, rq); |
| 2766 | return BLK_MQ_RQ_QUEUE_ERROR; |
| 2767 | } |
| 2768 | dm_put_live_table(md, srcu_idx); |
| 2769 | |
| 2770 | if (ti->type->busy && ti->type->busy(ti)) |
| 2771 | return BLK_MQ_RQ_QUEUE_BUSY; |
| 2772 | |
| 2773 | dm_start_request(md, rq); |
| 2774 | |
| 2775 | /* Init tio using md established in .init_request */ |
| 2776 | init_tio(tio, rq, md); |
| 2777 | |
| 2778 | /* |
| 2779 | * Establish tio->ti before queuing work (map_tio_request) |
| 2780 | * or making direct call to map_request(). |
| 2781 | */ |
| 2782 | tio->ti = ti; |
| 2783 | |
| 2784 | /* Clone the request if underlying devices aren't blk-mq */ |
| 2785 | if (dm_table_get_type(map) == DM_TYPE_REQUEST_BASED) { |
| 2786 | /* clone request is allocated at the end of the pdu */ |
| 2787 | tio->clone = (void *)blk_mq_rq_to_pdu(rq) + sizeof(struct dm_rq_target_io); |
| 2788 | (void) clone_rq(rq, md, tio, GFP_ATOMIC); |
| 2789 | queue_kthread_work(&md->kworker, &tio->work); |
| 2790 | } else { |
| 2791 | /* Direct call is fine since .queue_rq allows allocations */ |
| 2792 | if (map_request(tio, rq, md) == DM_MAPIO_REQUEUE) { |
| 2793 | /* Undo dm_start_request() before requeuing */ |
| 2794 | rq_end_stats(md, rq); |
| 2795 | rq_completed(md, rq_data_dir(rq), false); |
| 2796 | return BLK_MQ_RQ_QUEUE_BUSY; |
| 2797 | } |
| 2798 | } |
| 2799 | |
| 2800 | return BLK_MQ_RQ_QUEUE_OK; |
| 2801 | } |
| 2802 | |
| 2803 | static struct blk_mq_ops dm_mq_ops = { |
| 2804 | .queue_rq = dm_mq_queue_rq, |
| 2805 | .map_queue = blk_mq_map_queue, |
| 2806 | .complete = dm_softirq_done, |
| 2807 | .init_request = dm_mq_init_request, |
| 2808 | }; |
| 2809 | |
| 2810 | static int dm_init_request_based_blk_mq_queue(struct mapped_device *md) |
| 2811 | { |
| 2812 | unsigned md_type = dm_get_md_type(md); |
| 2813 | struct request_queue *q; |
| 2814 | int err; |
| 2815 | |
| 2816 | memset(&md->tag_set, 0, sizeof(md->tag_set)); |
| 2817 | md->tag_set.ops = &dm_mq_ops; |
| 2818 | md->tag_set.queue_depth = BLKDEV_MAX_RQ; |
| 2819 | md->tag_set.numa_node = NUMA_NO_NODE; |
| 2820 | md->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE; |
| 2821 | md->tag_set.nr_hw_queues = 1; |
| 2822 | if (md_type == DM_TYPE_REQUEST_BASED) { |
| 2823 | /* make the memory for non-blk-mq clone part of the pdu */ |
| 2824 | md->tag_set.cmd_size = sizeof(struct dm_rq_target_io) + sizeof(struct request); |
| 2825 | } else |
| 2826 | md->tag_set.cmd_size = sizeof(struct dm_rq_target_io); |
| 2827 | md->tag_set.driver_data = md; |
| 2828 | |
| 2829 | err = blk_mq_alloc_tag_set(&md->tag_set); |
| 2830 | if (err) |
| 2831 | return err; |
| 2832 | |
| 2833 | q = blk_mq_init_allocated_queue(&md->tag_set, md->queue); |
| 2834 | if (IS_ERR(q)) { |
| 2835 | err = PTR_ERR(q); |
| 2836 | goto out_tag_set; |
| 2837 | } |
| 2838 | md->queue = q; |
| 2839 | dm_init_md_queue(md); |
| 2840 | |
| 2841 | /* backfill 'mq' sysfs registration normally done in blk_register_queue */ |
| 2842 | blk_mq_register_disk(md->disk); |
| 2843 | |
| 2844 | if (md_type == DM_TYPE_REQUEST_BASED) |
| 2845 | init_rq_based_worker_thread(md); |
| 2846 | |
| 2847 | return 0; |
| 2848 | |
| 2849 | out_tag_set: |
| 2850 | blk_mq_free_tag_set(&md->tag_set); |
| 2851 | return err; |
| 2852 | } |
| 2853 | |
| 2854 | static unsigned filter_md_type(unsigned type, struct mapped_device *md) |
| 2855 | { |
| 2856 | if (type == DM_TYPE_BIO_BASED) |
| 2857 | return type; |
| 2858 | |
| 2859 | return !md->use_blk_mq ? DM_TYPE_REQUEST_BASED : DM_TYPE_MQ_REQUEST_BASED; |
| 2860 | } |
| 2861 | |
| 2862 | /* |
| 2863 | * Setup the DM device's queue based on md's type |
| 2864 | */ |
| 2865 | int dm_setup_md_queue(struct mapped_device *md) |
| 2866 | { |
| 2867 | int r; |
| 2868 | unsigned md_type = filter_md_type(dm_get_md_type(md), md); |
| 2869 | |
| 2870 | switch (md_type) { |
| 2871 | case DM_TYPE_REQUEST_BASED: |
