1 #ifndef _LINUX_BLKDEV_H 2 #define _LINUX_BLKDEV_H 3 4 #include <linux/sched.h> 5 6 #ifdef CONFIG_BLOCK 7 8 #include <linux/major.h> 9 #include <linux/genhd.h> 10 #include <linux/list.h> 11 #include <linux/llist.h> 12 #include <linux/timer.h> 13 #include <linux/workqueue.h> 14 #include <linux/pagemap.h> 15 #include <linux/backing-dev-defs.h> 16 #include <linux/wait.h> 17 #include <linux/mempool.h> 18 #include <linux/bio.h> 19 #include <linux/stringify.h> 20 #include <linux/gfp.h> 21 #include <linux/bsg.h> 22 #include <linux/smp.h> 23 #include <linux/rcupdate.h> 24 #include <linux/percpu-refcount.h> 25 #include <linux/scatterlist.h> 26 27 struct module; 28 struct scsi_ioctl_command; 29 30 struct request_queue; 31 struct elevator_queue; 32 struct blk_trace; 33 struct request; 34 struct sg_io_hdr; 35 struct bsg_job; 36 struct blkcg_gq; 37 struct blk_flush_queue; 38 39 #define BLKDEV_MIN_RQ 4 40 #define BLKDEV_MAX_RQ 128 /* Default maximum */ 41 42 /* 43 * Maximum number of blkcg policies allowed to be registered concurrently. 44 * Defined here to simplify include dependency. 45 */ 46 #define BLKCG_MAX_POLS 2 47 48 struct request; 49 typedef void (rq_end_io_fn)(struct request *, int); 50 51 #define BLK_RL_SYNCFULL (1U << 0) 52 #define BLK_RL_ASYNCFULL (1U << 1) 53 54 struct request_list { 55 struct request_queue *q; /* the queue this rl belongs to */ 56 #ifdef CONFIG_BLK_CGROUP 57 struct blkcg_gq *blkg; /* blkg this request pool belongs to */ 58 #endif 59 /* 60 * count[], starved[], and wait[] are indexed by 61 * BLK_RW_SYNC/BLK_RW_ASYNC 62 */ 63 int count[2]; 64 int starved[2]; 65 mempool_t *rq_pool; 66 wait_queue_head_t wait[2]; 67 unsigned int flags; 68 }; 69 70 /* 71 * request command types 72 */ 73 enum rq_cmd_type_bits { 74 REQ_TYPE_FS = 1, /* fs request */ 75 REQ_TYPE_BLOCK_PC, /* scsi command */ 76 REQ_TYPE_DRV_PRIV, /* driver defined types from here */ 77 }; 78 79 #define BLK_MAX_CDB 16 80 81 /* 82 * Try to put the fields that are referenced together in the same cacheline. 83 * 84 * If you modify this structure, make sure to update blk_rq_init() and 85 * especially blk_mq_rq_ctx_init() to take care of the added fields. 86 */ 87 struct request { 88 struct list_head queuelist; 89 union { 90 struct call_single_data csd; 91 unsigned long fifo_time; 92 }; 93 94 struct request_queue *q; 95 struct blk_mq_ctx *mq_ctx; 96 97 u64 cmd_flags; 98 unsigned cmd_type; 99 unsigned long atomic_flags; 100 101 int cpu; 102 103 /* the following two fields are internal, NEVER access directly */ 104 unsigned int __data_len; /* total data len */ 105 sector_t __sector; /* sector cursor */ 106 107 struct bio *bio; 108 struct bio *biotail; 109 110 /* 111 * The hash is used inside the scheduler, and killed once the 112 * request reaches the dispatch list. The ipi_list is only used 113 * to queue the request for softirq completion, which is long 114 * after the request has been unhashed (and even removed from 115 * the dispatch list). 116 */ 117 union { 118 struct hlist_node hash; /* merge hash */ 119 struct list_head ipi_list; 120 }; 121 122 /* 123 * The rb_node is only used inside the io scheduler, requests 124 * are pruned when moved to the dispatch queue. So let the 125 * completion_data share space with the rb_node. 126 */ 127 union { 128 struct rb_node rb_node; /* sort/lookup */ 129 void *completion_data; 130 }; 131 132 /* 133 * Three pointers are available for the IO schedulers, if they need 134 * more they have to dynamically allocate it. Flush requests are 135 * never put on the IO scheduler. So let the flush fields share 136 * space with the elevator data. 137 */ 138 union { 139 struct { 140 struct io_cq *icq; 141 void *priv[2]; 142 } elv; 143 144 struct { 145 unsigned int seq; 146 struct list_head list; 147 rq_end_io_fn *saved_end_io; 148 } flush; 149 }; 150 151 struct gendisk *rq_disk; 152 struct hd_struct *part; 153 unsigned long start_time; 154 #ifdef CONFIG_BLK_CGROUP 155 struct request_list *rl; /* rl this rq is alloced from */ 156 unsigned long long start_time_ns; 157 unsigned long long io_start_time_ns; /* when passed to hardware */ 158 #endif 159 /* Number of scatter-gather DMA addr+len pairs after 160 * physical address coalescing is performed. 161 */ 162 unsigned short nr_phys_segments; 163 #if defined(CONFIG_BLK_DEV_INTEGRITY) 164 unsigned short nr_integrity_segments; 165 #endif 166 167 unsigned short ioprio; 168 169 void *special; /* opaque pointer available for LLD use */ 170 171 int tag; 172 int errors; 173 174 /* 175 * when request is used as a packet command carrier 176 */ 177 unsigned char __cmd[BLK_MAX_CDB]; 178 unsigned char *cmd; 179 unsigned short cmd_len; 180 181 unsigned int extra_len; /* length of alignment and padding */ 182 unsigned int sense_len; 183 unsigned int resid_len; /* residual count */ 184 void *sense; 185 186 unsigned long deadline; 187 struct list_head timeout_list; 188 unsigned int timeout; 189 int retries; 190 191 /* 192 * completion callback. 193 */ 194 rq_end_io_fn *end_io; 195 void *end_io_data; 196 197 /* for bidi */ 198 struct request *next_rq; 199 }; 200 201 static inline unsigned short req_get_ioprio(struct request *req) 202 { 203 return req->ioprio; 204 } 205 206 #include <linux/elevator.h> 207 208 struct blk_queue_ctx; 209 210 typedef void (request_fn_proc) (struct request_queue *q); 211 typedef void (make_request_fn) (struct request_queue *q, struct bio *bio); 212 typedef int (prep_rq_fn) (struct request_queue *, struct request *); 213 typedef void (unprep_rq_fn) (struct request_queue *, struct request *); 214 215 struct bio_vec; 216 typedef void (softirq_done_fn)(struct request *); 217 typedef int (dma_drain_needed_fn)(struct request *); 218 typedef int (lld_busy_fn) (struct request_queue *q); 219 typedef int (bsg_job_fn) (struct bsg_job *); 220 221 enum blk_eh_timer_return { 222 BLK_EH_NOT_HANDLED, 223 BLK_EH_HANDLED, 224 BLK_EH_RESET_TIMER, 225 }; 226 227 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *); 228 229 enum blk_queue_state { 230 Queue_down, 231 Queue_up, 232 }; 233 234 struct blk_queue_tag { 235 struct request **tag_index; /* map of busy tags */ 236 unsigned long *tag_map; /* bit map of free/busy tags */ 237 int busy; /* current depth */ 238 int max_depth; /* what we will send to device */ 239 int real_max_depth; /* what the array can hold */ 240 atomic_t refcnt; /* map can be shared */ 241 int alloc_policy; /* tag allocation policy */ 242 int next_tag; /* next