| 2872 | r = dm_init_request_based_queue(md); |
| 2873 | if (r) { |
| 2874 | DMWARN("Cannot initialize queue for request-based mapped device"); |
| 2875 | return r; |
| 2876 | } |
| 2877 | break; |
| 2878 | case DM_TYPE_MQ_REQUEST_BASED: |
| 2879 | r = dm_init_request_based_blk_mq_queue(md); |
| 2880 | if (r) { |
| 2881 | DMWARN("Cannot initialize queue for request-based blk-mq mapped device"); |
| 2882 | return r; |
| 2883 | } |
| 2884 | break; |
| 2885 | case DM_TYPE_BIO_BASED: |
| 2886 | dm_init_old_md_queue(md); |
| 2887 | blk_queue_make_request(md->queue, dm_make_request); |
| 2888 | blk_queue_merge_bvec(md->queue, dm_merge_bvec); |
| 2889 | break; |
| 2890 | } |
| 2891 | |
| 2892 | return 0; |
| 2893 | } |
| 2894 | |
| 2895 | struct mapped_device *dm_get_md(dev_t dev) |
| 2896 | { |
| 2897 | struct mapped_device *md; |
| 2898 | unsigned minor = MINOR(dev); |
| 2899 | |
| 2900 | if (MAJOR(dev) != _major || minor >= (1 << MINORBITS)) |
| 2901 | return NULL; |
| 2902 | |
| 2903 | spin_lock(&_minor_lock); |
| 2904 | |
| 2905 | md = idr_find(&_minor_idr, minor); |
| 2906 | if (md) { |
| 2907 | if ((md == MINOR_ALLOCED || |
| 2908 | (MINOR(disk_devt(dm_disk(md))) != minor) || |
| 2909 | dm_deleting_md(md) || |
| 2910 | test_bit(DMF_FREEING, &md->flags))) { |
| 2911 | md = NULL; |
| 2912 | goto out; |
| 2913 | } |
| 2914 | dm_get(md); |
| 2915 | } |
| 2916 | |
| 2917 | out: |
| 2918 | spin_unlock(&_minor_lock); |
| 2919 | |
| 2920 | return md; |
| 2921 | } |
| 2922 | EXPORT_SYMBOL_GPL(dm_get_md); |
| 2923 | |
| 2924 | void *dm_get_mdptr(struct mapped_device *md) |
| 2925 | { |
| 2926 | return md->interface_ptr; |
| 2927 | } |
| 2928 | |
| 2929 | void dm_set_mdptr(struct mapped_device *md, void *ptr) |
| 2930 | { |
| 2931 | md->interface_ptr = ptr; |
| 2932 | } |
| 2933 | |
| 2934 | void dm_get(struct mapped_device *md) |
| 2935 | { |
| 2936 | atomic_inc(&md->holders); |
| 2937 | BUG_ON(test_bit(DMF_FREEING, &md->flags)); |
| 2938 | } |
| 2939 | |
| 2940 | int dm_hold(struct mapped_device *md) |
| 2941 | { |
| 2942 | spin_lock(&_minor_lock); |
| 2943 | if (test_bit(DMF_FREEING, &md->flags)) { |
| 2944 | spin_unlock(&_minor_lock); |
| 2945 | return -EBUSY; |
| 2946 | } |
| 2947 | dm_get(md); |
| 2948 | spin_unlock(&_minor_lock); |
| 2949 | return 0; |
| 2950 | } |
| 2951 | EXPORT_SYMBOL_GPL(dm_hold); |
| 2952 | |
| 2953 | const char *dm_device_name(struct mapped_device *md) |
| 2954 | { |
| 2955 | return md->name; |
| 2956 | } |
| 2957 | EXPORT_SYMBOL_GPL(dm_device_name); |
| 2958 | |
| 2959 | static void __dm_destroy(struct mapped_device *md, bool wait) |
| 2960 | { |
| 2961 | struct dm_table *map; |
| 2962 | int srcu_idx; |
| 2963 | |
| 2964 | might_sleep(); |
| 2965 | |
| 2966 | map = dm_get_live_table(md, &srcu_idx); |
| 2967 | |
| 2968 | spin_lock(&_minor_lock); |
| 2969 | idr_replace(&_minor_idr, MINOR_ALLOCED, MINOR(disk_devt(dm_disk(md)))); |
| 2970 | set_bit(DMF_FREEING, &md->flags); |
| 2971 | spin_unlock(&_minor_lock); |
| 2972 | |
| 2973 | if (dm_request_based(md) && md->kworker_task) |
| 2974 | flush_kthread_worker(&md->kworker); |
| 2975 | |
| 2976 | /* |
| 2977 | * Take suspend_lock so that presuspend and postsuspend methods |
| 2978 | * do not race with internal suspend. |
| 2979 | */ |
| 2980 | mutex_lock(&md->suspend_lock); |
| 2981 | if (!dm_suspended_md(md)) { |
| 2982 | dm_table_presuspend_targets(map); |
| 2983 | dm_table_postsuspend_targets(map); |
| 2984 | } |
| 2985 | mutex_unlock(&md->suspend_lock); |
| 2986 | |
| 2987 | /* dm_put_live_table must be before msleep, otherwise deadlock is possible */ |
| 2988 | dm_put_live_table(md, srcu_idx); |
| 2989 | |
| 2990 | /* |
| 2991 | * Rare, but there may be I/O requests still going to complete, |
| 2992 | * for example. Wait for all references to disappear. |
| 2993 | * No one should increment the reference count of the mapped_device, |
| 2994 | * after the mapped_device state becomes DMF_FREEING. |
| 2995 | */ |
| 2996 | if (wait) |
| 2997 | while (atomic_read(&md->holders)) |
| 2998 | msleep(1); |
| 2999 | else if (atomic_read(&md->holders)) |
| 3000 | DMWARN("%s: Forcibly removing mapped_device still in use! (%d users)", |
| 3001 | dm_device_name(md), atomic_read(&md->holders)); |
| 3002 | |
| 3003 | dm_sysfs_exit(md); |
| 3004 | dm_table_destroy(__unbind(md)); |
| 3005 | free_dev(md); |
| 3006 | } |
| 3007 | |
| 3008 | void dm_destroy(struct mapped_device *md) |
| 3009 | { |
| 3010 | __dm_destroy(md, true); |
| 3011 | } |
| 3012 | |
| 3013 | void dm_destroy_immediate(struct mapped_device *md) |
| 3014 | { |
| 3015 | __dm_destroy(md, false); |
| 3016 | } |
| 3017 | |
| 3018 | void dm_put(struct mapped_device *md) |
| 3019 | { |
| 3020 | atomic_dec(&md->holders); |
| 3021 | } |
| 3022 | EXPORT_SYMBOL_GPL(dm_put); |
| 3023 | |
| 3024 | static int dm_wait_for_completion(struct mapped_device *md, int interruptible) |
| 3025 | { |
| 3026 | int r = 0; |
| 3027 | DECLARE_WAITQUEUE(wait, current); |
| 3028 | |
| 3029 | add_wait_queue(&md->wait, &wait); |
| 3030 | |
| 3031 | while (1) { |
| 3032 | set_current_state(interruptible); |
| 3033 | |
| 3034 | if (!md_in_flight(md)) |
| 3035 | break; |
| 3036 | |
| 3037 | if (interruptible == TASK_INTERRUPTIBLE && |
| 3038 | signal_pending(current)) { |
| 3039 | r = -EINTR; |
| 3040 | break; |
| 3041 | } |
| 3042 | |
| 3043 | io_schedule(); |
| 3044 | } |
| 3045 | set_current_state(TASK_RUNNING); |
| 3046 | |
| 3047 | remove_wait_queue(&md->wait, &wait); |
| 3048 | |
| 3049 | return r; |
| 3050 | } |
| 3051 | |
| 3052 | /* |
| 3053 | * Process the deferred bios |
| 3054 | */ |
| 3055 | static void dm_wq_work(struct work_struct *work) |
| 3056 | { |
| 3057 | struct mapped_device *md = container_of(work, struct mapped_device, |
| 3058 | work); |
| 3059 | struct bio *c; |
| 3060 | int srcu_idx; |
| 3061 | struct dm_table *map; |
| 3062 | |
| 3063 | map = dm_get_live_table(md, &srcu_idx); |
| 3064 | |
| 3065 | while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) { |
| 3066 | spin_lock_irq(&md->deferred_lock); |
| 3067 | c = bio_list_pop(&md->deferred); |
| 3068 | spin_unlock_irq(&md->deferred_lock); |
| 3069 | |
| 3070 | if (!c) |
| 3071 | break; |
| 3072 | |
| 3073 | if (dm_request_based(md)) |
| 3074 | generic_make_request(c); |
| 3075 | else |
| 3076 | __split_and_process_bio(md, map, c); |
| 3077 | } |
| 3078 | |
| 3079 | dm_put_live_table(md, srcu_idx); |
| 3080 | } |
| 3081 | |
| 3082 | static void dm_queue_flush(struct mapped_device *md) |
| 3083 | { |
| 3084 | clear_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags); |
| 3085 | smp_mb__after_atomic(); |
| 3086 | queue_work(md->wq, &md->work); |
| 3087 | } |
| 3088 | |
| 3089 | /* |
| 3090 | * Swap in a new table, returning the old one for the caller to destroy. |
| 3091 | */ |
| 3092 | struct dm_table *dm_swap_table(struct mapped_device *md, struct dm_table *table) |
| 3093 | { |
| 3094 | struct dm_table *live_map = NULL, *map = ERR_PTR(-EINVAL); |
| 3095 | struct queue_limits limits; |
| 3096 | int r; |
| 3097 | |
| 3098 | mutex_lock(&md->suspend_lock); |
| 3099 | |
| 3100 | /* device must be suspended */ |
| 3101 | if (!dm_suspended_md(md)) |
| 3102 | goto out; |
| 3103 | |
| 3104 | /* |
| 3105 | * If the new table has no data devices, retain the existing limits. |
| 3106 | * This helps multipath with queue_if_no_path if all paths disappear, |
| 3107 | * then new I/O is queued based on these limits, and then some paths |
| 3108 | * reappear. |
| 3109 | */ |
| 3110 | if (dm_table_has_no_data_devices(table)) { |
| 3111 | live_map = dm_get_live_table_fast(md); |
| 3112 | if (live_map) |
| 3113 | limits = md->queue->limits; |
| 3114 | dm_put_live_table_fast(md); |
| 3115 | } |