tag */ 243 }; 244 #define BLK_TAG_ALLOC_FIFO 0 /* allocate starting from 0 */ 245 #define BLK_TAG_ALLOC_RR 1 /* allocate starting from last allocated tag */ 246 247 #define BLK_SCSI_MAX_CMDS (256) 248 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8)) 249 250 struct queue_limits { 251 unsigned long bounce_pfn; 252 unsigned long seg_boundary_mask; 253 unsigned long virt_boundary_mask; 254 255 unsigned int max_hw_sectors; 256 unsigned int chunk_sectors; 257 unsigned int max_sectors; 258 unsigned int max_segment_size; 259 unsigned int physical_block_size; 260 unsigned int alignment_offset; 261 unsigned int io_min; 262 unsigned int io_opt; 263 unsigned int max_discard_sectors; 264 unsigned int max_hw_discard_sectors; 265 unsigned int max_write_same_sectors; 266 unsigned int discard_granularity; 267 unsigned int discard_alignment; 268 269 unsigned short logical_block_size; 270 unsigned short max_segments; 271 unsigned short max_integrity_segments; 272 273 unsigned char misaligned; 274 unsigned char discard_misaligned; 275 unsigned char cluster; 276 unsigned char discard_zeroes_data; 277 unsigned char raid_partial_stripes_expensive; 278 }; 279 280 struct request_queue { 281 /* 282 * Together with queue_head for cacheline sharing 283 */ 284 struct list_head queue_head; 285 struct request *last_merge; 286 struct elevator_queue *elevator; 287 int nr_rqs[2]; /* # allocated [a]sync rqs */ 288 int nr_rqs_elvpriv; /* # allocated rqs w/ elvpriv */ 289 290 /* 291 * If blkcg is not used, @q->root_rl serves all requests. If blkcg 292 * is used, root blkg allocates from @q->root_rl and all other 293 * blkgs from their own blkg->rl. Which one to use should be 294 * determined using bio_request_list(). 295 */ 296 struct request_list root_rl; 297 298 request_fn_proc *request_fn; 299 make_request_fn *make_request_fn; 300 prep_rq_fn *prep_rq_fn; 301 unprep_rq_fn *unprep_rq_fn; 302 softirq_done_fn *softirq_done_fn; 303 rq_timed_out_fn *rq_timed_out_fn; 304 dma_drain_needed_fn *dma_drain_needed; 305 lld_busy_fn *lld_busy_fn; 306 307 struct blk_mq_ops *mq_ops; 308 309 unsigned int *mq_map; 310 311 /* sw queues */ 312 struct blk_mq_ctx __percpu *queue_ctx; 313 unsigned int nr_queues; 314 315 /* hw dispatch queues */ 316 struct blk_mq_hw_ctx **queue_hw_ctx; 317 unsigned int nr_hw_queues; 318 319 /* 320 * Dispatch queue sorting 321 */ 322 sector_t end_sector; 323 struct request *boundary_rq; 324 325 /* 326 * Delayed queue handling 327 */ 328 struct delayed_work delay_work; 329 330 struct backing_dev_info backing_dev_info; 331 332 /* 333 * The queue owner gets to use this for whatever they like. 334 * ll_rw_blk doesn't touch it. 335 */ 336 void *queuedata; 337 338 /* 339 * various queue flags, see QUEUE_* below 340 */ 341 unsigned long queue_flags; 342 343 /* 344 * ida allocated id for this queue. Used to index queues from 345 * ioctx. 346 */ 347 int id; 348 349 /* 350 * queue needs bounce pages for pages above this limit 351 */ 352 gfp_t bounce_gfp; 353 354 /* 355 * protects queue structures from reentrancy. ->__queue_lock should 356 * _never_ be used directly, it is queue private. always use 357 * ->queue_lock. 358 */ 359 spinlock_t __queue_lock; 360 spinlock_t *queue_lock; 361 362 /* 363 * queue kobject 364 */ 365 struct kobject kobj; 366 367 /* 368 * mq queue kobject 369 */ 370 struct kobject mq_kobj; 371 372 #ifdef CONFIG_PM 373 struct device *dev; 374 int rpm_status; 375 unsigned int nr_pending; 376 #endif 377 378 /* 379 * queue settings 380 */ 381 unsigned long nr_requests; /* Max # of requests */ 382 unsigned int nr_congestion_on; 383 unsigned int nr_congestion_off; 384 unsigned int nr_batching; 385 386 unsigned int dma_drain_size; 387 void *dma_drain_buffer; 388 unsigned int dma_pad_mask; 389 unsigned int dma_alignment; 390 391 struct blk_queue_tag *queue_tags; 392 struct list_head tag_busy_list; 393 394 unsigned int nr_sorted; 395 unsigned int in_flight[2]; 396 /* 397 * Number of active block driver functions for which blk_drain_queue() 398 * must wait. Must be incremented around functions that unlock the 399 * queue_lock internally, e.g. scsi_request_fn(). 400 */ 401 unsigned int request_fn_active; 402 403 unsigned int rq_timeout; 404 struct timer_list timeout; 405 struct list_head timeout_list; 406 407 struct list_head icq_list; 408 #ifdef CONFIG_BLK_CGROUP 409 DECLARE_BITMAP (blkcg_pols, BLKCG_MAX_POLS); 410 struct blkcg_gq *root_blkg; 411 struct list_head blkg_list; 412 #endif 413 414 struct queue_limits limits; 415 416 /* 417 * sg stuff 418 */ 419 unsigned int sg_timeout; 420 unsigned int sg_reserved_size; 421 int node; 422 #ifdef CONFIG_BLK_DEV_IO_TRACE 423 struct blk_trace *blk_trace; 424 #endif 425 /* 426 * for flush operations 427 */ 428 unsigned int flush_flags; 429 unsigned int flush_not_queueable:1; 430 struct blk_flush_queue *fq; 431 432 struct list_head requeue_list; 433 spinlock_t requeue_lock; 434 struct work_struct requeue_work; 435 436 struct mutex sysfs_lock; 437 438 int bypass_depth; 439 atomic_t mq_freeze_depth; 440 441 #if defined(CONFIG_BLK_DEV_BSG) 442 bsg_job_fn *bsg_job_fn; 443 int bsg_job_size; 444 struct bsg_class_device bsg_dev; 445 #endif 446 447 #ifdef CONFIG_BLK_DEV_THROTTLING 448 /* Throttle data */ 449 struct throtl_data *td; 450 #endif 451 struct rcu_head rcu_head; 452 wait_queue_head_t mq_freeze_wq; 453 struct percpu_ref mq_usage_counter; 454 struct list_head all_q_node; 455 456 struct blk_mq_tag_set *tag_set; 457 struct list_head tag_set_list; 458 struct bio_set *bio_split; 459 }; 460 461 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ 462 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */ 463 #define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */ 464 #define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */ 465 #define QUEUE_FLAG_DYING 5 /* queue being torn down */ 466 #define QUEUE_FLAG_BYPASS 6 /* act as dumb FIFO queue */ 467 #define QUEUE_FLAG_BIDI 7 /* queue supports bidi requests */ 468 #define QUEUE_FLAG_NOMERGES 8 /* disable merge attempts */ 469 #define QUEUE_FLAG_SAME_COMP 9 /* complete on same CPU-group */ 470 #define QUEUE_FLAG_FAIL_IO 10 /* fake timeout */ 471 #define QUEUE_FLAG_STACKABLE 11 /* supports request stacking */ 472 #define QUEUE_FLAG_NONROT 12 /* non-rotational device (SSD) */ 473 #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */ 474 #define QUEUE_FLAG_IO_STAT 13 /* do IO stats */ 475 #define QUEUE_FLAG_DISCARD 14 /* supports