| 3116 | |
| 3117 | if (!live_map) { |
| 3118 | r = dm_calculate_queue_limits(table, &limits); |
| 3119 | if (r) { |
| 3120 | map = ERR_PTR(r); |
| 3121 | goto out; |
| 3122 | } |
| 3123 | } |
| 3124 | |
| 3125 | map = __bind(md, table, &limits); |
| 3126 | |
| 3127 | out: |
| 3128 | mutex_unlock(&md->suspend_lock); |
| 3129 | return map; |
| 3130 | } |
| 3131 | |
| 3132 | /* |
| 3133 | * Functions to lock and unlock any filesystem running on the |
| 3134 | * device. |
| 3135 | */ |
| 3136 | static int lock_fs(struct mapped_device *md) |
| 3137 | { |
| 3138 | int r; |
| 3139 | |
| 3140 | WARN_ON(md->frozen_sb); |
| 3141 | |
| 3142 | md->frozen_sb = freeze_bdev(md->bdev); |
| 3143 | if (IS_ERR(md->frozen_sb)) { |
| 3144 | r = PTR_ERR(md->frozen_sb); |
| 3145 | md->frozen_sb = NULL; |
| 3146 | return r; |
| 3147 | } |
| 3148 | |
| 3149 | set_bit(DMF_FROZEN, &md->flags); |
| 3150 | |
| 3151 | return 0; |
| 3152 | } |
| 3153 | |
| 3154 | static void unlock_fs(struct mapped_device *md) |
| 3155 | { |
| 3156 | if (!test_bit(DMF_FROZEN, &md->flags)) |
| 3157 | return; |
| 3158 | |
| 3159 | thaw_bdev(md->bdev, md->frozen_sb); |
| 3160 | md->frozen_sb = NULL; |
| 3161 | clear_bit(DMF_FROZEN, &md->flags); |
| 3162 | } |
| 3163 | |
| 3164 | /* |
| 3165 | * If __dm_suspend returns 0, the device is completely quiescent |
| 3166 | * now. There is no request-processing activity. All new requests |
| 3167 | * are being added to md->deferred list. |
| 3168 | * |
| 3169 | * Caller must hold md->suspend_lock |
| 3170 | */ |
| 3171 | static int __dm_suspend(struct mapped_device *md, struct dm_table *map, |
| 3172 | unsigned suspend_flags, int interruptible) |
| 3173 | { |
| 3174 | bool do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG; |
| 3175 | bool noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG; |
| 3176 | int r; |
| 3177 | |
| 3178 | /* |
| 3179 | * DMF_NOFLUSH_SUSPENDING must be set before presuspend. |
| 3180 | * This flag is cleared before dm_suspend returns. |
| 3181 | */ |
| 3182 | if (noflush) |
| 3183 | set_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); |
| 3184 | |
| 3185 | /* |
| 3186 | * This gets reverted if there's an error later and the targets |
| 3187 | * provide the .presuspend_undo hook. |
| 3188 | */ |
| 3189 | dm_table_presuspend_targets(map); |
| 3190 | |
| 3191 | /* |
| 3192 | * Flush I/O to the device. |
| 3193 | * Any I/O submitted after lock_fs() may not be flushed. |
| 3194 | * noflush takes precedence over do_lockfs. |
| 3195 | * (lock_fs() flushes I/Os and waits for them to complete.) |
| 3196 | */ |
| 3197 | if (!noflush && do_lockfs) { |
| 3198 | r = lock_fs(md); |
| 3199 | if (r) { |
| 3200 | dm_table_presuspend_undo_targets(map); |
| 3201 | return r; |
| 3202 | } |
| 3203 | } |
| 3204 | |
| 3205 | /* |
| 3206 | * Here we must make sure that no processes are submitting requests |
| 3207 | * to target drivers i.e. no one may be executing |
| 3208 | * __split_and_process_bio. This is called from dm_request and |
| 3209 | * dm_wq_work. |
| 3210 | * |
| 3211 | * To get all processes out of __split_and_process_bio in dm_request, |
| 3212 | * we take the write lock. To prevent any process from reentering |
| 3213 | * __split_and_process_bio from dm_request and quiesce the thread |
| 3214 | * (dm_wq_work), we set BMF_BLOCK_IO_FOR_SUSPEND and call |
| 3215 | * flush_workqueue(md->wq). |
| 3216 | */ |
| 3217 | set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags); |
| 3218 | if (map) |
| 3219 | synchronize_srcu(&md->io_barrier); |
| 3220 | |
| 3221 | /* |
| 3222 | * Stop md->queue before flushing md->wq in case request-based |
| 3223 | * dm defers requests to md->wq from md->queue. |
| 3224 | */ |
| 3225 | if (dm_request_based(md)) { |
| 3226 | stop_queue(md->queue); |
| 3227 | if (md->kworker_task) |
| 3228 | flush_kthread_worker(&md->kworker); |
| 3229 | } |
| 3230 | |
| 3231 | flush_workqueue(md->wq); |
| 3232 | |
| 3233 | /* |
| 3234 | * At this point no more requests are entering target request routines. |
| 3235 | * We call dm_wait_for_completion to wait for all existing requests |
| 3236 | * to finish. |
| 3237 | */ |
| 3238 | r = dm_wait_for_completion(md, interruptible); |
| 3239 | |
| 3240 | if (noflush) |
| 3241 | clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); |
| 3242 | if (map) |
| 3243 | synchronize_srcu(&md->io_barrier); |
| 3244 | |
| 3245 | /* were we interrupted ? */ |
| 3246 | if (r < 0) { |
| 3247 | dm_queue_flush(md); |
| 3248 | |
| 3249 | if (dm_request_based(md)) |
| 3250 | start_queue(md->queue); |
| 3251 | |
| 3252 | unlock_fs(md); |
| 3253 | dm_table_presuspend_undo_targets(map); |
| 3254 | /* pushback list is already flushed, so skip flush */ |
| 3255 | } |
| 3256 | |
| 3257 | return r; |
| 3258 | } |
| 3259 | |
| 3260 | /* |
| 3261 | * We need to be able to change a mapping table under a mounted |
| 3262 | * filesystem. For example we might want to move some data in |
| 3263 | * the background. Before the table can be swapped with |
| 3264 | * dm_bind_table, dm_suspend must be called to flush any in |
| 3265 | * flight bios and ensure that any further io gets deferred. |
| 3266 | */ |
| 3267 | /* |
| 3268 | * Suspend mechanism in request-based dm. |
| 3269 | * |
| 3270 | * 1. Flush all I/Os by lock_fs() if needed. |
| 3271 | * 2. Stop dispatching any I/O by stopping the request_queue. |
| 3272 | * 3. Wait for all in-flight I/Os to be completed or requeued. |
| 3273 | * |
| 3274 | * To abort suspend, start the request_queue. |
| 3275 | */ |
| 3276 | int dm_suspend(struct mapped_device *md, unsigned suspend_flags) |
| 3277 | { |
| 3278 | struct dm_table *map = NULL; |
| 3279 | int r = 0; |
| 3280 | |
| 3281 | retry: |
| 3282 | mutex_lock_nested(&md->suspend_lock, SINGLE_DEPTH_NESTING); |
| 3283 | |
| 3284 | if (dm_suspended_md(md)) { |
| 3285 | r = -EINVAL; |
| 3286 | goto out_unlock; |
| 3287 | } |
| 3288 | |
| 3289 | if (dm_suspended_internally_md(md)) { |
| 3290 | /* already internally suspended, wait for internal resume */ |
| 3291 | mutex_unlock(&md->suspend_lock); |
| 3292 | r = wait_on_bit(&md->flags, DMF_SUSPENDED_INTERNALLY, TASK_INTERRUPTIBLE); |
| 3293 | if (r) |
| 3294 | return r; |
| 3295 | goto retry; |
| 3296 | } |
| 3297 | |
| 3298 | map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock)); |
| 3299 | |
| 3300 | r = __dm_suspend(md, map, suspend_flags, TASK_INTERRUPTIBLE); |
| 3301 | if (r) |
| 3302 | goto out_unlock; |
| 3303 | |
| 3304 | set_bit(DMF_SUSPENDED, &md->flags); |
| 3305 | |
| 3306 | dm_table_postsuspend_targets(map); |
| 3307 | |
| 3308 | out_unlock: |
| 3309 | mutex_unlock(&md->suspend_lock); |
| 3310 | return r; |
| 3311 | } |
| 3312 | |
| 3313 | static int __dm_resume(struct mapped_device *md, struct dm_table *map) |
| 3314 | { |
| 3315 | if (map) { |
| 3316 | int r = dm_table_resume_targets(map); |
| 3317 | if (r) |
| 3318 | return r; |
| 3319 | } |
| 3320 | |
| 3321 | dm_queue_flush(md); |
| 3322 | |
| 3323 | /* |
| 3324 | * Flushing deferred I/Os must be done after targets are resumed |
| 3325 | * so that mapping of targets can work correctly. |
| 3326 | * Request-based dm is queueing the deferred I/Os in its request_queue. |
| 3327 | */ |
| 3328 | if (dm_request_based(md)) |
| 3329 | start_queue(md->queue); |
| 3330 | |
| 3331 | unlock_fs(md); |
| 3332 | |
| 3333 | return 0; |
| 3334 | } |
| 3335 | |
| 3336 | int dm_resume(struct mapped_device *md) |
| 3337 | { |
| 3338 | int r = -EINVAL; |
| 3339 | struct dm_table *map = NULL; |
| 3340 | |
| 3341 | retry: |
| 3342 | mutex_lock_nested(&md->suspend_lock, SINGLE_DEPTH_NESTING); |
| 3343 | |
| 3344 | if (!dm_suspended_md(md)) |
| 3345 | goto out; |
| 3346 | |
| 3347 | if (dm_suspended_internally_md(md)) { |