DISCARD */ 476 #define QUEUE_FLAG_NOXMERGES 15 /* No extended merges */ 477 #define QUEUE_FLAG_ADD_RANDOM 16 /* Contributes to random pool */ 478 #define QUEUE_FLAG_SECDISCARD 17 /* supports SECDISCARD */ 479 #define QUEUE_FLAG_SAME_FORCE 18 /* force complete on same CPU */ 480 #define QUEUE_FLAG_DEAD 19 /* queue tear-down finished */ 481 #define QUEUE_FLAG_INIT_DONE 20 /* queue is initialized */ 482 #define QUEUE_FLAG_NO_SG_MERGE 21 /* don't attempt to merge SG segments*/ 483 484 #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ 485 (1 << QUEUE_FLAG_STACKABLE) | \ 486 (1 << QUEUE_FLAG_SAME_COMP) | \ 487 (1 << QUEUE_FLAG_ADD_RANDOM)) 488 489 #define QUEUE_FLAG_MQ_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ 490 (1 << QUEUE_FLAG_STACKABLE) | \ 491 (1 << QUEUE_FLAG_SAME_COMP)) 492 493 static inline void queue_lockdep_assert_held(struct request_queue *q) 494 { 495 if (q->queue_lock) 496 lockdep_assert_held(q->queue_lock); 497 } 498 499 static inline void queue_flag_set_unlocked(unsigned int flag, 500 struct request_queue *q) 501 { 502 __set_bit(flag, &q->queue_flags); 503 } 504 505 static inline int queue_flag_test_and_clear(unsigned int flag, 506 struct request_queue *q) 507 { 508 queue_lockdep_assert_held(q); 509 510 if (test_bit(flag, &q->queue_flags)) { 511 __clear_bit(flag, &q->queue_flags); 512 return 1; 513 } 514 515 return 0; 516 } 517 518 static inline int queue_flag_test_and_set(unsigned int flag, 519 struct request_queue *q) 520 { 521 queue_lockdep_assert_held(q); 522 523 if (!test_bit(flag, &q->queue_flags)) { 524 __set_bit(flag, &q->queue_flags); 525 return 0; 526 } 527 528 return 1; 529 } 530 531 static inline void queue_flag_set(unsigned int flag, struct request_queue *q) 532 { 533 queue_lockdep_assert_held(q); 534 __set_bit(flag, &q->queue_flags); 535 } 536 537 static inline void queue_flag_clear_unlocked(unsigned int flag, 538 struct request_queue *q) 539 { 540 __clear_bit(flag, &q->queue_flags); 541 } 542 543 static inline int queue_in_flight(struct request_queue *q) 544 { 545 return q->in_flight[0] + q->in_flight[1]; 546 } 547 548 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q) 549 { 550 queue_lockdep_assert_held(q); 551 __clear_bit(flag, &q->queue_flags); 552 } 553 554 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) 555 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) 556 #define blk_queue_dying(q) test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags) 557 #define blk_queue_dead(q) test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags) 558 #define blk_queue_bypass(q) test_bit(QUEUE_FLAG_BYPASS, &(q)->queue_flags) 559 #define blk_queue_init_done(q) test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags) 560 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags) 561 #define blk_queue_noxmerges(q) \ 562 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags) 563 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags) 564 #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags) 565 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags) 566 #define blk_queue_stackable(q) \ 567 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags) 568 #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags) 569 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \ 570 test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags)) 571 572 #define blk_noretry_request(rq) \ 573 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \ 574 REQ_FAILFAST_DRIVER)) 575 576 #define blk_account_rq(rq) \ 577 (((rq)->cmd_flags & REQ_STARTED) && \ 578 ((rq)->cmd_type == REQ_TYPE_FS)) 579 580 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1) 581 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL) 582 /* rq->queuelist of dequeued request must be list_empty() */ 583 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist)) 584 585 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) 586 587 #define rq_data_dir(rq) ((int)((rq)->cmd_flags & 1)) 588 589 /* 590 * Driver can handle struct request, if it either has an old style 591 * request_fn defined, or is blk-mq based. 592 */ 593 static inline bool queue_is_rq_based(struct request_queue *q) 594 { 595 return q->request_fn || q->mq_ops; 596 } 597 598 static inline unsigned int blk_queue_cluster(struct request_queue *q) 599 { 600 return q->limits.cluster; 601 } 602 603 /* 604 * We regard a request as sync, if either a read or a sync write 605 */ 606 static inline bool rw_is_sync(unsigned int rw_flags) 607 { 608 return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC); 609 } 610 611 static inline bool rq_is_sync(struct request *rq) 612 { 613 return rw_is_sync(rq->cmd_flags); 614 } 615 616 static inline bool blk_rl_full(struct request_list *rl, bool sync) 617 { 618 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 619 620 return rl->flags & flag; 621 } 622 623 static inline void blk_set_rl_full(struct request_list *rl, bool sync) 624 { 625 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 626 627 rl->flags |= flag; 628 } 629 630 static inline void blk_clear_rl_full(struct request_list *rl, bool sync) 631 { 632 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 633 634 rl->flags &= ~flag; 635 } 636 637 static inline bool rq_mergeable(struct request *rq) 638 { 639 if (rq->cmd_type != REQ_TYPE_FS) 640 return false; 641 642 if (rq->cmd_flags & REQ_NOMERGE_FLAGS) 643 return false; 644 645 return true; 646 } 647 648 static inline bool blk_check_merge_flags(unsigned int flags1, 649 unsigned int flags2) 650 { 651 if ((flags1 & REQ_DISCARD) != (flags2 & REQ_DISCARD)) 652 return false; 653 654 if ((flags1 & REQ_SECURE) != (flags2 & REQ_SECURE)) 655 return false; 656 657 if ((flags1 & REQ_WRITE_SAME) != (flags2 & REQ_WRITE_SAME)) 658 return false; 659 660 return true; 661 } 662 663 static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b) 664 { 665 if (bio_data(a) == bio_data(b)) 666 return true; 667 668 return false; 669 } 670 671 /* 672 * q->prep_rq_fn return values 673 */ 674 #define BLKPREP_OK 0 /* serve it */ 675 #define BLKPREP_KILL 1 /* fatal error, kill */ 676 #define BLKPREP_DEFER 2 /* leave on queue */ 677 678 extern unsigned long blk_max_low_pfn, blk_max_pfn; 679 680 /* 681 * standard bounce addresses: 682 * 683 * BLK_BOUNCE_HIGH : bounce all highmem pages 684 * BLK_BOUNCE_ANY : don't bounce anything 685 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary 686 */ 687 688 #if BITS_PER_LONG == 32 689 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) 690 #else 691 #define BLK_BOUNCE_HIGH -1ULL 692 #endif 693 #define BLK_BOUNCE_ANY (-1ULL) 694 #define BLK_BOUNCE_ISA (DMA_BIT_MASK(24)) 695 696 /* 697 * default timeout for SG_IO if none specified 698 */ 699 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ) 700 #define BLK_MIN_SG_TIMEOUT (7 * HZ) 701 702 #ifdef CONFIG_BOUNCE 703 extern int init_emergency_isa_pool(void); 704 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio); 705 #else 706 static inline int init_emergency_isa_pool(void) 707 { 708 return 0; 709 } 710 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio) 711 { 712 } 713 #endif /* CONFIG_MMU */ 714 715 struct rq_map_data { 716 struct page **pages; 717 int page_order; 718 int nr_entries; 719 unsigned long offset; 720 int null_mapped; 721 int from_user; 722 }; 723 724 struct req_iterator { 725 struct bvec_iter iter; 726 struct bio *bio; 727 }; 728 729 /* This should not be used directly - use rq_for_each_segment */ 730 #define for_each_bio(_bio) \ 731 for (; _bio; _bio = _bio->bi_next) 732 #define __rq_for_each_bio(_bio, rq) \ 733 if ((rq->bio)) \ 734 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) 735 736 #define rq_for_each_segment(bvl, _rq, _iter) \ 737 __rq_for_each_bio(_iter.bio, _rq) \ 738 bio_for_each_segment(bvl, _iter.bio, _iter.iter) 739 740 #define rq_iter_last(bvec, _iter) \ 741 (_iter.bio->bi_next == NULL && \ 742 bio_iter_last(bvec, _iter.iter)) 743 744 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 745 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform" 746 #endif 747 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 748 extern void rq_flush_dcache_pages(struct request *rq); 749 #else 750 static inline void rq_flush_dcache_pages(struct request *rq) 751 { 752 } 753 #endif 754 755 extern int blk_register_queue(struct gendisk *disk); 756 extern void blk_unregister_queue(struct gendisk *disk); 757 extern void generic_make_request(struct bio *bio); 758 extern void blk_rq_init(struct request_queue *q, struct request *rq); 759 extern void blk_put_request(struct request *); 760 extern void __blk_put_request(struct request_queue *, struct request *); 761 extern struct request *blk_get_request(struct request_queue *, int, gfp_t); 762 extern struct request *blk_make_request(struct request_queue *, struct bio *, 763 gfp_t); 764 extern void blk_rq_set_block_pc(struct request *); 765 extern void blk_requeue_request(struct request_queue *, struct request *); 766 extern void blk_add_request_payload(struct request *rq, struct page *page, 767 unsigned int len); 768 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq); 769 extern int blk_lld_busy(struct request_queue *q); 770 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src, 771 struct bio_set *bs, gfp_t gfp_mask, 772 int (*bio_ctr)(struct bio *, struct bio *, void *), 773 void *data); 774 extern void blk_rq_unprep_clone(struct request *rq); 775 extern int blk_insert_cloned_request(struct request_queue *q, 776 struct request *rq); 777 extern void blk_delay_queue(struct request_queue *, unsigned long); 778 extern void blk_queue_split(struct request_queue *, struct bio **, 779 struct bio_set *); 780 extern void blk_recount_segments(struct request_queue *, struct bio *); 781 extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int); 782 extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t, 783 unsigned int, void __user *); 784 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t, 785 unsigned int, void __user *); 786 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t, 787 struct scsi_ioctl_command __user *); 788 789 extern void blk_start_queue(struct request_queue *q); 790 extern void blk_stop_queue(struct request_queue *q); 791 extern void blk_sync_queue(struct request_queue *q); 792 extern void __blk_stop_queue(struct request_queue *q); 793 extern void __blk_run_queue(struct request_queue *q); 794 extern void __blk_run_queue_uncond(struct request_queue *q); 795 extern void blk_run_queue(struct request_queue *); 796 extern void blk_run_queue_async(struct request_queue *q); 797 extern int blk_rq_map_user(struct request_queue *, struct request *, 798 struct rq_map_data *, void __user *, unsigned long, 799 gfp_t); 800 extern int blk_rq_unmap_user(struct bio *); 801 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t); 802 extern int blk_rq_map_user_iov(struct request_queue *, struct request *, 803 struct rq_map_data *, const struct iov_iter *, 804 gfp_t); 805 extern int blk_execute_rq(struct request_queue *, struct gendisk *, 806 struct request *, int); 807 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *, 808 struct request *, int, rq_end_io_fn *); 809 810 static inline struct request_queue *bdev_get_queue(struct block_device *bdev) 811 { 812 return bdev->bd_disk->queue; /* this is never NULL */ 813 } 814 815 /* 816 * blk_rq_pos() : the current sector 817 * blk_rq_bytes() : bytes left in the entire request 818 * blk_rq_cur_bytes() : bytes left in the current segment 819 * blk_rq_err_bytes() : bytes left till the next error boundary 820 * blk_rq_sectors() : sectors left in the entire request 821 * blk_rq_cur_sectors() : sectors left in the current segment 822 */ 823 static inline sector_t blk_rq_pos(const struct request *rq) 824 { 825 return rq->__sector; 826 } 827 828 static inline unsigned int blk_rq_bytes(const struct request *rq) 829 { 830 return rq->__data_len; 831 } 832 833 static inline int blk_rq_cur_bytes(const struct request *rq) 834 { 835 return rq->bio ? bio_cur_bytes(rq->bio) : 0; 836 } 837 838 extern unsigned int blk_rq_err_bytes(const struct request *rq); 839 840 static inline unsigned int blk_rq_sectors(const struct request *rq) 841 { 842 return blk_rq_bytes(rq) >> 9; 843 } 844 845 static inline unsigned int blk_rq_cur_sectors(const struct request *rq) 846 { 847 return blk_rq_cur_bytes(rq) >> 9; 848 } 849 850 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q, 851 unsigned int cmd_flags) 852 { 853 if (unlikely(cmd_flags & REQ_DISCARD)) 854 return min(q->limits.max_discard_sectors, UINT_MAX >> 9); 855 856 if (unlikely(cmd_flags & REQ_WRITE_SAME)) 857 return q->limits.max_write_same_sectors; 858 859 return q->limits.max_sectors; 860 } 861 862 /* 863 * Return maximum size of a request at given offset. Only valid for 864 * file system requests. 