| 3348 | /* already internally suspended, wait for internal resume */ |
| 3349 | mutex_unlock(&md->suspend_lock); |
| 3350 | r = wait_on_bit(&md->flags, DMF_SUSPENDED_INTERNALLY, TASK_INTERRUPTIBLE); |
| 3351 | if (r) |
| 3352 | return r; |
| 3353 | goto retry; |
| 3354 | } |
| 3355 | |
| 3356 | map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock)); |
| 3357 | if (!map || !dm_table_get_size(map)) |
| 3358 | goto out; |
| 3359 | |
| 3360 | r = __dm_resume(md, map); |
| 3361 | if (r) |
| 3362 | goto out; |
| 3363 | |
| 3364 | clear_bit(DMF_SUSPENDED, &md->flags); |
| 3365 | |
| 3366 | r = 0; |
| 3367 | out: |
| 3368 | mutex_unlock(&md->suspend_lock); |
| 3369 | |
| 3370 | return r; |
| 3371 | } |
| 3372 | |
| 3373 | /* |
| 3374 | * Internal suspend/resume works like userspace-driven suspend. It waits |
| 3375 | * until all bios finish and prevents issuing new bios to the target drivers. |
| 3376 | * It may be used only from the kernel. |
| 3377 | */ |
| 3378 | |
| 3379 | static void __dm_internal_suspend(struct mapped_device *md, unsigned suspend_flags) |
| 3380 | { |
| 3381 | struct dm_table *map = NULL; |
| 3382 | |
| 3383 | if (md->internal_suspend_count++) |
| 3384 | return; /* nested internal suspend */ |
| 3385 | |
| 3386 | if (dm_suspended_md(md)) { |
| 3387 | set_bit(DMF_SUSPENDED_INTERNALLY, &md->flags); |
| 3388 | return; /* nest suspend */ |
| 3389 | } |
| 3390 | |
| 3391 | map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock)); |
| 3392 | |
| 3393 | /* |
| 3394 | * Using TASK_UNINTERRUPTIBLE because only NOFLUSH internal suspend is |
| 3395 | * supported. Properly supporting a TASK_INTERRUPTIBLE internal suspend |
| 3396 | * would require changing .presuspend to return an error -- avoid this |
| 3397 | * until there is a need for more elaborate variants of internal suspend. |
| 3398 | */ |
| 3399 | (void) __dm_suspend(md, map, suspend_flags, TASK_UNINTERRUPTIBLE); |
| 3400 | |
| 3401 | set_bit(DMF_SUSPENDED_INTERNALLY, &md->flags); |
| 3402 | |
| 3403 | dm_table_postsuspend_targets(map); |
| 3404 | } |
| 3405 | |
| 3406 | static void __dm_internal_resume(struct mapped_device *md) |
| 3407 | { |
| 3408 | BUG_ON(!md->internal_suspend_count); |
| 3409 | |
| 3410 | if (--md->internal_suspend_count) |
| 3411 | return; /* resume from nested internal suspend */ |
| 3412 | |
| 3413 | if (dm_suspended_md(md)) |
| 3414 | goto done; /* resume from nested suspend */ |
| 3415 | |
| 3416 | /* |
| 3417 | * NOTE: existing callers don't need to call dm_table_resume_targets |
| 3418 | * (which may fail -- so best to avoid it for now by passing NULL map) |
| 3419 | */ |
| 3420 | (void) __dm_resume(md, NULL); |
| 3421 | |
| 3422 | done: |
| 3423 | clear_bit(DMF_SUSPENDED_INTERNALLY, &md->flags); |
| 3424 | smp_mb__after_atomic(); |
| 3425 | wake_up_bit(&md->flags, DMF_SUSPENDED_INTERNALLY); |
| 3426 | } |
| 3427 | |
| 3428 | void dm_internal_suspend_noflush(struct mapped_device *md) |
| 3429 | { |
| 3430 | mutex_lock(&md->suspend_lock); |
| 3431 | __dm_internal_suspend(md, DM_SUSPEND_NOFLUSH_FLAG); |
| 3432 | mutex_unlock(&md->suspend_lock); |
| 3433 | } |
| 3434 | EXPORT_SYMBOL_GPL(dm_internal_suspend_noflush); |
| 3435 | |
| 3436 | void dm_internal_resume(struct mapped_device *md) |
| 3437 | { |
| 3438 | mutex_lock(&md->suspend_lock); |
| 3439 | __dm_internal_resume(md); |
| 3440 | mutex_unlock(&md->suspend_lock); |
| 3441 | } |
| 3442 | EXPORT_SYMBOL_GPL(dm_internal_resume); |
| 3443 | |
| 3444 | /* |
| 3445 | * Fast variants of internal suspend/resume hold md->suspend_lock, |
| 3446 | * which prevents interaction with userspace-driven suspend. |
| 3447 | */ |
| 3448 | |
| 3449 | void dm_internal_suspend_fast(struct mapped_device *md) |
| 3450 | { |
| 3451 | mutex_lock(&md->suspend_lock); |
| 3452 | if (dm_suspended_md(md) || dm_suspended_internally_md(md)) |