865 */ 866 static inline unsigned int blk_max_size_offset(struct request_queue *q, 867 sector_t offset) 868 { 869 if (!q->limits.chunk_sectors) 870 return q->limits.max_sectors; 871 872 return q->limits.chunk_sectors - 873 (offset & (q->limits.chunk_sectors - 1)); 874 } 875 876 static inline unsigned int blk_rq_get_max_sectors(struct request *rq) 877 { 878 struct request_queue *q = rq->q; 879 880 if (unlikely(rq->cmd_type == REQ_TYPE_BLOCK_PC)) 881 return q->limits.max_hw_sectors; 882 883 if (!q->limits.chunk_sectors || (rq->cmd_flags & REQ_DISCARD)) 884 return blk_queue_get_max_sectors(q, rq->cmd_flags); 885 886 return min(blk_max_size_offset(q, blk_rq_pos(rq)), 887 blk_queue_get_max_sectors(q, rq->cmd_flags)); 888 } 889 890 static inline unsigned int blk_rq_count_bios(struct request *rq) 891 { 892 unsigned int nr_bios = 0; 893 struct bio *bio; 894 895 __rq_for_each_bio(bio, rq) 896 nr_bios++; 897 898 return nr_bios; 899 } 900 901 /* 902 * Request issue related functions. 903 */ 904 extern struct request *blk_peek_request(struct request_queue *q); 905 extern void blk_start_request(struct request *rq); 906 extern struct request *blk_fetch_request(struct request_queue *q); 907 908 /* 909 * Request completion related functions. 910 * 911 * blk_update_request() completes given number of bytes and updates 912 * the request without completing it. 913 * 914 * blk_end_request() and friends. __blk_end_request() must be called 915 * with the request queue spinlock acquired. 916 * 917 * Several drivers define their own end_request and call 918 * blk_end_request() for parts of the original function. 919 * This prevents code duplication in drivers. 920 */ 921 extern bool blk_update_request(struct request *rq, int error, 922 unsigned int nr_bytes); 923 extern void blk_finish_request(struct request *rq, int error); 924 extern bool blk_end_request(struct request *rq, int error, 925 unsigned int nr_bytes); 926 extern void blk_end_request_all(struct request *rq, int error); 927 extern bool blk_end_request_cur(struct request *rq, int error); 928 extern bool blk_end_request_err(struct request *rq, int error); 929 extern bool __blk_end_request(struct request *rq, int error, 930 unsigned int nr_bytes); 931 extern void __blk_end_request_all(struct request *rq, int error); 932 extern bool __blk_end_request_cur(struct request *rq, int error); 933 extern bool __blk_end_request_err(struct request *rq, int error); 934 935 extern void blk_complete_request(struct request *); 936 extern void __blk_complete_request(struct request *); 937 extern void blk_abort_request(struct request *); 938 extern void blk_unprep_request(struct request *); 939 940 /* 941 * Access functions for manipulating queue properties 942 */ 943 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn, 944 spinlock_t *lock, int node_id); 945 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *); 946 extern struct request_queue *blk_init_allocated_queue(struct request_queue *, 947 request_fn_proc *, spinlock_t *); 948 extern void blk_cleanup_queue(struct request_queue *); 949 extern void blk_queue_make_request(struct request_queue *, make_request_fn *); 950 extern void blk_queue_bounce_limit(struct request_queue *, u64); 951 extern void blk_limits_max_hw_sectors(struct queue_limits *, unsigned int); 952 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int); 953 extern void blk_queue_chunk_sectors(struct request_queue *, unsigned int); 954 extern void blk_queue_max_segments(struct request_queue *, unsigned short); 955 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int); 956 extern void blk_queue_max_discard_sectors(struct request_queue *q, 957 unsigned int max_discard_sectors); 958 extern void blk_queue_max_write_same_sectors(struct request_queue *q, 959 unsigned int max_write_same_sectors); 960 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short); 961 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int); 962 extern void blk_queue_alignment_offset(struct request_queue *q, 963 unsigned int alignment); 964 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min); 965 extern void blk_queue_io_min(struct request_queue *q, unsigned int min); 966 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt); 967 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt); 968 extern void blk_set_default_limits(struct queue_limits *lim); 969 extern void blk_set_stacking_limits(struct queue_limits *lim); 970 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, 971 sector_t offset); 972 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev, 973 sector_t offset); 974 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev, 975 sector_t offset); 976 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b); 977 extern void blk_queue_dma_pad(struct request_queue *, unsigned int); 978 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int); 979 extern int blk_queue_dma_drain(struct request_queue *q, 980 dma_drain_needed_fn *dma_drain_needed, 981 void *buf, unsigned int size); 982 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn); 983 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long); 984 extern void blk_queue_virt_boundary(struct request_queue *, unsigned long); 985 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn); 986 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn); 987 extern void blk_queue_dma_alignment(struct request_queue *, int); 988 extern void blk_queue_update_dma_alignment(struct request_queue *, int); 989 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *); 990 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *); 991 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int); 992 extern void blk_queue_flush(struct request_queue *q, unsigned int flush); 993 extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable); 994 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); 995 996 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *); 997 extern void blk_dump_rq_flags(struct request *, char *); 998 extern long nr_blockdev_pages(void); 999 1000 bool __must_check blk_get_queue(struct request_queue *); 1001 struct request_queue *blk_alloc_queue(gfp_t); 1002 struct request_queue *blk_alloc_queue_node(gfp_t, int); 1003 extern void blk_put_queue(struct request_queue *); 1004 extern void blk_set_queue_dying(struct request_queue *); 1005 1006 /* 1007 * block layer runtime pm functions 1008 */ 1009 #ifdef CONFIG_PM 1010 extern void blk_pm_runtime_init(struct request_queue *q, struct device *dev); 1011 extern int blk_pre_runtime_suspend(struct request_queue *q); 1012 extern void blk_post_runtime_suspend(struct request_queue *q, int err); 1013 extern void blk_pre_runtime_resume(struct request_queue *q); 1014 extern void blk_post_runtime_resume(struct request_queue *q, int err); 1015 #else 1016 static inline void blk_pm_runtime_init(struct request_queue *q, 1017 struct device *dev) {} 1018 static inline int blk_pre_runtime_suspend(struct request_queue *q) 1019 { 1020 return -ENOSYS; 1021 } 1022 static inline void blk_post_runtime_suspend(struct request_queue *q, int err) {} 1023 static inline void blk_pre_runtime_resume(struct request_queue *q) {} 1024 static inline void blk_post_runtime_resume(struct request_queue *q, int err) {} 1025 #endif 1026 1027 /* 1028 * blk_plug permits building a queue of related requests by holding the I/O 1029 * fragments for a short period. This allows merging of sequential requests 1030 * into single larger request. As the requests are moved from a per-task list to 1031 * the device's request_queue in a batch, this results in improved scalability 1032 * as the lock contention for request_queue lock is reduced. 1033 * 1034 * It is ok not to disable preemption when adding the request to the plug list 1035 * or when attempting a merge, because blk_schedule_flush_list() will only flush 1036 * the plug list when the task sleeps by itself. For details, please see 1037 * schedule() where blk_schedule_flush_plug() is called. 1038 */ 1039 struct blk_plug { 1040 struct list_head list; /* requests */ 1041 struct list_head mq_list; /* blk-mq requests */ 1042 struct list_head cb_list; /* md requires an unplug callback */ 1043 }; 1044 #define BLK_MAX_REQUEST_COUNT 16 1045 1046 struct blk_plug_cb; 1047 typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *, bool); 1048 struct blk_plug_cb { 1049 struct list_head list; 1050 blk_plug_cb_fn callback; 1051 void *data; 1052 }; 1053 extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug, 1054 void *data, int size); 1055 extern void blk_start_plug(struct blk_plug *); 1056 extern void blk_finish_plug(struct blk_plug *); 1057 extern void blk_flush_plug_list(struct blk_plug *, bool); 1058 1059 static inline void blk_flush_plug(struct task_struct *tsk) 1060 { 1061 struct blk_plug *plug = tsk->plug; 1062 1063 if (plug) 1064 blk_flush_plug_list(plug, false); 1065 } 1066 1067 static inline void blk_schedule_flush_plug(struct task_struct *tsk) 1068 { 1069 struct blk_plug *plug = tsk->plug; 1070 1071 if (plug) 1072 blk_flush_plug_list(plug, true); 1073 } 1074 1075 static inline bool blk_needs_flush_plug(struct task_struct *tsk) 1076 { 1077 struct blk_plug *plug = tsk->plug; 1078 1079 return plug && 1080 (!list_empty(&plug->list) || 1081 !list_empty(&plug->mq_list) || 1082 !list_empty(&plug->cb_list)); 1083 } 1084 1085 /* 1086 * tag stuff 1087 */ 1088 extern int blk_queue_start_tag(struct request_queue *, struct request *); 1089 extern struct request *blk_queue_find_tag(struct request_queue *, int); 1090 extern void blk_queue_end_tag(struct request_queue *, struct request *); 1091 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *, int); 1092 extern void blk_queue_free_tags(struct request_queue *); 1093 extern int blk_queue_resize_tags(struct request_queue *, int); 1094 extern void blk_queue_invalidate_tags(struct request_queue *); 1095 extern struct blk_queue_tag *blk_init_tags(int, int); 1096 extern void blk_free_tags(struct blk_queue_tag *); 1097 1098 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt, 1099 int tag) 1100 { 1101 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth)) 1102 return NULL; 1103 return bqt->tag_index[tag]; 1104 } 1105 1106 #define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */ 1107 1108 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *); 1109 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector, 1110 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags); 1111 extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector, 1112 sector_t nr_sects, gfp_t gfp_mask, struct page *page); 1113 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, 1114 sector_t nr_sects, gfp_t gfp_mask, bool discard); 1115 static inline int sb_issue_discard(struct super_block *sb, sector_t block, 1116 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags) 1117 { 1118 return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9), 1119 nr_blocks << (sb->s_blocksize_bits - 9), 1120 gfp_mask, flags); 1121 } 1122 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block, 1123 sector_t nr_blocks, gfp_t gfp_mask) 1124 { 1125 return blkdev_issue_zeroout(sb->s_bdev, 1126 block << (sb->s_blocksize_bits - 9), 1127 nr_blocks << (sb->s_blocksize_bits - 9), 1128 gfp_mask, true); 1129 } 1130 1131 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm); 1132 1133 enum blk_default_limits { 1134 BLK_MAX_SEGMENTS = 128, 1135 BLK_SAFE_MAX_SECTORS = 255, 1136 BLK_DEF_MAX_SECTORS = 2560, 1137 BLK_MAX_SEGMENT_SIZE = 65536, 1138 BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL, 1139 }; 1140 1141 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) 1142 1143 static inline unsigned long queue_bounce_pfn(struct request_queue *q) 1144 { 1145 return q->limits.bounce_pfn; 1146 } 1147 1148 static inline unsigned long queue_segment_boundary(struct request_queue *q) 1149 { 1150 return q->limits.seg_boundary_mask; 1151 } 1152 1153 static inline unsigned long queue_virt_boundary(struct request_queue *q) 1154 { 1155 return q->limits.virt_boundary_mask; 1156 } 1157 1158 static inline unsigned int queue_max_sectors(struct request_queue *q) 1159 { 1160 return q->limits.max_sectors; 1161 } 1162 1163 static inline unsigned int queue_max_hw_sectors(struct request_queue *q) 1164 { 1165 return q->limits.max_hw_sectors; 1166 } 1167 1168 static inline unsigned short queue_max_segments(struct request_queue *q) 1169 { 1170 return q->limits.max_segments; 1171 } 1172 1173 static inline unsigned int queue_max_segment_size(struct request_queue *q) 1174 { 1175 return q->limits.max_segment_size; 1176 } 1177 1178 static inline unsigned short queue_logical_block_size(struct request_queue *q) 1179 { 1180 int retval = 512; 1181 1182 if (q && q->limits.logical_block_size) 1183 retval = q->limits.logical_block_size; 1184 1185 return retval; 1186 } 1187 1188 static inline unsigned short bdev_logical_block_size(struct block_device *bdev) 1189 { 1190 