| 3453 | return; |
| 3454 | |
| 3455 | set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags); |
| 3456 | synchronize_srcu(&md->io_barrier); |
| 3457 | flush_workqueue(md->wq); |
| 3458 | dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE); |
| 3459 | } |
| 3460 | EXPORT_SYMBOL_GPL(dm_internal_suspend_fast); |
| 3461 | |
| 3462 | void dm_internal_resume_fast(struct mapped_device *md) |
| 3463 | { |
| 3464 | if (dm_suspended_md(md) || dm_suspended_internally_md(md)) |
| 3465 | goto done; |
| 3466 | |
| 3467 | dm_queue_flush(md); |
| 3468 | |
| 3469 | done: |
| 3470 | mutex_unlock(&md->suspend_lock); |
| 3471 | } |
| 3472 | EXPORT_SYMBOL_GPL(dm_internal_resume_fast); |
| 3473 | |
| 3474 | /*----------------------------------------------------------------- |
| 3475 | * Event notification. |
| 3476 | *---------------------------------------------------------------*/ |
| 3477 | int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action, |
| 3478 | unsigned cookie) |
| 3479 | { |
| 3480 | char udev_cookie[DM_COOKIE_LENGTH]; |
| 3481 | char *envp[] = { udev_cookie, NULL }; |
| 3482 | |
| 3483 | if (!cookie) |
| 3484 | return kobject_uevent(&disk_to_dev(md->disk)->kobj, action); |
| 3485 | else { |
| 3486 | snprintf(udev_cookie, DM_COOKIE_LENGTH, "%s=%u", |
| 3487 | DM_COOKIE_ENV_VAR_NAME, cookie); |
| 3488 | return kobject_uevent_env(&disk_to_dev(md->disk)->kobj, |
| 3489 | action, envp); |
| 3490 | } |
| 3491 | } |
| 3492 | |
| 3493 | uint32_t dm_next_uevent_seq(struct mapped_device *md) |
| 3494 | { |
| 3495 | return atomic_add_return(1, &md->uevent_seq); |
| 3496 | } |
| 3497 | |
| 3498 | uint32_t dm_get_event_nr(struct mapped_device *md) |
| 3499 | { |
| 3500 | return atomic_read(&md->event_nr); |
| 3501 | } |
| 3502 | |
| 3503 | int dm_wait_event(struct mapped_device *md, int event_nr) |
| 3504 | { |
| 3505 | return wait_event_interruptible(md->eventq, |
| 3506 | (event_nr != atomic_read(&md->event_nr))); |
| 3507 | } |
| 3508 | |
| 3509 | void dm_uevent_add(struct mapped_device *md, struct list_head *elist) |
| 3510 | { |
| 3511 | unsigned long flags; |
| 3512 | |
| 3513 | spin_lock_irqsave(&md->uevent_lock, flags); |
| 3514 | list_add(elist, &md->uevent_list); |
| 3515 | spin_unlock_irqrestore(&md->uevent_lock, flags); |
| 3516 | } |
| 3517 | |
| 3518 | /* |
| 3519 | * The gendisk is only valid as long as you have a reference |
| 3520 | * count on 'md'. |
| 3521 | */ |
| 3522 | struct gendisk *dm_disk(struct mapped_device *md) |
| 3523 | { |
| 3524 | return md->disk; |
| 3525 | } |
| 3526 | EXPORT_SYMBOL_GPL(dm_disk); |
| 3527 | |
| 3528 | struct kobject *dm_kobject(struct mapped_device *md) |
| 3529 | { |
| 3530 | return &md->kobj_holder.kobj; |
| 3531 | } |
| 3532 | |
| 3533 | struct mapped_device *dm_get_from_kobject(struct kobject *kobj) |
| 3534 | { |
| 3535 | struct mapped_device *md; |
| 3536 | |
| 3537 | md = container_of(kobj, struct mapped_device, kobj_holder.kobj); |
| 3538 | |
| 3539 | if (test_bit(DMF_FREEING, &md->flags) || |
| 3540 | dm_deleting_md(md)) |
| 3541 | return NULL; |
| 3542 | |
| 3543 | dm_get(md); |
| 3544 | return md; |
| 3545 | } |
| 3546 | |
| 3547 | int dm_suspended_md(struct mapped_device *md) |
| 3548 | { |
| 3549 | return test_bit(DMF_SUSPENDED, &md->flags); |
| 3550 | } |
| 3551 | |
| 3552 | int dm_suspended_internally_md(struct mapped_device *md) |
| 3553 | { |
| 3554 | return test_bit(DMF_SUSPENDED_INTERNALLY, &md->flags); |
| 3555 | } |
| 3556 | |
| 3557 | int dm_test_deferred_remove_flag(struct mapped_device *md) |
| 3558 | { |
| 3559 | return test_bit(DMF_DEFERRED_REMOVE, &md->flags); |
| 3560 | } |
| 3561 | |
| 3562 | int dm_suspended(struct dm_target *ti) |
| 3563 | { |
| 3564 | return dm_suspended_md(dm_table_get_md(ti->table)); |
| 3565 | } |
| 3566 | EXPORT_SYMBOL_GPL(dm_suspended); |
| 3567 | |