return queue_logical_block_size(bdev_get_queue(bdev)); 1191 } 1192 1193 static inline unsigned int queue_physical_block_size(struct request_queue *q) 1194 { 1195 return q->limits.physical_block_size; 1196 } 1197 1198 static inline unsigned int bdev_physical_block_size(struct block_device *bdev) 1199 { 1200 return queue_physical_block_size(bdev_get_queue(bdev)); 1201 } 1202 1203 static inline unsigned int queue_io_min(struct request_queue *q) 1204 { 1205 return q->limits.io_min; 1206 } 1207 1208 static inline int bdev_io_min(struct block_device *bdev) 1209 { 1210 return queue_io_min(bdev_get_queue(bdev)); 1211 } 1212 1213 static inline unsigned int queue_io_opt(struct request_queue *q) 1214 { 1215 return q->limits.io_opt; 1216 } 1217 1218 static inline int bdev_io_opt(struct block_device *bdev) 1219 { 1220 return queue_io_opt(bdev_get_queue(bdev)); 1221 } 1222 1223 static inline int queue_alignment_offset(struct request_queue *q) 1224 { 1225 if (q->limits.misaligned) 1226 return -1; 1227 1228 return q->limits.alignment_offset; 1229 } 1230 1231 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector) 1232 { 1233 unsigned int granularity = max(lim->physical_block_size, lim->io_min); 1234 unsigned int alignment = sector_div(sector, granularity >> 9) << 9; 1235 1236 return (granularity + lim->alignment_offset - alignment) % granularity; 1237 } 1238 1239 static inline int bdev_alignment_offset(struct block_device *bdev) 1240 { 1241 struct request_queue *q = bdev_get_queue(bdev); 1242 1243 if (q->limits.misaligned) 1244 return -1; 1245 1246 if (bdev != bdev->bd_contains) 1247 return bdev->bd_part->alignment_offset; 1248 1249 return q->limits.alignment_offset; 1250 } 1251 1252 static inline int queue_discard_alignment(struct request_queue *q) 1253 { 1254 if (q->limits.discard_misaligned) 1255 return -1; 1256 1257 return q->limits.discard_alignment; 1258 } 1259 1260 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector) 1261 { 1262 unsigned int alignment, granularity, offset; 1263 1264 if (!lim->max_discard_sectors) 1265 return 0; 1266 1267 /* Why are these in bytes, not sectors? */ 1268 alignment = lim->discard_alignment >> 9; 1269 granularity = lim->discard_granularity >> 9; 1270 if (!granularity) 1271 return 0; 1272 1273 /* Offset of the partition start in 'granularity' sectors */ 1274 offset = sector_div(sector, granularity); 1275 1276 /* And why do we do this modulus *again* in blkdev_issue_discard()? */ 1277 offset = (granularity + alignment - offset) % granularity; 1278 1279 /* Turn it back into bytes, gaah */ 1280 return offset << 9; 1281 } 1282 1283 static inline int bdev_discard_alignment(struct block_device *bdev) 1284 { 1285 struct request_queue *q = bdev_get_queue(bdev); 1286 1287 if (bdev != bdev->bd_contains) 1288 return bdev->bd_part->discard_alignment; 1289 1290 return q->limits.discard_alignment; 1291 } 1292 1293 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q) 1294 { 1295 if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1) 1296 return 1; 1297 1298 return 0; 1299 } 1300 1301 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev) 1302 { 1303 return queue_discard_zeroes_data(bdev_get_queue(bdev)); 1304 } 1305 1306 static inline unsigned int bdev_write_same(struct block_device *bdev) 1307 { 1308 struct request_queue *q = bdev_get_queue(bdev); 1309 1310 if (q) 1311 return q->limits.max_write_same_sectors; 1312 1313 return 0; 1314 } 1315 1316 static inline int queue_dma_alignment(struct request_queue *q) 1317 { 1318 return q ? q->dma_alignment : 511; 1319 } 1320 1321 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr, 1322 unsigned int len) 1323 { 1324 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask; 1325 return !(addr & alignment) && !(len & alignment); 1326 } 1327 1328 /* assumes size > 256 */ 1329 static inline unsigned int blksize_bits(unsigned int size) 1330 { 1331 unsigned int bits = 8; 1332 do { 1333 bits++; 1334 size >>= 1; 1335 } while (size > 256); 1336 return bits; 1337 } 1338 1339 static inline unsigned int block_size(struct block_device *bdev) 1340 { 1341 return bdev->bd_block_size; 1342 } 1343 1344 static inline bool queue_flush_queueable(struct request_queue *q) 1345 { 1346 return !q->flush_not_queueable; 1347 } 1348 1349 typedef struct {struct page *v;} Sector; 1350 1351 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); 1352 1353 static inline void put_dev_sector(Sector p) 1354 { 1355 page_cache_release(p.v); 1356 } 1357 1358 /* 1359 * Check if adding a bio_vec after bprv with offset would create a gap in 1360 * the SG list. Most drivers don't care about this, but some do. 1361 */ 1362 static inline bool bvec_gap_to_prev(struct request_queue *q, 1363 struct bio_vec *bprv, unsigned int offset) 1364 { 1365 if (!queue_virt_boundary(q)) 1366 return false; 1367 return offset || 1368 ((bprv->bv_offset + bprv->bv_len) & queue_virt_boundary(q)); 1369 } 1370 1371 struct work_struct; 1372 int kblockd_schedule_work(struct work_struct *work); 1373 int kblockd_schedule_delayed_work(struct delayed_work *dwork, unsigned long delay); 1374 int kblockd_schedule_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay); 1375 1376 #ifdef CONFIG_BLK_CGROUP 1377 /* 1378 * This should not be using sched_clock(). A real patch is in progress 1379 * to fix this up, until that is in place we need to disable preemption 1380 * around sched_clock() in this function and set_io_start_time_ns(). 1381 */ 1382 static inline void set_start_time_ns(struct request *req) 1383 { 1384 preempt_disable(); 1385 req->start_time_ns = sched_clock(); 1386 preempt_enable(); 1387 } 1388 1389 static inline void set_io_start_time_ns(struct request *req) 1390 { 1391 preempt_disable(); 1392 req->io_start_time_ns = sched_clock(); 1393 preempt_enable(); 1394 } 1395 1396 static inline uint64_t rq_start_time_ns(struct request *req) 1397 { 1398 return req->start_time_ns; 1399 } 1400 1401 static inline uint64_t rq_io_start_time_ns(struct request *req) 1402 { 1403 return req->io_start_time_ns; 1404 } 1405 #else 1406 static inline void set_start_time_ns(struct request *req) {} 1407 static inline void set_io_start_time_ns(struct request *req) {} 1408 static inline uint64_t rq_start_time_ns(struct request *req) 1409 { 1410 return 0; 1411 } 1412 static inline uint64_t rq_io_start_time_ns(struct request *req) 1413 { 1414 return 0; 1415 } 1416 #endif 1417 1418 #define MODULE_ALIAS_BLOCKDEV(major,minor) \ 1419 