| 3568 | int dm_noflush_suspending(struct dm_target *ti) |
| 3569 | { |
| 3570 | return __noflush_suspending(dm_table_get_md(ti->table)); |
| 3571 | } |
| 3572 | EXPORT_SYMBOL_GPL(dm_noflush_suspending); |
| 3573 | |
| 3574 | struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, unsigned type, |
| 3575 | unsigned integrity, unsigned per_bio_data_size) |
| 3576 | { |
| 3577 | struct dm_md_mempools *pools = kzalloc(sizeof(*pools), GFP_KERNEL); |
| 3578 | struct kmem_cache *cachep = NULL; |
| 3579 | unsigned int pool_size = 0; |
| 3580 | unsigned int front_pad; |
| 3581 | |
| 3582 | if (!pools) |
| 3583 | return NULL; |
| 3584 | |
| 3585 | type = filter_md_type(type, md); |
| 3586 | |
| 3587 | switch (type) { |
| 3588 | case DM_TYPE_BIO_BASED: |
| 3589 | cachep = _io_cache; |
| 3590 | pool_size = dm_get_reserved_bio_based_ios(); |
| 3591 | front_pad = roundup(per_bio_data_size, __alignof__(struct dm_target_io)) + offsetof(struct dm_target_io, clone); |
| 3592 | break; |
| 3593 | case DM_TYPE_REQUEST_BASED: |
| 3594 | cachep = _rq_tio_cache; |
| 3595 | pool_size = dm_get_reserved_rq_based_ios(); |
| 3596 | pools->rq_pool = mempool_create_slab_pool(pool_size, _rq_cache); |
| 3597 | if (!pools->rq_pool) |
| 3598 | goto out; |
| 3599 | /* fall through to setup remaining rq-based pools */ |
| 3600 | case DM_TYPE_MQ_REQUEST_BASED: |
| 3601 | if (!pool_size) |
| 3602 | pool_size = dm_get_reserved_rq_based_ios(); |
| 3603 | front_pad = offsetof(struct dm_rq_clone_bio_info, clone); |
| 3604 | /* per_bio_data_size is not used. See __bind_mempools(). */ |
| 3605 | WARN_ON(per_bio_data_size != 0); |
| 3606 | break; |
| 3607 | default: |
| 3608 | BUG(); |
| 3609 | } |
| 3610 | |
| 3611 | if (cachep) { |
| 3612 | pools->io_pool = mempool_create_slab_pool(pool_size, cachep); |
| 3613 | if (!pools->io_pool) |
| 3614 | goto out; |
| 3615 | } |
| 3616 | |
| 3617 | pools->bs = bioset_create_nobvec(pool_size, front_pad); |
| 3618 | if (!pools->bs) |
| 3619 | goto out; |
| 3620 | |
| 3621 | if (integrity && bioset_integrity_create(pools->bs, pool_size)) |
| 3622 | goto out; |
| 3623 | |
| 3624 | return pools; |
| 3625 | |
| 3626 | out: |
| 3627 | dm_free_md_mempools(pools); |
| 3628 | |
| 3629 | return NULL; |
| 3630 | } |
| 3631 | |
| 3632 | void dm_free_md_mempools(struct dm_md_mempools *pools) |
| 3633 | { |
| 3634 | if (!pools) |
| 3635 | return; |
| 3636 | |
| 3637 | if (pools->io_pool) |
| 3638 | mempool_destroy(pools->io_pool); |
| 3639 | |
| 3640 | if (pools->rq_pool) |
| 3641 | mempool_destroy(pools->rq_pool); |
| 3642 | |
| 3643 | if (pools->bs) |
| 3644 | bioset_free(pools->bs); |
| 3645 | |
| 3646 | kfree(pools); |
| 3647 | } |
| 3648 | |
| 3649 | static const struct block_device_operations dm_blk_dops = { |
| 3650 | .open = dm_blk_open, |
| 3651 | .release = dm_blk_close, |
| 3652 | .ioctl = dm_blk_ioctl, |
| 3653 | .getgeo = dm_blk_getgeo, |
| 3654 | .owner = THIS_MODULE |
| 3655 | }; |
| 3656 | |
| 3657 | /* |
| 3658 | * module hooks |
| 3659 | */ |
| 3660 | module_init(dm_init); |
| 3661 | module_exit(dm_exit); |
| 3662 | |
| 3663 | module_param(major, uint, 0); |
| 3664 | MODULE_PARM_DESC(major, "The major number of the device mapper"); |
| 3665 | |
| 3666 | module_param(reserved_bio_based_ios, uint, S_IRUGO | S_IWUSR); |
| 3667 | MODULE_PARM_DESC(reserved_bio_based_ios, "Reserved IOs in bio-based mempools"); |
| 3668 | |
| 3669 | module_param(reserved_rq_based_ios, uint, S_IRUGO | S_IWUSR); |
| 3670 | MODULE_PARM_DESC(reserved_rq_based_ios, "Reserved IOs in request-based mempools"); |
| 3671 | |
| 3672 | module_param(use_blk_mq, bool, S_IRUGO | S_IWUSR); |
| 3673 | MODULE_PARM_DESC(use_blk_mq, "Use block multiqueue for request-based DM devices"); |
| 3674 | |
| 3675 | MODULE_DESCRIPTION(DM_NAME " driver"); |
| 3676 | MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>"); |
| 3677 | MODULE_LICENSE("GPL"); |