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor)) 1420 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \ 1421 MODULE_ALIAS("block-major-" __stringify(major) "-*") 1422 1423 #if defined(CONFIG_BLK_DEV_INTEGRITY) 1424 1425 enum blk_integrity_flags { 1426 BLK_INTEGRITY_VERIFY = 1 << 0, 1427 BLK_INTEGRITY_GENERATE = 1 << 1, 1428 BLK_INTEGRITY_DEVICE_CAPABLE = 1 << 2, 1429 BLK_INTEGRITY_IP_CHECKSUM = 1 << 3, 1430 }; 1431 1432 struct blk_integrity_iter { 1433 void *prot_buf; 1434 void *data_buf; 1435 sector_t seed; 1436 unsigned int data_size; 1437 unsigned short interval; 1438 const char *disk_name; 1439 }; 1440 1441 typedef int (integrity_processing_fn) (struct blk_integrity_iter *); 1442 1443 struct blk_integrity { 1444 integrity_processing_fn *generate_fn; 1445 integrity_processing_fn *verify_fn; 1446 1447 unsigned short flags; 1448 unsigned short tuple_size; 1449 unsigned short interval; 1450 unsigned short tag_size; 1451 1452 const char *name; 1453 1454 struct kobject kobj; 1455 }; 1456 1457 extern bool blk_integrity_is_initialized(struct gendisk *); 1458 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *); 1459 extern void blk_integrity_unregister(struct gendisk *); 1460 extern int blk_integrity_compare(struct gendisk *, struct gendisk *); 1461 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *, 1462 struct scatterlist *); 1463 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *); 1464 extern bool blk_integrity_merge_rq(struct request_queue *, struct request *, 1465 struct request *); 1466 extern bool blk_integrity_merge_bio(struct request_queue *, struct request *, 1467 struct bio *); 1468 1469 static inline 1470 struct blk_integrity *bdev_get_integrity(struct block_device *bdev) 1471 { 1472 return bdev->bd_disk->integrity; 1473 } 1474 1475 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk) 1476 { 1477 return disk->integrity; 1478 } 1479 1480 static inline bool blk_integrity_rq(struct request *rq) 1481 { 1482 return rq->cmd_flags & REQ_INTEGRITY; 1483 } 1484 1485 static inline void blk_queue_max_integrity_segments(struct request_queue *q, 1486 unsigned int segs) 1487 { 1488 q->limits.max_integrity_segments = segs; 1489 } 1490 1491 static inline unsigned short 1492 queue_max_integrity_segments(struct request_queue *q) 1493 { 1494 return q->limits.max_integrity_segments; 1495 } 1496 1497 #else /* CONFIG_BLK_DEV_INTEGRITY */ 1498 1499 struct bio; 1500 struct block_device; 1501 struct gendisk; 1502 struct blk_integrity; 1503 1504 static inline int blk_integrity_rq(struct request *rq) 1505 { 1506 return 0; 1507 } 1508 static inline int blk_rq_count_integrity_sg(struct request_queue *q, 1509 struct bio *b) 1510 { 1511 return 0; 1512 } 1513 static inline int blk_rq_map_integrity_sg(struct request_queue *q, 1514 struct bio *b, 1515 struct scatterlist *s) 1516 { 1517 return 0; 1518 } 1519 static inline struct blk_integrity *bdev_get_integrity(struct block_device *b) 1520 { 1521 return NULL; 1522 } 1523 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk) 1524 { 1525 return NULL; 1526 } 1527 static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b) 1528 { 1529 return 0; 1530 } 1531 static inline int blk_integrity_register(struct gendisk *d, 1532 struct blk_integrity *b) 1533 { 1534 return 0; 1535 } 1536 static inline void blk_integrity_unregister(struct gendisk *d) 1537 { 1538 } 1539 static inline void blk_queue_max_integrity_segments(struct request_queue *q, 1540 unsigned int segs) 1541 { 1542 } 1543 static inline unsigned short queue_max_integrity_segments(struct request_queue *q) 1544 { 1545 return 0; 1546 } 1547 static inline bool blk_integrity_merge_rq(struct request_queue *rq, 1548 struct request *r1, 1549 struct request *r2) 1550 { 1551 return true; 1552 } 1553 static inline bool blk_integrity_merge_bio(struct request_queue *rq, 1554 struct request *r, 1555 struct bio *b) 1556 { 1557 return true; 1558 } 1559 static inline bool blk_integrity_is_initialized(struct gendisk *g) 1560 { 1561 return 0; 1562 } 1563 1564 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 1565 1566 struct block_device_operations { 1567 int (*open) (struct block_device *, fmode_t); 1568 void (*release) (struct gendisk *, fmode_t); 1569 int (*rw_page)(struct block_device *, sector_t, struct page *, int rw); 1570 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); 1571 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); 1572 long (*direct_access)(struct block_device *, sector_t, void __pmem **, 1573 unsigned long *pfn); 1574 unsigned int (*check_events) (struct gendisk *disk, 1575 unsigned int clearing); 1576 /* ->media_changed() is DEPRECATED, use ->check_events() instead */ 1577 int (*media_changed) (struct gendisk *); 1578 void (*unlock_native_capacity) (struct gendisk *); 1579 int (*revalidate_disk) (struct gendisk *); 1580 int (*getgeo)(struct block_device *, struct hd_geometry *); 1581 /* this callback is with swap_lock and sometimes page table lock held */ 1582 void (*swap_slot_free_notify) (struct block_device *, unsigned long); 1583 struct module *owner; 1584 }; 1585 1586 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int, 1587 unsigned long); 1588 extern int bdev_read_page(struct block_device *, sector_t, struct page *); 1589 extern int bdev_write_page(struct block_device *, sector_t, struct page *, 1590 struct writeback_control *); 1591 extern long bdev_direct_access(struct block_device *, sector_t, 1592 void __pmem **addr, unsigned long *pfn, long size); 1593 #else /* CONFIG_BLOCK */ 1594 1595 struct block_device; 1596 1597 /* 1598 * stubs for when the block layer is configured out 1599 */ 1600 #define buffer_heads_over_limit 0 1601 1602 static inline long nr_blockdev_pages(void) 1603 { 1604 return 0; 1605 } 1606 1607 struct blk_plug { 1608 }; 1609 1610 static inline void blk_start_plug(struct blk_plug *plug) 1611 { 1612 } 1613 1614 static inline void blk_finish_plug(struct blk_plug *plug) 1615 { 1616 } 1617 1618 static inline void blk_flush_plug(struct task_struct *task) 1619 { 1620 } 1621 1622 static inline void blk_schedule_flush_plug(struct task_struct *task) 1623 { 1624 } 1625 1626 1627 static inline bool blk_needs_flush_plug(struct task_struct *tsk) 1628 { 1629 return false; 1630 } 1631 1632 static inline int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask, 1633 sector_t *error_sector) 1634 { 1635 return 0; 1636 } 1637 1638 #endif /* CONFIG_BLOCK */ 1639 1640 #endif 1641